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Once widely used as a dielectric or coolant, polychlorinated biphenyls (PCBs) are now known as one of the most pervasive persistent organic pollutants to contaminate our aquatic environment, particularly in coastal regions where a majority of chemical plants were located. Although PCBs were banned domestically in 1979 and internationally in 2001, high PCB levels in top predators and adverse effects on reproduction are still observed today, emphasizing the need to identify the mechanisms by which PCBs continue to accumulate in coastal food webs. To advance knowledge and inform coastal management, we test how life stage, trophic position, and prey network structure of a high profile coastal predator, red drum (Sciaenops ocellatus) influences PCB accumulation. Preliminary results demonstrate a strong linear relationship between size and total PCB concentration, and variances in total concentration levels among males within the mature size class. Homolog and congener profiles differed among the ontogenetic classes as well. After analyzing stable isotope, gut content, and age (otolith) data, this study will reveal how red drum trophic level (δ15N), prey network structure, and relative PCB concentration shift as individuals mature, and whether or not the strongest trophic links are key pathways for PCB accumulation. Results will inform management strategies by identifying the life stage at which red drum accumulate PCBs the fastest, the prey species that are essential to PCB accumulation, and indicate population and ecosystem health of red drum that inhabit Altamaha fed estuaries along the Georgia coast. |
