Use of river habitat survey to determine the spawning habitat characteristics of twaite shad (alosa fallax fallax)

Abstract

The spawning habitat of twaite shad comprises a fast-flowing shallow area of unconsolidated gravel/pebble and/or cobble substrate. The River Habitat Survey flow types « smooth flow », « rippled flow » and « unbroken standing waves » were significantly (P < 0.05) associated with the presence or absence of shad eggs. The presence of eggs was significantly associated with the higher energy flow types « rippled flow » and « unbroken standing waves », and the absence of eggs was significantly associated with the lower energy flow type « smooth flow ».