A Meta-analysis of Mercury Levels in Lavaca Bay Texas

Abstract

Lavaca Bay is a secondary bay to Matagorda Bay on the central Texas Coast. In 1970 Texas Department of Health (TDH) closed parts of Lavaca Bay to the harvesting of oysters due to mercury contamination as a result of contaminated wastewater discharged into the bay by a chlor-alkali plant operated by Alcoa. In 1988 TDH closed the area around Dredge Island which is adjacent to the chlor-alkali plant to the taking of finfish and crabs due to elevated mercury levels. In 1994 it was proposed that the area around Dredge Island and area around the chlor-alkali plant were placed on the National Priorities List (NPL). In December of 2001 the Record of Decision (ROD) was signed to initiate the remediation process.

The purpose of this study is to use a meta-analysis to determine if the mercury levels in secondary and tertiary trophic levels have changed between years 1992 and 2012, and if the levels in red drum (Sciaenops ocellatus) and oysters (Crassostrea virginica) have decreased over time. The meta-analysis used biota and sediment collected and analyzed for total mercury in 2012, historical data from Texas Department of Health (TDH), U.S. Environmental Protection Agency (EPA), and Woodward-Clyde (1992).