Elemental fingerprints of otoliths from Hudson River striped bass Morone saxatilis were used to define resident, estuarine, and ocean migratory contingents, which had previously been determined by otolith microprobe analysis of Sr:Ca. Using solution-based inductively coupled plasma mass-spectrometry, 7 metals were quantified in whole otoliths. Discriminant analysis of elements showed a high degree of separation among the 3 migratory contingents. Barium was significantly higher in otoliths from the freshwater resident group, while Sr and Na were significantly lower in comparison to mesohaline and ocean contingents. Identification of contingents by the bulk chemistry method indicated that divergent migratory patterns persist over lifetimes for Hudson River striped bass.

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The Hudson River commercial striped bass (Morone saxatilis) fishery has been closed since 1976 due to high polychlorinated biphenyl (PCB) contamination. Accurate forecasting of PCB levels in striped bass has been confounded by high variance in contamination among individuals. We investigated the relationship between habitat use and PCB contamination in Hudson River and Long Island Sound striped bass using electron microanalysis of otolith strontium to generate time series of individual salinity habitation. Males with highly contaminated levels (mean PCB = 8.3 ppm) showed freshwater resident behavior, rarely experiencing salinities >5 ppt. Several individuals showed large habitat shifts. Shifts from brackish or marine habitats to freshwater habitats were often associated with high PCB levels. A third pattern was apparent in large females, where polyhaline/euhaline salinity habitation was associated with lower PCB levels. Total PCB body burden was inversely correlated with mean salinity encountered during the most recent growth season prior to capture. Fish with recent exposure to polyhaline salinities showed high variability in PCB body burdens (0.4-9.0 ppm), suggesting a local source of PCB contamination in the New York Harbor region.

Since 1976, the commercial striped bass fishery in the Hudson River (NY) has been closed due to total polychlorinated biphenyl (t-PCB) concentrations that exceed the U.S. Food and Drug Administration's advisory level of 2 µg/gwet weight. Extensive monitoring of Hudson River striped bass demonstrated much more variability in t-PCB levels among individual striped bass than could be explained by their age, sex, or lipid contents. To investigate the possible role of differential habit use among subpopulations of striped bass in controlling their PCB exposures, 70 fish collected throughout the Hudson River estuary and Long Island Sound in 1994-1995 were analyzed for PCB congeners, and their lifetime migration behaviors were estimated by otolith microchemistry. The mean salinity encountered during the fish's last growth season prior to capture was inversely correlated with the t-PCB body burden. Striped bass permanently residing in fresh and oligohaline portions of the estuary adjacent to known PCB sources had elevated t-PCB levels and congeneric patterns with higher proportions of di-, tri-, and tetrachlorobiphenyls. Conversely, fish spending the majority of their life in more saline waters of the estuary or migrating frequently throughout the salinity gradient contained lower PCB levels composed of more highly chlorinated congeners. The approach used in this study allows habitat use to be incorporated into exposure assessments for anadromous fish species such as striped bass.