Decades of logging activities near rivers in B.C.'s Interior are driving up the temperatures of coho salmon habitats and threatening the species' survival, according to a new study. The study by Simon Fraser University and Fisheries and Oceans Canada (DFO), published last month in the Canadian Journal of Fisheries and Aquatic Sciences, looked into 28 tributaries of the North Thompson River watershed from Kamloops to Valemount.