AbstractsBiology & Animal Science

Certain populations of young-of-the-year (YOY) bluefish, Pomatomus saltatrix, reside in contaminated estuaries of the mid-Atlantic bight during periods of rapid growth and development. YOY bluefish from the Tuckerton, NJ area of Great Bay (TK) were fed daily in a laboratory with common prey fish, menhaden and mummichog, from two sites: TK (reference) or Hackensack River (HR) (contaminated). Bluefish were also collected from the HR and TK site for analysis. HR-fed and field-caught bluefish and HR prey fish and stomach contents contained significantly elevated concentrations of PCBs, DDTs, and mercury. HR bluefish had reduced growth, feeding, and activity. tPCB and tDDT concentrations in prey in the stomachs of HR bluefish were higher than those in the field-caught specimens. Prey with higher body burdens may become slower and easier to capture. If bluefish are preferentially foraging on such prey, greater amounts of contaminants can be trophically transferred. PCB congeners accumulated at different concentrations creating PCB fingerprints which correlated with feeding ecology of the fish. PCB fingerprints in the HR-fed bluefish were nearly identical to each other and closest to that of the mummichog, their sole prey during the last month of the feeding experiment. PCB fingerprints of field-caught bluefish were similar to menhaden, the dominant prey in HR field bluefish stomachs. In contaminated marine systems PCB fingerprints can be utilized to establish trophic levels and possibly prey preference in individual fish. In addition to altered behavior and growth, the HR-fed and field bluefish had significantly enlarged, irregular thyroid follicles, lined with thickened epithelial cells compared to the TK fish. The mean concentration of dopamine metabolites and the dopaminergic activity levels were significantly lower in HR field fish than in TK field. In contrast the mean concentrations of dopamine and serotonin and their metabolites and norepinephrine were significantly greater in the HR-fed bluefish compared the TK-fed. Overall the exposed fish displayed neurological and hormonal disruptions that may be responsible for their altered behavior and growth. In conclusion, the altered growth, feeding, activity and physiology of YOY bluefish exposed to these contaminated regimes may have detrimental effects on migration fitness and recruitment success. Includes abstract