RESEARCH AND DEVELOPMENT OF STEELHEAD TROUT …

RESEARCH AND DEVELOPMENT OF STEELHEAD TROUT Oncorhynchus mykiss

AQUACULTURE IN SEA CAGES

BY

MICHAEL DAVID CHAMBERS

B.S., University of Wisconsin, 1985

M.S., Texas A&M University, 1994

DISSERTATION

Submitted to the University of New Hampshire

in Partial Fulfillment of

the Requirements for the Degree of

Doctor of Philosophy

in

Zoology

December, 2013

UMI Number: 3579692

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This dissertation has been examined and approved.

Dissertation Director, Dr. W. Huntting Howell, Professor of Zoology,University of New Hampshire

Dr. Winsor H. Watson III, Professor of Zoology, University of New Hampshire

Dr. Richard Langan,Affiliate Professor of Biological Sciences, University of New Hampshire

Dr. Ey^fyn S. Sawyer,President and CEO, Sea Run Holdings, Freeport, ME

________________

Dr. Tim Dempster,Senior Lecturer, Department of Zoology, University of Melbourne

/he 6. Zo/3Date

DEDICATION

This dissertation is dedicated to my family here in New Hampshire and in

Wisconsin. My accomplishments during this journey would never have been possible

without your patience, love and support. And to my father who taught me a very

important life lesson, once you start something, you must finish it!

ACKNOWLEDGMENTS

Where to begin? Let’s start with the UNH BSC staff that makes everything

possible. They provide us with P-cards for purchasing power, they set up PO’s for

contracting outside venders and they process time sheets so that students and SCUBA

divers could get paid on time. For this, I’m gratefully indebted to Meriel Bunker,

Theresa Hammer, Nancy Wallingford, Tammy McGlone and Patrice MacNevin.

The UNH OOA program created the impetus for my research. I’m appreciative to

all the hard working personnel over the years that made the project possible. The names

are too many to mention and would add another chapter to this thesis so I’ll settle for the

most recent crew associated with the research. This includes Captains Tim McClare and

Gita George, divers extraordinaire Elizabeth Kintzing, Rob Love, Gunnar Ek, Graham

McKay and Tom Langley.

I’m very thankful to the following: 1.) UNH Facility Managers David Shay, Noel

Carlson, Nate Rennels and Deb Lampson as well as staff members and students, Jessica

Cranney, Chris Rillahan, Jon Bunker, and James Quadrino for collecting, processing data,

constructing cage systems and maintaining experiments, 2.) Captains Bryan Soares and

Debra Brewitt for their patience in sharing pier space, the crane and playing musical

chairs with the cage frames as they were relocated to and from the pier, 3.) NH Sea

Grant team Jon Pennock, Ken LaValley (now Cooperative Extension) Sally Nelson,

Jennifer Bedsole, Eric Chapman, Sarah Redmond (ME Sea Grant), Steve Jones, Gabby

Bradt, Rebecca Zeiber, Steve Adams and Dari ward (especially in borrowing water

sampling equipment) for their tremendous support during the research efforts. 4.) Sumner

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Brook Trout farms (Dick and Jess Pemier) and Great Bay Aquaculture (George Nardi)

for supplying juvenile steelhead trout and cod for the experiments. 5.) Our Norwegian

counter parts Pal Lader, Arne Fredheim, Erik Hoy, Martin Fore, Heidi Moe and Kevan

Frank for their aquaculture collaborations and the 6.) UNH Ocean Engineering

Department Jud DeCew, Barbaras Celikkol, Ken Baldwin , Rob Swift, Igor Tsukrov for

their technology guidance with systems design and operation.

A special thanks to Hunt Howell for his patience, fortitude, guidance and

friendship. He made this remarkable journey possible and so will forever be indebted. To

my committee members Win Watson, Richard Langan, Evelyn Sawyer and Tim

Dempster for their wisdom and guidance throughout the dissertation process.

Funding agencies primarily responsible for the research was: 1.) the International

Copper Association, especially Hal Stillman and Robert Dwyer for their expert opinion

on copper alloy applications, 2.) Riverdale Mills for generously contributing the Seawire

netting that was expedited to UNH by Jeff Beaton and Larry Walsh for the spring 2010

experiment 3.) The Norway Research Council for funding the BELAT project (Chapter 2).

This was made possible through a joint partnership between UNH, SINTEF Fisheries and

Aquaculture, and AquaCulture Engineering in Trondheim, Norway, 4.) NOAA

Saltonstall Kennedy Program award Number NA10NMF4270213 for their support in the

submerged trout research (Chapter 3) and 5.) NH Sea Grant for their financial support in

my aquaculture extension activities (Chapter 4).

I also want to recognize UNH for the use of their facilities especially the Judd

Gregg Marine Research Facility Pier. The pier was the launching area for the studies and

provided research vessels and crane to safely deploy cage systems and fish.

V

Finally, I want to acknowledge my family for their remarkable patience and

support during this amazing journey. Hopefully now, the time taken from them working

late nights and weekends can be paid back in full.

VI

TABLE OF CONTENTS

DEDICATION....................................................................................................................... Ill

ACKNOWLEDEMENTS..................................................................................................... IV

LIST OF TABLES................................................................................................................XII

LIST OF FIGURES.............................................................................................................XIII

ABSTRACT........................................................................................................................XVI

CHAPTER PAGE

INTRODUCTION.................................................................................................................. 1

I. EFFECTS OF BIOFOULING ON COMPARATIVE GROWTH AND SURVIVAL OF

JUVENILE ATLANTIC COD Gadus morhua CULTUREED IN OCEAN PENS 6

Abstract....................................................................................................................... 6

Introduction................................................................................................................. 7

Materials and Methods.............................................................................................. 9

Cage design............................................................................................................9

Stocking and Feeding...........................................................................................10

Behavioral and Environmental Monitoring........................................................ 10

Data Collection..................................................................................................... 11

Results........................................................................................................................12

VII

Environmental 12

Cod Performance..................................................................................................12

Bio-fouling........................................................................................................... 13

Copper Content Analysis.................................................................................... 13

Discussion................................................................................................................. 14

Conclusion................................................................................................................ 16

II. FIELD MEASUREMENTS OF STEELHEAD TROUT Oncorhynchus mykiss

DISTRIBUTION, SWIMMING BEHAVIOR AND RESPONSE TO WATER

CURRENT EXPOSURE IN A SEA CAGE...................................................................... 23

Abstract..................................................................................................................... 23

Introduction...............................................................................................................24

Materials and Methods............................................................................................ 27

Location................................................................................................................ 27

Cage Design.........................................................................................................28

Environmental Data Collection...........................................................................28

Telemetry Set U p .................................................................................................29

Net Transmitters...................................................................................................30

Fish Transmitters..................................................................................................30

Data Processing and Statistics.............................................................................31

Net Transmitters............................................................................................. 31

Fish Transmitters............................................................................................ 31

Results....................................................................................................................... 33

Vlll

Environmental..................................................................................................... 33

Net Deformation.................................................................................................. 33

Fish Swimming Behavioral and Distribution.................................................... 34

Discussion.................................................................................................................35

III. SUBMERGED CULTURE OF STEELHEAD TROUT Oncorhynchus mykiss FOR

OPEN OCEAN AQUACULTURE IN THE NORTHEASTERN UNIITED STATES . 49

Abstract.....................................................................................................................49

Introduction...............................................................................................................50


Timing and Locations.......................................................................................... 52

Steelhead Trout................................................................................................... 53

Experiment 1 ....................................................................................................... 54

Experiment 2 ....................................................................................................... 55

Experiment 3 (Exposed Site)...............................................................................56

Growth, Condition and Fin Damage.................................................................. 57

Surface Rolling and Jumping Behavior.............................................................58

Statistical Analysis.............................................................................................. 58

Results.......................................................................................................................58

Experiment 1........................................................................................................58

Experiment 2 ........................................................................................................60

Experiment 3 ....................................................................................................... 62

Discussion.................................................................................................................63

IX

IV. TECHNOLOGY TRANSFER OF SMALL SCALE INTEGRATED MULITROPHIC

AQUACULTURE TO COMMERICAL FISHERMEN IN N H .......................................79

Abstract.....................................................................................................................79

Introduction...............................................................................................................80


Permitting.............................................................................................................83

Integrated Multi-trophic Aquaculture................................................................ 85

Culture Technology........................................................................................85

Steelhead Trout............................................................................................... 86

Blue Mussels................................................................................................... 86

Sugar Kelp.......................................................................................................87

Technology Transfer to NH Fishermen.............................................................87

Environmental Monitoring..................................................................................88

Market Survey of Steelhead Trout..................................................................... 89

Results....................................................................................................................... 90

Demonstration of Integrated Multi-trophic Aquaculture..................................90

Steelhead Trout............................................................................................... 90

Blue Mussels................................................................................................... 91

Sugar Kelp.......................................................................................................92

Fate of Nitrogen ................................................................................................. 94

Technology Transfer to NH Fishermen.............................................................95

Environmental Monitoring..................................................................................97

Water Quality.................................................................................................. 97

X

Benthic and Video Sampling..........................................................................97

Market Survey of Steelhead Trout.......................................................................... 98

Steelhead Trout Economics for NH Fishermen..................................................... 98

Discussion............................................................................................................... 100

Dissertation Synopsis..........................................................................................................121

APPENDIX A. ANIMAL CARE AND USE APPRO VEAL 2013................................125

APPENDIX B. ANIMAL CARE AND USE APPROVEAL 2010................................126

APPENDIX C. NH FISH & GAME AQUACULTURE PERMIT 2013........................128

LIST OF REFERENCES....................................................................................................130

XI

LIST OF TABLES

TABLE TITLE PAGE

1.1 Growth performance of cod in nylon and copper cages............................................... 18

2.1 Environmental ranges at the experimental site during the study period......................39

2.2 Mean distances of trout from net tags during four sampling periods.......................... 40

3.1 Mean weights, lengths, condition and nose abrasion from the different treatments

in Experiment 1.............................................................................................................. 66

3.2 Specific growth rates of each of the indicated treatments at the end of

Experiments 1,2 and 3 ..................................................................................................67

3.3 Mean weights, lengths, condition and nose abrasion from Experiment 2 ...................68

3.4 Growth and condition index for Experiment 3 ............................................................. 69

4.1 Consumer survey form for steelhead trout market evaluation......................................103

4.2 Nitrogen inputs and outputs from integrated multi-trophic aquaculture..................... 104

4.3 Water quality data collected during the demonstration project....................................105

4.4 Water sampling for nitrogen content from three locations........................................... 106

4.5 Economic spreadsheet of steelhead trout production at 100 m3...................................107

4.6 Economic spreadsheet of steelhead trout production at 500 m3...................................108

4.7 Economic spreadsheet of steelhead trout production at 1000 m3.................................109

Xll

LIST OF FIGURES

FIGURE TITLE PAGE

1.1 Floating raft with six net pens under the UNH pier...................................................... 19

1.2 Mean weight gain of Atlantic cod cultured in nylon and copper nets.........................20

1.3 Mean total bio-foul weight from each cage at the termination of the experiment ....21

1.4 Chemical analysis conducted on cod muscle, liver and gill from the control and

treatment ........................................................................................................................22

2.1 Google Earth photos of Fort Point, New Castle, NH, USA and the Judd Gregg

Marine Research Pier..................................................................................................... 41

2.2 Experimental cage design showing placement of the 4 HTI hydrophones and 12

net pingers...................................................................................................................... 42

2.3 An HTI model 795Z acoustic transmitter being implanted into the abdominal

cavity of a steelhead trout..............................................................................................43

2.4 An example of current velocities at the test cage site during ebb and flood tides......44

2.5 An illustration of a single fish and group of four fish, tracked on June 17................ 45

2.6 Density plot showing the distribution of a single trout on June 18 from 0800-

0900h..............................................................................................................................46

2.7 Relationship between swimming speed and current speed recorded by a Modular

Acoustic Velocity Sensor current meter.......................................................................47

2.8 Mean swimming speeds of the seven fish during day and night intervals.................. 48

Xlll

3.1 Aerial photo of the Judd Gregg Marine Research Pier in New Castle, NH and

proximity to the experimental sites............................................................................... 70

3.2 Cage design used in Experiment 1..................................................................................71

3.3 Control and treatment cages for Experiment 2.............................................................. 72

3.4 Steelhead trout attached with a fitted Star-Oddi™ pitch and roll data storage tag ...73

3.5 Visual representations of subjective snout index...........................................................74

3.6 Number of fish jumps per cage sampling during Experiments 1, 2 and 3...................75

3.7 An example of pitch recordings, taken from a fish in the submerged and surface

cages...............................................................................................................................76

3.8 Survival of trout in Experiments 1, 2 and 3................................................................... 77

3.9 Bio-fouling of the hydroid Tubularia on a fish net....................................................... 78

4.1 Trout cages moored at the mouth of the Piscataqua River, NH ..................................110

4.2 Natural settlement of sugar kelp on the trout cages in the Piscataqua River, NH....... I l l

4.3 Fishermen harvesting steelhead trout for local markets in Portsmouth, NH............... 112

4.4 Juvenile mussel spat that settled on the New Zealand fuzzy rope suspended

around the cage platform................................................................................................ 113

4.5 Mussels being set into modified lobster pots for relaying offshore near Gunboat

Shoals, NH...................................................................................................................... 114

4.6 Juvenile sugar kelp lines being deployed for growout on a floating platform ...........115

4.7 Sugar kelp after 4 months growout in the Piscataqua River, N H .................................116

4.8 The fate of nitrogen from fish food to the environment............................................... 117

4.9 NH fishermen towing empty cages to site for growout of steelhead trout, mussels

and sugar kelp in the Piscataqua River, N H .................................................................118

XIV

4.10 Harvest of steelhead trout from the sea cages with the Portsmouth fishermen...........119

4.11 Diver with a Go Pro™ underwater camera filming a 30 m bottom transect under

the sea cages in the Piscataqua River, NH....................................................................120

XV

ABSTRACT

RESEARCH AND DEVELOPMENT OF STEELHEAD TROUT Oncorhynchus mykiss

AQUACULTURE IN SEA CAGES

by

Michael David Chambers

University of New Hampshire, December, 2013

The overall research goal was to develop technological, behavioral and

operational information that could enhance marine aquaculture in New England. Our first

study field tested a copper alloy cage material (Seawire) to reduce bio-fouling, a major

impediment to cage farming. We found that the Seawire significantly reduced bio-

fouling. In the second study we investigated a bio-telemetry system (Hydroacoustic

Technologies Incorporated) to monitor steelhead trout (Oncorhynchus mykiss) movement

inside a net pen as the net was deformed by strong tidal currents (~ 0.50 m / sec.). Results

showed that the net became deformed at currents > 0.2 m / s, and at current speeds of 0.5

m / s, the net lost > 30% of its volume. Trout swimming behavior was influenced by tidal

velocity. As velocity increased, trout exhibited rheotaxis, and used less of the cage

volume. No significant day/night differences were found in swimming depth or speed.

The third study explored the possibility that steelhead trout, a physostomous species,

could be held in submerged net pens for prolonged periods of time. Treatments were

sampled for growth, SGR, K, survival, skin and nose abrasions, and jumping behavior.

XVI

Results indicated that trout could be submerged for days to weeks with no negative

effects.

Finally, NH commercial fishermen were successfully trained on small-scale,

integrated multi-trophic aquaculture (IMTA) of steelhead trout, blue mussels (Mytilus

edulis) and sugar kelp (Saccharina latissima). The IMTA results demonstrated that

nutrient extraction by the mussel and kelp exceeded the nutrient input from trout

production. A simple economic analysis of small-scale trout aquaculture indicated a

profit could be made, which could supplement the income of commercial fishermen.

Lastly, market surveys and sales of steelhead trout suggested consumer demand for a

locally raised product. Taste, texture, smell, and color all rated excellent in the survey

forms.

XVII

INTRODUCTION

The global demand for seafood continues to rise while many wild fish and

shellfish stocks are at or beyond sustainable harvest levels (FAO, 2012). Fisheries catches

have been declining over the past two decades (Pauly et al., 2003), and many stocks are

currently overexploited (Myers and Worm, 2003, Naylor and Burke, 2005). Since the

mid-1990s, aquaculture has been primarily responsible for the growth in global fish

production as capture production has leveled off. Its contribution to total world fish

supply climbed steadily from 20.9 percent in 1995 to 40.3 percent in 2010 (FAO 2012).

In 2010, world marine farming production was estimated at 36.1 million tons with

a value of US$37.9 billion (FAO Statistics and Information Branch of the Fisheries and

Aquaculture Department, 2012). Nearly all ocean farming is conducted inshore, in

contrast to offshore aquaculture that is still in its infancy. Offshore aquaculture may be

defined as taking place in areas of the open ocean exposed to significant wind and wave

action, and where there is a requirement for equipment and servicing vessels to survive

and operate in severe sea conditions from time to time (Drumm, 2010).

Drivers at local and global levels provide impetus for aquaculture to move to the

unprotected waters of the open sea. There are issues of competition for space with other

users, problems with water quality, and oftentimes there is a negative public perception

of aquaculture’s environmental and aesthetic impacts (Kapetsky et al., 2013).

The U.S. is the third largest consumer of seafood in the world behind China and

Japan (FAO 2012). At present, the U.S. imports 85% of its seafood, half of which is

1

aquaculture products. Seafood produced overseas does not always adhere to strict

oversight on farm practices or environmental standards. As U.S. consumers demand safe

and sustainable seafood, the U.S. needs to develop responsible measures to produce

environmentally safe and sustainable aquaculture practices.

The US government invested in ocean aquaculture in 2005 with the development

of the National Offshore Aquaculture (http://aquaculture.noaa.gov/us/2007.html). It cites

the increasing global demand for seafood, notes that the U.S. seafood trade deficit is >

$10 billion, emphasizes the need for a safe and reliable seafood supply, and recommends

that the U.S. aquaculture industry grows at the rate of 4-6 million metric tons per year.

There is an obvious need for aquaculture development in the US. However, one of

the most difficult obstacles to overcome is finding locations for new aquaculture farms.

Because of the difficulties associated with inshore locations, it is assumed that most new

aquaculture activities will be developed offshore in the Exclusive Economic Zone (3-200

miles) where there are fewer conflicts with existing user groups, and less risk of

pollution. The high energy (winds and waves) of such exposed locations, however,

present significant technical challenges in the design, testing and construction of

aquaculture systems that are capable of surviving in these areas. In addition to these

technical challenges, there are many biological, regulatory, social and economic

problems to be solved.

The University of New Hampshire (UNH) established the Open Ocean

Aquaculture (OOA) research farm in 1999 (http://ooa.unh.edu/). The overall goal of the

project was to stimulate the further development of commercial offshore aquaculture in

New England. Also important was to work closely with commercial fishermen, coastal

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http://aquaculture.noaa.gov/us/2007.html

http://ooa.unh.edu/

communities, private industry, and fellow marine research scientists to develop

technologies for the aquaculture of native, cold-water finfish and shellfish species in

exposed oceanic environments. The site was located 12 km offshore and in 50 m water

depth, away from traditional fishing activities, recreational vessels and commercial

traffic. The project was successful in demonstrating and developing new submersible

cage (Chambers et al., 2011), mooring (DeCew et al., 2012), mussel longline

technologies (Langan et al., 2003) and remote feeding systems (Rice et al., 2003). In

addition, it successfully produced several cold tolerant marine fish species (Howell et al.,

2005; Chambers et al, 2006,2007; Rillahan et al., 2009, 2011), and collected and

transmitted environmental data from the remote location to shore, in real time (Irish et al.,

2004, 2011). Although the project succeeded in generating significant amounts of data

and new information, the high maintenance costs, exposed nature of the site, and slow

growth of the marine fish species created operational and economic challenges.

