R/WQ-2a

Description:

Objectives: Determine if bay anchovy recruitment levels in the Chesapeake Bay are related to timing, intensity, spatial variability, and quality of algal blooms. Evaluate associated environmental factors and develop statistical models to describe, hindcast, and potentially forecast recruitments. Evaluate temporal-spatial variability in growth and mortality of bay anchovy young stages relative to algal bloom dynamics and other factors. Determine if carrying capacity of the Bay for production of the bay anchovy is dependent on primary production level and its inter-annual and regional variability in the Chesapeake Bay. Methodology: Evaluate time series of aircraft-derived, remotely sensed biomass and primary production data and analyze with respect to young-of-the-year recruitment levels, growth, and spatio-temporal variability in abundance of the most abundant planktivorous fish in Chesapeake Bay. Proceed from initial correlation analyses to more diagnostic, multivariate statistical modeling, ordination approaches (e.g., PCA and related approaches), and bioenergetics modeling to describe relationships and develop predictive models of recruitment variability of bay anchovy. Rationale: Recruitments of bay anchovy have declined from 2- to 5-fold in Chesapeake Bay while levels of primary production have increased over the past few decades as the Bay has become increasingly eutrophic. This project will investigate relationships or linkages between algal-bloom dynamics and production and recruitment of a key forage species that is important prey for striped bass, weakfish, and bluefish. Information on trophic linkages needed for multispecies fisheries management will be provided to fishery and resource managers. In addition, implications of consequences of reductions of nutrient loadings effects on foragefish production will support ecosystem-based, fisheries management plans that are required by the Chesapeake Bay Program's C2K Agreement and highlighted in the recently completed Chesapeake Bay Fisheries Ecosystem Plan.