COS 32-9 - Assessing mercury concentrations in New Jersey'€™s diamondback terrapins (Malaclemys terrapin)

Tuesday, August 9, 2016: 4:20 PM
207/208, Ft Lauderdale Convention Center
Natalie R. Sherwood, Biology and Molecular Biology, Montclair State University, Montclair, NJ and Meiyin Wu, Passaic River Institute, Montclair State University, Montclair, NJ
Background/Question/Methods

Mercury contamination in consumed foods poses a significant threat to human health globally. The consumption of mercury contaminated turtle meat is of special concern due to mercury’s capability to bioaccumulate and biomagnify. Turtles are long lived animals allowing for great concentration of bioaccumulation. They are also top predators allowing for mercury biomagnifications. Diamondback terrapins (Malaclemys terrapin) are one of the two species legally harvested in the state of New Jersey. Harvested turtles are usually sold to both local and global markets. We suspect that these turtles might have a high mercury concentration and are unknowingly being served at dinner tables around the world. This study aims to assess human consumption safety of diamondback terrapins. Twelve female and eight male turtles were collected from the Cape May area and nine males and four females were also collected from the Meadowlands area. Samples were collected from turtle carapace (n=37), blood (n=24), and front leg muscle (n=33). Mercury concentrations of collected samples were measured using Bacharach Coleman Cold Vapor AA Hg Analyzer.

 Results/Conclusions

The highest mean mercury concentrations were found in carapace with a concentration of 1.63ppm while blood had the lowest mean concentration of 0.30ppm. For the importance of human consumption safety mercury in muscle tissue was tested. Muscle mercury concentration ranged from 0.037 to 1.408ppm with a mean of 0.32ppm. Terrapin’s mercury concentration did not vary significantly between terrapins from the different study sites. 41% of all muscle samples surpassed the U.S. EPA fish mercury threshold of 0.3ppm. The result of this study suggests that on average, diamondback terrapins can pose a threat to human consumption safety. Although not statistically significant females at both study sites had higher mercury concentrations than males. This was to be expected since this species exhibit sexual dimorphism with female being larger than males. Mercury concentrations were analyzed for correlations with carapace length. Results showed female carapace length and muscle mercury concentrations were significantly correlated with a 90% confidence (p=0.0960).  Carapace length might represent a non-intrusive method for estimating mercury concentrations.