Abstract
AbstractStriped bass (Morone saxatilis) are anadromous fish that support an important fishery along the east coast of North America. In Chesapeake Bay, strong juvenile recruitment of striped bass can occur when larvae overlap with high concentrations of their zooplankton prey, but the mechanisms fostering the temporal overlap are unknown. Here, the influence of winter temperature on the peak abundances of a key prey, Eurytemora carolleeae, was estimated with a temperature-dependent developmental model. The role of these peaks in regulating striped bass recruitment was explored in three nursery areas: upper Chesapeake Bay, Choptank River, and Patuxent River. Model results indicated that cold winters delay the timing and increase the size of peak E. carolleeae spring abundance. When the model output was used in regression relationships with striped bass juvenile recruitment and freshwater discharge, the regression models explained up to 78% of annual recruitment variability. Results suggests that cold, wet winters could increase the chance of a match between striped bass larvae and high concentrations of their prey. This mechanistic link between winter temperatures and striped bass production, acting through prey dynamics, could further understanding of fish recruitment variability and indicates that warmer winters could negatively affect some striped bass populations.
Highlights
The match-mismatch hypothesis (Cushing, 1990) and the critical period hypothesis (Hjort, 1914) are fundamental theories, which have contributed our understanding of the factors underlying fish recruitment variability (Houde, 2008, 2016)
Metrics related to development of winter E. carolleeae cohorts improved the fit of regression models and accounted for more variability in striped bass recruitment than models without copepod metrics in the upper Chesapeake Bay (R2 increased from 0.67 to 0.79) and the Choptank River (R2 increased from 0.38 to 0.56) (Table 4)
Metrics associated with copepod development in winter did not account for more variability in striped bass recruitment in the Patuxent River, which had average winter water temperature that was at least 1C warmer than the other regions
Summary
The match-mismatch hypothesis (Cushing, 1990) and the critical period hypothesis (Hjort, 1914) are fundamental theories, which have contributed our understanding of the factors underlying fish recruitment variability (Houde, 2008, 2016). While both point to the spatial and temporal coincidence of fish larvae with their prey, identifying the processes that cause this overlap requires knowledge of the complex interactions between the environment, prey, and fish larvae. We investigate the interaction between environmental conditions and copepod development rates that influence the temporal overlap of high abundances of E. carolleeae with striped bass larvae.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
