Summary: | As Canada’s oil sands industry expands, the volume of diluted bitumen (dilbit) transported across North America increases, as does the risk of environmental contamination. This study examined the effects of dilbit exposure on swimming performance (Ucrit) and subcellular responses in Atlantic salmon cardiac and skeletal muscle. Ucrit was unaffected in fish exposed to the highest dilbit concentration, but the heart decreased reliance on lipids for energy production. Whereas, fish exposed to the lowest dilbit concentration increased Ucrit and their reliance on anaerobic metabolism in cardiac and red skeletal muscle. Both dilbit concentrations activated Phase I biotransformation in liver and muscle tissues, and upregulated stress-related genes in white muscle. Lastly, oxidative stress genes were downregulated in dilbit-exposed Atlantic salmon hearts but upregulated in sockeye hearts exposed similarly to dilbit. Results demonstrate that dilbit exposure causes subcellular tissue responses in Atlantic salmon, which are unique compared to sockeye, without impairing swimming performance. Fisheries and Oceans Canada 2020-11-12
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