Biopsy punches as a cost effective and efficient tool to monitor mercury in fish muscle

Poster-Academic
Poster Presentation

Prepared by H. Gerrish1, A. Cyr2, M. Castellini3, J. López4, T. O'Hara5
1 - University of Alaska Fairbanks, Biology and Wildlife, 1667 Meribel Road, Fairbanks, AK, 99709, United States
2 - College of Fisheries and Ocean Sciences, 905 North Koyukuk Drive, 245 O'Niell, Fairbanks, AK, 99775-7220, United States
3 - Wildlife Toxicology Lab, Department of Veterinary Medicine, University of Alaska Fairbanks, 901 Koyukuk Drive, 182 Arctic Health Research Building, Fairbanks, AK, 99709, United States
4 - University of Alaska Museum, Univeristy of Alaska Fairbanks College of Fisheries and Ocean Sciences, University of Alaska Museum, 907 Yukon Drive, Fairbanks, AK, 99775, United States
5 - Univeristy of Alaska Department of Veterinary Medicine, 901 Koyukuk Drive, 182 Arctic Health Research Building, Fairbanks, AK, 99709, United States


Contact Information: hngerrish@alaska.edu; (907)9781126


ABSTRACT

Mercury (Hg) is a toxic ubiquitous element that bioaccumulates and biomagnifies in fish. Fish are a significant food source for much of the world and form the main diet of many marine and freshwater species. Monitoring Hg content of fish to establish and maintain health and consumption guidelines is essential for food safety. Most Hg monitoring and analysis techniques in fish are labor intensive, lethal, and require many steps. Biopsy punches may offer a more efficient alternative for Hg analysis. This method would allow comparatively quick, easy, efficient, and cost effective monitoring of mercury, and put sample acquisition in the hands of sport fishermen, commercial fishing companies, resource managers, subsistence users, and researchers, including catch and release. Here we report the relative accuracy of biopsy punches when compared to currently established methods (full thickness muscle fillet). Muscle samples were taken from 127 fish from 6 species, freeze-dried, homogenized, and analyzed on a Milestone ® DMA-80 mercury analyzer (thermal decomposition, Hg amalgamation and atomic absorption detection). Values were then compared with those from a 6mm biopsy punch taken from the same area of each fish and subsequently analyzed wet, without processing, on the DMA-80. Mercury concentrations measured in biopsy punches and full muscle samples were strongly correlated (slope = 1.12, r2 = 0.95), demonstrating that the biopsy punch could be an accurate tool to replace full muscle sampling. Several caveats were identified with the need for optimization of the DMA-80 analytical method, issues that could be solved with further research. Additional questions have arisen, notably can this technique be applied in a non-lethal manner for live capture and release of fish for monitoring purposes. Such possibilities are promising and would allow Hg monitoring to be more accessible to members of the community and provide opportunities for easier outreach, education, and communication.