Heavy metals in the eastern oyster,Crassostrea virginica, of the Mississippi sound

Abstract

Levels of metals in oysters in the Sound are of profound interest not only because they document those geographic areas where metal pollution levels may be problematic but because they may disclose possible problems to consumers of oysters. At the present time objective federal standards for heavy metals in oysters and other seafood are restricted to mercury. The closure of Mississippi oyster reefs has been predicated upon bacteriological standards with little if any attention paid to heavy metals. A study of fourteen metals in oysters of the Sound was began in 1988 with objectives differing from that of the Status and Trends Program (STP) in three ways. STP levels are reported on dry weight basis of composites from three sites. In the present study, oysters were analyzed and reported on wet weight basis. Additionally analyses were made of individual specimens to indicate expected specimen to specimen variations and were conducted on oysters from the three STP and two other important oyster reef sites. In the future three or more additional sites will be added to this continuing survey effort. Metals chosen for this study were lead (Pb), cadmium (Cd), iron (Fe), copper (Cu), cobalt (Co), manganese (Mn), zinc (Zn), silvermore » (Ag), nickel (Ni), mercury (Hg), aluminum (Al), chromium (Cr), molybdenum (Mo), and vanadium (V).« less