Chair of the Working Group on Effectiveness of Recovery Actions for Atlantic Salmon (WGERAAS) Dennis Ensing.
'Anadromy, in the strict sense of the word, is a strategy in aquatic organisms where individuals migrate from a large body of water (lake or sea) upstream on a body of flowing water (river or stream) for the purpose of spawning. However, in the current use of the word it refers solely to populations of aquatic organisms that migrate from the sea to freshwater to spawn. Atlantic salmon is probably the most well know example, but other examples are shads, sturgeons, and even most populations of the three-spined stickleback.
Anadromy is more frequently encountered at northern latitudes because the marine environment in Arctic, boreal, and temperate climatic zones is more productive than freshwater environments, providing better feeding opportunities for individuals that venture out to sea.
For ICES working groups that focus on anadromous fish, anadromy is a very important factor in the work they do. Anadromous species and populations are generally at much greater risk of extinction because they utilise a much wider range of habitats and migrate over considerably longer distances for spawning, feeding, or overwintering compared to resident fish.'