Physiological and Genetic Aspects of Toxicity in Hudson River Species

Isaac Wirgin, Judith S. Weis, and Anne E. McElroy abstract The Hudson River Estuary has been polluted for many decades with organic contaminants including PCBs, dioxins/furans, PAHs, pesticides, and a variety of toxic metals, including cadmium and mercury. Most of these toxicants are poorly metabolized, highly persistent, bioaccumulative, and bio-magnify in Hudson River populations, sometimes to record high levels. Many surveys have quantified tissue levels of these contaminants in resource species, but despite public concern and a need to evaluate toxicities for regulatory actions, few studies have directly addressed their biological impacts on Hudson River populations. With several notable exceptions, toxicant-induced perturbations are not frequently observed in Hudson River populations, even those for which high levels of exposure have been documented. This may have resulted from the ability of populations to acquire resistance to high levels of contaminants, either through genetic adaptations or compensatory physiological acclimation responses. While offering short-term benefits to impacted populations, resistance maybe associated with evolutionary costs to populations and may compromise the viability of affected communities. Ideally, in the future, contaminant studies should focus on those species for which toxic alterations have been observed which may impact population viability, their levels of contamination should be quantified, and controlled laboratory experiments should be conducted to confirm that the contaminants of concern are able to induce these toxic manifestations in the affected taxon.

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