HABITAT USE AND COHORT RECRUITMENT PATTERNS OF JUVENILE BLUEFISH (POMATOMUS SALTATRIX) IN DIVERSE MARYLAND NURSERY SYSTEMS

Abstract

A popular recreational species, bluefish (Pomatomus saltatrix) has been declining since the mid-1980s. This thesis examines patterns of juvenile habitat use, growth rate, and cohort recruitment patterns in three Maryland systems: the Chesapeake Bay, the Coastal Bays, and shallow coastal areas (<20>m): potential nursery habitats where little research has been conducted. Notable differences in growth rate were observed among systems, with consistently higher rates in the Chesapeake compared to the Coastal Bays. Juvenile growth was also amongst the highest reported in the literature. Likewise, relative cohort contribution varied between systems suggesting that late spawning groups may not consistently utilize the upper Chesapeake, and a spawning group intervening between the spring and summer cohorts may occasionally appear in the coastal region. Finally, otolith microchemical analysis indicated that juveniles may exclusively use coastal nurseries, adding to evidence that bluefish may not be estuarine dependent.