Recruitment of young-of-the-year bluefish Pomatomus saltatrix to the New York Bight: variation in abundance and growth of spring- and summer-spawned cohorts

Abstract

Pomatomus saltatrix spawns offshore in continental shelf waters and juveniles migrate to near-shore or estuarine waters during their first growing season. In estuaries of the New York Bight during 1987 and 1988, young-of-the-year bluefish appeared in two discrete size groups. A spring-spawned cohort first recruited to estuaries in early to mid-June, whereas the summer-spawned cohort first recruited in middle to late August. In contrast with previous years when only spring-spawned fish were abundant, overall abundance of spring vs summer cohorts was similar, but there were significant differences in abundance among bays that depended on cohort. Much of this variation in abundance is probably caused by variation in advective transport of larvae from spawning groups to estuaries. Growth patterns differed substantially between the two cohorts. Spring-spawned bluefish grew more slowly than summer-spawned bluefish during the pre-recruitment oceanic phase of the early life history, perhaps because their northward transport causes them to encounter lower temperatures during the larval period. Both cohorts grow rapidly after estuarine recruitment, but spring-spawned bluefish are much larger than summer-spawned bluefish at the onset of fall migration. -from Authors