To overcome the challenges stated above, research at UNH helped develop a new

aquaculture model that could be adopted by fishermen. This model was smaller scale,

more affordable and pertinent to their existing infrastructure. Over the last five years, the

New England commercial fishing fleet has been faced with repeated management

measures established to rebuild declining stocks. By design, these measures have limited

fishing opportunities and significantly reduced the inshore small vessel fleet. More

recently, on May 1, 2010, a new management framework was established which changed

the regulation of fishing effort from a Days-at-Sea strategy to catch shares or a quota

system. The allocation groundfish fishermen received was conservative, and will result

in up to a 40% decrease in potential landings. This loss has been forecasted to reduce the

3

current groundfish fishing fleet by an additional 50% (NH Sea Grant, 2013). For many

local communities this will mean the loss of a historic fishing heritage. We see

aquaculture as an appropriate business alternative for the small vessel owner, to either

transition from wild harvest fisheries to farming, or to subsidize loss of income resulting

from limitations placed on individual landings.

Steelhead trout (Oncorhynchus mykiss) was considered for the new farming

model because of its unique characteristics for aquaculture. First, it has been

domesticated for >150 years, and is the basis for extensive commercial aquaculture

industries in Canada and Northern Europe. Second, unlike Atlantic salmon, the species

does not go through true smoltification, so juveniles > 100 g can go directly from a

freshwater hatchery to full strength seawater. Third, the species has a relatively fast

growth rate, reaching marketable size (1-3 kg) only 6-9 months after stocking at 100-

150g (www.dfo-mpo.gc.ca/Aquaculture/finfish/steelhead_e.htm). Finally, they are

disease resistant, are more temperature tolerant than Atlantic salmon, and have a high

market value.

Despite all the positive attributes for steelhead trout, a number of questions

remained concerning the usefulness for cage aquaculture in near shore New England

waters. First, was concern of their ability to survive in net environments located in high

current areas (> 0.35 m / sec), second, because of the nature of their swim bladder

(physostomous), it is not clear if they could tolerate prolonged periods of time away from

the surface, when cages need to submerged to avoid surface storm activity. Finally, it is

not clear if they could be grown economically and sold locally at a fair price. The overall

goal of my thesis research was to address these issues and determine if, in fact, it is

4

http://www.dfo-mpo.gc.ca/Aquaculture/finfish/steelhead_e.htm

feasible to raise steelhead trout on a small scale in NH waters. To address these concerns,

studies were designed and conducted between 2009 -2013 to examine biological and

technical methods to sustainably culture steelhead trout. Chapter one investigates a new

material (Seawire) that reduces bio-fouling on sea cage systems. This is a major

impediment to cage culture, especially during the warmer summer months. Chapter two

examines the reaction of trout to net deformation caused by strong tidal currents. The

distorted environment and crowding can cause stress to fish in culture. Chapter three

considers moving trout culture offshore to exposed locations. Here, potential waves,

currents and temperature extremes can make surface culture difficult. Submerging fish

can alleviate these problems though trout need to gulp air to maintain the swim bladder

for buoyancy. Finally, in chapter four, lessons learned from the OOA project and chapters

1-3 were applied to help train local fishermen on aquaculture as a means of

supplementing their income while fishing. This applied component was critical in

transferring technology to a user group that could adopt culture methods that were

applicable with their existing infrastructure. We continue to work with NH fishers to

build a successful aquaculture industry.

5

CHAPTER I

EFFECTS OF BIOFOULING ON COMPARATIVE GROWTH AND SURVIVAL OF

JUVENIL ATLANTIC COD (Gadus morhua) CULTUREED IN OCEAN PENS

Abstract

Bio-fouling on net pens has been a major concern for the marine aquaculture

industry. As cage systems increase in size, so does the surface area for the attachment of

colonial organisms creating drag on the net, reduced water flow important to fish health,

and increased operational expenses due to net cleaning. To solve this problem, the

International Copper Association (ICA) has been developing copper alloy netting for sea

cages. Copper netting has unique properties that minimize bio-fouling, reduce the risk of

fish escapement, prevent predators from entering the net pen, and is recyclable. To test

the alloy netting, an experiment was designed to compare juvenile cod cultured in

traditional nylon nets with Cu netting produced by Luvata ([email protected]). Six

0.78 m3 cages were stocked with 200, 29 g Atlantic cod (Gadus morhua) and grown for 4

months in coastal waters of New Hampshire, USA. Results of the study indicated no

significant differences in cod growth, survival, FCR, SGR, and CF between the two

treatments. A proximate analysis also indicated no differences in Cu levels in cod muscle,

liver and gill tissues taken from the control fish and fish raised in the Cu cage. Nylon nets

with antifouling paint accumulated significantly more bio-fouling then the Cu nets and

materials that were in contact with the Cu netting (plastic cable ties) fouled heavily with

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mailto:[email protected]

hydroids indicating minimal leaching to the environment. This study describes some of

the beneficial attributes of Cu netting, however future studies need to be conducted over a

longer period of time, on a larger scale, and in a more energetic environment to

definitively test the utility of this new product.

Introduction

The marine aquaculture industry is moving towards more environmentally

sustainable practices. A common issue with cage farming is the attachment of biological

communities to the culture net creating reduced water flow, decreased water quality and

excessive weight and drag on the cage floats (Fredriksson et al., 2003; Braithwaite and

McEvoy, 2005; Swift et al., 2006; Lader et al., 2008; de Nys and Guenther, 2009).

Aquaculture nets are prone to settlement and successional development of hydroids

(Green and Grizzle 2007) that significantly increase operational costs of farming due to

net cleaning (Hodson, et al., 1991; Braithwaite et al., 2007 and Solberg et al., 2002). To

combat this problem, the industry impregnates their nets with antifouling paints with

active ingredients such as cuprous oxide, cadmium and zinc (Hodson, et al., 1991;

Braithwaite et al., 2007 and Solberg et al., 2002; Dean et al., 2007; Brooks, 2003;

Brooks, 2000 and Voulvoulis et al., 1999. The active ingredients eventually leach out

over time (10-12 months) and thus fouling organism adheres to the net surface

(Braithwaite et al., 2007).

A new approach to circumvent this problem has been the development of new

containment materials that are stronger, resistant to bio-fouling and friendly to the

environment. The International Copper Association (ICA) has been investigating copper

alloy netting for fish farming (Chambers et al., 2011). Copper netting exhibits both

7

antifouling and anticorrosion properties. When copper netting is introduced into seawater,

an adherent protective patina layer is formed, that inhibits corrosion and resists the

attachment of fouling organisms. A clean net maintains water movement through the

cage for optimal fish health. Moreover, net cleaning is expensive, time consuming and

stressful to the fish. The strength of copper netting helps prevent escapement and deters

predators such as seals and sharks. Lastly, at the end of the copper netting shelf life, it can

be sold back to the manufacturer and recycled into another copper net or product.

Copper is naturally occurring in water, sediments and organisms, and is an

essential micronutrient for normal growth in plants and animals (Chester, 1990). As such,

fish diets for aquaculture maintain copper levels ranging from 5-14.8 mg / kg (Lie et al,

1989). Copper is also used as a biocide to treat fish disease including ectocommensal

ciliates (Noga, 2000), Amyloodinium (Van Duijn, 1973), Cryptocaryon (Tookwinas,

1990) and Monogenes (Thoney, 1990). Despite these positive attributes, it should be

noted that fish are much more sensitive to aqueous metals than humans, and too much

copper can cause metal poisoning. Copper toxicosis affects the gills, resulting in

osmoregulatory dysfunction, and can affect the kidney and liver (Cardeilhac & Whitaker,

1988). Therefore, oxidation levels from copper netting must be minimal for fish to

remain healthy.

Atlantic cod is one of the most valuable and commonly consumed species in the

western world, and declines of wild populations have brought a renewed interest in cod

aquaculture. In New England, research efforts have been underway at the University of

Hampshire’s (UNH), Open Ocean Aquaculture (OOA) site (http://ooa.unh.edu/) to

develop grow out technologies for this species (Chambers et al., 2006, 2007; Rillahan et

8

http://ooa.unh.edu/

al., 2009, 2011). Recent developments in cod larval production in the US, Norway,

Canada and the UK have created a consistent supply of fingerlings for grow out in cages.

Despite successes in hatchery production, culture issues remain with ocean nursery and

grow out systems. One behavioral issue with cod is their tendency to bite at the net twine

creating holes through which the fish can escape (Moe et al. 2006). This has been a

problem in Norway that has slowed the expansion of the industry. It is clear that

alternative containment materials that reduce bio-fouling and escapement would be

beneficial to the industry.

The goal of this research was to compare the growth, survival and behavior of

juvenile Atlantic cod cultured in copper alloy and traditional, industry standard nylon net

pens with antifouling paint. It also compared fouling rates on the two net types, and

examined Cu levels that may have been absorbed into the fish from the copper netting.

The four month experiment was conducted at the UNH Marine Pier Facility in New

Castle, NH, USA during the spring and summer of 2010.

Methods and Materials

Cage design

A total of six floating cages were constructed, each with a volume of 0.78 m3.

These were attached to a wooden raft located near the UNH pier in Newcastle, NH, USA

(Fig. 1). Each cage frame was made from 2.5 cm diameter high density polyethylene pipe

(HDPE). Netting materials were stretched and cable tied to each frame. The three nylon

cages (control) were made from 1.25 cm x 1.25 cm mesh nylon coated with Flexgard™, a

cuprous oxide based antifouling paint (http://www.trademarkia.com/company-flexabar-

9

http://www.trademarkia.com/company-flexabar-

corporation-451575-page-1-2, New Jersey, USA). Flexgard is the industry standard

antifoul paint used for salmon aquaculture in the eastern US and Canada. The three

copper cages (treatment) utilized Seawire™, a copper silicone material produced by

Luvata ([email protected]. Appleton, WI USA). At the time of the experiment,

Luvata only produced a 2.5 cm x 2.5 cm mesh net. To match the copper net to the nylon

mesh size of 1.25 cm (the size necessary to maintain small cod in the cage), two pieces of

Seawire net were laid on top of each other and spaced to form a 1.25 cm x 1.25 cm mesh.

Cable ties and copper hog rings were used to secure the Seawire in place and keep it from

shifting into a larger mesh size.

Stocking and feed

Each cage was stocked at a density of 7.4 kg / m3 with 200, 29 ± 2.2 g cod

produced by Great Bay Aquaculture located in Newington, NH USA. Initially, the cod

were fed twice daily with a vibratory feeder at 1.5% body weight / day with a 3 mm,

Skretting™ Europa diet composed of 50% protein and 18% lipid (Portland, ME USA).

Later in the experiment, cod were hand fed to satiation, once daily.

Behavioral and environmental monitoring

Each cage was monitored with a Super Circuits ultra-high resolution camera

(Model # PC88WR-2, Austin, TX USA) and video was recorded on a Super Circuits 8

channel DVR (Model # DH200800D, Super Circuits, Austin, TX USA). Feeding,

swimming behavior and interactions with the nets were recorded on the DVR. Water

temperature, dissolved oxygen, salinity, pH, turbidity and tidal height were recorded

every 30 minutes with an YSI 6600 Multi-parameter Sonde (YSI, Yellow Springs, Ohio

USA). Light levels were monitored from the bottom of the cages with a HOBO Pendant

10

mailto:[email protected]

Temperature and Light Data Logger ( Onset Computer Corp, Cape Cod, MA USA), and

current speed and direction were measured periodically with a portable Marsh McBimey,

model 2000, flow meter (Hach Company, Berlin, MA USA).

Data collection

Random samples of 30 cod were collected monthly from each cage to measure

wet weight and total length. Fish were starved for 24 hours prior to sampling. At the

termination of the study, FCRs, based on 50 fish from each of the control and copper

nets, were calculated as [total feed weight fed * % dry matter] / [(mean harvest weight-

initial mean weight) * number of fish].

Standard indices of growth and condition of fish were calculated for each cage.

SGR (% day .) was calculated as [(In (W2) - In (W.)] / (t2 - t.) where W2and W. are the

mean live body weights at times t2 and t., respectively. Fulton’s condition factor was

calculated with the formula K = (W / L.) x 100, where W is the wet weight (g), and L is

the total length (cm).

Chemical analyses of 3 replicate tissue samples of gill, liver and muscle, each

weighing 5-10g and taken from 10 randomly selected fish from the copper alloy and

nylon nets, were run at the end of the experiment. Tissue samples were frozen in zip lock

bags and shipped to New Jersey Feed Labs in Trenton, NJ, USA. There, samples were

placed into a crucible and heated to 600°C for 2 hrs. The dry ash sample was then diluted

with hydrochloric acid and placed into an IC-AES (Inductively Coupled Plasma Atomic

Emission Spectrometry) to measure copper content (AOAC # 985.01)

Finally, each cage with fouling community was removed from the water and

weighed on an Ohaus ES series bench scale (Parsippany, NJ USA) for total weight.

11

Fouling organisms were identified and photographed. Each cage was then pressure

sprayed clean and re-weighed to obtain weight differences between fouled and clean

cages.

Unpaired t-tests were used to compare survival, FCR, SGR, K, copper uptake and

bio-fouling results between the control and treatment nets.

Results

Environmental

Environmental data collected during the study showed: a) current was

omnidirectional, and varied from 0.2 - 0.4 cm / sec; b) water temperature ranged from

6.4°C in April to 19.2°C in August; c) light levels in the bottom of net cages (-1.5 m)

ranged from 0-2 lumens / ft2; d) salinity ranged from 21.5 - 34.3 ppt.; and e) dissolved

oxygen ranged from 11.3 mg /1 in April to 6.3 mg /1 in August.

Cod performance

Fish increased in weight by 80.8 ± 2.2 g in the nylon cage and 84.9 ± 9.4 g in the

Cu cage during the 16 week trial (Figure 2 and Table 1). Mean weights from replicates in

each treatment were not significantly different (Kruskal-Wallis tests, P > 0.05) so all

replicate weights within treatment were combined. There was no significant difference in

mean weight (Unpaired t-test with Welch correction, P > 0.05) between fish raised in the

copper alloy and Flexgard treated nylon cages. Also not significantly different (Unpaired

t-tests, P > 0.05) were cod lengths, survival, FCR, SGR and K (Table 1).

In mid-May, three consecutive storms and runoff increased water turbidity in the

Piscataqua River. Shortly after this event, mortality was observed in all of the cages. Cod

12

postmortem samples (6 / cage) were submitted for necropsy at the UNH Veterinary

Diagnostic Laboratory in Durham, NH. The cod were diagnosed with Aeromonas

salmoncida septicemia, with focally marked fibrinonecrotizing dermatitis of the dorsal

fin. Consequently, slow chronic mortality was observed during the rest of the experiment

despite increased growth rates in all the cages.

Bio-fouling

As temperatures increased through the summer (up to 19°C), so did the amount of

bio-fouling on the HDPE frames and nylon nets. Organisms found on the two cage

treatments included the hydroid Tubularia crocea, the red gilled nudibranch (Coryphella

sp.), skeleton shrimp (Caprella sp.) and the tunicate Ciona intestinalis. Tubularia was the

dominant fouling species that reduced water flow through the cages. Bio-fouling rates

between the treated nylon net and copper netting were significantly different (T-test,

P<0.05). The mean (± SE) fouling weight (fouling community alone) of the nylon nets

was 22.8 ± 2.67 kg compared to a mean weight of 16.2 ± 2.95 kg for the copper net pens

(Figure 3). Fouling on the Cu cages only occurred on non-alloy materials (HDPE frame

and plastic cable ties). The 2 x 3 mm cable ties wrapped around the Cu twine had clumps

of Tubularia ranging from 125-180g. No fouling organisms were observed on the

Seawire netting.

Copper content analysis

Unpaired t-tests, with Welch corrections, were used to compare fish from copper

alloy cages (treatment) and the fish from the nylon Flexgard cages (control). There was

no significant difference (P > 0.05) in ppm copper between fish from the 2 cage types in

bodies (muscle) (P = 0.68), gills (P = 0.47) or livers (P = 0.52) (Fig. 4).

13

Discussion

Nylon nets covered with antifouling paint (Flexgard™) are commonly used to

prevent antifouling on aquaculture nets in North America. The disadvantages of these

nylon nets include wear, vulnerability to predators, susceptibility to cultured species with

biting behavior (e.g. cod), and bio-fouling once the antifouling coating is lost. Copper

alloy netting provides a new containment material that may resolve some of these issues.

Its strength, corrosion resistance, and antifouling properties provide longer wear, help to

maintain water flow, prevent escapement and exclude predators. Furthermore, because of

the reduced fouling communities and increased water flow, smaller mesh copper nets

could be used to hold juvenile fish. This would allow fingerling fish to be moved to net

pens at smaller sizes, thus reducing operating expenses associated with land based

hatcheries.

We found no significant differences in the growth, survival, FCR, SGR, and K

between cod cultured in the nylon nets with Flexgard antifoul paint and cod raised in the

copper nets. Despite the mortality caused by the bacteria infection Aeromonas

salmoncida, the survival of the fish in the control and treatment was similar. Moreover,

there were no difference in copper uptake in gill, liver and muscle tissue samples taken

from fish held in nylon cages with Flexgard™ antifoul paint (cuprous oxide based) and

the copper Seawire cages. Therefore, even though copper can be detrimental to fish, these

data indicate that the copper cages used for this experiment had no obvious negative

impact on fish growth or survival. Other findings were that nylon nets with antifouling

paint accumulated significantly more fouling biomass than the copper alloy nets, and that

the most abundant fouling organism, found on all cage frames, and on the twine of the

14

nylon nets, was the hydroid Tubularia crocea. Hydroids are common, and quickly settle

onto substrates before other species establish themselves (Harris, 1886; Harris & Irons,

1882 and Lovely, 1995). This species grew throughout the experiment, but remained

absent on all of the Seawire net material. The patina layer that forms on the Seawire net

helps prevent hydroid stolons from attaching. Hydroids use different attachments

methods on nylon nets that include growth between and around individual netting fibers

(de Nys and Guenther, 2009).

Cable ties that were used to secure the two layers of copper netting together did

foul with Tubularia. Hydroid colonies up to 180 g in weight were found on 2 x 3 mm

plastic ties that were in direct contact with the Seawire net. The significant fouling

growth on the cable tie, in direct contact with the Seawire, suggests localized copper

release. It also indicates that all fasteners used in copper alloy cage construction should

be made of similar copper fasteners to eliminate fouling.

Although this study found no adverse effects of copper alloy netting on cod,

future investigations should include longer term, commercial scale trials of copper alloy

netting. Inquiries should be conducted with marine fish species in cold, temperate and

tropical environments with different fouling communities. Other areas to research include

copper leaching into the environment over time and its effect on benthic communities

near the fish farm. Results of such studies will help determine copper netting shelf life,

corrosion strength, benefits to aquaculture and effects on the marine environment. The

data will also serve to guide the design and manufacture of future alloy nets for

aquaculture.

15

Conclusion

Bio-fouling is a major concern with cage farming throughout the world. At

present, the salmon farming industry uses nylon nets treated with an antifoul paint to

reduce bio-fouling. Seawire represents a new material that could deter bio-fouling while

minimizing escapement and preventing most predators from entering the cage

environment. Unlike nylon nets that are disposed of when worn out, Seawire maintains

its value and can be recycled. The cost of 2 cm mesh nylon net, treated with Flexgard is

$16.87 / m2 compared to Seawire with 2.4 cm mesh is $39.69 / m2. Despite the initial cost

difference, Seawire may be as cost effective as nylon by decreasing operational costs

associated with net cleaning, repair and rotation.

Seawire netting comes in roles 1.25 m x 31.25 m. Cages can be easily

manufactured to different dimensions with a pneumatic cutter and stapler. Seawire is a

welded copper mesh that maintains a rigid geometry even during high current episodes

when nylon nets can compress and loose volume. The rigidity may cause challenges in

the fabrication and deployment of commercial size cages. These operational methods and

expenses will need to be calculated to fully understand the cost benefits of using the wire

in an ocean environment.

Copper alloy netting has been investigated in larger scale systems in Tasmania,

Japan and more recently in Chile and Turkey. These cages used a UR30 woven copper

mesh of 40 mm for final grow out of larger fish. The woven net is collapsible on land and

is flexible in the water (http://www.ecosea.cl/). The mesh size is only available in large

sizes and not suitable for studies with juvenile fish. The cages used in the New

16

http://www.ecosea.cl/

Hampshire field trial were small (0.78 m3) and in close proximity for replicate purposes

and may not illustrate commercial significance. Setting of the experiment under a pier

and with a new aquaculture species (cod) may not have been the best scenario for this

study. Bacterial infection played a major part in the survival of the cod juveniles despite

their continued growth. Future studies are warranted to reveal benefits and drawbacks of

copper netting in aquaculture.

