Wednesday, March 23, 2011
U.S. outpacing Canada in marine cleanup efforts, which could save millions of creatures from death each year
Canada.com: U.S. outpacing Canada in marine cleanup efforts, which could save millions of creatures from death each year
They're known almost benignly as derelict fishing gear, but that doesn't begin to describe the toll they continue to exact on marine life.
Lost in storms or torn off by rocks, commercial fishing nets and traps can continue to fish on the ocean bottom for countless years after their owners have written them off and returned to safe harbour.
The extent of the problem is massive and its impact significant, as evidenced by just one small area of B.C.'s Boundary Bay near the Canada-U.S. border.
In a $34,000 pilot project using side-scan sonar, the Ministry of Environment in January detected no fewer than 1,829 crab traps, most of them commercial, within a 5.5-square-kilometre area. They'd been lost in storms, cut by propellers, or perhaps tossed overboard with not enough rope to retrieve them.
Working with Northwest Straits Initiative of Washington state, the program removed 218 of those traps in February, said ministry spokesman Colin Grewar.
B.C. also partnered with Parks Canada in February to remove part of a large purse seine net located almost 30 metres below the ocean surface off Pender Island's Tilly Point, at a cost of $10,000.
Of the 218 crab traps recovered, 189 used rot cord as legally required, meaning that in perhaps a couple of months the traps would open up and stop catching crabs. The legal traps contained 63 Dungeness and 31 red rock crabs.
That still leaves some 1,600 crab traps in Boundary Bay and untold thousands of other fishing gear all along the B.C. coast. It continues to catch unwitting prey — a sad end for marine life, but also for commercial and recreational fishermen whose own catches are effectively reduced.
"It was a long time coming," Ginny Broadhurst, director of Northwest Straits Initiative, said of the Boundary Bay cleanup. "Of course, it's just the beginning. That's just a tiny part of the world. We're hoping there'll be more work like that in B.C. waters."
U.S. cleanup efforts are far outpacing those on the Canadian side of the Salish Sea and are beginning to shed light on just how destructive derelict fishing gear can be.
With help from federal stimulus funding of $4.6 million U.S., the Northwest Straits Initiative has been able to remove 3,859 nets — enough to cover 225 hectares — at depths of up to 30 metres in Puget Sound. Many of them were monofilament gillnets, all but invisible to marine life.
"One of the biggest recovery actions that's ever taken place in Puget Sound," Broadhurst said. "It will have a very significant impact. With species in decline (such as rockfish), losing even a small number of animals can constitute a big portion of their population."
Another 1,000 nets remain to be retrieved, including at Point Roberts — a peninsula immediately south of the border at Tsawwassen that's infested with nets ensnaring Dungeness crabs.
"My gosh, nets piled one on another," Broadhurst said. "We still have a lot to go there. We want it cleaned out. It's just a waste. And, of course, once something is caught, it attracts a predator and they are caught, too. A nasty cycle."
Based on marine life found dead in the nets at the time of removal, staff estimate the 3,859 nets were responsible annually for the killing of 1,210 marine mammals, 21,364 birds, 67,877 fish and 2.2 million invertebrates.
"They don't go away, don't degrade at all," Broadhurst said of the nets, noting fishermen in Washington are asked to voluntarily report when and where they lose fishing gear.
On the B.C. coast, the multiagency Marine Mammal Response Network (24 hours, 1-800-465-4336) is designed to provide information on the number and location of marine life to better determine the threat to various species of becoming entangled or hooked by fishing gear, derelict or active.
A special response team had some high-profile success in 2009: it saved a Steller sea lion tethered by a rope at Race Rocks near Victoria, and two humpback whales wrapped with prawn gear, buoys and anchors in Knight Inlet.
"It's extremely dangerous," said Paul Cottrell, marine mammal co-ordinator for federal fisheries in Vancouver. "You need a special team to deal with these entanglements."
Of course, the rewards can be equally large. "The bottom line was wrapped through the mouth," he said of one whale disentanglement achieved from a seven-metre inflatable boat. "I'm the guy who made the cut. It was an incredible feeling."
B.C. is by no means alone in cases involving fishing gear and whales. "We get whales passing by that have U.S. gear on it, too," Cottrell said. "Grey whales, especially, are known to pick up gear."
The stomachs of two male sperm whales that died in 2009 off the Northern California coast were found to contain large amounts of fishing net scraps, rope and other plastic debris.
A total of 134 different types of nets were found inside them, all made from floating material, suggesting they were ingested as debris on the surface rather than as active gear. One animal had a ruptured stomach and the other was emaciated; "gastric impaction" is suspected to have killed both.
Of course, much smaller amounts of garbage or fishing gear can have fatal consequences. Stephen Raverty, veterinary pathologist at the provincial Animal Health Centre in Abbotsford, said "human interactions" — ingestion of foreign debris, entanglement in fishing gear, and boat and propeller strikes -are "a significant contributor" to whale morality.
Such debris and gear can obstruct the digestive tract and irritate the lining of the intestine, leading to bacteria invading the blood system and causing septicemia, or lead to suffocation.
More cetaceans — whales, dolphins, porpoises — appear to be found with evidence of net entanglement, he said, but it remains to be seen whether that is the result of a "heightened effort" to recover carcasses for examination.
In November 2010, B.C., Oregon, Washington and California agreed to create a coastwide marine debris alliance and develop a detailed marine debris strategic plan for the West Coast.
Derelict gear also can damage marine habitat, pose a hazard for boaters by entangling propellers and anchors, and endanger humans, especially divers.