Long-term variation in mercury concentrations in estuarine organisms with changes in releases into Lavaca Bay, Texas

• Published in: Marine pollution bulletin Vol. 44; no. 8; pp. 807 - 815
• Main Author: Sager, David R
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-08-2002; Elsevier
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Decapoda; Decapoda (Crustacea); Ecotoxicology, biological effects of pollution; Environmental Monitoring; Estuarine food web; Fishes; Food Chain; Food Contamination; Fundamental and applied biological sciences. Psychology; Geologic Sediments - chemistry; Lavaca Bay; Marine and brackish environment; Mercury; Mercury - analysis; Mercury - pharmacokinetics; Monitoring; Public Health; Remediation; Sediment; Texas; USA, Texas, Lavaca Bay; United States; North America; Texas; America; USA, Texas; ASW, USA, Texas, Lavaca Bay; Lavaca Bay; Estuarine food web; Sediment; Remediation; Mercury; Monitoring; Brackish water environment; Interspecific comparison; Estuaries; Sciaenops ocellatus; Long term variation; Biological monitoring; Heavy metal; Vertebrata; Food web; Bivalvia; Crassostrea virginica; Pisces; Water pollution; Bay; Invertebrata; Mollusca; Biological accumulation; Concentration distribution
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/S0025-326X(02)00064-4

Mercury releases into Lavaca Bay resulted in public health notices and a fishing closure for crabs and finfish. Mercury containing wastewater discharges were halted in 1970, but sediments were contaminated with mercury. The sediments are a source of mercury to the benthic food web via methylation. Mercury in water column feeding organisms has decreased markedly. Concentrations in benthic food web organisms remain elevated. Human consumption concerns for oysters have ended, but a closure for fishing for crabs and finfish continues. Monitoring of mercury in organisms since 1977 shows a gradual downward trend in mercury in crabs and finfish, but this was not sufficient to remove the closure. Continued releases of mercury, man's activities, and resuspension of sediments keep mercury in the sediment's biologically active zone. This enables the uptake of mercury via the benthic food web. If releases are ended, it will take years for the mercury to decrease to concentrations not of concern for human consumption. If more remediation to reduce the mercury concentrations in the sediments takes place, decrease of mercury in the organisms might occur more quickly.