17

Table 1.1. Growth performance of cod in nylon and copper cages. Means are ± SE. Unpaired T-tests showed no significant differences (P > 0.05) in any of the measured variables between cage types.______________________________________________

Nvlon cage Copper cageInitial weight (g) 29.2 ± 6.7 29.2 ± 6.7Final weight (g) 110.0 ± 1.25 114.1 ±2.28Weight gain (g) 80.8 ± 0.3 84.9 ± 1.3Initial length (cm) 15.4 ± 1.0 15.4 ± 1.0Final length (cm) 22.2 ±0.01 22.3 ±0.11Length gain (cm) 6.8 ± 0.02 6.9 ± 0.05Survival (%) 29.17 ± 1.20 27.67 ±2.41FCR 1.52 ±0.45 1.51 ±0.13SGR (%/day) 0.72 ± 0.07 0.75 ± 0.07Condition factor (K) 1.0 1.0

18

(A) (B)

Figure 1.1. Floating raft with six net pens under the UNH pier (A). Copper net pen stocked with 200, 29 g cod with auto feeder (B).

19

140

100

80

Nylon net

Copper net

April'10 May '10 June’10 July'10 Aug *10

Figure 1.2. Mean weight gain (±SE) of Atlantic cod cultured in nylon and copper nets. Mean weights from replicates in each treatment were not significantly different (Kruskal- Wallis tests, P>0.05) so all replicate weights within treatment were combined. There was no significant difference in mean weight (Unpaired t-test with Welch correction, P>0.05) between fish raised in the copper alloy and Flexgard™ treated nylon cages.

20

Figure 1.3. Mean total bio-foul weight (± SE) from each cage at the termination of the experiment. Bio-foul weight on the copper pens was significantly less (16.2 ± 1.70 kg) than the bio-foul weight on the nylon pens (22.8 ± 1.54 kg) (Unpaired T-test, P < 0.05).

21

M uscle Liver

Tissue

Figure 1.4. Chemical analysis conducted on cod muscle, liver and gill from the control, (nylon nets with Flexgard™ paint) and the treatment (copper Seawire pens). Unpaired t- tests, with Welch corrections, were used to compare the two, and there was no significant difference (P > 0.05) in ppm copper between fish from the 2 cage types in muscle (P = 0.68), gills (P = 0.47) or livers (P = 0.52).

22

CHAPTER n

FIELD MEASUREMENTS OF STEELHEAD TROUT Oncorhynchus mykiss

DISTRIBUTION, SWIMMING BEHAVIOR AND RESPONSE TO WATER

CURRENT EXPOSURE IN A SEA CAGE

Abstract

This study introduces a new way to measure the distribution and behavior of

steelhead trout in a sea cage in response to fluctuating tidal currents that deform the net.

Strong currents can significantly decrease the volume of net constraining fish to a

condensed area. An ultrasonic telemetry system (Hydroacoustic Technology Inc., model

291) was deployed around a 63 m3 sea cage stocked with 200 steelhead trout

(Oncorhynchus mykiss). Fish and cage movement were monitored using ultrasonic tags

implanted into the abdominal cavities of 8 sentinel trout, 12 more were attached around

the net bottom and midsection. The signals were detected by four omni-directional

hydrophones that were connected to a receiver on a nearby pier. Signals detected at 2

second intervals were used to plot 3 dimensional locations of both the fish and net. We

found that current flow inside the net was significantly reduced (32-53%) compared to

outside and that swimming behavior was influenced by tidal currents. As current speed

increased, the positions of fish became more restricted because they were swimming into

the current to maintain their position. In contrast, during slack tides, fish exhibited typical

23

schooling behavior and swam in a circular pattern. This study demonstrates the use of

acoustic telemetry on a small scale cage. This technology can be applied to a commercial

scale farm to improve fish welfare and cage design.

Introduction

Since the mid-1990s, aquaculture has been primarily responsible for the growth in

global fish production as capture production has leveled off. Its contribution to total

world fish supply climbed steadily from 20.9 percent in 1995 to 40.3 percent in 2010

(FAO 2012). Most marine aquaculture takes place in near shore waters that provide

protection from storms and easy access to the farms. However, these waters are prone to

user conflicts from traditional fishermen, commercial traffic, and recreational boaters.

Resistance also comes from seashore abutters who worry about their view-scape. Finally,

runoff from land can create unfavorable conditions for raising healthy fish. Moving

aquaculture production offshore into deeper, more energetic, waters alleviates some of

the above issues. However, moving into more exposed areas increases risk and operating

expenses, decreases days at sea to tend the farm, and creates technical challenges with

infrastructure.

Understanding high energy environments is essential to the biological

requirements of a marine fish. In ocean cage culture, fish are often exposed to more

intense physical and environmental perturbations (Oppedal, et el. 2010), which can lead

to increases in metabolism and thus reduced growth and even mortality. Stress responses

in farmed fish have been shown to result from environmental disturbances, farming

operations or high stocking densities (Begout & Lagardere 1993; Cooke et al., 2000;

24

Begout & Lagardere, 2004; Chandroo et al., 2005). Measuring and understanding these

stressors can help farmers improve their operations, increase production efficiency and

optimize fish welfare. When changes occur in a cage environment, natural defense

mechanisms, such as net avoidance behavior, take effect. These behaviors have evolved

to lessen the probability of death, to mitigate the higher metabolic costs incurred by

increased swimming, and / or to maintain physiological homeostasis (Olla et al. 1980,

Schreck et at. 1997).

Fish distribution within a net pen is affected by an array of parameters such as

temperature, feeding and light (Oppedal et al., 2001; Oppedal et al., 2007; Oppedal et al.,

2010). Distribution can also be effected indirectly by bio-fouling, since bio-fouling

increases net resistance to currents, which results in cage deformation and changes in

geometry (Lader et al., 2008; Braithwaithe et al, 2007; Swift et al., 2006; DeCew et al.,

2013; Ward et al., 2012). As cage culture moves further offshore into deeper waters,

larger nets can be used allowing fish to distribute into preferred areas within the cage

environment, e.g. above or below thermoclines, zones of higher oxygen, preferred light

levels and escapement from storm surge. Recent technological advances have made it

possible to investigate how individual fish, as well as groups of fish, respond to the

aforementioned parameters. For example, Rillahan et al. (2009, 2011) studied the

behavior of Atlantic cod in an offshore (12 km) submerged, bi-conical cage (Sea

Station™). They found that cod exhibited clear diurnal rhythms, with the highest

swimming activity during daytime hours. Analysis of cage utilization revealed that cod

did not use the entire cage volume, and that individual space use was limited to small

overlapping areas within the bottom half of the net. When the density of cod reached high

25

levels, as they grew, their typical diurnal pattern of independent swimming changed to

schooling behavior with no significant difference in day and night activity. Ward et al.

(2012) studied cod behavior in near shore, rectangular floating cages at stocking densities

ranging from 5-45 kg / m3). He found that at the lowest density the cod spent the majority

(~ 64%) of their time in the bottom third of the net pen. Then, as density increased, the

fish moved higher in the water column, and this behavior was most evident at night, at all

densities. At no time during the study were there any obvious occurrences of schooling

behavior, even at the highest density. Both of these studies illustrated the usefulness of

high resolution biotelemetry for continuously monitoring the behavior of cultured fish

under a variety of circumstances, and demonstrating how fish interact with each other and

the cage.

While investigations over the past 20 years have revealed a great deal about how

fish behave in net pens in calm to moderate conditions, little is known about how both the

nets, and the fish inside the nets, respond during the intermittent storm events that are

fairly typical for exposed offshore cages. During these storms the waves and currents

increase and net deformation is likely, which may, or may not, lead to alterations in the

normal behavior of the fish. One of the goals of this study was to determine if acoustic

telemetry could be used, as a tool, to monitor both the deformation of the net, and the

movements of the fish, in a net pen exposed to stronger than normal currents. We used a

63 m3 net pen moored at the mouth of a large estuary where tidal current were strong

enough to deform the net pen.

The test species was the steelhead trout (Oncorhynchus mykiss), that is

commercially grown in near shore, protected waters in Chile, Norway, Faroe Islands,

26

Canada, and to a limited extent in the USA (states of Washington and New Hampshire).

Despite its advantages as a species for aquaculture, very little is known about its behavior

in an aquaculture setting. Therefore, by using steelhead trout, we were able to gain

valuable information about this species, as well as data relevant to the response of fish to

strong currents and the resulting deformation of the net pen in which they resided.


A 63 m3 net pen was stocked with 200 steelhead trout (Oncorhynchus mykiss),

(Mean (± SD) fish weight 571.7 ± 170.8 g, length 35.6 ± 2.8 cm). Initial stocking density

was 1.8 kg / m3. A Hydroacoustic Technology Inc. acoustic telemetry system (HTI -

http://www.htisonar.com/), similar to the one used by Rillahan et al. (2009, 2011) and

Ward et al. (2012) to study cod behavior, was used to track fish behavior and net

deformation. Eight model 795Z transmitters were surgically implanted into the

abdominal cavity of individual fish to track their temporal and spatial distribution.

Twelve more transmitters were attached around the net (8-middle, 4-bottom) to monitor

the position of the net and deformation caused by tidal currents. Four hydrophones

hardwired to a receiver (Model 291), were used to monitor the positions of transmitters,

in three dimensions, using a suite of HTI programs. Transmitters in the fish and net

“pinged” every 1-3 seconds and theses acoustical signals were detected by each of the

hydrophones. These data were then used to calculate and plot the position of each

transmitter with a resolution of ~ 10 cm, every 2-5 seconds. Stored data were used to

determine the distribution and swimming activity of the fish and movements of the net.

Location

27

http://www.htisonar.com/

The study was conducted at the UNH Judd Gregg Pier Facility on Fort Point, New

Castle, NH, USA at the mouth of the Piscataqua River (Fig. 1). The telemetry receiver,

computer and video monitoring system were located in a small building at the end of the

pier adjacent to the experimental cage. The test cage was moored between two mooring

blocks (4 ton ea.) approximately 30 m from the end of the pier in a water depth of 8 m.

The site experienced 2 ebb and 2 flood cycles per day, with tidal amplitude ranging from

3-3.5 m.

Case design

The sea cage was constructed of two, 15 m circumference (10 cm dia.) high-

density polyethylene (HDPE) pipe that were bent into a ring and fused. One ring was

attached to the top of a 63 m3 cylindrical net measuring 4.6 m in diameter and 4 m in

depth. The second ring (sinker tube) was drilled with 1.25 cm holes and wrapped with a

1.25 cm dia. chain before attaching to the net bottom. The nylon net was made from a 2

mm twine and had a 2.5 x 2.5 cm knotless square mesh that was coated with a cuprous

oxide antifouling paint (Flexguard™). The HDPE rings and net were suspended from a 5

x 5 m floating platform (Fig. 2).

Environmental data collection

An Acoustic Data Current Profiler (ADCP) deployed on the ocean bottom (10 m

from the cage) recorded ambient water velocities and direction at 0.5 s intervals. A

Modular Acoustic Velocity Sensor (MAVS) suspended in the center of the cage 2 m

below surface measured water velocity every 1.0 seconds. Both current meters averaged

and stored data in 5 min bins. Additional environmental data (temperature, dissolved

28

oxygen, salinity, pH, tidal amplitude and turbidity) was collected by an YSI 6600 V2-2

Water Quality Sonde located at the end of the pier adjacent to the cage site (Table 1).

Telemetry set u p

The HTI model 291 telemetry-system (Hydroacoustic Technologies Inc., Seattle,

WA) utilizes four omni-directional hydrophones hardwired to a receiver to monitor the

positions of acoustic transmitters, in three dimensions, using a suite of HTI programs.

The hydrophones were mounted on aluminum posts (5 cm dia.) bolted to the comers of

the float platform, around the net. Two opposing hydrophones were set at a depth of 0.65

m, while the other two opposing hydrophones were at set at a depth of 2.5 m (Fig. 2).

Cabling for the hydrophones was integrated into a mooring line that ran to an

instrumentation shed on the pier. Hydrophones were hard-wired directly to a receiver,

and signals from each tag were transferred to a CPU for storage and analyses. Three-

dimensional positions of sentinel fish and selected points on the net pen were calculated

with a 10 cm resolution, every 2.0 seconds. HTI software was later used to display these

data in near real time (~ 1 minute delay) and also stored as raw data for future analyses.

These stored data points were subsequently processed to eliminate spurious detections

and thus improve the resolution and accuracy of the data. Values were calculated using

the methods previously described by Rillahan et al. (2009, 2011) and Ward et al. (2012).

The data were used to reveal the mean distribution and swimming speed of sentinel fish,

and changes in net geometry. Additional processing was conducted in Matlab and Excel,

data were imported into Tecplot for 3D visualization.

Net Transmitters

29

HTI model 795Z acoustic transmitters were used to monitor the position of the

net. Twelve tags were attached around the net (8-middle, 4-bottom) to monitor the

position of the net and deformation caused by tidal currents (Fig. 2). To isolate individual

transmitters from ambient noise and other transmitters, each was programmed to ping

with a unique inter-pulse interval, ranging from 2,000-3,100 ms. During post-processing,

data from repetitive signals were dissociated from background noise and then assigned to

the individual transmitters, allowing continuous and rapid sampling of multiple

transmitters.

Fish Transmitters

Approximately 200 steelhead trout were transferred from a local hatchery to the

UNH Pier Facility (New Castle, NH) in 1 ton insulated boxes filled with freshwater. The

trout were acclimated from freshwater to seawater (28 ppt.) over a 2 hr. period, and then

netted into the sea cage. Model 795Z transmitters were surgically implanted into the

abdominal cavities of eight individual fish to track their temporal and spatial distribution.

Prior to implanting, each tag was programmed to ping at inter-pulse intervals ranging

between 1100-1800 ms. Trout were anesthetized with tricaine methanesulfonate (MS222)

and the 2.5 x 0.8 cm tags were inserted intraperitonally through a 2 cm incision (Fig. 3) in

the abdominal wall. One suture was used to close the incision, and an external streamer

tag was placed into the dorsal musculature of the fish. The trout were then allowed to

recover for 30 min. before placement in the experimental sea cage. One week later, the

experiment was initiated. During this time, the HTI system was activated and calibrated.

30

To test the possible effect of the surgery and tags on the trout, nine fish were

randomly netted from the cage and transferred to a 2 m diameter x 1 m deep tank in the

UNH Coastal Marine laboratory. Three fish were surgically implanted with a ‘dummy’

tag (same as normal tags, but did not ping), three had surgery but had no ‘dummy’ tag

implanted, and the remaining three fish had no surgery. Fish were observed for tag

retention, initial weight and length verses final, and survival for one month. No difference

was observed between fish with and without tags.

Data processing and statistics

Net transmitters

Net deformation was estimated by determining the differences in net transmitter

(12) locations during slack, intermediate and fast tidal cycles. Changes in net volume

were calculated using scalar triple product, divergence and signed volume methods.

These volumetric calculations are summarized in DeCew et al. 2013.

Fish transmitters

The location of all the pingers was represented by X, Y, Z coordinates that were

calculated with the same frame of reference. Thus, fish could be localized with respect to

each other and with respect to the net. The mean positions of all tagged fish, during each

sampling period were used to calculate mean positions of individuals and groups of fish

during fast and slow current velocities and during night and day within the net pen.

Instantaneous swimming speeds were calculated by taking the square root of the sum of

the three-dimensional (X, Y, Z) distances the fish travelled during a time interval (ti to

t2), and dividing this by the length of the time interval (t2-ti).

31

V (((X2-X,)2) + ((Yr Y.)2) + ((ZrZ,)2)) / (t2-ti)

Mean swimming speeds were calculated during fast and slow current speeds, and

during the night (0200-0300 h) and day (1400-1500 h). Calculations were based on the

positions of the fish relative to the hydrophone array in a steady current, and thus do not

take into account for different ambient current speeds. An unpaired t-test was used to

compare day and night swimming speed (BL / s) of the same seven fish on June 18, 2010.

Linear regression analysis was used to examine the relationship between current speed

within the net pen and swimming speed.

Differences in fish depth were compared across six 1 hour time periods over 24

hours. The positions of fish were averaged individually, and as a group, to obtain a mean

depth estimate per sample period. In order to calculate the amount of the total cage

volume that was occupied by the fish at any given time (cage utilization) we used the

technique developed by Rillahan et al. (2011). First, we created a three dimensional

matrix (10m x 10m x 10m) that encompassed the cage, with grid spacing every 0.2 m in

the X, Y and Z axes dividing the net pen into 0.2 m3 units. Fish positional data was then

overlaid onto the grid and presence/absence was determined for each grid unit. Cage

volume use was then calculated by summing the total grid units utilized by a fish over the

sample period.

A combination of software programs was used to visualize and plot the

movements and positions of fish within the cage. Python Visual Studio 2.0 Alpha was

used to develop wire frame diagrams of the cage during the different tidal and current

episodes. These diagrams were then imported into TecPlot (Version 10) and fish tracks

32

were overlaid in the wire frame to show their movements relative to the modeled cage

environment.

Results

Environmental

Current flow at the study site was bidirectional, with the predominate flow along

the NW-SE vector which coincided with the direction of tidal flow into, and out of, the

river. Current direction was SE (mean 114°) during much of the tidal cycle due to local

bathymetry and eddies. Flow towards the W and NW was relatively slow (0.12 m/s), and

seen only briefly (about 1 hour), about two hours after slack low tide. Currents were

fastest (average 0.24 m/s) on the ebb tides (SE direction). Current speeds outside the net

(ADCP) reached 0.50 m/s during the ebb tide on June 18, 2010. However, current

velocities inside the cage (MAV) were reduced on average by 31% with a high of

approximately 50% (DeCew, et al. 2013). This current reduction was influenced by the

net twine diameter (2 mm) and fouling organisms that accumulated on the net (Fig. 4).

These field results are higher than tank tests (10-20%) conducted by Aames et al. (1990),

Fredheim (2005), and Patursson (2008).

Net Deformation

Net deformation was estimated by determining the differences in net tag (12) locations

during slack, intermediate and fast tidal cycles. Three methods were used to calculate

changes in net volume and included the scalar triple product method, divergence method

and the signed volume method. These volumetric calculations, and complete results, are

summarized in DeCew et al. 2013.

33

Fish Swimming Behavior and Distribution

Visual diagrams of the net pen illustrate individual (Fig. 5 a, b), group (Fig. 5 c,

d) and density plots (Fig. 6) of the trout tracked horizontally and vertically. This allowed

for 1 hour visual examinations in on June 17 and 18th on low and high current flows.

There were no significant differences (unpaired t-test, P > 0.05) in fish positions relative

to the net walls and bottom during high and low currents, or during night and day

intervals (Table 2).

Fish were more clustered together during periods with fast current speeds (Fig. 6

a, b), and less clustered during periods with slow current speeds (Fig. 6 c, d). This

influence of current speed was also manifested in terms of cage utilization. The fish

utilized less of the net volume (6.71 m3) during high currents (Fig. 6 a, b) and utilized

more net space during slow currents (14.2 m3), (Fig. 6 c, d).

Mean swimming speeds ranged from ~ 0 - 0.6 BL/s, varied between individuals,

varied over time for any given individual, and were negatively correlated with current

speed. Swimming speeds were faster during low currents and slower during high

currents (Fig. 7). Swimming speed decreased with increasing current speed because the

fish displayed rheotaxis, and simply held their position against the current. Because

current speed affected swimming speed, for day/night comparison of swimming speed,

we used data sets collected during different times of the day, but which had similar

current speeds. The comparison was made using data collected from the same four fish at

night on June 17 (0200-0300h) and during the day on June 26 (1100-1200h). Current

speeds were similar in the two time intervals (0.19 and 0.16 m/s day and night,

34

respectively). There was no significant difference (unpaired t-test, P=0.53) between

mean day (0.178 BL/s) and night (0.178 BL/s) swimming speeds (Fig. 8).

Mean (±SD) swimming depth, based on the same fish sampled during the

indicated time intervals in Table 2 ranged from 2-3 m, and did not differ over time

(ANOVA, p=0.82).

