Post-release stranding rates of stocked allis shad (Alosa alosa) larvae exposed to surface wave action

Abstract

The objectives of the present study were to test the effects of sudden wave action caused by ships on newly released larval shad thriving along shallow river beaches because heavy shipping traffic has developed in many shad river systems. Experiments were conducted in a wave tank simulating a cross-section of the river shore. Up to 17% of the one week old allis shad stranded within the first 7h after their release, but with increasing age of the released larvae, stranding rates decreased. Stranding rates were always highest directly after the release of fish and decreased throughout the experimental period of 7h. The stranding rates were further influenced by weather, with higher stranding rates when it was sunny and when water temperatures were low. These results can be used to improve release strategies and stocking procedures of shad larvae and may probably be applied to other larval fish species as well. © 2011 Blackwell Verlag, Berlin.