Linking habitat use of Hudson River striped bass to accumulation of polychlorinated biphenyl congeners

Since 1976, the commercial striped bass fishery in the Hudson River (NY) ha s been closed due to total polychlorinated biphenyl (t-PCB) concentrations that exceed the U.S. Food and Drug Administration's advisory level of 2 mu g/g-wet weight. Extensive monitoring of Hudson River striped bass demonstra ted much more variability in t-PCB levels among individual striped bass tha n could be explained by their age, sex, or lipid contents. To investigate t he possible role of differential habit use among subpopulations of striped bass in controlling their PCB exposures, 70 fish collected throughout the H udson River estuary and Long Island Sound in 1994-1995 were analyzed for PC B congeners, and their lifetime migration behaviors were estimated by otoli th microchemistry. The mean salinity encountered during the fish's last gro wth season prior to capture was inversely correlated with the t-PCB body bu rden. Striped bass permanently residing in fresh and oligohaline portions o f the estuary adjacent to known PCB sources had elevated t-PCB levels and c ongeneric patterns with higher proportions of di-, tri-, and tetrachlorobip henyls. Conversely, fish spending the majority of their life in more saline waters of the estuary or migrating frequently throughout the salinity grad ient contained lower PCB levels composed of more highly chlorinated congene rs. The approach used in this study allows habitat use to be incorporated i nto exposure assessments for anadromous fish species such as striped bass.