Discussion

The HTI biotelemetry system is a powerful acoustical tracking instrument that

holds promise for monitoring fish and net movement in real time. The UNH pilot scale

cage served well to evaluate the usefulness of the HTI system on a sea cage with

steelhead trout. Acoustic biotelemetry systems have been used in the past to monitor fish

movement (Bjordal et al., 1986; Floen et al., 1988; Kils, 1989; Juell et al., 1993; Begout

Anras & Lagadere, 2004; Rillahan et al., 2009, 2011) however they have not been used to

measure fish distribution relative to net deformation. In this study we examined how the

fish reacted to changes in the net environment during high and low tidal cycles, with

associated high and low currents. This and our companion study (DeCew et al. 2013)

revealed that nets did deform at high current speeds, which reduced the cage volume and

forced fish to reposition themselves. As expected, the trout tended to swim into the

current when it flowed at a high speed, and thus their position in the net pen was guided

by their reactions to both the current speed and direction, and net deformation. Current

flow inside the net was significantly reduced (32-53%) compared to outside current

velocities. We suspect volume deformation, at a given current speed, was even greater

with the addition of fouling communities over time. These results were similar to those

35

reported by Lader et al. (2008), who measured net volume reduction at two farms in

Norway, and reported that at one site, a current of 0.13 m / s resulted in 20% loss in cage

volume. At the other site, a current speed of 0.35 m / s caused a 40% net volume

reduction.

In contrast to steelhead trout, numerous studies have been conducted on Atlantic

salmon swimming behavior in larger sea cages (Sutterlin et al., 1979; Juell et al., 1993;

Magurran, 1993; Juell, 1995; Johansson et al., 2009; F0re et al, 2009; Oppedal et al.,

2011). Because of their larger volumes and depths, larger cages often have temperature,

salinity, oxygen, current speed and light gradients (Juell, 1995; Juell & Fosseidengen,

2004; Johansson et al., 2006, 2007; Oppedal et al., 2007), all of which can affect the

distribution and movements of the fish. Interactions between individuals, and the net

walls, also influence the behavior of the group (Fore et al., 2009). In general, fish occupy

areas where the suite of environmental conditions are optimal, and avoid the net walls.

Such gradients, and choices, were not present in our small cage, so it seems unlikely that

variables such as temperature, salinity, or dissolved oxygen affected our results. We did

observe positive rheotaxis (Dodson & Mayfield 1979), at high current speeds, and more

circular swimming patterns at slower speeds, which is similar to the observations of

Atlantic salmon (Kils, 1989; Pitcher et al., 1993; F0re et al., 2009). It has been shown that

in natural streams, orientation, depth, and area occupied by trout can change with current

speed (Pert & Erman, 1994). When current speeds were > 0.2 m/s, the trout generally

swam into the current and occasionally some would change direction and orient tail to the

current before circling back.

36

We found no significant differences between night and day swimming depths.

These results differ from those described by Cubitt et al. (2005), Johansson et al. (2006,

2007, 2009), Dempster, et al. (2008), and Korsoen et al. (2009). In those studies, Atlantic

salmon swimming depths appeared to be controlled by changes in light intensity. Salmon

descended at dawn, stayed deeper during the day, and then ascended at dusk to swim

closer to the surface. Our differing results were probably due to our small volume (63

m3), and shallow depth (4 m) sea cage, which may well have restricted normal diurnal

rhythms. Moreover, if the daily vertical migration is associated with light, the light levels

between the top and bottom of our small net pen only differed by a small amount. As

with Huse et al. (1993), Juell et al. (1995), and Femo et al. (1995) the fish avoided the net

sides and bottom as an anti-collision behavior.

Mean swimming speeds of the trout ranged from - 0 - 0.6 BL/s, which is similar

to the range seen in Atlantic salmon held in net pens (Oppedahl et al. 2011). The activity

of rainbow trout (mean weight 254 g), measured as average hourly distance traveled, was

reported by Begout Anras & Lagadere (2004). They found that fish held at their lowest

density (27 kg / m3) were more active during the day. We saw no statistical difference

between day and night swimming rates, but it is difficult to compare our results to theirs

because of differences in fish size, stocking density, containment structure, net volume

and current velocities.

Although the HTI system proved useful in this environment, it was not without its

problems. Enormous amounts of fish and cage positional data were collected during the 4

week study, but not all the data could be used. The tags used were all pinging at the same

frequency, but with different periods. Therefore, because of the number of tags in use at

37

one time, there were often overlaps among the 20 tags, which prevented us from

distinguishing individual tags at every moment. In addition, the small size of the

experimental cage, and thus the close proximity of the hydrophones, made it more

difficult to triangulate signals. Triangulation uses the time of arrival differences between

the different hydrophones to calculate the distance from the pingers to each hydrophone.

If they are close together, as in our situation, the time of arrival differences are very small

and this led to some loss of data that had a poor resolution. Another issue that may have

complicated data collection was vibration of the hydrophone posts during strong currents

and when fouled with marine seaweed and debris. While equipment set up (hydrophone

location), cabling and HTI containment would be more challenging at a remote, deep

water site, the results would likely improve on a larger scale cage with increased

distances between transmitter and hydrophones.

In summary, the HTI system was used successfully too simultaneously, and

accurately, monitor both the shape and volume of a net pen, and the fish within it. As

such, we believe it has great potential as an aquaculture research tool that can lead to

improvements in net design, mooring systems, and fish welfare.

38

Table 2.1. Environmental ranges at the experimental site during the study period (June 2010)._________________________________________________________________________________

Parameter

Oxygen:Temperature:Salinity:Tidal amplitude (relative to MLLW) Current speed outside the net (ADCP) Current speed inside the net (MAYS)

Range

7.7 - 10.3 ppm11.3 -16.9°C (3-4°C on tidal change) 26 - 33 PSU -0.3 to 3.3 m 0 - 0.50 m / s 0 - 0.37 m / s

39

Table 2.2. Mean distances of trout from net tags (one up current and one down current) during four sampling periods. There were no significant differences (unpaired t-test, P > 0.05) in distances relative to the net walls and bottom during high and low currents, or during night and day intervals. This indicates that fish were evenly distributed in the cage during slow and fast currents, and during the night and dav.__________________________________________________

CurrentSpeed(m/s)

Mean distance of fish to tae (m) Date Hour

# of fish

Net tag location

Day slow 0.083 2.32 6/26 1100 3 up currentNight slow 0.138 1.82 6/17 1400 4 up currentDay slow 0.083 2.32 6/26 1100 2 down currentNight slow 0.138 2.78 6/17 1400 4 down current

Day fast 0.52 1.45 6/18 0800 5 down currentNight fast 0.37 1.45 6/29 1900 5 up currentDay fast 0.52 2.84 6/18 0800 5 up currentNight fast 0.37 2.91 6/29 1900 5 down current

A. B.

Figure 2.1. Google Earth photos of Fort Point, New Castle, NH, USA and the Judd Gregg Marine Research Pier (A). The boxed in area (in A) magnifies the UNH Pier and experimental cage site (B).

41

Hydrophone mounts

Hydrophone^)

Weighted tower rim

Acoustic source location

Figure 2.2. Experimental cage design showing placement of the 4 HTI hydrophones and 12 net pingers (acoustic sources). Also shown is the Modular Acoustic Velocity Sensor suspended in the middle of the net. Positioning of the hydrophones at two different depths allows triangulating the position of fish in 3 dimensions.

42

1 uu>dd ~ ^ ' Y

% K

*

Figure 2.3. An HTI model 795Z acoustic transmitter (left) being implanted into the abdominal cavity of a steelhead trout (right).

43

outsid«ci|« (A O C 9)> M lid ttn«6/ 4/2010

04

0 3

C 0.15 U

01

20 24

Time

Figure 2.4. An example of current velocities at the test cage site during ebb and flood tides. Currents were measured inside the cage with a Modular Acoustic Velocity Sensor and outside the cage, 10 m away, with an Acoustic Doppler Current Profiler.

44

a. Top View of Middle Net Tags and Single Fish b. Side View o f Middle Net Tags and Single Fish

d. Side View o f Middle Net Tags and Four Fishc. Top View of Middle Net Tags and Four Fish

Figure 2.5. An illustration of a single fish (a, b), and group of four fish (c, d), tracked on June 17 during at a current speed of 0.14 m / s. Red dots indicate the location of the net tags.

45

Side View Current FlowCurrent Flow

Top MewSide View

Current flow Current flow

Figure 2.6. Density plot showing the distribution of a single trout on June 18 from 0800- 0900h, when the current velocity was 0.50 m / s (ebb tide). Panel a. is a side view of the cage while panel b. is a top view. During this one hour event, the fish used 6.71 m3 (10.6%) of the available net environment. Panels c. (side view) and d. (top view) depict the density plot of three trout during a slack tide (0.083 m/s) on June 26 at 1 lOOh. During slack tide, the fish used 14.2 m3 (22.5%) of the net environment. The mean weight of the fish was approximately 600g.

46

0.6 . - - - - - - - - - - - - - -- -■ —.... -. . . -. . . . . -

# Swim speed (BL/s) = 0.25-0.35 current speed (m/s)0.5 - • * 10.4

0.3 - •

0.2•9' -. t + . — 4 i + !

0.1 I : *w w

% •

0 - •0.00 0.05 0.10 0.15 0.20 0.25 0.30

Current speed (m/sec)

Figure 2.7. Relationship between swimming speed (BL / sec) and current speed (m / sec) recorded by a Modular Acoustic Velocity Sensor (MAVS) current meter that was suspended inside the fish cage. The slope of the line (-0.35) was significantly different than zero (Regression analysis; P=0.01).

47

Mea

n (±

SD)

swim

0.250

0.200

0.150

0.100

0.050

0.000

Day Night

Figure 2.8. Mean (±SD) swimming speeds (BL / sec) of the same seven fish during day (1400-1500h) and night intervals (0200-0300h) on June 18th.

48

CHAPTER n i

SUBMERGED CULTURE OF STEELHEAD TROUT Oncorhynchus mykiss FOR

OPEN OCEAN AQUACULTURE IN THE NORTHEASTERN UNITED STATES

Abstract

To meet growing seafood demands, the US aquaculture industry will need to

consider farming the open ocean in a responsible manner. However, offshore

environments can be energetic (seas > 8 m) and difficult to maintain surface cage

systems. To minimize potential storm damage, submerged culture technologies can be

employed to safeguard the infrastructure and product. Steelhead trout (Oncorhynchus

mykiss) have potential as an offshore species, though they have open air bladders

(physostomous), and need access to air to inflate their swim bladders. To address this

concern, three experiments were developed to explore the ability of O. mykiss to cope

with extended periods of submergence.. The studies used small (~300 g) and large

(~1000 g) trout, in cages that ranged from 3.7 to 68 m3, that were submerged for periods

of one to four weeks. Data storage tags (DST), sonar and video were used to quantify

their ability to manage with submergence. Results indicated differences in growth,

condition, and mortality among the treatments. The study suggests O. mykiss can be

submerged for days to weeks with no negative effects.

49

Introduction

The New England ground fishery has nearly collapsed because of overfishing and

habitat loss (Hennessey and Healey, 2000). This shortage has stimulated new ideas to

produce seafood and to provide economic opportunities for harvesters that have, or will,

become displaced from traditional fisheries (Hennessey and Healey, 2000). Among the

most logical of the long-term solutions is the further development of marine aquaculture,

which has the capacity to produce the needed seafood, provide economic opportunities

for displaced harvesters, and contribute to economic and community development,

particularly in New England.

It is widely accepted that new marine aquaculture development in the US will

occur offshore in less populated waters. The US government has attempted to facilitate

this by developing the National Offshore Aquaculture Act of 2005. In addition, regional

centers throughout the US (NH, HI, CA and FL) were funded in to explore hatchery,

nursery and grow out technologies for cage culture (Benetti, et al., 2010; Fredriksson, et

al., 2004; Tsukrov, et al., 2000; Chambers and Ostrowski, 1999 and Tamaru, et al 1998).

New marine finfish species, both temperate and tropical were successfully spawned,

raised in hatcheries and made available for ocean growout. Submerged cages (Sea

Station™) were preferred to help protect juvenile fish after they were transferred offshore

from turbulent conditions (e.g. wind and waves) at the surface. This later proved to be a

benefit in growout to escape winter storm events and hurricanes. Other benefits of

submerged culture were less ware on the culture system, more stable temperatures, and

less bio-fouling on the nets (Chambers and Howell, 2006).

50

Rainbow trout (O. mykiss), called steelhead when they transfer from fresh to salt

water, are commercially grown in protected waters in Chile, Norway, Faroe Islands,

Canada, and to a limited extent in the USA (Washington and New Hampshire). Steelhead

trout have great potential to succeed as an aquaculture species in New England. First,

they have been domesticated for >150 years and are the basis for recreational fisheries

and fresh water aquaculture throughout the world. As a result, juveniles are readily

available from numerous commercial hatcheries. Second, unlike Atlantic salmon, O.

mykiss does not go through true smoltification (internal metabolic processes that allows

fish to migrate from fresh to seawater), so juveniles can go directly from a freshwater

hatchery to full strength seawater (32 ppt.). Third, the species has a relatively fast growth

rates in sea cages, reaching marketable size (1-3 kg) in 8 months after stocking at 250g.

Finally, they are disease resistant, are more temperature tolerant than Atlantic salmon,

and have a high market value (>13.00 / kg).

Submerged cage culture has been successfully demonstrated for several species,

including Atlantic salmon (Oppedal et al., 2011; Dempster et al., 2008, 2009; Korspen et

al., 2009), Pacific threadfin (Ryan 2004), cobia (Rapp et al. 2007), Atlantic cod and

haddock (Chambers et al., 2006, 2007; Rillahan et al., 2009, 2011), and halibut (Howell

et al., 2005). Because suitable inshore aquaculture sites are becoming scarce, and winter

icing and storms can damage surface cages, there is growing interest in culturing

salmonid species in offshore, submerged sea cages. In addition to providing more

locations and avoiding ‘visual pollution’, submerged systems could reduce the risk of fish

escapees during storms (Naylor et al., 2005), and sea-lice infestations (Hevrpy et al.,

2003). Despite these advantages, submerged systems for salmonids are only beginning to

51

be considered, and much of the essential knowledge on how submergence will affect the

fish is lacking.

The uncertainty surrounding submergence is related to the assumption that

salmonids become negatively buoyant when submerged beneath a cage roof because they

cannot access the surface to gulp air to fill their swim bladders (Smith, 1982). Near shore,

sea cage studies in Norway demonstrated that Atlantic salmon cope with submergence

quite well (Oppedal et al., 2011; Dempster el al., 2008, 2009; Korspen et al., 2009;

Osland et al., 2001). They feed actively and grow well, albeit at a slower rate than those

in surface cages. Dempster et al. (2008) found that 1.7 kg salmon increased their

swimming speeds by 1.5 times when submerged, compared to fish in control cages, and

suggested that the slower growth was due to the increased energetic expenditure for

swimming. They noted, however, that temperature and light differences between fish held

in surface cages, verses deeper submerged cages, may also have contributed to the

observed growth differences.

To investigate the ability of steelhead trout to incur periods of submergence, three

experiments were conducted to test the null hypotheses that the behavior, growth,

incidence of fin damage, and mortality in submerged cages does not differ from trout

held in surface cages under similar environmental conditions.


Timing and Locations

The project lasted 24 months, and involved three separate, but related,

experiments. In the first, which occurred from June through August 2011, we studied

juvenile trout in small inshore cages located near the University’s Judd Gregg Marine

52

Research Pier (JGP) in New Castle, NH (Fig. 1). The second experiment took place from

October through December 2011, in the same location. This time, larger trout and cages

were used. The third and final experiment was conducted in the summer of 2012 (June -

August), at a study location ~ 0.8 km seaward from the JGP that had more exposure to

wind and waves.

Steelhead Trout

In all three experiments, juvenile steelhead trout were purchased from Sumner

Brook Trout Farm in Ossipee, NH. Sumner Brook acquires eyed eggs from Trout Lodge

in Sumner, WA. that were certified disease free and are all diploid. Fingerlings were

raised in flow through, freshwater raceways for 8 months to a size of ~ 150 g. Prior to fish

transfer to sea cages, the trout were fed a 3 mm, Skretting Bio-Transfer diet for 7 days.

This diet helps transition salmonid smolts from fresh to salt water environments. It has

elevated dietary salts that encourage the development of osmoregulatory ability, while

added betaine acts as an osmoprotectant by relieving gastrointestinal stress. Fish were

transported to the Jackson Estuarine Marine Lab in Great Bay, NH in insulated 1 m3

containers. Here, they were acclimated from freshwater to brackish bay water (20 ppt.) in

flow through, fiberglass tanks for two weeks. They were then moved to a sea cage near

the JGP for final acclimation to 30 ppt.

Fish were hand fed to satiation daily with a sinking, Bio Oregon Trout diet (45%

protein, 24% lipid), trout in submerged cages were fed through a flexible PVC hose that

extended from the surface down into the center of each cage 1 m. Underwater video

cameras were used to help determine feeding satiation in these treatments.

53

Because environmental variables can influence swimming behavior and depth of

salmonids (Johansson et al., 2006, 2007; Oppedal et al., 2001, 2007), we collected a

series of environmental measurements. HOBO® temperature loggers were installed 1 m

below the surface of each cage and an YSI 6600 V2-2 Water Quality Sonde, located at

the end of the pier adjacent to the cage site, collected additional environmental data

(temperature, dissolved oxygen, salinity, pH, tidal amplitude and turbidity). Lastly,

current speeds were measured weekly in each cage, at 1 m depth intervals. Finally,

mortalities, if any, were recorded daily.

Experiment 1

In experiment 1, six, 3.75 m3 cylindrical cages (Fig 2a.) were constructed from a

2.5 cm mesh Seawire™ netting. Seawire is a stiff, copper alloy net material that

minimizes bio-fouling that can reduce water flow and quality (Chambers et al., 2012). On

10th June 2011, each cage was stocked with 55 trout with a mean (± SEM) starting weight

of 255.6 (14.4) g and length of 27.6 (0.4) cm. The experimental design had two

treatments (A & B) and a control (C), each with two replicates, for a total of six cages.

Control cages (C1 and C2) were maintained at the surface throughout the study to allow

fish to gulp air. Treatment cages, each equipped with a nylon netting cover, were

submerged 1 m during the study to prevent fish from accessing the surface to fill their gas

bladders (Fig 2b.).

The replicate treatment cages Al and A2 were submerged for two weeks, brought

to the surface for one day, re-submerged for two weeks, brought to the surface for one

day, etc. until the experiment was complete after 8 weeks. The replicate treatment cages

B1 and B2 were submerged for 4 weeks, brought to the surface for one day, re

54

submerged for the next 4 weeks, and then brought to the surface at the end of the

experiment.

Data from replicate pairs were compared, and because there was no difference in

any of the measured variables (Mann-Whitney U tests, P > 0.1), data from the replicate

pairs were combined.

Experiment 2

In the second phase of the submergence project, two 68 m3 floating cages were

deployed at the aforementioned inshore site. Each of the 4.6 x 4.6 x 3.2 m cages were

constructed of 2.5 cm knotless nylon twine, and were supported at the surface by high-

density polyethylene floating frames with wooden walkways (Fig. 3). The control cage

was maintained at the surface so the trout could freely gulp air to fill their swim bladders

(Fig. 3. A.) while the treatment cage (submerged) had a nylon mesh net roof to retain the

fish from surfacing (Fig. 3. B.). These were then submerged 1 m below surface for

sequentially greater periods of time using a series of ropes and weights attached to the to

the float platform.

The second experiment began in October 2011, using fish retained from

experiment 1. Each cage was stocked with 84 trout with a mean (± SEM) weight of

1070.4 (53.7) g and a mean length of 41.3 (0.7) cm. The experimental design had a

single treatment (submerged) and a single surface control. Prior to the start of the

experiment, a random sample of 10 fish from the control and treatment cages were

captured, anesthetized, and fitted with electronic data storage tags (Star-Oddi™ tilt tags).

