The sight of an abandoned fishing net trapping fish or strangling seals never comes as a surprise for B.C. commercial diver Bourton Scott.

Scott's day job is beneath the ocean's surface, inspecting underwater structures for different clients. But during nearly every dive, he comes across lost or discarded fishing material — or "ghost gear" — that is still snaring wildlife.

"When a net's lost, it continually fishes — it doesn't stop fishing," said Scott. "[And] since the animals that are caught aren't being harvested or removed, it baits more animals into the net."

The result is "an ongoing death trap."

The Emerald Sea Protection Society crew uses a remotely operated vehicle from their boat to locate nets beneath the surface of the water. (Robin Leveille/Ghost Nets)

It's unknown how much ghost gear is lying beneath the surface of B.C.'s coastal waters. The materials can sit underwater for decades, even centuries, disrupting marine ecosystems and killing wildlife.

After years of witnessing the damage first-hand, Scott decided to launch a cleanup program with his close friend Gideon Jones.

It's called the Emerald Sea Protection Society (ESPS), and the group's effort to remove nets along the Gulf Islands — located between Vancouver Island and B.C.'s south coast — is featured in a new documentary called Ghost Nets.

Seals trapped

According to the protection society, an estimated 800,000 tonnes of ghost fishing gear makes its way into oceans around the world each year. The nets, ropes and traps are often lost in storms, snags or when they're run over by other vessels.

Experts say it's hard to quantify exactly how much of it makes its way into waters around coastal B.C. But annual work done by the region's Fisheries and Oceans Canada staff highlight how significant the problem is.

Watch the documentary Ghost Nets on CBC Gem

Earlier this year, staff recovered more than 200 lost, abandoned and illegal crab traps in Boundary Bay near White Rock. Crews released more than 1,200 live crabs back into the water.

Last fall, a highly publicized ghost net lost inside the Fraser River trapped a number of seals.

South of the border, research has also been done to shed light on the issue. One study looked at 870 ghost nets recovered off Washington state in the U.S. They contained more than 32,000 marine animals, including more than 500 birds and mammals.

Ghost nets trapped beneath the surface can snag active nets and other fishing materials, becoming even more problematic for fishers and ocean wildlife. (Robin Leveille/Ghost Nets)

According to Joel Baziuk, deputy director of the Global Ghost Gear Initiative, ghost nets have a potentially devastating impact on harvestable fish populations, catching anywhere from five to 30 per cent of the total available stocks each year.

The material is also a major contributor to ocean plastic pollution.

"As much as 47 to 70 per cent of all the plastic in the ocean by weight is lost fishing gear," said Baziuk. "Most fishing gear these days is plastic, so it contributes to that problem as well. And if the numbers are right ... it's every bit as much a problem as the other plastic debris."

Warning: Video contains graphic images

A CBC News crew captured video of a number of seals drowned by a gillnet near the mouth of the Fraser River. 0:59

Finding a solution

Volunteer and non-profit groups like the Emerald Sea Protection Society are shouldering much of the work removing nets from along the B.C. coast line. The team currently runs off a collection of public donations and grants — members even pay out of pocket for some expenses. Commercial fishers have chipped in, volunteering vessels to remove heavy netting.

"Fishers are part of the solution," said Baziuk. "No fisher ever wants to lose their net, it costs them money ... It's obviously a very hard economic loss for fishers when they lose a net."

The group recently cut out part of a large net outside Pender Island that divers initially discovered in the 1970s. The removal has been ongoing for nearly 10 years, spearheaded by the Washington-based Northwest Strait Foundation.

Even though they are no longer actively attached to fishing vessels, ghost nets continue to fish by catching marine life as they wade through the water. (Robin Leveille/Ghost Nets)

Recovered net materials can be recycled into new fibres to make swimwear and carpet tiles.

The Emerald Sea Protection Society hopes more funding will trickle down from the federal government. The DFO has recently signed a partnership with the Global Ghost Gear Initiative to promote clean waterways.

"The issue is definitely getting some attention," said ESPS co-founder Gideon Jones. "We would love to see that translated into usable funds that groups like us could apply for."