ETHOFISH

The Effect of Turbidity and Hypoxia On the behaviour of coastal marin FISHes

PROJECT NUMBER QLRT-2001-00799European Commission, Directorate General Fisheries

Of all the environmental factors affecting the distribution and abundance of fishes along the coastal zones, water oxygen content and turbidity are among the most heavily affected by pollution and eutrophication, and may co-occur.

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Hypoxia and turbidity in Europe

Fig. 1 Hypoxia and turbidity in Europe. Hypoxia (white dots is indicated by 2 mg/l and turbidity is indicated by >0.5 g/l of suspended particles (dark grey dots) and by eutrphication (light grey dots). Numbers refer to sources of reference.

• To assemble and further develop an integrative methodology for in situ evaluation of the effects of turbidity and hypoxia on fish physiological and behavioural performance.

• To determine experimentally the threshold values beyond which oxygen and turbidity levels are liable to alter fish physiological and behavioural performance.

• To integrate the results obtained in a conceptual and predictive model.

THE AIMS OF ETHOFISH

ETHOFISH is a highly integrated project

1) We will study 5 species (cod, herring, sole, plaice, grey mullet)

2) We will investigate the fish’s responses to hypoxia and turbidityat three levels: laboratory, mesocosm, field

3) We will use a number of techniques at each level.

4) A high level of interactions between laboratories is envisioned

ETHOFISH DIAGRAM

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Yr1Yr2Yr3

Yr3

All yrs

Participants:

1) IMC Torregrande (Italy): Coordinator

2) SAMS, Oban, Scotland (UK)

3) University of Copenhagen (Denmark)

4) CREMA , La Rochelle (France)

5) University of Bergen (Norway)

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International Marine Centre,Torregrande, Sardinia, Italy

-P. Domenici, A. Shingles, R.S. Ferrari, M. Cannas

- Organismal Biology:Physiological Ecology, Functional Morphology, Biomechanics

- Predator-prey interactions in fish and other marine animals -Schooling-the effect of environmental factors on fish physiology and behaviour

-Lab studies:Kinematics (high speed video), respirometry, video techniques

-Field studies:Field video, ROV, telemetry

Scottish Association for Marine Science Dunstaffnage Marine Laboratory Oban, Scotland

•R Batty, M Burrows, L Robb, R Harvey•Behaviour, physiology and and ecology of fishes•Juvenile flatfishes, larval and adult clueids•Tradeoffs between predation risk & feeding

•Shoaling•Population consequences of individual processes

•Modelling•Field studies•Underwater TV

•(foraging, migration, habitat selection)•Trawl surveys

•Lab studies•Large tanks (0.5- 3m) in controlled conditions

•Advanced video analysis techniques

Marine Biological LaboratoryHelsingor,

University of Copenhagen

J. F. Steffensen, N. Herbert

Fish Physiology Group:-Physiological adaptation to extreme environments-Exercise physiology-Physiology of the secondary circulatory system in teleosts

Lab Studies:-Respirometry-Cardiovascular physiology-Videoanalsysis for behavioural responses to environmental stress

Field Studies:Underwater acoustics (with subcontractor Danish Institute for Fisheries Research -Bo Lundgren)

CREMACentre de Recherches sur les

Ecosystèmes Marins et Aquacoles

L’Houmeau, France

G. Claireaux, D.J. McKenziePhysiological ecology of coastal fishes:

o Study the environmental influences on the interactions between morphology, physiology and behaviour.o Examine the ecological repercussions of these interactions.

Laboratories studies:obioenergetics, respirometry,ofish swimming performance,ocardiovascular physiology.

Mesocosm and field studies:ofish behaviour in controlled conditions.otelemetryo(habitat selection, feeding behaviour).

Methodological overview

LABORATORY METHODS

Habitat selection boxes

Respirometry

Video analysis

FIELD/MESOCOSM METHODS

10 fully monitoredtidal ponds220 m2

Telemetry Field video

UW acoustics

Fig.4: Matching between the characteristics required for the investigation in each work package and the characteristics of the methodologies available to the consortium. Light grey indicates complete matching, green-red shading indicates partial matching, red indicates no matching. * indicates that area of recording depends on water depth. Ltd = limited, ultd= unlimited.

The context in which Ethofish will operate

Lethal level?

The threshold concept

Ethofish thresholds: significant changes in fish behaviour that can affect the abundance and distribution of fish, e.g. via avoidance,or a decrease in growth and survival. e.g. At what oxygenation level do fish start showing avoidance behaviour?

Other examples:

The complexity of the effect of hypoxia on spontaneous activity:

- Hypoxia can change the spontaneous activity level in fish:Some fish (usually benthic species) decrease their activity, in accordance with the lower aerobic metabolic scope

- Other species (usually pelagic) increase their activity, as a behavioural response to avoid hypoxia.

Energy available

Growth

Reproduction

Activity

Preliminary results on the effect of hypoxia onthe swimming activity of grey mullets

Hypoxia causes an increase in spontanous swimming activity,which could result in a further decrease in energy available for growth, reproduction. (especially in lagoons)

% oxygen saturation

From: Domenici et al, 2000

Proc. Royal Soc. B. 269: 2103-2111

The effect of hypoxia on schooling herring

Main expected achievements:

• [1] establishment of a link between laboratory studies, studies in mesocosm and field studies, using the most advanced techniques for monitoring behaviour in various environmental conditions.

• [2] an understanding of the impact of water turbidity and oxygenation on three major components of the behavioural repertoire of fish: habitat selection, predator-prey interactions and schooling-aggregation.

• [3] Predictive ability for the effect of the environmental variables studied on ecologically relevant behaviour.

• [4] Provide hypoxia and turbidity thresholds necessary for the well-functioning of the coastal marine ecosystems, which can be references for

environmental regulations.