Spatio-Temporal Distribution of Eggs and Age-0 Striped Bass (Morone Saxatilis) in the Shubenacadie River Estuary

Abstract

The spatio-temporal distribution of age-0 striped bass was evaluated in the Shubenacadie estuary from May to September, 2010 and 2011. From mid-May to the end of June each year there were 2-3 large spawning events resulting in 1000 to 8000 eggs/m3 water filtered. First feeding larvae density peaked around 400/m3 in 2010 and 800/m3 in 2011. Spatio-temporal distribution of eggs and larvae ? 7 mm total length was dictated by the magnitude of freshwater run-off and tide size. The upstream transportation limit on the flood tide was the salt front. Advection from the estuary into Cobequid Bay occurred both years. Mean (SE) total length of juveniles in late-August was 7.5 (3.16) cm in 2010, but only 4.5 (1.49) cm in 2011. The high abundance of eggs indicates the adult population is healthy, but abundance and growth of early life stages are greatly affected by fluctuations in freshwater run-off and temperature.