| Summary: | Many anthropogenic activities negatively affect the environment and stress the organisms living here in various ways. Due to global warming it is likely that freeze-thaw events will replace permanent freezing of soils in arctic regions. Metals are some of the most common contaminants in soil in Europe, and recent interest in increasing mineral deposit mining activity in arctic regions further emphasizes the need for focus on the environmental impact in these areas. In the present study it was investigated how the combination of freeze-thaw events and copper contamination of soil affected the Icelandic, freeze tolerant annelid worm, Enchytraeus albidus . Worms were exposed to one of three temperature treatments (constant +1.5⁰C, constant -6⁰C, or daily cycles between +1.5 and -6⁰C) in combination with one of several different copper (CuCl 2 ) concentrations in soil. The results showed a distinct synergy between freeze-thaw cycles and copper stress, leading to an elevated mortality of enchytraeids subjected to these conditions. Enchytraeids subjected to conditions of constant freezing and copper stress were not as severely affected. To examine this synergy an array of analyses were conducted. Glucose and glycogen content in the worms were measured to assess the degree of cryoprotectant accumulation. It was hypothesized that cryoprotective glucose will have formed in worms exposed to constant freezing of -6⁰C, while the formation may be inhibited in worms exposed to freeze-thaw cycles. Bioaccumulation of copper was also quantified to expose any increase in body burden in freeze-thaw treated worms. Regardless of the physiological responses, it is evident that arctic organisms are negatively affected by the environmental impact of global warming and exploitation of mineral deposits through mining.
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