Research to find out why salmon are getting smaller

Research is under way to find out why salmon returning to the north's rivers are getting smaller – as well as scarcer.

Scotland’s fisheries trusts and district salmon fishery boards are participating in a national project designed to gather information on the sizes and ages of wild adult Atlantic salmon.

The project is funded by Marine Scotland and will help inform national and international management aimed at safeguarding salmon for future generations. In particular, it will help to inform the understanding of trends in the size, and age, of salmon returning to Scotland’s rivers.

"Over the past few decades it has become clear that salmon returning to Scotland’s rivers are getting smaller. This is important as it is the size, and age, of female salmon that determines how many eggs they produce and therefore how many salmon will be produced in future generations," said Fisheries Management Scotland.

"In order to better manage and protect salmon, additional information on the sizes and ages of salmon in Scotland is required."

Scales record information throughout the life of the salmon and can be used to determine the age of the fish, how many years an individual fish spent in the river and in the marine environment and how fast it grew at different life stages.

The project is supporting Fisheries Management Scotland members to collect weights, lengths and scale samples from returning adult salmon.

As well as providing information on the age and sizes of rod caught salmon in local rivers the information will also help inform national and international management aimed at safeguarding salmon for future generations of anglers.

This project is funded by Marine Scotland Science and delivered in partnership with Fisheries Management Scotland and Scottish Fisheries Coordination Centre.

Meanwhile, Fisheries Management Scotland are asking anglers to remain vigilant and report pink salmon caught in Scottish rivers – already several in Sutherland have been found.

Pink salmon are native to Pacific Ocean waters but have spread to parts of northern Europe after being released into rivers in Russia in the 1960s.

There are concerns pink salmon could out-compete native fish species for food and habitat.

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