These tags, as shown in Figure 4, were attached externally, just anterio-laterally of the

dorsal fin. They recorded temperature (° C), depth (m), pitch angle (degrees head up or

55

head down) and roll angle (degrees side-to-side) at either 45 (pitch and roll) or 90

(temperature and depth) second intervals. To test tag retention and survival, six trout

were placed into a 2 m round fiberglass tank with flow through water at the UNH Coastal

Marine Laboratory (CML). Three of the trout were surgically implanted with dummy

Star-Oddi tags while the remaining three fish were not tagged. After 1 month, all six fish

had adapted to the tank, were feeding well and the three tags were still attached firmly to

the trout.

Delays with the cage manufacturer extended the trial into the fall. With

decreasing winter temperatures causing a cessation in feeding (< 5°C) and problems with

the DST tags becoming fouled in the net, the submergence schedules had to be modified.

Instead of the 2, 3 and 4 week schedule, the treatment cage was submerged for 17 days,

brought to the surface for 4 days while we reattached the data storage tags, and then re

submerged for 31 days (Nov. 4 through Dec. 5 ).

Experiment 3 (Exposed site)

In the second year of the research, the two inshore cages used in experiment 2

were towed seaward to an exposed location approximately 0.8 km from the original site.

Steelhead trout ~100 g were purchased in early May 2012 and held at the UNH Jackson

Estuarine Lab for 2 weeks to help transition them to brackish bay water (20ppt). In early

June, they were transferred to the UNH JGP (full strength salinity - 30ppt). They were

held in a net pen at the pier until they had increased to a mean weight of 308.1 g (+/-

81.1) and mean length 28.1 cm (+/- 1.8). Fish were transferred to the experimental pens

(200 / cage) on June 19th, and on June 20th, the treatment cage was submerged 2 m below

surface. Again, one cage served as a control and was maintained at the surface. The

56

experimental pen was raised to the surface on June 27th, one week later and the first set

of data was collected from fish (n = 25) in both the submerged and surface cages.

Following this 24 hour surface time, the cage was submerged for sequentially longer

periods of time (2, 3 and 4 weeks), each separated by 24 hours at the surface.

To quantify the fish swimming angles, a weighted vertical white line was placed

in the center of each cage to a depth of 1 m off the net bottom. A Go-Pro™ video

camera, mounted on a 2.3 m PVC pole, was lowered into each cage and attached to the

side net for 30 minutes on each sampling date. Video was captured as the fish passed by

the vertical white line, and later analyzed with Ethovision XT fish tracking software to

determine mean tilt angle as the fish moved past the vertical line.

Growth. Condition and Fin Damage

Fish were sampled bi-monthly throughout each experiment. A random sample of

25 fish from each cage was anesthetized with MS222, weighed and measured. Standard

indices of growth and condition were calculated for each sampling date. Specific growth

rate (SGR, % day'1) was calculated as ((In (W2 ) - In (W))) / (t2 -ti)) x 100, where W2 and

Wi are the mean live body weights at times t2 and ti, respectively. Fulton’s condition

factor (K) was calculated with the formula K = ((W/L3) x 100), where W is the wet

weight (g), and L is the total length (cm). During scheduled resurfacing of the treatment

cages, fish in both control and treatment cages were visually examined for fin damage

and/or snout abrasions that can be caused when the fish encounters the cage ‘roofs’ as

they try to surface to obtain air and refill their swim bladders. The degree of snout

damage was assigned using a subjective index from 1 (undamaged) to 5 (extreme

damage) based upon Hoyle et al. (2007).

57

Surface Rolling and Jumping Behavior

Jumping and rolling behavior of both the control (surface) and treatment

(submerged) cages were observed each time the treatment cages were brought to the

surface. When the treatment cages were raised, the total number of jumps and rolls in all

cages, during the first 30-min period, were counted. All counts were standardized to rolls

or jumps fish'1 h r_1 (e.g. Furevik et al., 1993; Juell & Fosseidengen, 1995).

Statistical Analyses

In Experiment 1, statistical analyses varied with experimental design. On those

dates when only one of the submerged treatments was brought to the surface,

comparisons to the control (surface) fish were made with Mann-Whitney U tests. On

those dates when both submerged treatments were resurfaced, either one-way ANOVA,

followed by Tukey-Kramer multiple comparison test, or a Kruskal-Wallis test, followed

by Dunn’s Multiple Comparison test (if the data were not normally distributed) were

used. Response variables compared included fish length and weight, survival percentage

(square root arcsine transformed), incidence of fin, snout and body injuries, and

condition. In Experiments 2 and 3, where there were not statistical replicates, differences

in the same response variables between treatments were compared using Mann-Whitney

U tests.

Results

Experiment 1

After 18 days of submergence, the fish in the surface cages (C) were significantly

heavier than those in the submerged cages (A) and also were in better condition (heavier

58

per unit length; Table 1). There were no differences in mean length or abrasions on the

snout between surface and submerged fish. On the second sampling date both treatments

(2 and 4 weeks submergence, A and B respectively) were sampled, along with the control

(surface) cages (C). There were no significant differences in mean lengths or snout

condition (ANOVA, P > 0.05) between treatments, or between treatments and the

controls. Fish in the surface (control) cages were significantly heavier than those

submerged for 2 weeks (P < 0.05), but no different than those that had been submerged

for 4 weeks (ANOVA, P > 0.05). There was no difference in the condition of the fish

submerged for 2 and 4 weeks (ANOVA, P > 0.05), but the condition of the control

(surface) fish was significantly higher that both treatments (ANOVA, P < 0.05). On the

third sampling date fish in the control (surface) cage were significantly (Mann-Whitney

U-test, P < 0.05) heavier, longer, and in better condition than those in the 2 weeks

submergence treatment (A). There were no differences, however, in snout abrasions

(Mann-Whitney U-test, P > 0.05) between the treatment and control fish. At the end of

the experiment, on August 11th, fish in the surface (control) cages were significantly

heavier and longer than those in both of the treatment cages (ANOVA, P < 0.01). Fish in

the control cages (C) were also in significantly better condition (ANOVA, P < 0.001)

than those in the 2 weeks submergence treatment (A), but not better than those in the 4

weeks submergence (B) treatment (ANOVA, P > 0.05). There was no difference in

condition between fish in the two treatments, or between nose abrasions in the fish in two

treatments and the control (ANOVA, P > 0.05). Overall, trout in the control cages had

significantly better weight, length, condition and less nose abrasions than fish that were

submerged for 2 weeks and 4 weeks.

59

At the end of the 2 and 4 week intervals, trout in the submerged cages were

brought to the surface. In all cases, fish that had been submerged, jumped more

frequently than control (surface maintained) fish, presumably to fill their depleted swim

bladders with air (Fig. 6).

Mean (+/- SE) survival rates for treatments A and B, and the control (C), in

Experiment 1 were 66.4% (+/-6.3), 40.9% (+/-10.0), and 90.9% (+/- 5.4), respectively

(Fig. 7). After square root arcsine transformation of these data, an analysis of variance

(ANOVA) found that the means were not significantly different (P > 0.05). The

relatively low survival in Treatments A and B were caused by either bacterial or viral

infection, characterized by skin lesions, and perhaps exacerbated by the periodic

submergence of these two treatments.

Trout survival was the lowest during the two week submergence period. This may

be due to the additive handling and submergence over the eight week trial.

Specific growth rates (SGR) were calculated for fish in each treatment (A, B) and

the control (C) in both Experiments 1 and 2 (Table 2). In Experiment 1, growth rates

were highest in the surface control fish (C), intermediate in the 4 weeks submergence

treatment (B), and lowest in the 2 weeks submergence treatment (A). The lower growth

rate of fish in the 2 weeks submergence treatment compared to fish in the 4 weeks

submergence treatment may have been due to the stress associated with more frequent

handling during sampling.

Experiment 2

In experiment two, 17 days after submergence, there were no differences in mean

weight, mean length, mean condition or mean nose abrasions between surface and

60

submerged fish (Mann-Whitney U-tests, P > 0.05; Table 3). However, on the final

sampling date, after the treatment fish had been submerged continuously for 31 days, fish

held at the surface (control) were significantly heavier than fish that had been submerged

(Mann-Whitney U-test, P < 0.05). In fact, surface fish gained weight more than twice as

fast as submerged fish. There were no significant differences in mean length, mean

condition or mean nose abrasions between surface and submerged fish (Mann-Whitney

U-tests, P > 0.05).

On both sampling dates, fish that had been submerged jumped more frequently

than control (surface maintained) fish, presumably to fill their depleted swim bladders

with air (Fig. 6).

Survival was good in both the surface (88%) and submerged cage (92%). No

statistical comparison was possible due to single replicates, and the cause of death from

the few fish that died is unknown.

As indicated above, the pitch and roll tags were attached externally (Fig. 4.)

because internal (surgical) placement would have made it difficult, if not impossible, to

get the pitch and roll axes of the tag aligned with the same axes of the fish. Because the

tags were external, some became snagged in the cage netting, effectively changing their

orientation relative to the axes of the fish. For this reason, pitch and roll data from

several of the tags was suspect, and therefore not used.

While acute pitch angles (20-30°) were common as the individual fish moved up

and down in the cage, mean weekly pitch angle did not change over the course of

experiment 2, in either the surface (control) or submerged cages (Fig. 7). Mean weekly

pitch angle in fish held in both the surface and submerged cages varied from -3° to +3 °.

61

If submerged fish were compensating for lost buoyancy by swimming upward, we would

have expected a ‘heads up’ (+) orientation to develop over time, but this was not

apparent.

Experiment 3

Results were similar in the 1, 2, and 3 week submergence periods and can be

found in Table 4. Mean lengths did vary between the surface and submerged treatment

during week one and week two periods. During the first week submergence, the surface

cage was significantly longer that the submerged cage. This reversed during the second

week submergence with the submerged fish becoming significantly longer than the

surface. After this point, length, weight, specific growth rates (Table 2) and body

abrasions were all similar.

Most notable in Experiment 3 was survival and jumping events (upon resurfacing)

during the third and fourth week submergence trials. At samplings 1 and 2 weeks after

submergence, survival was similar at 99% (surface) and 98% (submerged). After 3 weeks

submergence, the survival was again similar at 83% and 84% respectfully. A divergence

occurred after 4 weeks submergence with a survival of 74 % in the surface and 43% in

the subsurface cage (Fig. 6). Also interesting was jumping events decreased when the

trout were resurfaced at the third and fourth intervals perhaps indicating that fish in both

cages were under stress (Fig. 8). During this time period, high temperatures (> 16°C) and

heavy bio-fouling of the hydroid Tubularia recruited onto the net and cage frames.

Ethovison XT fish tracking software was used to analyze the underwater video of

trout swimming angle past a vertical line suspended within the center of the cages.

Results indicated no differences in swimming angle + 3° in both the control and treatment

62

cages.

Discussion

The three experiments conducted to test differences between steelhead trout held

in surface verses subsurface cages showed varied results. At the end of Experiments 1

and 2, fish maintained at the surface were significantly heavier than those in submerged

cages, but in Experiment 3 there were no differences. Location and cage size may have

been responsible for these observed differences. Experiment 1, done with relatively

small fish (-300 g), was conducted in small diameter (1.25 m), cylindrical copper-alloy

cages at an inshore site exposed to fast tidal currents (0.5 m / s). Snout damage was

severe in all treatments and more so in the submerged cages, probably because of the

small cage size and copper-alloy cage material. Submerged fish may have incurred more

nose abrasions in trying to reach the surface to access air. Survival was poor in the

submerged cages, suggesting that the stresses of snout damage and submergence were

additive.

In Experiment 2, fish (-1000 g), and cages (68 m3) were larger and made of soft

nylon mesh, snout damage was virtually non-existent, and survival was good in both the

surface and submerged cage. At the conclusion, surface fish were significantly heavier,

indicating that submergence alone can have negative effects on growth performance. It

should be noted, however, that fish were submerged for 31 days, which is probably a

longer time than would be necessary in an aquaculture application that would avoid a

storm, phytoplankton and jellyfish bloom and or warm surface temperatures during the

summer (> 16°C). The mechanisms for compromised growth, however, remain elusive.

63

We saw no change in the swimming angle and vertical depth, which would have

suggested severe swim bladder depletion as reported by Dempster et al. (2008,2009) and

Korsoen et al. (2009).

In the third experiment, with smaller trout again, 1 and 2 week submergence

period indicated now significant differences between the surface and subsurface cages.

However, during the 3 and 4 submergence periods, survival and jumping changed

significantly in both treatments that may have been brought on by changes in the cage

environment. The cause of this was probably due to warm water temperatures (> 16°C)

and heavy bio-fouling of Tubularia on the nets. Tublaria has a flowery head with

stinging nematocysts that can irritate the outer mucous membrane of fish (Fig. 9).

Anecdotal evidence has shown this to be more of a problem during July and August when

surface water temperatures can reach up to 20°C. The trout were not vaccinated in any of

the above experiments that may have safe guarded them during this exposure. Secondary

bacterial infections caused by stress (temperature and bio-fouling) may have altered

survival rates and jumping behavior. An indication of this stress can be seen in the

jumping data in Figure 6. Here, jumping in both cages decreased by the end of the

experiment.

While we do not have conclusive data, we believe that steelhead trout can be

submerged for days to weeks with no negative effects, and this is an important finding for

those interested in culturing this species. We were logistically unable to conduct the

experiments in deep (> 10m) water, and hence our submerged cages, while below the

surface, were still relatively shallow. Because pressure (depth) may have an effect on the

behavior and physiology of forcibly submerged fish, these experiments should be

64

repeated in cages submerged to greater depths (> 10 m) in open ocean conditions.

Duration of successful submergence will depend on the species, size, temporal season,

and depth (Dempster et al., 2008, 2009).

Ultimately, cage submergence can be used as an effective management tool to

temporarily escape adverse situations at sea. The additional cost associated with

submergence must be taken into consideration by farmers and balanced out with the

potential risk of maintaining live stock at the surface. As fish farming expands offshore,

it will be important to develop management tools that can measure fish welfare, biology

and oceanographic data in real time. With this, farm managers can react appropriately to

safeguard their product in varying ocean conditions.

65

T able 3.1. M ean w eights, lengths, cond itions and nose abrasion ind ices o f the fish in the 2 w eek subm ergence treatm ent (A ), the 4 w eek subm ergence treatm ent (B ) and the surface contro l (C ) on the sam pling dates in E xperim en t 1. C om parisons betw een fish in the treatm ents and con tro l, fo r each o f the lis ted response variab les, w ere m ade w ith e ith er M ann-W hitney U -tests (June 29 and Ju ly .29) o r A nalysis o f V ariance (Ju ly 14 and A ugust 1U.____________________ ;_________________________________________________________________________________

S am plingD ate T reat

M ean w eight (s)

M eanlength (cm )

M eancondition

M eansnou t

6/29/2011 A 328.9 ± 10.4 29.5 ± 0 .26 1.26 1.7C 360.5 ± 9 .8 29 .6 ± 0 .2 6 1.37 1.5

C om parison C > A ( P < 0 .0 5 ) A = C /P < 0 .05) C > A f P < 0 .0001) A = C (P > 0.05)

7/14/2011 A 372.1 ± 12.9 30.6 ± 0 .2 8 1.27 1.9B 377.2 ± 1 3 .8 30.7 ± 0 .3 0 1.28 1.6C 414.7 ± 14.9 30.9 ± 0 .3 1 1.37 1.7

C om parisons A = B (P < 0 .05) C > A (P < 0 .05) C = B (P > 0 .05)

A = B = C (P < 0 .05) A = B (P < 0 .05) C > A ( P < 0 .0 1 ) C > B fP < 0 .01)

A = B = C (P < 0 .05)

7/29/2011 A 404.5 ± 6 3 .9 31.4 ± 4 .9 1.25 1.6C 498 .2 ± 7 .3 8 32.8 ± 0 .3 7 1.39 1.7

C om parison C > A / p < o . o n C > A f P c O . O l ) C > A f P < 0 .0001) A = C (P > 0 .05)

8/11/2011 A 427 .2 ± 19.5 32.4 ± 0 .3 7 1.22 1.9B 459 ± 19.1 32.4 ± 0 .4 0 1.32 1.9C 560.5 ± 18.2 34.1 ± 0 .3 1 1.39 2.2

C om parison A = B (P > 0 .05) A = B (P > 0 .05) A = B ( P > 0 .0 5 ) A = B = C ( P > 0 . 0 5 )C > A ( P < 0 . 0 0 I ) C > A ( P < 0 . 0 0 1 ) B = C (P > 0.05)C > B f P < 0 . 0 1 ) C > B / P < 0 . 0 1 ) _____________ C > A ( P < 0 . 0 0 1 ) __________________________

Table 3.2. Specific growth rates (SGR (%/d)) of each of the indicated treatments at the end of Experiments 1.2 and 3._______________________________________________

Experiment Treatment Duration SGR f%/d)

1 A 8 weeks 0.8561 B 8 weeks 0.9761 C (control) 8 weeks 1.309

2 Submerged 7 weeks 0.3262 Surface 7 weeks 0.695

3 Submerged 10 weeks 1.163 Surface 10 weeks 1.33

67

Table 3.3. Mean weights, lengths, conditions and nose abrasion indices of the fish in the submerged and control cage on each of the sampling dates in Experiment 2. Comparisons between fish in the treatment and control, for each of the listed response. variables, were made with Mann-Whitnev U-tests._______________________________________________________

Sampling Mean Mean Mean MeanDate Treatment weight (s) length condition snout

10/27/2011 Submerged 1132.3 ± 58.9 41.5 ±0.66 1.59 ±0.08 1.0 ±0Surface 1183.8 ±67.4 41.0 ±0.79 1.73 ±0.13 1.2 ±0.2

Comparison Sub = Surf Sub = Surf Sub = Surf Sub = Surf2 week sub (P > 0.05) (P> 0.05) (P> 0.05) (P> 0.05)

12/6/2011 Submerged 1301.7 ±93.4 42.3 ±0.73 1.1 ±0.09 1±0Surface 1579 ±80.5 44.2 ±0.61 1.28 ±0.15 1 ±0

Comparison Sub < Surf Sub = Surf Sub = Surf Sub = Surf4 week sub (P < 0.05) (P> 0.05) (P> 0.05) (P> 0.05)

Table 3,4. G rowth and condition index fo r trout subm erged for 1 , 2 . 3 and 4 weeks during Experim ent 3.

DaleM eanLength (cm)

M ean W eight (g)

MeanCondition

Initial slock 6/19/12 28.14+1.83 308.17+81.08 1.0

Subm ersion6/27/12 Surface Submerged

29 .9± l.84 31.9+1.39SM fl^S S M te fg e d 376±95.I7 425.4+74.6

S u /ite e S u b m rs e d 1.38 1.3

Com parison (Unpaired t test)

Surface > Subm erged P>0.05

Surface = Submerged P<0.05

Surface = Submerged P>0.05

Tw o week Submersion

7/12/12 32.52+2.3 33.84±2 8 488 .8± 136.3 535.9+109.2 00


Surface < Submerged P>0.05



Three week Submersion

8/3/12 35.53+2.31 35.31+2.3 618.85+152.4 602.81+140.6 1.35 1.35


Surface - Submerged P<0.05

Surface = Submerged P<0,05


Four week Submersion

8/31/12 37.72±2.8 37.0+2.4 824.0+273.3 727.7±2!8.7 1.38 1.35


Surface = Subm erged P<Q.Q5



i \ p Mu - ) 1 9

} \ p. 'Nitt M

j f '

\ M l I'll t

fV-f

■#*/

N o ' l | ; n n p s h m M . t i i K

Figure 3.1. Aerial photo of the Judd Gregg Marine Research Pier in New Castle, NH and proximity of the experimental sites.

70

Figure 3.2. Cage design used in Experiment 1. Six, 3.75 m3 copper-alloy cages were suspended in a 4 x 5 m floating platform made of High Density Polyurethane (A). Diagram B. illustrates cage dimensions, the Control cage C (surface) and the submerged treatments cages A and B, one m below the surface to keep fish from refilling their swim bladders.

Figure 3.3. (A) Control cage left where trout were allowed access to the surface to gulp air. (B) Treatment cage with net nylon roof submerged 1 m below surface. Note feeding tube in upper left of image.

