The Estuary

Allis Shad (Alosa alosa) and Twaite Shad (Alosa fallax)

Allis and twaite shad are the only two members of the herring family found in fresh water in the UK. Both look like large herring (adult allis shad can be over 2 kg in weight), and were formerly eaten in this country before numbers declined and the fisheries collapsed. In the middle of the 19th Century, the value of shad rivalled that of salmon, and in the River Severn, shad made up about one-third of all catches. The fish enter estuaries in early spring and move up into the rivers. Nocturnal spawning over gravel beds occurs in April / May, before they return to the sea by the end of summer.

Twaite (top) and Allis Shad.