The treadmill for fish is called the flume and is in Nofima’s facility in Sunndalsøra.
The treadmill for fish is called the flume and is in Nofima’s facility in Sunndalsøra. Phto: Frank Gregersen/Nofima

Project Year 2014

Fish get fit in the gym

Salmon smolts are sorted, and those with the best prospects are exercised so that they perform better and give a better yield as adults.

The aquaculture industry has long had a problem with survival rates of smolts that are stocked at sea. Losses can be as much as 20 per cent, and a significant number of these are fish in poor physical condition, which makes them more susceptible to disease and to dying soon after stocking.

«The research results show that salmon have a better survival rate after stocking and a greater resistance to disease if they have been through this exercise system. In the FitSmolt project, we will be focusing on how the smolt can develop a greater resistance to disease, how we can get them to cope with different types of stress better and how they can grow quickly, but with natural organ development,» says Nofima Senior Scientist Harald Takle.

The project consists of three parts in which results will be coordinated so as to be used to improve the smolt’s robustness. In the first stage, we have shown that sorting of young salmon based on swimming ability gives a post-smolt with 24 per cent stronger heart muscles, 16 per cent greater gill area and 66 per cent lower transport costs from swimming. The increased heart capacity improves the fish’s growth and disease resistance. Part two is about training the smolt to make it stronger with the aid of various swimming exercises. In this way, it is possible to find out if the smolt has a higher survival rate if it is physically well-trained before being stocked into the sea. The heart capacity, ability to cope with disease and general performance are tested after the smolt has been stocked into the sea.

«We also wish to compare farmed smolt with wild salmon smolt, to look for differences in heart capacity and to find markers to identify these differences. The wild salmon will come from the Lærdal river, since we know that this produces strong smolt with good swimming capacity. The long-term objective is to ensure that future generations of farmed salmon will be at least as robust as their wild cousins,» explains Takle.

The Research Council of Norway and The Norwegian Seafood Research Fund

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