ETHOFISH The Effect of Turbidity and Hypoxia On the behaviour of coastal marin FISHes PROJECT NUMBER QLRT European 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.

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 turbidity at 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

Yr1 Yr2 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)

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 Laboratory Helsingor, 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)

CREMA Centre de Recherches sur les Ecosystèmes Marins et Aquacoles L’Houmeau, France  G. Claireaux, D.J. McKenzie  Physiological ecology of coastal fishes: oStudy the environmental influences on the interactions between morphology, physiology and behaviour. oExamine the ecological repercussions of these interactions.  Laboratories studies: obioenergetics, respirometry, ofish swimming performance, ocardiovascular physiology.  Mesocosm and field studies: ofish behaviour in controlled conditions. otelemetry o(habitat selection, feeding behaviour).

Methodological overview

LABORATORY METHODS Habitat selection boxes Respirometry Video analysis

FIELD/MESOCOSM METHODS 10 fully monitored tidal ponds 220 m 2 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 on the 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: 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.