Salmon Population Modeller

How salmon stocks work – the number of eggs that a salmon produces, and the numbers that survive through the different life stages, from parr to smolt to returning adult – can be difficult to grasp, yet this is the key to understanding how we can boost salmon numbers. To help anglers and others understand this better the AST and the Institute of Fisheries Management (IFM) commissioned the Salmon Population Modeller.

The AST / IFM Salmon Population Modeller is web-based demonstration tool designed to provide anglers, managers and everyone interested in salmon with a clearer understanding of how salmon stocks work (stock dynamics) and what the constraints are on increasing salmon numbers. It is intended to illustrate typical levels of loss at the different stages of the salmon life cycle, and the impact that changing these can have on the viability of the stock.

Access the Modeller.

Before using it, you should read the introductory note that appears when you open the modeller; for more detail you can click on “How it Works” (top right of the screen).

To help you understand the Modeller we have also produced:

  • A video, with Ronald Campbell of the Tweed Foundation taking you through the modeller step by step and explaining its technical aspects. See the video below.
  • An article setting out the key features of the modeller and of salmon stock dynamics in more depth and effects of various impacts on the different life stages. Read the article.