Time is critical to find a solution to a massive obstruction in British Columbia's Fraser River as 90,000 salmon wait downstream and an estimated two million more sockeye are about to arrive, federal Fisheries Minister Jonathan Wilkinson said Tuesday.

The minister said dozens of people are working against the clock looking for ways to clear a path that allows salmon to get through the area where a massive rockslide came down in the river northwest of Kamloops.

The slide was discovered in June and has created a five-metre waterfall nearly impassable for the salmon.

"We don't have a lot of time," Wilkinson said during a news conference.

"A number of the chinook runs are already circling and waiting to get up. The sockeye run, which is perhaps two million, will start to arrive within a couple weeks. So, we expect somewhere between 3,000 and 6,000 fish per day arriving below the rock slide."

He said rock scalers, engineers and blasters are trying to find a solution to the natural disaster.

"It is imperative we do whatever we can to enable as many fish as possible to pass through the slide to secure sustainability of these runs, and obviously the communities who rely on these stocks," Wilkinson said.

"This is obviously a very challenging situation, one that could have long-term consequences for the communities on the river and far beyond."

Fish ladder constructed

He said the salmon, including dwindling chinook stocks and valuable sockeye, use the river to get to spawning areas in tributaries throughout central and northern B.C.

The salmon are vital to B.C.'s Indigenous people as food and ceremonial sources and provide thousands of jobs in the province's commercial and sport fishing industries.

A rock slide at a pinch point in the Fraser River has created a five-metre waterfall, preventing salmon from passing. (Chris Corday/CBC)

The longer the salmon are delayed by the slide, the less energy they'll have to reach their spawning areas because they don't eat once they enter the river from the ocean, Wilkinson said.

"They certainly can't sit below the rock slide forever."

Wilkinson said the crews at the site are working to move boulders to create a safe route for the fish.

Helicopters are netting salmon in buckets, with about 5,000 moved so far. A fish ladder has also been constructed to help salmon past the slide site but treacherous river conditions are preventing its installation.

Wilkinson said hot weather forecast for this week could see water levels drop, giving crews a better chance to move rocks and test the ladder.

'A complete natural disaster'

Grand Chief Ed John of the First Nations Summit, one of the largest Indigenous organizations in B.C., said he visited the slide site and is concerned about the devastation it could cause.

"It is a complete natural disaster we have in front of us," he said. "To call it a rock slide is an underestimation. It's actually a big landslide that's now created a blockage in the river."

John, who is a member of a north-central First Nation that depends on Fraser River sockeye, said the slide is an emergency that impacts indigenous and non-indigenous people and the salmon as a species.

"Time is a critical factor now," he said.

The Tsilhqot'in Nation near Williams Lake declared a local state of emergency Tuesday due to the threat of the slide to the salmon fishery, a primary food source for the First Nation.

The Tsilhqot'in called on the Department of Fisheries and Oceans to stop all marine and recreational fisheries for salmon that are destined to spawn past the slide site.

Doug Donaldson, B.C.'s forests, lands and natural resource operations minister, said almost 200 sockeye from the Early Stuart run were removed from the slide area and taken to a provincial hatchery to preserve the gene pool.