In appearance it resembles an Atlantic herring but has a row of six to ten distinctive spots on its silvery flanks.

The flanks are silvery, sometimes with a bronzy tinge, and there are a distinctive row of six to ten large dark spot just behind the gill cover though these may fade when the fish is dead.

[3] Populations have been reduced primarily through overfishing, pollution, habitat destruction and migratory route obstruction in the Victorian Era.

[4] It is estimated that the estuarine phase, or the time that they are in the estuaries migrating from spawning grounds to sea, has a duration in A. fallax of up to a year and a half.

[4] Alosa fallax has been placed in Appendix III of the Bern Convention (1979) that lists protected fauna species as well as in appendix II and V of the European Community Habitats Directive (1992) that list, respectively, species whose conservation requires the designation of special areas of conservation and that are subject to management measures.

The aim is to open 150 miles (240 km)* of the river for the fish to increase its freshwater breeding habitat.