Acronym OPP
Category
Aquaculture
Title Optimized post-smolt production Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Ragnar Joensen Coordinator email NA
Coordinator institution
NA
Institutions involved
NA - erko Settefisk AS (Norway) ,
NA - Grieg Seafood Finnmark AS (Norway) ,
NA - Lerøy Norway Seafoods AS (Norway) ,
NA - Lingalaks AS (Norway) ,
NOFIMA - Norwegian Institute of Food, Fisheries and Aquaculture Research (Norway) ,
NA - Smøla Hatchery and hatchery (Norway) ,
UiB - University of Bergen (Norway) ,
Start year 2013 End year 2017 Funding (€) € 190,500 Website https://prosjektbanken.forskningsradet.no/en/project/FORISS/229957?Kilde=FORISS&distribution=Ar&chart=bar&calcType=funding&Sprak=no&sortBy=date&sortOrder=desc&resultCount=30&offset=150&TemaEmne.2=Fiskeri Summary Atlantic salmon is the most important farmed-fish species in Norway and accounts for 90% of the salmon on the market globally, today most of this production occurs in open sea cages. Environmental concerns, such as sea lice and escapes of farmed fish, during the production phase at sea is limiting further growth of the industry. Atlantic salmon are usually transferred from land-based freshwater facilities to sea cages once they reach a certain size (~100 g) and have undergone a seawater preparatory adaption. These post-smolts (young seawater adapted salmon up to 1 kg) are most sensitive shortly after transfer as they are adapting to a new marine environment and it is during this period the industry also experiences the highest losses. In closed-containment aquaculture systems fish are separated from the external environment through a rigid barrier, these can be land based systems using recirculated water or closed units in the sea. A shift to these types of facilities for post-smolt production up to 1 kg could reduce the environmental footprint of salmon farming and allow us to control and optimize the rearing conditions. However, there is a lack of knowledge on the optimal rearing environment for post-smolts therefore the aim of this project was to provide insight on the effects of some key husbandry conditions on post-smolt performance and welfare in both sea- and land-based closed systems.
Commercial feasibility of farming post-smolt Atlantic salmon in closed systems in the sea relies on increasing fish density above the regulated limit for open sea cage farming, 25 kg of fish per cubic meter (kg/m3). Therefore, we tested five different densities (25, 50, 75, 100 and 125 kg/m3) in flow-through seawater systems for eight weeks. Given the peak expression of genes that are important for cognition and memory in the brain of the post-smolt, densities around 75 kg/m3 may in fact be optimal for welfare. Determining the requirements for water exchange required by post-smolts will also largely influence the design and dimensioning of closed-containment systems in the sea. We found that, in closed systems in the sea in which water is not recirculated and treated the water flow should be maintained above 0.3 litres per kilo fish per minute to avoid energy costly physiological regulatory responses to increased water carbon dioxide. Furthermore, this project also identifies several welfare markers, that can be used to predict the resilience of the fish and it`s potential for adaptation to changes in the environment.
The optimal strategy for farming large post-smolts in land-based recirculating aquaculture systems (RAS), with respect to salinity and water velocity is not known. It has been found that in earlier life stages of salmon exercising fish through increasing the water velocity in the tanks has a positive effect on performance and welfare. Therefore, as part of this project we did a long-term study on (post-smolts) from 70 g up to 800 g, reared in three separate RAS at different salinities (12, 22 and 32 ppt) and subjected to moderate (~1 body length/second) or low (~0.3 body length/second) water velocity. Results suggest that a brackish salinity close to the internal salt balance of the fish (~12 ppt) and moderate exercise training has a positive effect on post-smolt performance, welfare and survival in RAS.
In conclusion, the knowledge gained in this project will contribute towards optimizing post-smolt Atlantic salmon production in closed-containment aquaculture systems on land and in the sea. Overall, this work can assist in reducing the time fish spend in open sea cages, and therefore also reduce the environmental footprint of salmon farming and the risk for the salmon farmer.
Keywords
Aquaculture development;
Animal welfare;
Recirculating systems;
Salmon;
Fish;
Fish biology;
Marine Region
76
Not associated to marine areas
0
Marine Region Map
