Environmental and biological factors are joint drivers of mercury biomagnification in subarctic lake food webs along a climate and productivity gradient

Subarctic lakes are getting warmer and more productive due to the joint effects of climate change intensive land-use practices (e.g. forest clear-cutting peatland ditching), processes that potentially increase leaching peat- soil-stored mercury into lake ecosystems. We sampled biotic communities from primary producers (algae) top consumers (piscivorous fish), in 19 subarctic situated on a latitudinal (69.0–66.5° N), climatic (+3.2 °C temperature +30% precipitation north south) catchment (pristine forestry areas) gradient. first tested how productivity influence biomagnification food webs focusing trophic magnification slope (TMS) baseline (THg baseline) level, both derived linear regression between total (log10THg) organism level (TL). examined suite environmental variables thought explain THg TMS with stepwise generalized multiple models. Finally, we assessed affect content predators lakes. found all studied lakes, but variable values. In models, was best explained by negative relationships chain length, climate-productivity gradient, properties, elemental C:N ratio predator (full model R2 = 0.90, p < 0.001). The examining variation values included same positive (R2 0.69, 0.014). Mass-standardized common (1 kg northern pike, Esox lucius) increased towards Results indicate increasing eutrophication via forestry-related activities levels at base web predators, suggesting sources nutrients should be considered future bioaccumulation studies.