The influence of episodic river flow events on striped bass (<italic>Morone saxatilis</italic>) spawning in Chesapeake Bay, USA

Abstract

The upper Chesapeake Bay is an important and dynamic nursery habitat for striped bass (<italic>Morone saxatilis</italic>) eggs and larvae. The hypothesis that pulses in flow cause temperature changes that cue striped bass spawning was evaluated with field surveys and historical data analyses. Water temperatures in April and May were negatively correlated with river flow (1956-2002), suggesting that water temperatures decrease during flow events and then increase as flow diminishes, potentially providing a cue for spawning. Survey data from the upper bay in 2007 and 2008 were analyzed in conjunction with historical data on striped bass eggs in tributaries of Chesapeake Bay. Results suggest that increasing water temperatures are the dominant cue for striped bass spawning. Temperature increases after pulsed flow events may cue striped bass spawning and may result in more favorable prey abundances and better larval survival compared to years when spawning is cued by water temperature increases alone.