There is currently have a very poor understanding of how climate change will affect food web structure and mercury accumulation in lakes on the Arctic Coastal Plain of Alaska. In this study, researchers are addressing this knowledge gap by adopting a space-for-time approach. Fish and food web ecology, and mercury accumulation patterns, are being investigated in several lakes that represent a gradient in temperature/ice phenology of up to two ice-free weeks and 10°C. They are also comparing food web structure and rates of mercury biomagnification among the lakes, and relating these to several climate variables. Finally, they are relating past trends in mercury accumulation in lake sediments to indices of lake productivity using paleolimnological techniques applied to sediment cores.