Oyster Reef and Estuarine Landscape Restoration Kenneth L. Heck, Jr. NGI Conference, May 2007.
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Transcript of Oyster Reef and Estuarine Landscape Restoration Kenneth L. Heck, Jr. NGI Conference, May 2007.
Oyster Reef and Oyster Reef and Estuarine Landscape Estuarine Landscape
RestorationRestoration
Kenneth L. Heck, Jr.Kenneth L. Heck, Jr.NGI Conference, May 2007NGI Conference, May 2007
Why Oyster Reef Why Oyster Reef Restoration ?Restoration ?
In addition to the multimillion dollar US In addition to the multimillion dollar US fishery they support, oyster reefs provide fishery they support, oyster reefs provide key ecological functions:key ecological functions:
-serve as habitat for finfish & shellfish-serve as habitat for finfish & shellfish-stabilize shorelines -stabilize shorelines -filter suspended solids and -filter suspended solids and
phytoplankton from the water columnphytoplankton from the water column-sequester excess nutrients -sequester excess nutrients
(nitrogen, phosphorous, and carbon)(nitrogen, phosphorous, and carbon)
Video of a healthy Alabama oyster Video of a healthy Alabama oyster reefreef
QuickTime™ and aH.263 decompressor
are needed to see this picture.
Program ObjectivesProgram Objectives
to develop the scientific understanding necessary to to develop the scientific understanding necessary to direct oyster restoration and enhancement in the direct oyster restoration and enhancement in the Northern Gulf of Mexico.Northern Gulf of Mexico.
to assist in developing a long-term strategy for to assist in developing a long-term strategy for sustained productivity of Gulf oyster reefs and the sustained productivity of Gulf oyster reefs and the associated ecological benefits that they provide.associated ecological benefits that they provide.
to provide this information to state and federal to provide this information to state and federal management agencies, the fishing industry and the management agencies, the fishing industry and the general public through outreach activities. general public through outreach activities.
Alabama Oyster FisheryAlabama Oyster Fishery(Source: NMFS)(Source: NMFS)
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000
Landings (kg meat)
Frederic (3)
Opal (3)& Erin (2)
Camille (5)
Ethel (3) Elena (3)
Ivan and Katrina
X
Alabama Oyster HabitatAlabama Oyster Habitat
Live oyster reef
Buried oyster shell deposits
2007 Reefs
2008 Reefs
Restoration ChallengesRestoration Challenges• Dissolved Oxygen
• Recruitment
20 0 10 0 10 5
2
1
# spat m-2 d-1
(Hoese et al. 1972)
• Predation
Addressing ChallengesAddressing Challenges Reef CreationReef Creation
– Increased vertical relief of reefs may combat Increased vertical relief of reefs may combat low dissolved oxygen.low dissolved oxygen.
– Reef restoration for ecosystem benefits Reef restoration for ecosystem benefits Larval SupplyLarval Supply
– Repeat survey of Hoese (1972) and develop 3-Repeat survey of Hoese (1972) and develop 3-D hydrodynamic modelD hydrodynamic model
Living Shoreline ProtectionLiving Shoreline Protection– Stop shoreline erosion and stabilize marshesStop shoreline erosion and stabilize marshes– Enhance fishery habitatEnhance fishery habitat– Facilitate seagrass colonizationFacilitate seagrass colonization
Reef CreationReef Creation
Heck & Powers
Breakwater Reefs
Powers & Heck
Large reefs
Heck et al.
