Methylmercury Concentrations More Strongly Associated With Trait Variation Than Food Web Position in Plethodontid Salamanders.

This article focuses on investigating the drivers of methylmercury (MeHg) exposure in three plethodontid salamander species across two ecoregions of New York State, USA: the Adirondack Mountains (ADK) and the Finger Lakes National Forest (FLNF). The study found that MeHg concentrations varied by species, habitat type (semiaquatic vs. terrestrial), and salamander color morph, with semiaquatic salamanders exhibiting higher MeHg levels than terrestrial ones in the FLNF but not in the ADK. Contrary to expectations, trophic position and diet proxies (δ15N and δ13C stable isotopes) did not predict MeHg exposure, while snout–vent length was a significant predictor for one semiaquatic species (Eurycea bislineata), and the striped morph of the terrestrial Plethodon cinereus had higher MeHg concentrations than the unstriped morph. Overall, salamander MeHg concentrations in New York were elevated compared to other regions, and similar between the ADK, a known Hg hotspot, and the FLNF, suggesting the need for further mercury research in these forested ecosystems.