Wednesday, 16 October 2013

Ecological collapse


Sudden disappearance of sardines has serious economic and ecological effects on the B.C. coast



14 October, 2013

A $32-million commercial fishery has inexplicably and completely collapsed this year on the B.C. coast.

The sardine seine fleet has gone home after failing to catch a single fish. And the commercial disappearance of the small schooling fish is having repercussions all the way up the food chain to threatened humpback whales.

Jim Darling, a Tofino-based whale biologist with the Pacific Wildlife Foundation, said in an interview Monday that humpbacks typically number in the hundreds near the west coast of Vancouver Island in summer. They were observed only sporadically this year, including by the commercial whale-watching industry.

Humpbacks are telling us that something has changed,” he said. “Ocean systems are so complex, it’s really hard to know what it means. For one year, I don’t think there’s any reason to be alarmed, but there is certainly reason to be curious.”

Humpbacks instead were observed farther offshore, possibly feeding on alternative food sources such as herring, sandlance, anchovies, or krill, but not in the numbers observed near shore in recent years.

The sardine, also known as pilchard, has a uniquely fascinating history.

Sardines supported a major fishery on the B.C. coast in the mid-1920s to mid-1940s that averaged 40,000 tonnes a year.

Then the fish mysteriously disappeared — for decades — until the first one was observed again in 1992 during a federal science-based fishery at Barkley Sound on the west coast of Vancouver Island.

With the re-emergence of the sardines came the humpbacks, around 1995, becoming so numerous in coastal waters off Vancouver Island that they supplanted grey whales as the star attraction of the whale-watching industry.

Peter Schultze, a senior guide and driver with Ocean Outfitters, said humpbacks are normally found seven to 10 kilometres or closer to shore, but this year were about 18 to 32 kilometres out. That meant for more travel time and fuel burned and less time with the humpbacks, if they were observed at all. “There were a lot of days where people got skunked.”

Overfishing had long been blamed for the disappearance of sardines from B.C. waters. But scientists today attribute the overriding cause to changes in ocean conditions that proved unfavourable to sardines.

B.C. started commercial fishing for sardines in 2002, and in 2013 had an allowable catch of about 25,000 tonnes, which compares with a total estimated population of 659,000 tonnes.

This year was unexpected,” said Lisa Mijacika, a resource manager with Fisheries and Oceans Canada in Vancouver, noting fishing did take place in California and Oregon. “They are a migratory fish heavily influenced by ocean conditions.”

Scientists from Canada, the U.S., and Mexico will meet in December to try to find answers to the sardine’s movements.

There are now 50 B.C. commercial sardine licences, half held by First Nations.

The fishery normally operates from July to November, but not this year.

They’ve given up looking, pulled the plug,” confirmed Lorne Clayton, executive-director of the Canadian Pacific Sardine Association. “It certainly was disappointing. It’s cost them time, fuel, and crew to go out and look, with no compensation.”

While seiners fishing close to the surface got skunked, he noted that commercial hake fishermen with trawl nets at depths of 200 to 350 metres reported catching hake “filled with sardines,” Clayton said.

I think they didn’t come to the surface this year. Right now, it’s all speculation.”

Darling said that doesn’t explain the sudden change in humpback behaviour off the island. “If sardines were there in any number, you’d think the whales would have figured that out,” he said. “I don’t think anyone really has a bead on what’s going on.”

Clayton said the B.C. sardine fishery has a wholesale value of about $32 million, with the fish going into the canned market, as well as for reduction and oil. The loss of the fishery this year could have repercussions for next.

Not only does it affect their livelihood but it puts a hole in the marketplace,” he said. Even if sardines come back next season, “you may have to claw your way back into the marketplace.”

Clayton said that ocean temperatures tides, plankton and light are all factors that could be influencing the sardines.

In a given year, fishermen have to search them out to go fishing. They don’t just arrive at your boat.”

He noted that the sardine fishery also collapsed this year in South Africa. “They disappeared entirely with no evidence at all.”

Darling said society should question whether the greater value of sardines is as prey for natural predators in the ocean, including the humpbacks upon which the whale-watching industry depends so heavily.

Would it not make sense to leave the fish that are driving the whole system and supporting virtually everything? There are some important questions to be asked about the sardine fishery.”

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