
ACS ES&T Water, Год журнала: 2025, Номер unknown
Опубликована: Апрель 10, 2025
Increased lake eutrophication, influenced by changing climate and land use, alters aquatic cycling bioaccumulation of mercury (Hg). Additionally, seasonally dynamic circulation plankton community composition can confound our ability to predict changes in biological Hg concentrations sources. To assess temporal variation, we examined seasonal total (THg) methylmercury (MeHg) stable isotope values seston, waters, sediments, fish from two adjacent urban eutrophic lakes Madison, Wisconsin. In Lake Monona, surface sediment THg were elevated due comparably higher urbanization historical industrial inputs, whereas Mendota sediments had lower corresponding with largely agricultural suburban surrounding watershed. Surface water MeHg similar between dynamic, but profiles exhibited the meta- hypolimnia, highlighting column production. Seston often highest at shoulder seasons, possibly owing metalimnetic delivery, also differences biomass clarity. The Δ199Hg δ202Hg seston lakes, despite differing values, suggesting a shared bioaccumulated source MeHg. Measurement isotopes further elucidated that predominantly pelagic-sourced
Язык: Английский