By Evelyn von AlmassyHaida Gwaii ObserverThe Cassin's auklet die-off event looks to be over, and the mystery surrounding their deaths is solved. From Alaska down to northern California, above average sea temperatures along the west coast this winter pushed out the cold-water food source for tens of thousands auklets, replacing it with a less-nutriousous warm-water variety, effectively starving the sea birds to death.Last December, BC Parks sent several carcases to the Canadian Wildlife Service for investigation after hundreds of the dead birds washed up in Tlell between Wiggins Road and Misty Meadows campground.The birds were found following a strong southeast storm that hit Haida Gwaii on Dec. 18, with winds over 100 km/hour. But as the bodies of thousands of Cassin's auklets were also on the shores up and down the North American west coast, it became evident the die-off wasn't caused by the storm as first predicted."There is no relationship between how stormy the fall-winter was, and this die-off," said Dr. Julia Parrish at the University of Washington, who took over the investigations from Environment Canada. Previous winters, most notably in 2006-07, were much stormier. But in the fall of 2014 there was a serious elevation of sea-surface temperature above normal. This so-called "blob," says Dr. Parrish, "is a very, very large body of water that hit the coastline from Alaska south to southern California." It literally squeezed out any of the normal cooler water. This wide, warm, water ribbon was several hundred kilometres long, reaching deep into the ocean. The winds in the Pacific were not strong enough this year to bring in the cooler water.Other researchers were also involved in autopsies. Dr. Julia Lankton, of the National Wildlife Health Centre, in Madison, Wisconsin, conducted several weeks-long autopsies on the auklets, to help arrive at the conclusions. She also found the juveniles born this year were emaciated, with rarely any food in their stomachs.The Cassin's Auklet population next year may see a decrease, as "Some very preliminary data suggests that the number of occupied burrows at monitored colonies in B.C. may be lower than normal." Dr. Parrish said.The highest concentrations of carcases washing ashore were on the south outer coast of Washington and the northern half of Oregon states. The auklet's highest-known death rates occurred in South Oregon, with 150 carcasses per kilometre, right around Christmas time. The bird's status was changed to a Species of Special Concern by the Committee on the Status of Endangered Wildlife Canada (COSEWIC) in November 2014