PW18 Field Biological Monitoring of Ecosystem Impairment
Exhibit Hall
8:00 AM - Wednesday
(PW275) Contaminant residues in blue crabs and oysters from the Pensacola Bay region.
Karouna-Renier, N1, Snyder, R1, Allison, J1, Wagner, M1, Rao, K1, 1 University of West Florida, Pensacola, FL, USA
ABSTRACT- As part of an environmental health study of northwest Florida, we conducted an initial screening level assessment of contaminants in blue crabs (Callinectes sapidus; hepatopancreas and remaining edible tissues) and oysters (Crassostrea virginica) collected in bays and bayous in the Pensacola, FL area. Tissue samples were analyzed for mercury, arsenic (total), cadmium, chromium, copper, lead, nickel, selenium, tin, zinc, 17 dioxin/furan compounds, and 12 dioxin-like PCB congeners. Contaminant levels were compared to Screening Values (SV) promulgated by the U.S. EPA in 2000 for establishing consumption advisories. The majority of samples fell below the respective detection limits for chromium, nickel, lead, and tin. Selenium levels in all samples were below EPA SV for subsistence fishers (2.457 ppm). Copper concentrations in oysters collected from an industrial waterway (Bayou Chico) were roughly four times those found in the remaining samples. Zinc concentrations were within ranges reported in other studies. An estimation of inorganic arsenic levels (2% of total) suggested that samples collected throughout the region may exceed the SV for recreational fishers (0.0256 ppm). However, no specific geographic pattern was evident. All crab tissue, 17 of 20 hepatopancreas, and 9 of 29 oyster samples exceeded the mercury SV for subsistence fishers (0.049 ppm). In oysters, mercury concentrations were highest in samples collected from bridge pilings and lowest in commercial oyster beds. No geographic pattern was observed for crabs. The combined PCB/dioxin WHO-98 TEQs exceeded the SV for recreational fishers (0.256 ppt) in 12 of 20 crab tissue, all hepatopancreas, and 14 of 22 oyster samples (using non-detects=0). Nearly all of the oyster samples collected from commercial beds were below the SV. In general, the highest TEQs for all sample types occurred in western Escambia Bay, bayous within the city, and northern Pensacola Bay. (Supported by Grant RO4/CCR421909-01 from CDC).
Key words: dioxin, shellfish, PCB, metals