TP2 Wildlife Toxicology
Ballroom F, Level 4
2:10 PM - 5:30 PM, Tuesday, 11 November 2003
Chair: McMurry, Scott ,
(260) Mercury Concentration in Kemp′s Ridley Sea Turtles from the Gulf of Mexico and South Atlantic.
WANG, H.-C.1, LANDRY, A.1, KENYON, F.2, GILL, G.2, KENYON, L.2, PRESTI, S.3, SHAVER-MILLER, D.4, 1 TEXAS A&M UNIVERSITY, COLLEGE STATION, TEXAS, USA2 TEXAS A&M UNIVERSITY AT GALVESTON, GALVESTON, TEXAS, USA3 ANIMAL MEDICAL CLINIC, SARASOTA, FLORIDA, USA4 U.S. GEOLOGICAL SURVEY, CORPUS CHRISTI, TEXAS, USA
ABSTRACT- Marine pollution is a possible cause for mortality in the critically endangered Kemp′s ridley sea turtle (Lepidochelys kempii). The unknown relationship between sea turtle health and the contaminant environment mandates determining the role chemical pollutants play in sea turtle survival and recovery. Research described herein compares mercury concentration in the blood and carapace tissue of live Kemp′s ridleys captured along the Texas and Louisiana coasts, home to the US′ largest petrochemical industry, during 1997 and 2000 to 2002. These concentrations are contrasted with those from ridleys captured in South Carolina waters and on the Rancho Nuevo, Mexico nesting beach to detect regional and size related differences in mercury uptake. Overall, mercury concentrations (n = 181) in ridleys from Texas and Louisiana were always higher in carapace tissue (mean = 1279.2 ppb) than in blood (mean = 24.9 ppb), regardless of capture site. Peak concentrations were detected in carapace tissue of nesting females from Mexico, followed by those in juveniles from Texas/Louisiana and subadults from South Carolina, respectively. The positive correlation (p < 0.05) between mercury concentration and increasing size of turtle supports the hypothesis that carapace tissue represents an effective, non-invasive indicator of mercury uptake and bioaccumulation in ridleys. Mercury concentrations in ridleys from Texas (mean = 1606.6 ppb) and Louisiana (mean = 1132.4 ppb) well exceeded those in conspecifics from South Carolina (mean = 721.1 ppb), regardless of turtle size. Ridleys captured near a mercury-contaminated Superfund site in Lavaca Bay, Texas yielded the highest mercury concentrations (mean = 1958.9 ppb) recorded for counterparts from the industrialized upper Texas and Louisiana coasts. Dead ridleys stranding along the Texas coast yielded higher mercury concentrations (mean = 1182.4 ppb) than did carcasses of loggerhead (mean = 240.3 ppb) and green sea turtles (mean = 529.7 ppb).
Key words: Kemp′s ridley sea turtle, mercury, blood, carapace tissue