Skip to main content
Go to the home page of the European Commission (opens in new window)
English English
CORDIS - EU research results
CORDIS
Content archived on 2024-04-16

The interaction between fish farm induced environmental change and fish health in intensive mariculture

Objective

The principal aims of the research are to quantify the relationships amongst farm design, husbandry practice, hydrography and ecological change and assess the potential for ecological change to affect the health of fish farmed in marine waters and hence influence the long term viability of fish farm sites. A secondary aim is the development of guidelines and models which will allow an assessment of the degree of ecological change and the production potential of specific sites to be made.
Continuous ventilation of the fish cages by a steady current allows high levels of oxygenation and effective flushing of soluble waste products. There is no evidence of high levels of ammonia in marine cages but suboptimal levels of oxygen were frequently observed. These occurred during prolonged periods of low current speeds.

A steady current regime disperses the waste solid materials away from the immediate vicinity of the cages thus reducing the environmental impact on the benthos and allows greater oxygen stability within the cages.

A shallow site where the sediment is regularly scoured by high current speeds may be better than a deeper site with a less favourable current regime. A poorly flushed shallow site is, however, likely to have a very limited holding capacity and may give rise to the production of hydrogen sulphide in close proximity to the fish.

The relationships between fish health and benthic impact are less clear. Hydrogen sulphide is evolved from heavily impacted sediments and is toxic to fish. The relationship between benthic impact and gill damage has not been very well reflected in growth or mortality data and hydrogen sulphide has never been detected within fish cages.

Experiments on the response of salmon to chronic sublethal levels (7.8 mM) of hydrogen sulphide showed a relatively rapid (2 to 6 weeks) deterioration in gill tissues followed by slow but progressive repair and little effect on growth. Liver tissues showed increasing degeneration with continued exposure.

The response of salmon to single doses of high (21.5 mM and 29.5 mM) but sublethal levels of hydrogen sulphide showed that it is likely that the majority of the fish exposed to either level would eventually die or have severely compromised health.

Finally, a series of guidelines have been proposed which may help fish farmers avoid many of the fish health problems associated with environmental change at fish farm sites.
The project will be based on a coordinated programme of field and laboratory work and will be divided into a series of phases which overlap to ensure that the field and laboratory studies will be fully integrated.

Phase 1 of the work will be carried out to determine threshold levels of water quality parameters which have the potential to cause stress and induce pathological change and histological damage to fish farmed in marine waters.

The aims of Phase 2 are to investigate the ways in which cage design, husbandry and the hydrography of the site interact to affect those water quality parameters studied in Phase 1.

Phase 3 is designed to assess the changes in water quality parameters measured at the field sites in the context of the effects of such changes on the health of the fishes.

Throughout the project attempts will be made to use the data to formulate simple models which could be used as an aid to the assessment of the degree of ecological change and predict the optimum production which could be sustained at a given site. This is Phase 4.

Fields of science (EuroSciVoc)

CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: https://op.europa.eu/en/web/eu-vocabularies/euroscivoc.

You need to log in or register to use this function

Programme(s)

Multi-annual funding programmes that define the EU’s priorities for research and innovation.

Topic(s)

Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.

Data not available

Call for proposal

Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.

Data not available

Funding Scheme

Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.

Data not available

Coordinator

Scottish Association of Marine Science
EU contribution
No data
Address
Dunstaffnage Marine Laboratory
PA34 4AD Oban
United Kingdom

See on map

Total cost

The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.

No data

Participants (3)

My booklet 0 0