Ecosystem services study reefs
AL Marine Resources Divison Perdido Bay Reefs
Fisheries Habitat Fisheries Habitat ProgramProgram
Reef ElevationReef Elevation
u
High Relief (1.0
m)
Low Relief
(0.1 m)
2.5 m
1 m
2 m
Anoxic
Hypoxic
Normoxic
Cedar Point Reef Shellbank Reef
Sand Reef
1 HR
2 HR
3 LR4 LR
8 LR 7 LR
5 HR 6 HR
1 LR7 LR
8 LR
6 LR4 HR
5 HR
2 HR
3 HR
5 LR 6 HR
7 LR8 HR
4 LR
3 LR1 HR
2 HRCedar Point Reef Shellbank Reef
Sand Reef
1 HR
2 HR
3 LR4 LR
8 LR 7 LR
5 HR 6 HR
1 LR7 LR
8 LR
6 LR4 HR
5 HR
2 HR
3 HR
5 LR 6 HR
7 LR8 HR
4 LR
3 LR1 HR
2 HR
Fisheries Habitat Fisheries Habitat ProgramProgram
High vs. Low reliefHigh vs. Low relief
Cedar Point Reef Shellbank Reef
Sand Reef
1 HR
2 HR
3 LR4 LR
8 LR 7 LR
5 HR 6 HR
1 LR7 LR
8 LR
6 LR4 HR
5 HR
2 HR
3 HR
5 LR 6 HR
7 LR8 HR
4 LR
3 LR1 HR
2 HRCedar Point Reef Shellbank Reef
Sand Reef
1 HR
2 HR
3 LR4 LR
8 LR 7 LR
5 HR 6 HR
1 LR7 LR
8 LR
6 LR4 HR
5 HR
2 HR
3 HR
5 LR 6 HR
7 LR8 HR
4 LR
3 LR1 HR
2 HR
0
20
40
60
80
100
120
Low High
Reef Height
0
20
40
60
80
100
120
# L
ive
Spa
t / m
2
Low High
Reef Height
Fisheries Habitat Fisheries Habitat ProgramProgram
Cost - BenefitCost - Benefit
High relief reefs, 625 mHigh relief reefs, 625 m33 of of cultch @ $24 mcultch @ $24 m33 = $15,000 = $15,000
Low relief, 62.5 mLow relief, 62.5 m33 of cultch @ of cultch @ $24 m $24 m33 = $1,500 = $1,500
Note: 1 mNote: 1 m33 = 1.3 yd = 1.3 yd33, cost per , cost per ydyd33 ~ $18 ~ $18
Mobile Bay Results: June 2006 Mobile Bay Results: June 2006
Cedar Point Reef Area H
Sand Reef Area A
Shellbank Reef Area
Mobile Bay
Cedar Point Reef Area H
Sand Reef Area A
Shellbank Reef Area
Mobile Bay
0
20
40
60
80
100
120
140
# L
ive
Oys
ters
/ m
2
Cedar Point Reef Sand Reef Shellbank Reef0
20
40
60
80
100
120
140
# L
ive
Oys
ters
/ m
2
0
20
40
60
80
100
120
140
160
# L
ive
Spa
t / m
2
Cedar Point Reef Sand Reef Shellbank ReefSite
0
20
40
60
80
100
120
140
160
# L
ive
Spa
t / m
2
0
10
20
30
40
50
60
70
# D
ead
Spat
/ m
2
Cedar Point Reef Sand Reef Shellbank ReefSite
0
10
20
30
40
50
60
70
2
Fisheries Habitat Fisheries Habitat ProgramProgram
Oyster RecruitmentOyster Recruitment(Powers, Park, Graham)(Powers, Park, Graham)
Survey 18 sites Survey 18 sites throughout Mobile throughout Mobile Bay every three Bay every three weeks for oyster weeks for oyster settlement.settlement.
Jan 2006 – Dec 2007Jan 2006 – Dec 2007 Synoptic Synoptic
measurements of measurements of larval supplylarval supply
Fisheries Habitat Fisheries Habitat ProgramProgram
Spat Recruitment MethodsSpat Recruitment Methods
Fisheries Habitat Fisheries Habitat ProgramProgram
Predation: Oyster Drills
Fisheries Habitat Fisheries Habitat ProgramProgram
Spat/m2/day CR11 CR12 CR13
Larvae/1000L
30-100 μ
Larvae/1000L
100-500 μ
Source: C-K Kim
Living Shoreline Living Shoreline Restoration Restoration
GoalsGoals
Oyster reef Oyster reef construction, fish construction, fish use, shoreline use, shoreline stabilization, stabilization, marsh regrowth marsh regrowth and seagrass and seagrass colonization.colonization.
• Sparse biotic community
• Eroding shoreline
• Oyster bar foundation
• Shoreline stabilized
• Seagrass colonization?
• Some small fish and invertebrates
• Large oyster reef
• Expanded emergent marsh
• Expanded seagrass?
