http://www.canada.com/vancouversun/news/story.html?id=d2934362-9c7b-4023 -943e-acc351e0c276&k=52559
Climate shift blamed for mass die-off The auklets are so sensitive to climate changes they are considered to be "sentinels" or canaries in the coalmine Margaret Munro Scientists report thousands of dead Cassin's auklet chicks at two West Coast sites may be linked to climate change. Hundreds of thousands of Cassin's auklet chicks starved to death last year on Triangle Island, their fluffy corpses left to litter the largest bird colony on Canada's West Coast. The 40,000 auklets on the craggy Farallon Islands, west of San Francisco, also had an "unprecedented breeding failure" and abandoned their nests en masse, say scientists, who are now linking the 2005 disaster at the colonies to a strange quirk in the climate off Alaska. An "anomaly" in the Gulf of Alaska impacted the jet stream and may have been responsible for delaying the upwelling of nutrient-rich ocean waters that fuel production of krill and other key foods for seabirds from British Columbia south to California, a team of U.S. and Canadian scientists report in the Geophysical Research Letters last week. The adult auklets, unable to find enough to eat, cut their losses and abandoned their nests. "The whole colony just felt like a morgue," says biologist Mark Hipfner, of the Canadian Wildlife Service, who watched the failure unfold on Triangle Island off the B.C. coast. Close to one million Cassin's auklets flock to the island each year, making it by far the largest breeding colony for the birds in the world. "I've seen it bad before, but I've never seen it that bad," says Hipfner, who recalls the "eerie silence" on the colony that is normally "deafening." Within days of hatching, the chicks were abandoned in their burrows by parents who couldn't find enough food to feed their young. Auklets are dark, chunky seabirds that weigh about as much as a robin. They are incredible flying machines, travelling up to 50 km a day to and from feeding grounds during breeding season, says Hipfner, who directs seabird research and monitoring on Triangle. But the auklets are so sensitive to climate changes they are like "sentinels" or canaries in the coalmine, Hipfner and his U.S. colleagues say in the new report. The 2005 breeding failure highlights how anomalies in the climate can hit the bottom of the food web and then reverberate all the way up. While the auklets showed the most dramatic and immediate effects, the scientists say the lack of krill likely impacted everything from salmon to whales. There are fears global warming will eventually wipe out the seabird colonies. "What we are concerned about is that events like we saw last year are going to become more frequent because of climate change," Hipfner says. "That's what we're really worried about." The Forallones off California had another breeding failure this year, which has some scientists wondering if serious change is already underway. The auklets on Triangle Island had a "reasonably good year" with more than half the 500,000 breeding pairs rearing chicks this summer, says Hipfner. But the continuing problems in the U.S could impact the auklets that breed in Canada. The forecast is calling for an El Nino this winter, and the biologists hope it is a mild one. "I don't think the birds need two big hits in three years," says Hipfner. "That would be tough." Strong El Ninos warm waters along the Pacific coast and were tied to die-offs of auklets chicks in 1998 and 1983. But the 2005 breeding failure was the worst on record and came without warning -- and without El Nino. These scientists suggest it was tied to the "unusual atmospheric blocking" in the Gulf of Alaska last May that caused the jet stream to shift southwards. The resulting reduction in northern winds may have prevented the usual upwelling of cold, nutrient-rich water that fuels production of krill and plankton. Hipfner likens the upwelling of nutrients to "putting gasoline" in a car engine. "If you don't get that fuelling in late winter and early spring you don't get plankton production and the whole system comes to a standstill," he says. The conditions along the Pacific coast returned to normal by June last year, but the damage was already done. "Even though the oceanographic conditions returned to normal, this shift apparently came too late to support additional reproductive attempts by the birds," the researchers report. While abandoning chicks sounds harsh, such strategies are essential to the long-term survival of the colonies, says Hipfner. "The key, if you are a Cassin's auklet, is not so much to raise a chick each year, as to make sure you survive," he says. - - - ALARM RAISED Scientists report thousands of dead Cassin's auklet chicks at two West Coast sites may be linked to climate trends. Triangle is one of the Scott Islands Group, some 45 km off the top of Vancouver Island Farallon Islands, part of a national wildlife refuge off San Francisco (c) The Vancouver Sun 2006 _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
