OTN Loan - Salmonids in Trondheimsfjorden

The aim of the Trondheimfjord project is to get better knowledge of marine migrations of anadrome species (Atlantic salmon, Brown trout) from rivers draining to the Trondheim Fjord. The fjord is a national salmon fjord (a kind of MPA), which means that salmon aquaculture is prohibited. But outside the fjord, one of the most intensive areas for open net pen salmon aquaculture in Norway is located.

The two overall hypotheses to test are that a) Atlantic salmon only spent few days in the protected fjord system before heading out to the open sea and b) that brown trout stay within the protected fjord system during the whole marine feeding season. Additionally, we will explore in more details the individual migratory behaviour of the tagged fish and related that to physiological status, previous growth rates, sex and body size.

The outcome will be crucial knowledge for regional coastal zone planning and will be of high value as background information when the Norwegian traffic light system, which regulate the aquaculture production, will be evaluated in the years to come.