Figure 3.4. Steelhead trout (~ 1000 g) attached with a fitted Star-Oddi™ pitch and roll data storage tag.

Snout Damage Index

4 S

Figure 3.5. Visual representations of subjective snout index, ranging from no damage (1) to severe damage (5). Nose damage can occur when fish in the submerged treatments try to resurface to gulp air and fill their swim bladders.

74

1. 0.08

0.0?

0.06c1 0-051£ 0.04a

0.03i,

0 J02

0J01

0

IS urface S ubm erged

4 w eek s

2 . 0.100 0.090

| 0.080 | 0.070 |- 0.060 ,s 0.050 j s 0.040 fc 0.030

0.0200.0100.000

S urface S ubm erged

2 w eek s

I J 0 □Sab Sarf Sab Sab Sarf Sab Sarf Sab Sab Sarr

2 week 4 week 6 week 8 week

3 0.08

007

Figure 3.6. Number of jumps fish'1 minute"1 upon surfacing of submerged cages on the indicated sampling dates during the Experiments 1, 2 and 3.

75

Tagged fish #1017, Control cage

» • XU* « '

Fig. 3.7. An example of pitch recordings, taken from a fish in the submerged cage (Tag 1037-top) and a fish in the surface cage (Tag 1017- bottom), taken during the 5th week of Experiment 2.

76

10090

80

70

60

50

40

30

2010

0 I2 weeks 4 weeks

TreatmentSurface

2 .

>

taVi

1009080706050403020100

2 Week 4 WeekTreatment

• Surface i Submerged

3. 100

90

80

70

60

50Vip 40

30

20

10

■ Surface■ Submerged

1 week 2 week 3 week 4 week

Treatment

Figure 3.8. Survival of trout in Experiments 1, 2 and 3 at different submergence periods.

77

Figure 3.9. (A) Bio-fouling of the hydroid Tubularia on a fish net. (B) A heavily fouled net being pulled up for fish sampling.

78

C H A P T E R IV

TECHNOLOGY TRANSFER OF SMALL SCALE INTEGRATED MULITROPHIC

AQUACULTURE TO COMMERICAL FISHERMEN IN NH

Abstract

Over the last five years, the commercial fishing fleet in New England has been

subjected to increasingly restrictive management measures established to rebuild

declining stocks. By design, these measures have limited fishing opportunities and

significantly reduced the inshore small vessel fleet. To help support New Hampshire

(NH) fishermen, an extension program was developed by the University of New

Hampshire (UNH) and NH Sea Grant, to train fishers on small scale integrated multi-

trophic aquaculture (IMTA). Because federal and state regulatory agencies had concerns

about nitrogen input from fish production in the coastal waters of the state, a program

was designed to measure nitrogen uptake from shellfish and seaweed integrated with the

finfish production. The program was evaluated as the fishermen were taught the

necessary husbandry skills for culturing steelhead trout, blue mussels and sugar kelp

together. Nitrogen extraction by the mussels and kelp exceeded the nitrogen added from

trout production, and thus had a positive effect on the ecosystem. The training program

provided the fishermen with a new skill set, that they could adopt either part time or full

time, to provide additional income.

79

Introduction

Commercial fishing has been a vital component of New England’s economy for

over two centuries, and has grown to a half-a-billion dollar per year industry. Equally

important, recent economic studies based on National Marine Fisheries Service (NMFS)

data suggests that every job created in the seafood industry generates one-and-a-half jobs

in the regional economy: jobs in other sectors such as food processing, tourism,

restaurants and boatyards (Hoagland et. al 2005).

Over the last five years, however, the commercial fishing fleet in New England

has been subjected to increasingly restrictive management measures established to

rebuild declining stocks. By design, these measures have limited fishing opportunities

and significantly reduced the inshore small vessel fleet. The catch allocation groundfish

fishermen receive will result in a 40% decrease in potential landings, and may reduce the

current groundfish fishing fleet by 50% (NH Sea Grant, 2013). For many local

communities this will mean the loss of their historic fishing heritage. New Hampshire had

180 commercial fishing permits in 2009. The number declined by about 50% from 2009

to 2010, and the value of New Hampshire’s landings decreased by approximately 40%

(NH Sea Grant, 2013).

As fishers become displaced by federal management measures, they could adopt

small-scale aquaculture operations. They have vessels, water front infrastructure, and

experience working on the ocean, all of which would be useful in transitioning to

aquaculture. Although we envision that such a transition would be gradual for any given

individual, aquaculture could eventually become full time employment for some. It is

80

worth noting that the US is the third largest consumer of seafood in the world, yet we

import over $10 billion annually. Marine aquaculture has the potential to contribute to US

seafood production, reduce our reliance on imported seafood (FAO, 2010), and provide

economic opportunities to displaced fishers.

UHN established an Open Ocean Aquaculture research farm in 1999

(http://ooa.unh.edu/) to develop new technologies for growing seafood in New England.

The site was located 12 km offshore, in 50 m water depth, away from commercial

fishing, recreational boating and navigational routes. To escape surface energies (waves)

experienced offshore, submersible cage and mooring systems were employed. Culture

methods for new marine fish species were investigated (cod, haddock and halibut) to

relieve fishing pressures on wild stocks. The project developed and demonstrated new

submersible cages (Chambers et al., 2011), mooring systems (DeCew et al., 2012),

mussel longline technologies (Langan et al., 2003) and remote feeding systems (Rice et

al., 2003). It also demonstrated that is was feasible to produce cold water, marine finfish

in submerged cages (Howell et al., 2005; Chambers et al, 2006,2007; Rillahan et al.,

2009,2011), and collect environmental data in real time from the offshore site (Irish et

al., 2004,2001). Although the project succeeded in generating significant amounts of

data and new information, the high costs, exposed nature of the site, and slow growth of

the fish species cultured, created operational and economic challenges.

Based upon the experiences and lessons learned from the offshore project, an

alternative aquaculture model was designed that would emphasize small-scale production

closer to shore. These smaller systems would be more affordable and user friendly for

fishermen. However, concerns were made by the EPA regarding near shore aquaculture

81

http://ooa.unh.edu/

in an already nitrogen impaired Piscataqua River. To address EPA’s concern of N

loading, we decided to us an integrated multi-trophic aquaculture (IMTA) farming

system. IMTA is where the culture of a fed product (i.e. fish) is combined with the

culture of organic and nonorganic extractive species that bio-mitigate nutrients from the

farm and surrounding waters. This creates product diversification, improves farm output,

helps maintain a clean environment and is more socially acceptable. Integrated

aquaculture is a biologically and technically feasible method to reduce the environmental

impacts of by-products from fish culture. The concept of developing an "environmentally

clean" aquaculture, based on the integrated culture of fish, mollusks and macro-algae,

was first proposed by Gordin et al. in 1981. The system was subsequently tested (Gordin,

1982; Gordin et al., 1990; Shpigel et al., 1991) and further developed (McDonald, 1987)

with shrimp and oysters in land-based facilities (Wang, 1990; Wang et al., 1990; Qian et

al., 1999).

Fish farming releases nutrients to the environment causing hyper-nitrification

(Gowen and Bradbury, 1987). The negative impact of aquaculture derives mainly from

particulate and dissolved nutrients from animal excretion and uneaten food (Krom and

Neori, 1989). IMTA promotes economic and environmental sustainability by converting

byproducts and uneaten feed from fed organisms into harvestable crops, thereby reducing

eutrophication, and increasing economic diversification (Neori et al., 2004; Troell et al.,

2003; Toumay, 2006). More recently, IMTA has been investigated extensively in

Atlantic Canada with salmon, blue mussels and kelp (Neori et al., 2004; Ridler et al.,

2006, 2007; Robinson, et al., 2007). However, uptake efficiency in open-water IMTA is

still unknown (Reid et al, 2007).

82

To encourage NH fishermen on small scale IMTA, extension programs were

developed through the Saltonstall Kennedy program and NH Sea Grant. These programs

enabled local fishermen to participate in and learn small-scale integrated aquaculture of

steelhead trout, blue mussel and sugar kelp grown. With this experience, fishermen can

determine if IMTA will be a suitable business alternative to fishing full time.

Method and Materials

Permitting

As part of the state permitting process, an application is filed with NH Fish and

Game (NHFG) for a preliminary evaluation. Following this, NHFG forwards the

application to the Army Corps of Engineers, NH Port Authority, NH Department of

Environmental Services, NH Health and Human Resources, the US Coast Guard and

National Marine Fisheries Service for their review and comments. After this, a public

hearing was set and letters of intent (Certified) must be sent to the abutters nearest the

aquaculture site. Written comments are accepted up to two weeks after the public

hearing. A onetime application fee to NHFG is $200 per requested site. If granted, an

annual permit and production fee is assessed at $750 / acre / year for suspended culture,

and $0.45 / kg for product sold.

If the application is accepted and passes public scrutiny, permits are then granted

by the following agencies: 1.) NH Fish & Game (Aquaculture Li); 2.) NH Port Authority

(Mooring Permit); 3.) Army Corps of Engineers (for anchor placement on the bottom);

and 4.) US Coast Guard (Aids to Navigation and lighting on structures).

83

Before the application can be submitted, an environmental survey had to be conducted at

each requested site. Environmental information was gathered on the bottom depth,

substrate content, tidal current direction and speed. In addition, NHFG sends divers down

to each intended site to inspect and verify habitat structure and resident biota. Other

information gathered for the state permitting process included the following:

1. Site coordinates (GPS)

2. Water quality (dissolved oxygen, pH, temperature and salinity)

3. Proximity to historical sites

4. Critical habitat for marine organisms

5. Proximity to commercial traffic

6. Potential user conflict by fishermen and recreational boaters

7. Product to be raised

8. Culture system

9. Planned annual production (biomass)

To sample the bottom of each site, a Van Veen sampler was used to collect

sediment. These samples were photographed and placed in to 3.75 1 plastic bags with

labels for analysis on shore. Water quality was derived with a hand held Y SI5 to obtain

information on DO, temperature, and salinity and a “Red Sea” test kit was used to sample

ammonia, nitrite and nitrate.

Eight NH fishermen gathered the necessary data required for permitting and six

applications were filled for permit in the Piscataqua River, NH. A public hearing was

held for the sites on May 24th 2010. At the public hearing, site descriptions and

84

operational methods were described for small scale trout farming. Although the public

hearing was generally positive, the EPA stepped in and expressed concerns about the

addition of nitrogen input trout farming to the already nitrogen impaired Piscataqua

River. This halted the aquaculture permitting process until a nitrogen mitigation plan

could be developed.

In response to the EPA’s concerns, we gathered biological data and

mathematically modeled nitrogen uptake of blue mussels and sugar kelp that could be

cultured alongside the steelhead trout. As a result, the EPA approved a demonstration

project that would involve integrated multi-trophic aquaculture (IMTA) to bio extract

nutrients from the river.

NH Fish & Game Department then issued a commercial aquaculture license for

the IMTA demonstration project. The site was located near shore in New Castle, NH.

Here, the bottom substrate consisted of sand and cobble, the water depth was 8.2 m at

MLW, and the current speed could flow up to 0.50 m / sec. An environmental monitoring

program, consisting of water column chemistry, benthic sampling, and video transects,

was established to assess any impacts to the Piscataqua River.

Integrated Multi-trophic Aquaculture

Culture Technology

Two high density polyethylene (HDPE) cages were moored between two 750 kg

Jeyco anchors (Fig. 4.1. A). Each anchor line was 30 m long, made from 5 cm dia.

Polysteel line and shackled to an upper bridle on the fish cage. Each of the two cages

85

1

measured 4.5 x 4.5 m, had a net depth of 3.5 m, and a volume of 68 m . The combined

float platform had a radar reflector and solar light per U.S. Coast Guard requirements.

Steelhead trout

Steelhead trout juveniles (Oncorhynchus my kiss) were purchased from Sumner

Brook Fish Farm in Ossipee, NH. Sumner Brook sourced the eggs from Trout Lodge in

Sumner, Washington. The diploid (all female) juveniles (-150 g mean weight) were

transported in insulated 1 m3 containers supplied with oxygen to the Jackson Estuarine

Laboratory on Great Bay, NH where they were acclimated from freshwater to brackish

water (20 ppt.). After 2 weeks in this land based, flow through system, the trout were then

moved to full strength ocean water (30-32 ppt.) at the Judd Gregg Marine Research Pier

(JGP) in New Castle, NH. There, they were placed into sea cages under the pier and

acclimated to their new marine environment.

Blue mussels

The fish cage platform was used to capture and grow blue mussels (Mytilus

edulis) on suspended lines (Fig 4.1.B). Galvanized eye bolts were screwed into the

perimeter of the wooden walkways at 0.7 m intervals. From these, New Zealand fuzzy

rope was suspended to collect mussel spat. Each line was 4 m long and had a 2.0 kg sash

weight tied to the end to keep it vertical during strong tidal currents (0.35 m / sec.). The

fuzzy rope was made from loops of polyester line providing abundant surface area for

mussel settlement. Mussels typically spawn twice per year in early and late summer in

the Gulf of Maine and adhere to bottom substrate and materials in the water column

(Langan et al. 2003).

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Sugar kelp

Sugar kelp (Laminaria saccharina) is endemic to New England waters and

naturally settles on subsurface substrate. The HDPE cage platforms provided essential

habitat for kelp settlement (Fig. 4.2). In the late fall of 2012, sorus tissue (gametophyte)

was collected from mature kelp and spawned in captivity. With the help of Ocean

Approved in Portland, ME (http://www.oceanapproved.com/) and ME Sea Grant, kelp

spores were successfully spawned onto twine that was seeded for ocean growout on

empty fish cages at the JGP.

Technology Transfer to NH Fishermen

A priority of the project was to involve commercial fishermen in the

demonstration project, thereby giving them both experience and training on the

techniques for small scale aquaculture. Recruitment and selection of fishermen was

accomplished in an initial meeting with the New Hampshire Commercial Fishermen’s

Association. In this initial meeting, set up with the assistance of UNH and NH Sea

Grant, we explained the past and current projects, talked about cage options, the steps

involved in aquaculture, went over the costs of fish, feed, and cages, and did a simple

economic projection. As a result, 8 commercial fishermen expressed serious interest in

working together to grow seafood for local markets. Following this, a series of informal

meetings were held that focused on: 1) reinforcement and deployment of fish cage

frames; 2) net antifoul treatment and deployment; 3) trout transfer and acclimation to

seawater; 4) feed acquisition, management and distribution; 5) net and platform

maintenance; and 6) trout harvest and transfer to markets.

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http://www.oceanapproved.com/

Environmental Monitoring

As mandated by the EPA, NH fish & Game and the NH Department of

Environmental Services, an environmental monitoring (EM) program was established for

the demonstration project. The EM program was designed, vetted through the EPA and

carried out by UNH staff. The program included the following:

1. Water samples were collected using a one-liter Niskin bottle. Samples were

taken 2 m below surface at three different locations: 1) inside the cage; 2) 15 m up

current; and 3) 15 m down current from the cage. Sampling occurred in May before the

fish were transferred to the sea cages, in August at midterm of the growout, and again in

December after the final harvest. A “Red Sea” test kit was used to measure ammonia,

nitrite and nitrate. Other environmental data collected included dissolved oxygen, pH,

salinity, and current speed and direction.

2. Sediment samples were collected by SCUBA divers at the same locations and

dates noted above. They were collected with a 5.0 cm diameter by 10 cm long PVC pipe

with cap. Each sample (~ 600 ml) was placed into a labeled zip lock bag and frozen for

later analysis.

3. Divers were also used to gather under water video of the substrate in the

vicinity of the cage. Video was taken 1 m off the bottom along a 30 m transect (NE-SW

direction) line extending 15 m up current and 15 m down current of the cage site. This

was used to detect any changes in the benthic community, or deposition of fish food that

could lead to anoxic spots. Video samples were collected on the same dates as above and

archived on a DVD for the regulatory agencies.

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Summary reports of the findings, as well as the video, were submitted to New

Hampshire Fish & Game and the EPA after each sampling.

Market Survey of Steelhead Trout

A market survey form was developed to gather information about the fish from

wholesalers, retailers, restaurants and consumers. The survey asked questions pertaining

to meat quality, color, smell, texture and taste. Price point and amount of fish taken per

week were also included (Table 4.1). Restaurants and wholesalers were contacted to

ascertain their interest in receiving the product and answering the survey form. Orders

were taken prior to the first harvest in the fall of 2012. Entities that received fresh trout,

and provided feedback for the survey, were the following:

1. Black Trumpet (Portsmouth, NH)

2. Brown Trading Company (Portland, ME)

3. Common Man Restaurant (Portsmouth, NH)

4. Gonic Smokehouse (Rochester, NH)

5. Jumping Jays Fish Cafe (Portsmouth, NH)

6. Portsmouth fishermen’s community (Portsmouth, NH)

7. Restaurant 106 (Portsmouth, NH)

8. River House (Portsmouth, NH)

9. Sanders Fish Market (Portsmouth, NH)

10. Seaport Fish (Portsmouth, NH)

11. Thai House Two (Lee, NH)

12. UNH dining facilities (Durham, NH)

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Results

Demonstration of Integrated Multi-trophlc Aquaculture

Although the fishermen were most interested in raising steelhead trout, the EPA’s

concern over added nitrogen mandated that IMTA be part of the demonstration project.

Our conceptualized IMTA plan, which included trout, mussels and sugar kelp, was

approved for one site in the Piscataqua River. Informal meetings throughout the growout

cycle helped inform the fishermen on the culture techniques for the added species, and all

three species were successfully grown.

Steelhead trout

Steelhead trout were relocated from Sumner Brook Trout farms to the JGP on

May 15, 2011 (n=200) and again on June 30, 2011 (n=800). They were used in a study to

investigate their tolerances to withstand periods of submergence (Chapter 3, funded by

Saltonstall Kennedy). After the research, 311 trout (mean length of 37.36 ± 2.6 cm, and

mean weight of 775.5 ± 246 g) were donated to the fishermen who wished to try raising

them. The group gathered each week to conduct cage and net maintenance, and they took

turns hand feeding once / day with a 6 mm, Bio Trout fish pellet (45% protein, 22%

lipid). In November 2012, harvesting commenced and continued once / week until mid-

December (Fig. 4. 3). At harvest, fish were netted from the sea cages, placed into a

saltwater ice bath, bled, gutted, rinsed, and packed on ice in 25 kg totes before delivery to

the markets. At final harvest, the fish had a mean length of 41.1 ± 0.63 cm and mean

weight of 1127.7 ± 96.4 g. The feed conversion ratio was 1.24, specific growth rates were

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0.32 % / day and survival was 98 %. Total harvest weight for the season was 415.61 kg.

The fishermen sold the trout to two local seafood retail markets for $13.20 / kg.

After harvest, the nets were removed and cleaned, and the frames were towed into

the JGP area for winter storage. The demonstration site was left to fallow for 5 months

until the next growout cycle in the spring of 2013.

Blue mussels

Wild mussel spat naturally settled on the fish net and on fuzzy rope suspended

around the cage platform (Fig. 4.4). Mussel spat that settled on the fish net was cleaned

off by hand and later sorted into 4 m long mesh sleeves (‘socks’) at the JGP. They were

then hung from a growout raft under the JGP for continued nutrient extraction.

On November 15, 2012, the mussels were sampled and had a mean length of 9.8 ±

3.4 mm, a mean weight of 0.10 ± 0.045 g, and a density of ~ 75,456 / m of dropper line.

In total, the 52,4 m dropper lines had a combined weight of 1153 kg. A mussel sub

sample (tissue and shell) was sent to the New Jersey Feed Labs in Trenton, NJ for

proximate analysis. Results from the analyses indicated a nitrogen content of 1.4% for the

mussel tissue and 0.68% for the shell weight totaling ~ 2% for the entire mussel. These

results were similar to those of Rice (1999), who found that the N content of mussel

tissue ranged from 1.3-1.6 %. By multiplying the total weight of mussels (1153 kg) by

the nitrogen content of the mussel (2% by weight), we estimated the total nitrogen

extracted and sequestered by the mussels at this point in time to be 23 kg. The mussels

were left to grow, and continue extracting N from the Piscataqua River, until the fall of

2013.

