The Fraser River sockeye run has crashed, from an expected 10 to 13 million fish to an estimated 1.7 million. Speculation on the reasons runs from warmer sea temperatures to the impact of sea lice on smolts passing fish farms in the Georgia Strait.

In an interview with The Tyee, marine scientist Alexandra Morton argued that there may be many reasons for the decline, but evidence points to a large contribution from fish farms and their sea lice

“The Somass River sockeye run on the southwest corner of Vancouver Island this summer is actually above the estimates,” she said. “They were projecting 350,000 and now it looks like 500,000 fish.”

While the Somass is adjacent to a cod farm, Morton said cod farms will threaten wild cod, but don’t pose the same threat to our wild salmon.

As well, Morton’s contacts on the Fraser River have told her that much of the reduced run is heading up the Harrison River, a tributary of the Fraser.

“We need to look at that run and find out if they run out to sea via Juan de Fuca, where there are no fish farms, or Campbell River, which is plugged with them,” she said.

Morton hopes that more sockeye may yet turn up in the Fraser. But she said she looked at this generation of sockeye smolts when they went to sea in 2007 via the Georgia Strait, and they were covered with sea lice.

She says, “Every time I see a generation of salmon infected with sea lice…they don’t come back. It is that easy.”

Crawford Kilian is a contributing editor of The Tyee.