Twaite shad are now rare in the Firth of Forth and are a protected species. This fish is a member of the herring family. This species returns from the sea to spawn in spring, usually between April and June, hence the alternative name of ‘May fish’.
The majority of adults die after spawning, though UK populations appear to have an unusually high proportion of repeat spawners – up to 25%. After hatching the fry develop and slowly drift downstream.
Population declines in many parts of Europe have been attributed to pollution, overfishing and migratory route obstructions.
