Ecology of Juvenile Bluefish, Pomatomus saltatrix, in Maryland Coastal Waters and Chesapeake Bay

Abstract

Shallow coastal ocean environments may function as important nursery habitats for juvenile bluefish, yet little ecological research has been conducted in ocean habitats. This thesis examines seasonal production, growth rates, and diet composition of juveniles in Maryland's coastal ocean environment and the Chesapeake Bay estuary. Summer-spawned juveniles dominated in ocean habitats and exhibited rapid growth rates, 2.0 - 2.4 mm d^-1, which were likely fueled by an abundant forage base of young-of-the-year bay anchovy present in ocean environments during late summer/early fall. This summer cohort was rare in the Chesapeake Bay, where spring-spawned juveniles dominated. These results suggest ocean habitats provide principal nurseries for summer-spawned bluefish, and that the Chesapeake Bay and other estuaries are principal nurseries for spring-spawned juveniles. Accordingly, year class strength is likely shaped by contributions of juveniles from both oceanic and estuarine nursery habitats.