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The JGP area is prohibited to shellfish harvest due to its proximity to the

Portsmouth sewage treatment facility located 2.4 km up river (National Shellfish

Sanitation Program, 2011). Seawater and mussels samples were taken from the JGP and

trout demonstration site by the NH Department of Environmental Services in the spring,

summer and fall of 2013. Results indicated that bacteria levels were below FDA/EPA

standards for shellfish harvest. Despite this information, NH regulations states that

shellfish grown in prohibited waters must be relayed for at least six months in open

waters. To facilitate mussel relay, the entrepreneurial fishermen modified lobster pots

(1.2 x 0.5 x 0.30 m) to hold and store mussels on the bottom at an open, offshore site. In

August 2013, 10 preliminary pots were stocked with 50 kg of mussels and set near the

trout cage site in 10 m depth. They were checked monthly for 3 months to observe

survival, siltation and movement of the mussels within the pot. The mussels survived

well although some of the pots, particularly in soft sediment, had silt in the bottom which

made it difficult to pull them up and purge.

Based upon these preliminary results, another 25 traps were modified and filled

with ~ 2050 kg of mussels that were taken to Gunboat Shoals, NH, and set in 20 m water

depth for the winter (Fig. 4.5). This time the pots had deeper runners (5.0 cm) to help

keep the mussels off bottom and create better water flow for oxygenation and feeding.

The pots will be retrieved in the spring of 2014, cleaned, graded and taken to market. In

addition to the lobster pots placed offshore, 1250 kg of mussels were set overboard onto

the bottom to create a small mussel reef. The GPS location was recorded, and divers will

visit the site in the summer of 2014 to monitor growth, survival and predation.

Sugar kelp

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Mature kelp blades (15), filled with gametophytes, were collected in November

2012 and brought to Ocean Approved for spawning. Sorus tissue was cut from the center

of the kelp blades into 15x10 cm strips, cleaned of any epiphytes with a soft cloth, and

refrigerated for 24 hrs. The next day, the spore strips were placed into two, 500 ml

beakers of seawater at a temperature of 11 ° C. The water temperature was allowed to

increase to 15.5 °C at which point the gametophytes released spores into the beaker

forming a tan color in the water. Each beaker was then poured into a 75 1 glass aquaria

filled with seawater. Inside the aquaria were 8 spools of twine for spore settlement. Each

spool was made of 5 cm dia. PVC pipe that was 30 cm long. Nylon twine (0.5 mm dia.)

was wrapped around the pipe to provide a soft substrate. After kelp settlement, fresh sea

water was cycled through the tanks once per week for six weeks. The spools, each with

100 m of twine (6000 spores / m), were delivered to UNH JGP in January of 2013. Here,

the seeded twine was wrapped around a heavier gauge (1.25 cm) polyester line (3.0 m

long), and suspended horizontally in cage frames (Fig. 4.6), or vertically suspended from

the floating docks at the pier.

Sugar kelp was grown throughout the winter and spring of 2013 (Fig. 4. 7).

Winter growth (January to early April) averaged 7.7 cm per day and had a mean length of

0.85 m by mid-April. As water temperatures increased from April to June (7-12°C), kelp

growth accelerated to 35.22 cm / day, averaged 2.5 m in length and had a mean weight of

3.5 kg / m by mid-June. Samples of fresh kelp were taken weekly from May 15 through

June 25 to the Black Trumpet restaurant in Portsmouth, NH. Here the kelp was

experimented with to create new recipes and to consider market viability. Customer

feedback was very positive and orders began to increase. Unfortunately by July, water

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temperatures increased to 16 °C and epiphytes (Bryozoan sp.) began to cover the kelp

blades degrading their quality. The project demonstrated that kelp can be successfully

grown, however it is a seasonal product (fall-spring) for fresh markets. Kelp could be

better utilized by harvesting and processing (blanching and freezing or drying) in the

spring to increase shelf life and expand marketability.

Fate of nitrogen

The fish raised in 2012 were fed a total of 515.35 kg of Bio Oregon trout diet. The

approximate fate of the nitrogen, based upon food fed to the trout, is shown in Figure 4.8.

About 5% of the N was lost to the environment through uneaten feed, about 40% of the

nitrogen consumed by the fish was retained in their tissue (Hardy, 2012), about 50% was

excreted through the gills, and about 10% was lost in their feces.

With this model, total nitrogen input to the river from fish feed was 37.1 kg. This

was derived by taking the amount of protein in Bio Oregon diet (45%) and multiplying

this by the N content of the protein of the feed (16%). This gives you an N value of 7.2 %

N. This value was then multiplied by the total amount of feed fed (515.35 kg) to arrive at

37.1 kg of N.

It was estimated that the trout retained 40% of the nitrogen they consumed, less

5% lost to the environment (Hardy, 2012). At harvest ~ 14.0 kg of N was removed from

the ecosystem (Table 4.2). This was derived by the following calculation:

Total N - ((Total N fed x 95%) x 40%))

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Ultimately, nitrogen was removed from the Piscataqua River by culturing mussels

and kelp. These organisms absorb nitrogen by organic and inorganic means. By October

2013, 3072 kg of mussels had been produced. With an N content of 2%, the total N

sequestered in the shell and tissue was 61.44 kg. Sugar kelp has a N content of 2.4 %

(Chopin, 2011). At a total weight of ~ 638 kg, 15.31 kg of this was N. Combined

together, mussel and kelp extracted 76.75 kg (61.44 kg + 15.31 kg) of N from the river

(Table 4.2).

These results were significant in that they proved that more N could be taken from

the river system then N put in from trout farming. The EPA and NH Fish & Game were

impressed with the demonstration and so have allowed the fishermen to triple trout

production in 2013.

Technology Transfer to NH Fishermen

Extension efforts engaged eight commercial fishermen on small scale aqua

farming in the Piscataqua River. Initial meetings were held in 2011 to outline culture

technologies, site selection, fish husbandry and economics. The fishers calculated their

potential expenses (vessel time, fuel costs, labor), as well as the potential income, to

assess the economics of the proposed project. Interest was high, and 6 fishermen came

forward to apply for commercial aquaculture permits in 2011 (see permitting section 2.2).

Results of the permitting process steered growout efforts toward an IMTA

approach. With this, the fishermen were trained “hands on” with IMTA and helped gather

nutrient uptake data for the permitting agencies. The training process started with a visit

to Sumner Brook Trout Farms. There, the fishers learned how the fish were grown, culled

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and harvested for live transport. During the visit, trout fingerlings were sorted and

sampled for their transfer to the sea cages in the spring of 2012. Prior to fish transfer, the

fishermen were guided on cage reinforcement, mooring attachment, net deployment and

live transport systems. The trout were initially used in experiments by UNH researchers

until September 2012 (section 2.2). Afterwards, the fishermen took responsibility of the

cage systems and fish growout. During this period, the fishermen were taught feed

management protocol, how to identify and remove external parasites (sea lice) from the

trout. Also, they learned about size grading, as well as different ways to remove fouling

organisms from the nets (Fig. 4.9).

The fishermen took weekly turns feeding the fish. This activity was usually

conducted at the end of the day as they came back from their fishing grounds. Once a

week, the fishers would gather for a work party to exchange nets, conduct maintenance

on the cages, cull fish, or harvest (See http://nhsustainablefisheries.blogspot.com/).

Fishermen were taught the basics of mussel spat collection and growout. They

cut, added sash weights and deployed spat lines around the cage platform. They later

helped with relocating the spat lines to a raft under the JGP for the winter. To overcome

obstacles with inshore water quality (Section 3.13), the fishermen pooled their resources

and modified 35 lobster pots into small holding containers for mussel depuration. These

were later taken to Gun Boat Shoals to relay for six months.

NH kelp farming is still in its infancy. Additional growout trials will continue in

2013-2014. This product, once set on growout lines, can be raised rapidly throughout the

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winter months and early spring. Markets are still developing for fresh kelp, and prices

will dictate whether or not interest will continue for this marine seaweed.

The fishermen brought inherent knowledge to the project that was gained from

working many years on the ocean. They quickly learned and adapted the new skill sets

they were taught for aquaculture. In the end, they were able to sell the trout for $13.20 /

kg (Fig. 4.10) and have over 3000 kg of mussels in relay for sale in 2014.

Environmental Monitoring

Water quality

Environmental and water quality data were collected on three different dates

throughout the trout growout in 2012-13 (Table 4.3 and 4.4). Water temperatures

decreased from 17.5°C in July to 5.3°C by January. Current speeds during this time

ranged from slack to 0.35m / sec and the direction was NE-SW. The pH of the seawater

differed slightly from 7.6 to 8.0. Dissolved oxygen levels were the lowest in September

(87.96 % saturation) and highest in January (103.5 % saturation). Water samples

collected for nitrogen analysis indicated no differences in ammonia, nitrite or nitrate

levels between the sample locations (Table 4.4).

Benthic and video sampling

The bottom samples consisted of sand (60 %), with some silt (20 %) and

fragmented shell and rocks (20 %). Larger rocks, scattered throughout the area, were

covered with encrusting colonies of sponges and seaweeds. Numerous lobster and crabs

inhabited the areas along the entire 30 m transect at each sample period.

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No visual differences appeared along the 30 m transect throughout the IMAT

growout. Also, no fish food or anoxic areas were seen in the study site. The captured

video files were recorded onto a DVD and mailed to the EPA and NH Fish & Game for

their review. The video files were also archived, and benthic samples were frozen for

future analysis, if warranted (Fig. 4.11).

Market survey of steelhead trout

The steelhead trout were marketed between 2010 and 2012. Results of the market

survey were positive, with particular interest in a product that was raised locally.

Reported weekly demands ranged from 15-25 kg / restaurant, at they were willing to pay

-$15 / kg. Whole gutted fish at > 1.5 kg were acceptable, but larger fillets were preferred.

Surveyors commented on their mild taste that differed from farm-raised salmon. On a

scale of 1 (excellent) - 5 (poor), freshness, smell, texture and taste all rated number 1.

Steelhead Trout Economics for NH Fishermen

Simple economic spreadsheets for steelhead trout production, at three different

production scales, are given in Tables 4.5,4.6 and 4.7. Each table estimates the expenses

and income over a 3 year period, and assumes a stocking density of 20 kg / m3 at harvest.

Since fishermen already own and operate their vessels, no labor, boat payment or boat

insurance was included. Survival from stocking to harvest was estimated at 85%, feed

conversation ratio at 1.2, and yield (gutted weight to whole weight) at 75%. Price for

each 450 g fingerling ($5.00) from Sumner Brook Trout farms was based on prices we

have paid in the past. Selling price for harvested product at 2.5 kg round weight (1.87 kg

gutted weight) is given as $14 / kg, which was been the price paid in 2013. Feed cost

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($2993 / mt) has been steady for the last two years. An additional charge of $0.50 / kg

was estimated for processing and distribution.

Profit improves as cage size increases from 100 to 1000 m3 (largest scale of

production). This is due to similar operational expenses to feed and maintain a single

large cage. Increased cage volume allows for more production per unit of effort. As cage

size increases, however, so does the amount of nitrogen added to the environment. For

this reason, larger cage(s) would likely be sited in deeper waters (>15 m) that have

moderate current flow (> to 0.20 m / sec) to help dissipate the added nutrients. Thus,

although there are greater economic rewards at a larger scale (>1000 m3), moving the

cage further offshore could increase the costs and risks of fanning. If profits increase

with scale, as we predict, and if larger scale systems have to move offshore, it is likely

that farmers will partner in a cooperative venture to share in the capital investment, and

spread the risk. They may also consider crop insurance that is now becoming available

through the FDA.

Results from these simple spreadsheets indicate that raising steelhead trout could

be profitable for commercial fishermen, particularly if done on a larger scale. There are

two primary reasons for this. First are cost savings for the fishermen. These individuals

already have vessels, vessel insurance, and other infrastructure, associated with their

primary business of fishing. All of these represent a considerable saving should they

initiate fish farming. Second, steelhead trout are relatively fast growing, have a good

food conversion ratio, and command a relatively high market price, which reduces

production costs and maximizes income.

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It is likely that state and federal regulatory agencies will insist that steelhead trout

culture, particularly in coastal areas, be accompanied by shellfish and /or seaweed culture

to mitigate the addition of nutrients to the environment. Although these secondary crops

would add additional expenses to the operation (e.g. labor), these costs would be

recovered by their sale and could improve income gains to the farm.

Discussion

Results from the IMTA of steelhead trout, blue mussels and sugar kelp proved

successful in extracting more nitrogen from the Piscataqua River than was added from

trout production (Table 4.2). This is important as Reid (2007) reported uptake efficiency

from IMTA in open water is essentially unknown. What we do know is that mussel and

kelp recycle nutrients derived from fish waste (ammonia and phosphorus). Inorganic

nutrients are extracted directly by the kelp from the environment (Chopin, 2006; Neori et

al., 2004) while organic nutrients released by the fish are consumed by the mussels

(Lander et al., 2004; Troell et al., 2003; Mazzola and Sara, 2001). We were able to

culture three species in situ and quantify N input and uptake that resulted in ecosystem

benefits from aquaculture. Not only were the extractive organisms healthy for the

environment, they produced additional economic value to the farmer.

During the IMTA demonstration, NH fishermen were able to train “hands on”

with the basic skills to culture all three species. Additional training will be necessary to

improve current aquaculture methods for the steelhead. This includes developing a

custom vaccine for bath immersion, using new antifoul paint products to reduce bio-

fouling and working with a semi-moist feed formulation that will aid trout acclimate to

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seawater. Also important will be the development of larger scale, robust, flexible

platforms that can safely maintain and grow multiple species together.

Blue mussels and sugar kelp can be grown in concert with the trout. However, the

mussels could not be sold due to the water classification of the cage site. This is due to

the proximity of a waste water treatment plant 2.8 km up river. This classification may

change in 2014 based upon water and shellfish samples collected by NH Department of

Environmental Services. Their data indicated the water quality was safe for shellfish

harvest at the cage site. If EPA re-classifies the head waters of the Piscataqua River, this

would greatly improve the logistics and economics for shellfish production.

Environmental monitoring indicated no negative effects to the bottom or to the

water column from farming on a small scale. This information has been given to the

regulatory agencies, and we are optimistic that this will help guide future permitting, and

allow the expansion of ocean farming.

Results of this EMTA project, although still preliminary, could be used in other

New England coastal areas. In particular, the fishing communities of the northeast where

fishery management initiatives have limited wild harvests. An important part of the

fishing industries strategy for maintaining their heritage and livelihood is to find

alternative ways to complement and diversify their operations. Aquaculture plays an

important role in maintaining an active water front and fishing heritage. Specific benefits

include alternative and economically viable uses for underutilized fishing vessels,

employment opportunities for displaced fishermen, business and marketing opportunities

101

for suppliers, restaurants, wholesale and retail outlets, and the benefit of locally produced,

high quality seafood for local, regional and national consumers.

The market survey suggested that steelhead trout is highly regarded, and that a

fresh, locally raised product is more preferable than a foreign import. Market capacity is

still unknown.

The fishermen are eager to increase aquaculture production in NH. Initial farming

sites that were applied for in 2011 are now being revisited for IMTA culture in 2014.

However, it is likely that inshore siting will be limited. Ultimately, if fishermen choose to

expand cage farming, they will have to consider moving offshore to deeper, more

exposed locations. Open ocean aquaculture will increase capital investment, daily

operational costs, and risk from oceanic storms. To overcome these obstacles, the

fishermen could form a cooperative to share investment, risk, and rewards. If they choose

to move offshore, UNH and NH Sea Grant will be on standby to assist them with the

expansion of marine aquaculture in New England.

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Table 4.1. Consumer survey form that accompanied the steelhead trout delivered to seafood markets and restaurants in New England.____________________________

1. Approximate Yield (weight of filets / weight of whole fish):_____________

2. Product: Scale of 1 (excellent) to 5 (poor). Please enter a number.

Freshness (appearance of gills, eyes, skin)_________

Smell (fresh to old)___________

Texture (firm to soft)____________

Taste (excellent to poor)____________

Additional comments on product:

3. What is the optimal size/form of this product? Please check one or more.

Whole gutted (1-2 lbs.)_________

Whole gutted (2-4 lbs.)_________

Whole gutted (>4 lbs.)_________

Filets_________

Steaks_________

4. Comparison of this product to salmon:

________Same

________Different

________If different, describe difference.

5. Approximate price paid for similar product(s) ($/lb.) ___________________

6. What would be your demand (lbs.) daily/weekly/monthly)_______________

7. Is ‘produced locally’ important in marketing?

_______Very important

_______Somewhat important

_______Not at all important

8. General Comments (from wholesaler and consumers):- Overall impression:

- Suggestions for improvements:

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Table 4.2.Nitrogen inputs and outputs from integrated multi-trophic aquaculture

Nitrogen input from feed

Total N Total N retained Date inout (kg) in trout (kg)Dec. 2012 37.10 14.0

Total N loss to environment 23.1 kg

Nitrogen extraction bv mussels (weight/m = 25.6 kg)

Total weight Total N Date Total line (m) (kg) Oct. 2013 120 3072

extracted (@ 2.0%) 61.44 kg

Nitrogen extraction bv sugar kelp (weigh t /m = 11.6 kg)

Total weight Date Total line (m) (kg)June 2013 55 638

Total Nextracted (@ 2.4%) 15.31 kg

Total N input from trout production Total N extraction from mussels and kelp

23.1kg 76.75 kg

Net N extracted from the river 53.65 kg

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Table 4.3. Water quality data collected on 7/26/2012, 9/29/2012 and 1/9/2013 during the demonstration project.

Date Temp Current Current DO Salinity

(°C) Direction (°) Speed f°) dH (%) (pot)

7/26 16.3 220 0.18 7.97 101.4 29

9/26 17.5 45 0.35 7.6 87.96 30.8

1/9 5.3 35 0.1 8.0 103.5 30.1

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Table 4.4. Water sampling for nitrogen content was conducted on 7/26/2012,9/29/2012 and 1/9/2013 from three locations; 1) inside the cage, 2) 15 m up current and 3) 15 m down current of the fish cages._______________________________________________

Date 7/26/2012

Water TestDown current of cage Inside case

Up current of cage

NH3 0-0.25 0-0.25 0-0.25

N02 0 0 0

NQ3 0.05-0.1 0.05-0.1 0.05-0.1

Date 9/26/2012

Water TestDown current of cage Inside cage

Up current of cage

NH3 0-0.25 0-0.25 0-0.25

N02 0 0 0

N03 0.05-0.1 0.05-0.1 0.05-0.1

Date 1/9/2013

Water TestDown current of cage Inside cage

Up current of cage

NH3 0-0.25 0-0.25 0-0.25

N02 0 0 0

NQ3 0.05-0.1 0.05-0.1 0.05-0.1

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Table 4.5 Economic spreadsheet (3 yr.) for steelhead trout production in a 100 m3 cage at 20 kg / m3

Expenses Process &Cost / Total Cost Cage/Nets/ Handling

Year Item Number1 fingerllng of flngerllngs

1 Fingerlings 900 5 45002 Fingerlings 900 5 45003 Fingerlings 900 5 4500

IncomeMean total Total round

No. alive wgt. at wgt. At Crop value at Year at harvest4 harvest (kg) harvest (kg) harvest (kg)5

1 765 2.5 1912.5 206172 765 2.5 1912.5 206173 765 2.5 1912.5 20617

Total: $ 61,850

Feed cost2 Mooring Boat fuel3 $0.50/kg Total costs

6,866 10,000 3,000 956 25322.256,866 0 3,000 956 15322.256,866 0 3,000 956 15322.25

Total: $ 55,967

Profit/Loss over 3 years

Costs = $ 55,967Income = f 61,850Gain = $ 5,883

Notes: All expense and income amounts are in US dollars.1 Number stocked is designed to achieve a harvest stocking density of (20 kg/m3).2 Feed costs are based on an estimated FCR of 1.2, and is calculated based on the weight that survive to harvest.3 Boat fuel is estmated at $3.75/gal; 4 gallons/d over 100 days.4 Number alive at harvest is based on 85% survival.5 Crop value at harvest is based on 77% gutted, heads on weight, valued at $14/kg.

