Variations in trace metal concentrations in American oysters (Crassostrea virginica) collected from Galveston Bay, Texas
During 1992-93, various metals were found in the soft part of particular oysters, including iron, copper, and zinc. Variations in metal concentrations were found when different sites were compared and when different sampling times within a site were compared. High concentrations of zinc were found on the west side of Galveston Bay, while one site in lower Galveston Bay had higher concentrations of multiple metals. All metals concentrations, except arsenic, were highest in the summer and lowest in the winter. These changes may have been caused by environmental fluctuations or by biological activity.