Mercury Concentrations in Invasive Burmese Pythons ( Python bivitattus ) of Southwest Florida

We determined mercury (Hg) concentrations in various tissues of Burmese pythons ( Python bivitattus ; n = 227) caught in southwest Florida from 2012–2018 as part of a program to control this invasive species. Mercury ranged as high as 4.86 mg/kg in liver tissue from a snake that was 4.7 m long but overall averaged 0.12 ± 0.19 mg/kg in tail tips (n = 123). These levels were relatively low as compared to concentrations reported in pythons from Everglades National Park, a recognized Hg hotspot. These results show that snakes, particularly watersnakes, present another opportunity to biomonitor Hg at the aquatic-terrestrial interface. Although capturing snakes presents obvious challenges, which differ from sampling other taxa typically used in monitoring programs, taking advantage of this program to control an invasive species was cost effective and alleviated concerns about sampling and possibly reducing native snake populations.