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Harbour seal cull needed
It's necessary to protect summer chinook run on Puntledge River, sport fish advisory board says
Larry Pynn
Vancouver Sun
Monday, March 26, 2007
CREDIT: Chuck Russell, Vancouver Sun Files
Harbour seals' population has stabilized over the years.
Sport fishermen are calling for a renewed cull of harbour seals near Courtenay on Vancouver Island just as research shows the species has increased 10-fold as a result of protection in local waters.
Legislation in Canada and the U.S. in the early 1970s made it illegal to kill marine mammals without a permit, ending an era of culls and bounties and giving rise to today's thriving harbour seal population.
The population is now relatively stable at 52,000 harbour seals using 650 haul-out sites (beach locations where seals rest) in the Strait of Georgia and Washington state's Puget Sound, according to Peter Olesiuk, a research biologist with Fisheries and Oceans Canada in Nanaimo.
Olesiuk will deliver a presentation to a Vancouver marine conference this week showing the harbour seal population in local waters has increased about 10-fold between the early-1970s and mid-1990s.
Gerry Scott, with the Comox local of the Sport Fish Advisory Board, said in an interview that fishermen are not calling for a widespread cull of harbour seals throughout the Strait of Georgia, but feel it is necessary on the Puntledge River to protect a summer run of spawning chinook that is down to a few thousand fish.
He said the seals show up at night under the bridge and use the city lights to gobble up young fish as they come downstream in spring.
"It's amazing, they literally turn upside down and start eating. We have to ensure the survival of those fish," he said.
Andrew Trites, director of marine mammal research at the Fisheries Centre at the University of B.C., said salmon runs decline for a variety of reasons, often directly the result of human actions.
He's seen no hard research to show the Puntledge River cull of a decade ago achieved anything.
Seals are easy scapegoats because they can be seen following salmon during spawning migrations in the fall, he said. People fail to realize seals may be of "net benefit" to salmon because they eat a greater number of hake throughout the year. "Hake are one of the largest predators of salmon," he said.
Harbour seals aren't the only ones that benefited from the marine mammal protection legislation.
Steller sea lions have increased steadily in local waters, and are estimated at 500 to 1,500, Olesiuk reports. It is a species of special concern in B.C., officially threatened in Alaska.
California sea lions have extended their non-breeding range northward, with counts fluctuating at 1,000 to 2,500 since the 1980s. Both species of sea lion were rare in local waters prior to the early 1970s.
Northern elephant seals that breed off California and generally forage offshore are also being observed in small numbers at Race Rocks near Victoria. The species had almost been hunted to extinction.
The Fisheries Department culled a total of 52 harbour seals in 1997 and 1998 to benefit chinook salmon on the Puntledge River, and is now in discussion with local stakeholders, including sport fishermen and first nations, who are pushing for the controversial management tactic to be repeated.
Bruce Adkins, the department's area chief of oceans habitat enhancement for the south coast, said harbour seals position themselves beneath the bridge over the Courtenay River downstream of the Puntledge and eat juvenile salmon going downriver and adults returning to spawn.
He said returns were improved after the cull a decade ago, but noted the situation is clouded by the fact other rivers in the area that had no seal cull also had good production. He said more research is needed to better assess the potential benefits of another cull.
Trites noted that a seal cull designed to save salmon in Alaska backfired on the Copper River in the 1960s when the population of starry flounders (a species of flatfish) on which the seals fed exploded. That in turn led to a collapse of the razor clam fishery, a favourite prey of the flounders.
Paul Adams, executive director of the B.C. Wildlife Federation, said harbour seal populations remain a controversial topic among anglers.
The federation remains committed to a scientific-based management approach to all species, he said, urging both senior governments to devote more money to wildlife research.
He said he would consider support for control methods if evidence shows that an increase in numbers of one species such as the harbour seal had a detrimental impact on others.
Paul Watson of the Sea Shepherd Conservation Society said in a telephone interview that churning fish into feed for livestock, commercial cat food, and fish farms is a vastly bigger threat to fish stocks than seals.
Olesiuk will present his findings at the 2007 Georgia Basin Puget Sound Research Conference today through Thursday in Vancouver.
lpynn@png.canwest.com© The Vancouver Sun 2007
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