National Adult Salmon Sampling Project

Over the past few decades it appears that salmon returning to Scotland’s rivers are getting smaller. This is important as it’s 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.

In order to protect salmon 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 it spent in the river and at sea and how fast it grew while there.

The project will support Fisheries Management Scotland members to collect weights, lengths and scale samples from returning adult salmon between July and September 2021.

Weights, lengths and scale samples from returning adult salmon will be taken between July and September 2021. Sampling will be undertaken so as to create the minimum of stress to the fish. Scales will be taken from the left flank of the fish as shown below. Scales will be read by Marine Scotland Science and the image and life histroy information of each salmon will be provided to the contributing DSFB/Trust.

Image provided by Inland Fisheries Ireland

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.

Fork length measurement being taken in the river to minimise stress to the salmon
Image of a scale taken from an adult salmon caught on the North Esk. The salmon was 51.5 cm long and weighed 1.62 kgs (roughly 3 ½ lbs). After hatching it spent 3 years in the river before heading to sea where it stayed for 1 winter before returning to the North Esk during May.


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