Salmon farms like this one off B.C.'s west coast use floating net pens to hold thousands of fish. (CBC)

Some of the 30,000 farmed Atlantic salmon that escaped yesterday near Campbell River have already been caught by anglers in the area, according to at least one experienced fishing guide working in the region.

The salmon swam away from a fish farm in Fredrick Arm, northeast of Campbell River, after one corner of an underwater pen collapsed, CBCNews.ca learned through a tip from a reader Wednesday.

Officials with Marine Harvest Canada, which operates the farm, confirmed an underwater anchor holding down a corner of the pen had slipped, pulled down the netting and opened an easy avenue for escape.

Clare Backman, the company's director of environmental compliance and community relations, said the company has only managed to recover a few hundred fish.

"It's a period of large tides right now, and a lot of the fish will have dispersed through the area, and we might not get them all back," Backman said Wednesday.

Vancouver Island fishing guide Henry Spit said the salmon began biting on the hooks of anglers within a few hours of their escape.

"Within hours of the release, Atlantics are biting the hooks. … A few have been angled so far. They've been caught, and they're 13- to 14-pound Atlantics," said Spit.

Spit says he does not believe the company's statements that the escaped fish will not harm native salmon stocks.

"These predators identify Pacific smolts as feed. There's a huge danger of [them] being a massive threat to the local indigenous stocks," he said.

Atlantic salmon a concern for many

Environmentalists and local First Nations leaders are also worried that the escape will have a negative impact on B.C.'s native Pacific salmon stocks.

The Georgia Strait Alliance has received a number of reports of Atlantic salmon jumping and travelling in large schools some distance from the farm.

"Now 30,000 hungry farmed fish have been unleashed in the pathway of the Fraser River juvenile fish that are currently passing by on their way to the ocean …They eat wild salmon fry, which are already in great danger from the sea lice from the fish farms," said Ruby Berry, a campaign coordinator of the Georgia Strait Alliance, in a written statement released Thursday.

Backman maintains that since the fish did not have any disease or sea lice, there is no danger to native salmon.

"There's no ability for these fish to spread anything to the wild salmon. First of all, they are quite healthy. They haven't needed any antibiotics. They haven't contracted any diseases at all. They are perfectly healthy fish that were scheduled to go to market within the next two to six months," Backman said.

But Berry is not convinced.

"These are adult fish and we know that they compete with the Pacific salmon for food, habitat and spawning opportunities … This is a completely preventable occurrence," she said.

"If the government had acted on its own committee's recommendation and required [salmon] farms to be in closed containment, we wouldn't be seeing repeated escapes of this invasive salmon species into the marine environment," said Berry, referring to a 2007 report by a legislative committee that recommended B.C. phase out underwater net pen salmon farms and develop closed containment land-based systems within five years.

Atlantic salmon have no business in the Pacific Ocean where they could out-compete and wipe out B.C.'s native salmon species, said Living Ocean Society executive director Jennifer Lash, who pointed to a 2001 study that found young Atlantic salmon in small B.C. streams.

"We do know that they can reproduce in these waters and that the young do compete with the other wild salmon that are in these waters," Lash said.

Local First Nation leaders also expressed their dismay with the recent escape.

"Escapes are inevitable with open net cages," said Chief Darren Blaney of the Homalco First Nation, in a written statement released Thursday morning. "How many other farms are like that and how many escapes have gone unreported?"

Marine Harvest Canada has been working with environmental groups to try to persuade the BC government to fund a pilot project to investigate the viability of closed containment aquaculture pens.