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 Editorials | Environmental | April 2007 
Fish-Farm Nets Take Toll on Sea Lions
 Shannon Moneo - The Globe and Mail
| | B.C. is home to more than 460 shell and finfish farms and is the fourth largest producer of farmed salmon in the world after Norway, Chile and the U.K. |
Victoria, BC - The 51 California sea lions who got trapped and then drowned in a three-layered fish-farm net in Tofino Inlet represent the tip of the iceberg because fish-farm operators are not required to report accidental entanglements, a marine activist says.
"The scale of the problem coast-wide could be extremely significant," said Catherine Stewart, campaign director for the B.C.-based Living Oceans Society. "We just don't know."
On April 12, Creative Salmon fish-farm employees discovered the 51 dead mammals while changing a net in one of its four open-net fish pens.
"In 20 years of farming I've never seen anything like this," said Creative Salmon's general manager, Spencer Evans. "Nobody wants to work with dead animals."
While it is not mandatory, the Tofino-based company reported the incident to the federal Department of Fisheries and Oceans, which can't provide accurate numbers of such deaths.
Fisheries is now advising fish-farm operators to report drowning deaths, as Creative Salmon chose to do. This year, 110 sea lions have drowned in Creative Salmon's nets. In 2006, 46 perished during attempts to reach the chinook salmon.
The rising 2007 death count could be due to the influx of herring, mackerel and pilchards. Roving sea lions, which are found from Baja California to Vancouver Island, are following the fish, said Friends of Clayoquot Sound spokesperson Maryjka Mychajlowycz.
Last year, about 600 California sea lions were counted in the Tofino area, where five fish farms operate. So far in 2007, 1,500 of the opportunistic feeders have been tallied, Ms. Mychajlowycz said.
The highly intelligent, playful California sea lions, which weigh up to 400 kilograms and may live 25 years, can stay underwater for about 10 to 15 minutes.
Mr. Evans estimated that the 1,500 sea lions now cruising Clayoquot Sound consume 20 tons of fish a day. That translates into an annual feed of one and a half million five-kilogram salmon.
The sea lions are affecting the bottom line for Creative Salmon, which has four of its six sites in operation. In addition to the significant number of salmon that were eaten by the sea lions, some chinook were injured, and the surviving fish are not thriving because they have been stressed.
According to Mr. Evans, the 51 sea lions first chewed through the perimeter predator net, then the shark guard (a false-bottomed net to keep dogfish at bay), to get at the grower net where the salmon reside.
It was in that gap where they gnawed away so they could literally suck out some of the 20,000 to 25,000 fish in the 30-metre-square by 15-metre-deep grower net.
But for some reason, the sea lions couldn't exit. "I don't understand why they didn't chew their way out," Mr. Evans said.
The 51 deaths all occurred at one location. Those deaths would have been nasty, with the sea lions struggling to free themselves.
"It's clearly not a pleasant way for animals to perish," said Andrew Thomson, Fisheries director of aquaculture management. "It's not an occurrence we want to ever have happen again."
Fisheries is investigating the incident to determine whether the open nets should be moved to a new location or if different equipment should be installed.
Comparing himself to a farmer on land, Mr. Evans said it comes down to building a better fence. He thinks having a greater distance between the predator and grower nets could be a solution.
A better option is a floating, concrete, closed-pen system, where salmon are raised in a solid walled container, Ms. Stewart said from Vancouver. Living Oceans wants fish farming to move toward closed containers, but the industry would prefer to deep-six the idea based on the high cost.
"Closed containment is a wonderful concept, but you can't grow salmon economically," Mr. Evans said. He doesn't know of any successful closed-pen operations. "You may as well say, go farm salmon on the moon."
But high costs are also associated with open-net fish farms, Ms. Stewart said. The farms freely leave waste like food and dead animals where it damages the marine environment.
And there are other drawbacks. "It takes two to five pounds of wild fish to make one pound of farmed salmon," Ms. Mychajlowycz said from Tofino.
Some of that uneaten food smothers the sea floor. A variety of chemicals are used. And open-pen critics say parasites like sea lice are responsible for the decline of wild salmon.
Closed-pen systems would contain the waste, other byproducts and parasites.
Clayoquot Sound, on the west side of Vancouver Island, was designated a United Nations Educational, Scientific and Cultural Organization Biosphere Reserve in 2000.
In addition to Creative Salmon's open-net sites, four other fish farms operate in the reserve, Ms. Mychajlowycz said.
B.C. is home to more than 460 shell and finfish farms and is the fourth largest producer of farmed salmon in the world after Norway, Chile and the U.K. Farmed salmon is B.C.'s largest agricultural export, and last year the estimated wholesale value was $370-million. |
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