Evaluation of two different biomarkers for use in the assessment of toxic chemical exposure in California sea lions (Zalophus californianus)

摘要

Industrial pollution is a significant environmental problem that has the potential to cause serious health consequences in humans and wildlife. In 1998, over 248 million pounds of toxic chemicals were reportedly released into the surface water of rivers, bays and the oceans (US EPA Toxic Release Inventory (tri), 1998) Examples of these toxicants, according to the TRL, include trichloroethylene, benzene, 1,3-butadiene, glycol ethers, polychlorinated biphenyls (PCBs), polycydic aromatic hydrocarbons (PAHs), and mercury. Once toxicants enter the aquatic environment, they can accumulate in the benthic sediments, be distributed throughout the water column, be incorporated by organisms, and then bioaccumulate up the food chain. The benthic sediments often act as an almost limitless reservoir for environmental contaminants and continually change in response to both abiotic and bio-tic conditions (Malins and Ostrander, 1991). The sea-surface microlayer, the upper 50 μm of the water column, is an area of particular concern for some species, as some contaminant concentrations, such as aromatic hydrocarbons, are 10-1000 times higher in this layer than in the water column below (Hardy, 1982; Hardy et al., 1985).