Federal fisheries experts are painting a devastating picture of the challenges facing Pacific salmon and point to climate change as the main culprit.

A new report from Fisheries and Oceans Canada found warming ocean temperatures and marine heat waves are affecting ocean food webs and causing declining salmon stocks. Fisheries staff say factors such as human activity that degrades fish habitat and a landslide on the Fraser River blocking millions of fish from spawning upstream are making things worse.

Andrew Thompson, regional director for fisheries management, says it’s been an extremely challenging year for salmon and there have been significant declines in a number of stocks.

In one of the most dramatic shifts, the federal Department of Fisheries has…