• Small and Large fish and invertebrates
• Sparse biotic community
• Eroding shoreline
• Oyster bar foundation
• Shoreline stabilized
• Seagrass colonization?
• Some small fish and invertebrates
• Large oyster reef
• Expanded emergent marsh
• Expanded seagrass?
• Small and Large fish and invertebrates
Filtration capacity of oyster Filtration capacity of oyster reefsreefs
http://http://www.youtube.com/watch?vwww.youtube.com/watch?v=1Zm-yMpHsaQ&feature=related =1Zm-yMpHsaQ&feature=related (click link to view video)(click link to view video)
Reef Construction at Point aux Reef Construction at Point aux PinesPines
Reef dimensions: 75 m long x 5 m wide x 1 m high
Monitoring of Replicated Areas Monitoring of Replicated Areas (with and w/o reef construction)(with and w/o reef construction)
Shoreline Stabilization Shoreline Stabilization Oyster Density and Oyster Density and
SettlementSettlement Water clarity (TSS)Water clarity (TSS) Chlorophyll a (water Chlorophyll a (water
column and benthic)column and benthic) Benthic Macroinfauna Benthic Macroinfauna Juvenile and Adult Fish Juvenile and Adult Fish
and Mobile Invertebratesand Mobile Invertebrates Seagrass ColonizationSeagrass Colonization
Historic Shoreline ChangeHistoric Shoreline Change
Erosion between 1978-1986 (actual date unknown) and 2006
Erosion between 2006-2007
Shoreline change: Point aux PinesShoreline change: Point aux Pines(May 2007 to May 2008)(May 2007 to May 2008)
• Estimate of shoreline change from marsh surveys
-3
-2.5
-2
-1.5
-1
-0.5
0
East West
Shoreline Change (m)
Control Reef
Shoreline change: Alabama PortShoreline change: Alabama Port
Data still being Data still being analyzed in ArcGISanalyzed in ArcGIS– Have shoreline data Have shoreline data
from December from December 2007, May 2008, 2007, May 2008, and pre-Gustav and pre-Gustav (August 29, 2008)(August 29, 2008) A
L 19
3
Bayfront Park
NOAA shapefile of shoreline, circa 2001
Line marking current shoreline, August 29, 2008
Large Fish: Gillnet Collections at Large Fish: Gillnet Collections at Point aux PinesPoint aux Pines
Some fisheries species enhanced Some fisheries species enhanced by oyster reefsby oyster reefs
Stone crabGag grouper
Speckled trout
Gray snapper
Southern flounder
Sheepshead Red drum
Blue crab
Summary (1)Summary (1)
Oyster restoration was successful in Oyster restoration was successful in that all reefs had live oystersthat all reefs had live oysters
Vertical relief did not have a Vertical relief did not have a pronounced impact on oyster pronounced impact on oyster density, although DO levels were density, although DO levels were rarely below 2mg/lrarely below 2mg/l
The Shellbank reefs (Bon Secour The Shellbank reefs (Bon Secour area) appear to be limited by larval area) appear to be limited by larval supply supply
Summary (2)Summary (2)
The breakwater reefs reduced wave The breakwater reefs reduced wave energy, trapped sediments, and reduced energy, trapped sediments, and reduced shoreline erosionshoreline erosion
Little change was seen in water clarity, and Little change was seen in water clarity, and no seagrass colonizationno seagrass colonization
Recruitment of oyster spat occurredRecruitment of oyster spat occurred Sport fish were attracted to the reefs Sport fish were attracted to the reefs Building such reefs may be a viable Building such reefs may be a viable
alternative to hardening shorelines, with alternative to hardening shorelines, with the added benefit of added fisheries the added benefit of added fisheries productionproduction
Cooperating/participating agenciesCooperating/participating agencies
National Marine Fisheries ServiceNational Marine Fisheries Service Alabama Marine Resources DivisionAlabama Marine Resources Division Dauphin Island Sea LabDauphin Island Sea Lab Mobile Bay National Estuary ProgramMobile Bay National Estuary Program Bon Secour Seafood, Inc.Bon Secour Seafood, Inc. Auburn University Extension ServiceAuburn University Extension Service University of South Alabama (Dr. University of South Alabama (Dr.
Sean Powers)Sean Powers)