Mercury Bioaccumulation in Everglades Pythons

Hart, K.; Krabbenhoft, D.; Snow, S.

Brief Description: Poster presented on USGS preliminary research results findings of high mercury levels in Burmese pythons. Full Description: The USGS and NPS are collaborating on an examination of mercury bioaccumulation in pythons captured in Everglades National Park. Interest in understanding the levels of mercury in pythons from the Everglades is two-fold: (1) an examination of the literature revealed no published papers with any information regarding mercury body burdens in pythons; and, (2) one possible population-control strategy for the pythons is allowing hunting, thus concerns exist for safe levels of mercury exposure to those who may consume python tissue. In the summer of 2009, the USGS Mercury Research Laboratory analyzed 24 python tail-tissue samples for their total mercury and methylmercury content. Samples included 13 females and 11 males, with a mean total length (TL) of 265.3 cm (range 168.5-471.0 cm, SD 64.6). The mean observed levels of mercury was 5.5 ppm (micrograms per gram, dry weight; range 0.2-17.4 ppm, SD 4.7). The results for methylmercury, which is the more toxic and bioaccumulative form of mercury, showed that on average 79% of the total mercury body burden in the pythons was in the methylated form. In addition, an initial examination of this data set revealed no apparent spatial trends, or any associations with sex, size, or location, perhaps because of the as yet small sample size. Currently the NPS and USGS are collaborating on a follow up effort to examine the mercury and methylmercury content of an additional 100 specimens. With this added information, we hope to better understand the high mercury bioaccumulation levels of pythons, so resource managers can better inform the public about potentially unsafe exposure levels from consuming python tissue.

Mercury Bioaccumulation in Everglades Pythons

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