For years, aboriginals along the Broughton Archipelago on the north end of Vancouver Island have watched wild salmon numbers dwindle.

On Saturday, they were joined by hundreds of people at the Vancouver Art Gallery who share their concern that one of B.C.'s most treasured resources is being wiped out.

This year, returns on wild salmon fell off dramatically.

Some environmentalists say wild salmon that swam by open-net fish farms to get to their spawning grounds didn't make it and were killed off by sea lice associated with the fish farms.

Biologist Alexandra Morton wants a judicial inquiry. She says it's the only way to get the Department of Fisheries and Oceans to explain what went wrong.

"The investigation has to be thorough if we want to keep our fish. Because this is exactly what happened with East Coast cod," she said.

In February, the B.C. Supreme Court ruled that fish farms are a federal responsibility. But that decision is under appeal.

Some aboriginal groups are worried about what this regulatory void could mean.

"I am extremely worried. I know that in our territories in the archipelago, every fish farm is up for doubling in size," said Bob Chamberlain of the Kwicksutaineuk-ah-kwaw-ah-mish First Nation.

Environmentalists want to see the Fisheries Department regulate fish farms, which would include moving the farms off wild-salmon migration routes.

The department says it will examine any potential causes behind the wild-salmon collapse in a post-season review.

Department officials are not willing to say what they will or won't do regarding fish farms until after the court case is settled.

The case is scheduled to resume later this motnh.

With a report from CTV British Columbia's Leah Hendry.