The effects of winter cold on acute and chronic cadmium bioaccumulation and toxicity in the banded killifish (Fundulus diaphanus)
University of New Brunswick
Metals such as cadmium (Cd) are important contaminants in fish. Fish experience seasonal temperature fluctuations that can potentially affect their exposure and sensitivity to metals. However, temperature effects are overlooked in ecotoxicology studies, especially for cold temperatures. I investigated the effects of cold on Cd bioaccumulation and toxicity in a freshwater fish, the banded killifish (Fundulus diaphanus). Killifish were gradually acclimated to either 4°C or 14°C over an 11-week period, then exposed to 0, 0.5 or 5 µg Cd L-1 for 28 d at both temperatures. At day 2, 5 and 28, I measured Cd bioaccumulation and markers of oxidative and ionoregulation stress. Cadmium accumulation increased over time, and was typically lower in cold acclimated fish. In agreement with the higher Cd bioaccumulation, Cd toxicity was generally higher in warm-acclimated fish. There was little evidence that cold and warm acclimated fish displayed differences in their sensitivity to Cd. Overall, our study suggests that cold does not exacerbate the effects of Cd on banded killifish.