Seasonal migration of juveniles of three herring species, Alosa, from an estuary in the Annapolis River, Nova Scotia

Abstract

The downstream migrating populations of juvenile American shad (Alosa sapidissima alewife (Alosa pseudoharengus and blueback herring (Alosa aestivalis were studied in the Annapolis River, Nova Scotia during the autumn of 1985 and 1986. Downstream migration of alosines occurred in September and the fish moved to the sea through the Annapolis Barrage in October. The daily period of onshore movement in the estuary was between 1800 and 2300 hours. Environmental factors associated with increased downstream migration were: increased precipitation, a rapid decrease in water temperature and moon phase (new)