Table 4.6 Economic spreadsheet (3 yr.) for steelhead trout production in a 500 m3 cage at 20 kg / m3

Expenses

Year Item Number1Cost/

fingeriingTotal Cost

of fingeriings Feed cost2Cage/Nets/

Mooring Boat fuel3

Process &Handling$0.50/kg Total costs

1 Fingeriings 4500 5 22500 34,334 21,000 3,000 4,781 85615.252 Fingerlings 4500 5 22500 34,334 0 3,000 4,781 64615.253 Fingeriings 4500 5 22500 34,334 0 3,000 4,781 64615.25

Total: $ 214,846Income

Mean total Total roundNo. alive wgt. at wgt. At Crop value

Year at harvest4 harvest (kg) harvest (kg) harvest (kg)sProfit/Loss over 3 years

1 3825 2.5 9562.5 1030842 3825 2.5 9562.5 103084 Costs = $ 214,8463 3825 2.5 9562.5 103084 Income = $ 309,251

Gain = $ 94,405Total: $ 309,251

Notes: All expense and income amounts are in US dollars.1 Number stocked is designed to achieve a harvest stocking density of (20 kg/m3).2 Feed costs are based on an estimated FCR of 1.2, and is calculated based on the weight that survive to harvest.3 Boat fuel is estmated at $3.75/gal; 4 gallons/d over 100 days.4 Number alive at harvest is based on 85% survival.5 Crop value at harvest is based on 77% gutted, heads on weight, valued at $14/kg.

Table 4.7 Economic spreadsheet (3 yr.) for steelhead trout production in a 1000 m3 cage at 20 kg / m3______

ExpensesProcess &

Year Item Number1Cost/

fingerlingTotal Cost

of fingeriings Feed cost2Cage/Nets/ Handling

Mooring Boat fuel3 $0.50/kg Total costs1 Fingeriings2 Fingeriings3 Fingeriings

IncomeNo. alive

Year at harvest4

900090009000

Mean total wgt. at

harvest (kg)

555

Total round wgt. At

harvest (kg)

450004500045000

Crop value harvest (kg)s

68,66668,66668,666

30,000 3,000 9,563 0 3,000 9,563 0 3,000 9,563

Total:

156228.5126228.5126228.5

$ 408,686

Profit/Loss over 3 years1 7650 2.5 19125 206168oVO 2 7650 2.5 19125 206168 Costs s $ 408,6863 7650 2.5 19125 206168 Income = $ 618,503

Gain = $ 209,817Total: $ 618,503

Notes: All expense and income amounts are in US dollars.1 Number stocked is designed to achieve a harvest stocking density of (20 kg/m3)2 Feed costs are based on an estimated FCR of 1.2, and is calculated based on the weight that survive to harvest.3 Boat fuel is estmated at $3.75/gal; 4 gallons/d over 100 days4 Number alive at harvest is based on 85% survival5 Crop value at harvest is based on 77% gutted, heads on weight, valued at $14/kg.

Figure 4.1. A. Two trout cages moored at the mouth of the Piscataqua River, NH used in the integrated multi-trophic aquaculture project. B. Diagram of a fish cage and net with the New Zealand fuzzy rope suspended from the perimeter of the wooden walkway.

Figure 4.2. Natural settlement of sugar kelp on the trout cages in the Piscataqua River, NH.

I l l

Figure 4.3. Fishermen harvesting steelhead trout for local markets in Portsmouth, NH.

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Figure 4.4. A. Juvenile mussel spat that settled on the New Zealand fuzzy rope suspended around the cage platform. B. Mussel spat that attached onto the nylon mesh fish nets.

Figure 4.5. A. Mussels being set into modified lobster pots for relaying offshore near Gunboat Shoals NH. B. The F/V Beatrice A relocating the mussel pots offshore. They will be harvested and sold in the spring of 2014.

Figure 4.6. A. Spools of juvenile sugar kelp line that was wrapped around 3.0 m polyester lines and submerged 0.5 m below surface in floating fish cage frames for growout (B).

115

u

i AFigure 4.7. Sugar kelp after 4 months growout in the Piscataqua River, NH. Kelp averaged 0.7 m length in April 2013.

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Nitrogen Input of Feed(45% protein, 22% lipid)

Excretion 50%

Retention 40% (Hardy, 2012)

Figure 4.8. The fate of nitrogen from fish food to the environment.

117

Figure 4.9. A. NH fishermen towing empty cages to site for growout of steelhead trout, mussels and sugar kelp in the Piscataqua River. B. Fishermen gathered around a cage to discuss fish health and feeding.

118

Figure 4.10. A. Harvest of steelhead trout from the sea cages with the Portsmouth fishermen. B. Trout fillets on ice at Sanders Fish Market in Portsmouth, NH for $ 14.99/lb.

119

Figure 4.11. A. Diver with a Go ProTM underwater camera filming a 30 m bottom transect under the sea cages in the Piscataqua River, NH. B. Diver preparing to take a sediment sample with a PVC pipe sampler (5 cm x 10 cm) at the end of the transect.

DISSERTATION SYNOPSIS

This dissertation research had three goals, all of which related to fostering marine

aquaculture in New England. The first (Chapter 1) investigated an alternative cage

material potentially useful in reducing or eliminating bio-fouling, which is a major

problem in cage culture wherever it is practiced. The second was to experimentally

investigate the responses of caged steelhead trout (Onchorhynchus my kiss) to different

culture environments. In Chapter 2, we examined the fishes’ response to high currents,

and associated net deformation, that would be typical of many coastal areas of New

England. In another section (Chapter 3), we gathered preliminary data on the ability of

steelhead to survive and grow in submerged cages, which may be necessary if the

industry grows and expands offshore. In the final chapter (4), we report on the final goals

of the research, which were to provide hands-on aquaculture training to commercial

fishermen, and to evaluate the efficacy of Integrated Multi-trophic Aquaculture (IMTA)

to mitigate the addition of nutrients by the finfish growing operations.

Results of the research reported in Chapter 1 showed that fish cages built from a

copper alloy mesh (Seawire™) had less bio-fouling compared to traditional, nylon mesh

nets, which became heavily fouled with the hydroid Tubularia sp. Further, cod held in

the Seawire and nylon mesh cages for extended periods of time displayed similar feed

conversion ratio, specific growth rates, condition factor and survival. Importantly, Cu

levels were similar in the tissues of cod (gill and liver) held in the two cage types,

indicating that there was no additional Cu ion absorption from the Seawire net material.

121

In addition to reducing bio-fouling, alloy netting such as Seawire also has greater

tensile strength than nylon, and thus is better at retaining fish in the cage, and keeping

predators out. This is especially important in areas with large populations of seals like

New England. Although Seawire has some positive attributes, it is more expensive than

nylon mesh, more difficult to build into cage shapes, and much heavier to deploy and

handle in the field. This initial higher cost, and other negative attributes, may be offset by

less need for net cleaning and mending. As well, Cu alloy nets can be recycled, so the

user can recoup some of the purchase price when the nets are retired.

In Chapter 2 we determined that a biotelemetry system could be used to

simultaneously monitor the shape of a fish cage, and the fish within it. At current speeds

of > 0.2 m / s, we detected some net deformation, and at current velocities of 0.5 m / s,

the net lost > 30% of its volume. During high tidal currents (>_0.35 m / s) trout exhibited

rheotaxis, and the group used a smaller percentage of the cage volume. During slack tides

the fish exhibited typical circular, schooling behavior that utilized more space in the cage.

No differences were found in trout swimming speed, or depth occupied, between night

and day. The small cage size (63 m3) we used may have affected trout behavior, which

makes it difficult to compare our results to other similar studies, or to extend these results

to larger commercial size cages. We believe, however, that understanding fish behavior

in cages is a worthwhile goal since behavior ultimately affects fish welfare and

production. Additional research is certainly warranted, and we are confident that the

techniques we developed will be useful to those who follow.

The three trout submergence studies reported in Chapter 3 had varied results.

Cage size (3.73 - 68 m3), cage material (Seawire™ vs. nylon nets) and fish size (300 -

122

1000 g) all contributed to the variation. Despite the variation, the data indicated that

steelhead trout can be submerged for days to weeks with no significant negative effects

on growth or survival. We believe, however, that surface cage systems are preferred

since fish in surface cages have access to the surface to refill their swim bladders. As a

management tool, however, submerging the cages for short periods of time (days to

weeks) to escape adverse surface situations conditions (e.g. storms, high water

temperature, ice, red tide) will be useful, and can now be done more confidently. Future

submergence research should be conducted at deeper depths (> 10 m) because increased

pressure may well have an effect on the behavior and physiology of forcibly submerged

fish.

The final chapter of the dissertation reports on our efforts to involve and train

several NH commercial fishermen on the techniques of small-scale aquaculture, and to

demonstrate and quantify integrated multi-trophic aquaculture as a means of nitrogen

mitigation. The IMTA model demonstrated that N extraction by shellfish and seaweed

exceeded the nitrogen input from trout production. The model was verified through

environmental monitoring, which indicated no measurable environmental effects from

fish production. The information gathered was reported to the EPA and NH Fish &

Game, and we are hopeful it will be useful as they consider future aquaculture permit

applications. The training program provided participating fishers with a new skill set that

they could adopt either part or full-time, to help offset economic hardships caused by

federal management measures that have decreased catch allocations. Seafood markets

were very interested in all three marine species raised during the project. The trout were

sold (gutted, heads on) for $13.20 / kg. The mussels have not yet been sold, but we

123

expect, based on the sale of other cultured mussels, to sell for > $4.00/kg. The sugar kelp

was test marketed at a local restaurant in Portsmouth, NH. Their estimated demand was

10-20 kg / week at a price of $20 / kg.

In summary, we believe we have achieved our overall goals. We have tested an

alternative cage material, and we have conducted experiments on steelhead trout that

have increased our understanding of their behavior and physiology when grown in strong

currents or in submerged cages. We have also provided hands-on aquaculture training to

commercial fishermen, and evaluated the efficacy of IMTA to mitigate the addition of

nutrients associated with finfish production. Finally, we have made an attempt to

evaluate the economics of steelhead aquaculture, at three different scales, which should

be useful as potential growers make early and fundamental decisions in their business

plans.

124

Appendix

A. UNH IACUC Approval 2013

University of New Hampshire

Research Integrity Services, Service Building 51 College Road, Durham, NH 03824-3585

Fax; 603-862-356427-Sep-2013

Chambers, Michael D School of Marine Science - EWOS 24 Cokwos Road Durham, NH 03824

IACUC # : 130803Project: Sea Grant Extension 2013-2016 Category: CApproval Date: 22-Aug-2013

The Institutional Animal Care and Use Committee (IACUC) reviewed and approved the protocol submitted for this study under Category C on Page 5 of the Application for Review of Vertebrate Animal Use in Research or Instruction • the research potentially involves minor short-term pain, discomfort or distress which will be treated with appropriate anesthetics/analgesics or other assessments.

Approval Is granted for a period of three years from the approval date above Continued approval throughout the three year period is contingent upon completion of annual reports on the use of animals. At the end of the three year approval period you may submit a new application and request for extension to continue this project Requests for extension must be filed prior to the expiration of the original approval.

Please Note:1. Ail cage, pen, or other animal identification records must indude your IACUC # listed above.2. Use of animals in research and instruction is approved contingent upon participation in the

UNH Occupational Health Program for persons handling animals. Participation is mandatory for aH principal investigators and their affiliated personnel, employees of the University and students alike. Information about the program, including forms, is available at http;//unh.edu/research/occupational-health-Droqram-anlmal-handlers.

If you have any questions, please contact me at 862-4629 or Julie Simpson at 862-2003.

IACUC,

Vice Chair

cc FileHowell, William

125

B. UNH IACUC Approval 2010

University of New Hampshire

Research Integrity Services, Office of Sponsored Research Service Building, 51 College Road, Durham, NH 03824-3585

Fax:603-862-3564

08-Mar-2010

Chambers, Michael Atlantic Marine Aquaculture Center Chase Ocean Engineering Lab Durham, NH 03824

IACUC#; 100204 Category: DProject: SINTEF Bilateral Escape- Use of Biotelemetry to Quantify Fish in Net Pat Movement

Simultaneously

The Institutional Animal Care and Use Committee (IACUC) has reviewed and recommended approval of the protocol submitted for this study contingent upon your response to the following:

1. As the study was proposed as a pilot study (Section 27, C), IACUC approval is limited to one yeaijstudy completion dats should be revised accordingly).2. In Section n, B (personnel information), the IACUC anticipated personnel other than those listed handling fish (e.g., graduate students or other project staff) In the study. Anyone handling animats on the study needs to be Inducted on the application.3. The researcher needs to explain why steelhead trout are being used in the study instead of Atlantic salmon.4. In Section IV, A (experimental design), the researcher needs to address the following:

a. Describe the process for acdhnadng /fefr to saltwater from freshwater, including where the process will take place, the duration, and pertinent Information, such as tank size, water temperature, densities, and feeding schedule.b. Estimate mortality during the acdimadon process (see 4a). c Indude information on the total duration of the expenment.d. Provide details of the process for transporting fish from the source to the pen, and for stacking the pen.

5. In Section V, C (evaluation of outcomes), the IACUC did not consider vocalization as an appropriate outcome for this study so removed this attribute.6. In Section VI, A (method to determine animal numbers), the researcher needs to provide the method for determining the number of animals proposed to have pingers inserted (eight). (The justification for the total number in the pen is adequate.)7. As this pen is a new animal facility, Dr. Dean Bder must inspect the pen and approve the standard operating procedure before any animals are transported to the site.8. The researcher stated that fish will be saved for future use a t the end o f the study. If the pen is to be removed from the ocean, the researcher needs to explain what will happen to the fish (i.e., where the fish will be housed and the details of transportation and stacking). This explanation should specifically Identify what will happen to the fish with pingers inserted.

126

9. In Section 7 of the Surgical Procedures Form (surgical procedures), the researcher needs to add Information about surgical site preparation (I.e., stte deaned with cNorhexkffne solution), aeration of the cooler, and the length of time for recovery after F&-222administration.

As soon as the IACUC receives an appropriate response to its concerns, above, it wffl Issue you an approval letter for this protocol. You may not commence activities in this protocol involving vertebrate animals until you frave received IACUC approval. Please respond to the IACUC within sixty days of this letter. If the IACUC does not receive a response within sixty days, your protocol will be withdrawn.

If you have any questions, please contact either Dean Elder at 862-4629 or Julie Simpson at 862- 2003.

For the IACUC,

A. Bolker, Ph.D.Chair

cc: File

127

C. NH Aquaculture Permit

H EAD Q U AR TER S: 11 H a re n Ofive, C on cord , N H 0 3 3 0 1 -6 5 0 0 (6 0 3 ) 2 71-3421 FAX (6 0 3 ) 2 7 1 -1 4 3 8

New HampshireFish and Game Department

irww.WMdNH.come-mari in to O w tk fU e n h g o v

TDD A c c e s s R e la y NH 1 -8 0 0 -7 3 5 -2 9 6 4

J u ly 1 7 .2 0 1 2

Michael Chambers/Hunt Howell UNH. Jere Chase Ocean Engineering Lab 24 Colovos Road Durham, New Hampshire 03(24

MARIHE AQVACVIiTVRE LICENSE 2812-13

In compliance with Part Fis (07 Rules on Aquaculture, the New Hampshire Fish A Came Department has reviewed and approved an application submitted by Michael Chambers aad Huat Howell, for cage culture of steelhead trout (Oncorhynchus m yiia) and blue mussel (Ktytlhu tdulls).

Conditions of the license include:

1. Steelhead juveniles may be provided by Summer Brook Trout Farm in Ossipee, N.H. The fish must be diploid and all female. Prior to movement Don the Ossipee hatchery to the coastal fish cages, health certificates must be reviewed by New Hampshire Fish A Game. Up to 600 may be stocked into the cages in 2012.Blue mussel will be gathered from the wild, caught on lines m coastal New Hampshire waters aad will be suspended around the perimeter of the cage platform.

2. The cage and surrounding cage platform will be moored in a New Hampshire Port Authority approved location using a double mooring block/anchor system. The dimensions of the surface cage shall not exceed 2S' x 30' and have a surrounding walkway of IS* width. The location lies off Newcastle beach at Lat43.04.365/Long 70.42.3>0. The water depth at this site is about 25 It MW. The cage must not be closer than 10' from the bottom on any tide. The area covered by this license is a 1/10 acre pkx.

3. Trout from the Ossipee, Summer Brook Trout Farm will be stocked into the cage at about 150g end be grown to 2-3kg. Hwvest and processing of the fish will be on site or seaward of the site such that no resulting waste remains are washed ashore. Continuing deployment of the cage system will require renewal of the annually issued Marine Aquaculture License.

4. The blue mussels caught there and elsewhere at the she may not be put to maeket as the location is not approved by NHDES for shellfish harvest. Mussels may be disposed of on dry land at a site approved by New Hampshire Fish A Game or at sea m water deeper than 75', beyond the line that demarcates the outer boundary ofthe nitrogen impaired estuary. Disposal either dry land or at sea, must be supervised and attended by New Hampshire Fish A Came. Should the licensee seek to market these blue mussels, an acceptable plan for relocating them to an area approved by NHDES for harvest and culturing them in the new location for a sufficient amount of time must be developed by the stale agencies (NHF A G. NHDES, and NHDHHS). The plan, which will include provisions for state personnel observation of the relocation operations and appropriate labeling and documentation of relocated product will become a required condition of this license.

(60S) 788-31*4 FAX (* 0 0 )7 8 * 4 8 2 3

•mail: reg l •w M H e.nh.gov

829B Hem S eeet Lancaster, NH 03684-3*12

REGIO N 1

(603) 744*5470 FAX (803) 744-8302

email: i e g 2 < wS0He.nh.gov

N ew Hampton. NH 0325*

REGION 2 PO Bo* 417

Durham, NH 03824-4732(8 0 3 )8 8 8 -1 0 9 6

FAX (803) 868-3306

8EGJQH3 2 2 5 Main Street

R E G IO N *15 A sh Brook Court K eene. NH 03431

< 003)362-9880 FAX (803) 362-879*

emaS: reg30 iisatei.nh.gov em ail reg4«w *dSte.nh.|

128

NH Fish and Game Cont.

5. Environmental monitoring at tbe cage site shall consist of biannual video inspections by underwater camera ofthe tea floor at key locations at and around the cage. In addition, water quality testing on a bimonthly frequency is required.Further detail of the required environmental monitoring is in the attached Environmental Monitoring Program

6. Any observed disease problems shall be reported immediately to the Executive Director and the Chief of Marine Fisheries Division of the New Hampshire Fish & Game Department, followed by a letter outlining die circumstances and providing as much dkail as possible.

7. Any control methods for eradication or removal of project fouling organisms, predators, or diseases other than by hand and pumped water shall be discussed with the Chief of Marine Fisheries, New Hampshire Fish ft Game Department Written approval of control methods must be obtained from the Executive Director prior to implementation.

8. The permittee shall notify the Executive Director and the Chief of Marine Fisheries within 48 hours of any unusual event as defined in Fis 807.08.

9. Aquaculture operations shall not interfere with or cause damage to recreational and/or commercial activities in and around the licensed she including, but not limited to, lobster traps, moorings, navigational aids, and piers.

10. Annual reports of disposal of aquaculture products shall be made in accordance with Fis 807.10.

11. A copy of records relevant to harvesting (i.e. dates, quantity harvested, etc.) and disposition of aquaculture product shall be retained by the permittee for a period of one year (or until turned over to New Hampshire Fish ft Game Department). Such records shall be subject to inspection at any time by fee Executive Director or his agent.

12. This license is valid upon the applicants receiving all necessary federal or state permits.

13. The permittee shall prepare and submit to New Hampshire Health and Human Services a Hazard Analysis Critical Control Point Plan (HACCP) thirty (30) days prior to the marketing of shellfish.A copy of this shall be sent to fee New Hampshire Fife ft Game Department

This license shall expire on December 31,2012, unless sooner revoked or rescinded. The annual report required by Fis 807.10 must be submitted by January 31 of 2013.

GN/BWS/vjb

Enclosure

cc: Doug Grout, Chief Marine FisheriesLt. Jeffrey A. Marston Law Enforcement Sandy Falicon, Rules Coordinator

129

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