Spatial and temporal trends in physiological biomarkers of adult eastern oysters, Crassostrea virginica, within an urban estuary.

Heavy metal contamination and water quality may alter reproductive capacity of oysters in highly urbanized, eutrophic ecosystems. This study assessed physiological biomarkers and heavy metal body burdens in adult oysters, Crassostrea virginica, placed at a highly urban and reference site. Condition index and Vitellogenin-like proteins were significantly different between sites, but protein concentration and activity of the electron transport system were not. Accumulation of Cd and Hg occurred at both sites, and Cd body burden was greater at the urban site. There was a negative relationship between condition index and Cd body burden at the urban site, while no relationship was found between physiological biomarkers and metal burden at the reference site. The results suggest that oyster condition and reproductive potential may be negatively influenced by the biotic and abiotic factors typically found within urban, eutrophic ecosystems. • Urban estuaries offer unique environmental parameters due to anthropogenic inputs and alterations to physical habitat. • Use of biomarkers to assess reproductive capacity by quantifying Vtg protein is a novel technique for oyster restoration. • Oysters are able to accumulate Cd, and to a lesser degree Hg, as adults at urbanized estuarine sites. • Anthropogenic stressors are site-specific and therefore oyster reproduction and physiology are also site-specific. [ABSTRACT FROM AUTHOR]