ETHOFISH The Effect of Turbidity and Hypoxia On the behaviour of coastal marin FISHes PROJECT NUMBER QLRT - 2001-00799 European Commission, Directorate General Fisheries.
The Effect of Turbidity and Hypoxia On the behaviour of coastal marin FISHes
PROJECT NUMBER QLRT-2001-00799
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.
THE AIMS OF ETHOFISH
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
Scottish Association for Marine Science
Marine Biological Laboratory
University of Copenhagen
Centre de Recherches sur les Ecosystèmes Marins et Aquacoles
Habitat selection boxes
10 fully monitored
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
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?
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.
Preliminary results on the effect of hypoxia on
the swimming activity of grey mullets
% oxygen saturation
Hypoxia causes an increase in spontanous swimming activity,
which could result in a further decrease in energy available
for growth, reproduction. (especially in lagoons)
The effect of hypoxia on schooling herring
From: Domenici et al, 2000
Proc. Royal Soc. B. 269: 2103-2111