Grizzly bear advocates say a significant number of the animals have died off in B.C., likely due to declining salmon stocks.

They are calling for a ban on salmon fishing in central and northern B.C., as well as the cancellation of the annual trophy hunt that starts Thursday.

Ian McAllister, of the B.C.-based wildlife conservation group Pacific Wild says overfishing along B.C.'s North Coast has worsened.

"The Gill Island fishery should have ensured that more salmon passed through to spawning grounds. Instead over six million pink salmon were intercepted by nets, in addition to tens of thousands of sockeye, chum and coho during the last openings," he said in a press release. "The few bears surviving this past winter really needed those fish."

But one grizzly expert says claims that the grizzly population is in danger of collapse are alarmist.

Sterling Miller, a senior biologist at the U.S. National Wildlife Federation, served on B.C.'s grizzly bear scientific panel a few years ago and studied salmon-eating grizzlies in Alaska for 21 years.

Miller says grizzlies are good at seeking alternate food sources, and doubts claims that adult grizzlies have died in their dens.

Miller says it's possible fewer fish may lead to fewer grizzly cubs being born but it will take years to see the impact of current low salmon runs.

With files from The Canadian Press