Physiological analyses

The physiological characteristics of reared salmon smolt differ from those of wild smolt. In the wild, the behavioural and metabolic changes relating to the development of migratory readiness take place in a specific sequence, regulated by the environment (for example the length of the day, water temperature). In hatchery conditions, those changes often happen abnormally, so that the stocked fish may only exhibit some of the characteristics of wild smolts.

The ability of salmon smolts to survive in the salinity of an ocean is commonly used as a measure for assessing their migratory status. The salinity tolerance of the smolts has turned out to be a relatively reliable measure of their smoltification, and it has been proved to predict release results. Good general condition and nutritional state of the smolt are also important to their migratory readiness and performance after release.

Goals

In this project, the physiological condition and migratory readiness of salmon smolts produced in several commercial hatcheries are being studied. With the information produced, rearing processes will be improved, and the changes in the quality of reared smolts and their impact on the profitability of stocking results will be assessed.

Scientists in charge of project

Matti Salminen

Marja Pasternack, Salmolab
Viikinkaari 6
00790 Helsinki

Cooperation partners

Salmolab, contract fisheries

Duration

2004-2012

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