Trace metal chemistry of Galveston Bay: Water, sediments and biota

Galveston Bay is the second largest estuary in Texas. It receives major ruban runoff from the Houston area, its major river drains the Dallas-Ft Worth Metroplex, and the area surrounding the Bay is intensely industrialized, with chemical and petroleum production being especially prominent. Consequently, there are serious concerns about the possible contamination of the Bay and previous studies have indicated toxic metals at elevated concentrations.An extensive investigation of the content of trace metals in Galveston Bay was conducted. Results of the water column and oyster analyses indicate that metal levels in open areas of Galveston Bay are currently similar to those in more pristine bays. Total Cu, Zn, Pb and Ag concentrations in the waters are 1,2-7,0-3 and 0-006 ug literEE-1 respectively, and are most regulated by the dynamics of sediment suspension and settling. Forty-four percent of the individual sediment sampling sites exhibited and 'anomalous' concentration with respect to at least one of the metals studied and about half of these sites were directly associated with dredge spoils. The study also indicated that many of the metals are signigicantly converted to a coprecipitate with pyrite in the top 10cm of sediment.