Due to widespread atmospheric deposition of mercury (Hg), all aquatic food chains are contaminated with toxic methylmercury (MeHg). High concentrations of MeHg are harmful to wildlife and human health. Spiders (hereafter referred to as Riverbank spider) have been proposed as monitors of methylmercury contamination in aquatic systems. Riparian spiders are exposed to methylmercury through their diet, and spider methylmercury concentrations are positively correlated with the proportion of methylmercury-contaminated aquatic insects in their diet. The use of spiders as monitors is complex, as methylmercury concentrations can vary not only between ecosystems, but also between different spider taxa and depending on spider body size. The aim of this study was to investigate how ecosystem contamination levels, spider taxa, and spider body size affect methylmercury concentrations in four riparian spider genera from two rivers with different mercury contamination levels. We investigated the methylmercury concentrations of four riparian spider genera (Tetragnatha , Larinioides , Pardossa and Ravi Dosa The research team collected spiders (M. sp.) from two locations along the Trinity River Clear Fork and Trinity River West Fork (Fort Worth, Texas, USA) and analyzed the methylmercury concentrations of spiders of each genus with different body sizes. The results showed that methylmercury contamination of the river ecosystem, spider taxonomy, and spider body size were important determinants of methylmercury concentrations in riparian spiders. The results suggest that any of the four riparian spider taxa obtained in this study can be used as monitors of methylmercury contamination in water, but they should not be used interchangeably because the effects of ecosystem contamination level, spider taxonomy, and body size are interdependent. Future studies using riparian spiders as monitors of bioaccumulative aquatic pollutants (e.g., methylmercury, polychlorinated biphenyls) should consider the potentially complex interactive effects of ecosystem contamination level, spider taxonomy, and spider body size. Environmental Toxicology 2024;00:1–7. © 2024 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals LLC on behalf of SETAC.
Todd, AC, Chumchal, MM, Drenner, RW, Allender, CW, Barst, BD, Capone, MT, Degges, AP, Hannappel, MP, Perry, CR, Peterson, RA, Martinez, TL, Schmeder, IE, Williams, TT, & Willingham, MG The influence of taxon and body size on mercury concentrations in spiders from two streams differing in levels of mercury contamination: implications for the use of riparian spiders as sentinels. Environmental Toxicology and Chemistry. https://doi.org/10.1002/etc.5968
