Concern is growing over the this year's sockeye salmon run on Canada's Fraser River, one of the largest sockeye runs in the world.

Canada's federal government is struggling to find a solution for a rockslide that is blocking the Fraser River near Lillooet in British Columbia.

"This has the potential to be the worst environmental disaster in British Columbia's history,” said Peter McCartney, a spokesperson for the NGO Wilderness Committee, according to report by CTV News in Vancouver.

There are an estimated 90,000 salmon trapped behind the rockslide, unable to reach spawning grounds upriver, but the peak of the Fraser sockeye run, as many as a couple million fish, is expected over the next week or so.

The slide was reported in June, but is believed to have happened months before. So far officials have been able to move just 14,000 fish over the rockslide, largely by carrying them over what has effectively become a dam on the river.