VANCOUVER -- Thousands of dead herring have been found scattered across the ocean floor in Deep Bay, B.C., 75 kilometres north of Nanaimo.

Rebecca Benjamin-Carey, a campaigner with Conservancy Hornby Island, received an anonymous tip on March 18 that a commercial fishing vessel dumped its haul of herring into the bay, which is just south of Denman Island.

The following day, Benajmin-Carey swam down to the ocean floor, and, to her dismay, found an estimated 45,000 dead herring.

“It’s shocking, really, that this could happen," she said. "Is this the first time it’s happened, or does this happen all the time?”

Benjamin-Carey recorded her findings and posted the video online. While the images show countless dead fish, she says the loss is even greater than what’s shown.

“These herring would have spawned probably eight more times. Each time, they lay about 20,000 eggs. So, that’s what we’re looking at here.”

 The Department of Fisheries and Oceans Canada says it’s aware of the alleged fish dumping.

"DFO's conservation and protection fishery officers are currently investigating this incident. Fisheries regulations prohibit commercial fishers from dumping any catch that has been caught in accordance with the Fisheries Act from their vessel," the department told CTV News in a statement.

Commercial fishers catch herring in B.C. waters every spring, during the spawning season. Herring roe is shipped primarily to Japan, where it’s considered a delicacy. The rest of the fish is turned into fertilizer or fish food. In the ocean, the small fish play a big role.

“They’re the foundation of the entire Salish Sea ecosystem. They’re what feed salmon, and salmon feed the orca. Thousands of birds will come here. You can’t go outside during the herring spawn and not see something incredible,” says Benjamin-Carey.

However, there’s growing concern around the herring population. Conservation groups say herring numbers in B.C. waters have dwindled by 40 per cent in the last four years. The Strait of Georgia is the last remaining section of the B.C. coastline with enough herring to support commercial fishing. Benjamin-Carey says overfishing has caused the four other main herring spawns in B.C. to collapse.

For several years now, Conservancy Hornby Island has been fighting to put an end to commercial herring fishing, even collecting over 170 thousand signatures in an online petition.

“We’re pushing for a moratorium on the herring fishery and having the government buy back licences and quotas, retrain fishermen so they can go into a different industry,” explains Benjamin-Carey.

DFO says it working to ensure there are enough herring to sustain the stock into the future.

Meanwhile, Benjamin-Carey those responsible for dumping thousands of dead fish into Deep Bay are held accountable.

“It’s just an incredible waste. For nothing.”

She also hopes the video she recorded of the dead herring will be widely shared, to start a larger conversation around the future of the little fish.