The accusations come just as the federal Department of Fisheries and Oceans bans fishing for all salmon species on a section of the Fraser River to conserve this year's low salmon population. Numbers for the Skeena River salmon run have also reached historic lows.
Aaron Hill of the group Watershed Watch said fishing boats targeting pink salmon in B.C.'s northern fisheries are inadvertently catching more than 165,000 salmon of other species, but then improperly releasing them.
The pink salmon swim "alongside chum and sockeye salmon and other species whose numbers are really low this year," said Hill. "So as a conservation measure, the fishermen are required to return those prohibited species back to the water with the least possible harm."
"But what's happening is because there's next to zero enforcement, (fishermen) race to catch as many fish as quickly as possible," he said, describing the video the group has posted online.
"The worst case is they're leaving fish on the deck to basically die before they throw them back because they're easier to handle instead of chasing a vigorous feisty fish that's flopping around all over your deck."
However, a spokesman for the Canadian Fishing Company — one of the largest companies operating in the area — said the video does not represent the whole story.
"There's a group that is trying to paint a picture, but you're getting selective footage and certainly it's not representative," said Rob Morley.
Morley said all of the boats who supply the company are instructed "to comply with the conditions of license, which says you must release non-target species with the least possible harm."
"I think this is about as clean a fishery as you can possibly find," Morley said. "Obviously there's always some people that are not going to do things properly. We believe it's a small percentage of the fleet, based on our own observations."
Morley said skippers are reprimanded if violations are observed, but enforcement powers lie with the federal Department of Fisheries and Oceans.
"It's really up to them to take enforcement action where and if it's needed," he said.
Under federal regulations, fishermen are required to sort through the fish they've caught and release any fish they weren't targeting "in a manner that causes the least possible harm to that fish."
However, Hill said that has to happen very quickly because mortality increases exponentially once a fish has been out of the water for more than a minute.
The video captured by Hill in an area just south of Kitimat appears to show some salmon laying unsorted on boat decks for upwards of six minutes before being tossed or kicked off the side.
A spokesman for Fisheries and Oceans Canada said the footage is problematic, but since the video was posted a number of days after filming, enforcement is difficult.
"It's a concern to me when we receive information significantly after the fact," said Larry Paike, the department's conservation director for B.C. "Effective enforcement requires that we receive information in a timely manner, and we could have addressed this issue much earlier."
Paike said Fisheries' boat and dockside observers have not indicated any problems so far this year, but the video warrants a more in-depth investigation.
Specifically, Paike is concerned about Hill's accusation that 24,000 fish that should have been released were discovered in processing plants.
"That doesn't jive with what we've observed, but we'll follow up with the processing companies to determine if those records are in fact true," said Paike.
Morley said the amount of non-targeted fish they catch is very small — only two per cent of their daily take — and an even smaller percentage end up in their processing plants.
"The vast majority of these fish are being put back to the water with the least possible harm," he said. "It's a fishery that is providing valuable jobs to people who haven't had strong seasons for awhile."
DFO's Paike noted they conducted an investigation of release and retention practices in 2012 the same area where the video was filmed.
"Plain clothes" officers "covertly observed" the fleet during fishing, he said.
"We found no violations."
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