Abnormally warm weather off the Pacific coasts of Alaska and Canada has decimated the plankton population off shore from Northern California, Oregon and Washington state, causing widespread seabird mortality and potentially devastating the marine food chain, the San Francisco Chronicle reported on Tuesday.
The decline is caused by a slackening of what is known as ”upwelling:” The seasonal movement of cold, nutrient-rich offshore water into areas near shore.
If it continues it could lead to a general decline in near-shore oceanic life, with far fewer fish, birds and marine mammals, scientists said.
The absence of krill could even threaten the blue whale population, the report said.
Already, bird nesting has collapsed to its worst state in 30 years, marine ecologist Bill Sydeman told the paper. ”We’ve never seen anything like it,” Sydeman said. ”For krill predators in this system, it’s a very serious situation.”
Other biologists said that they were seeing highly reduced numbers of fish.
”We do salmon surveys every spring and summer,” said oceanographer Bill Peterson.
”Normally, we catch several hundred salmon in the spring. This year we caught eight. And we usually get several thousand fish in the summer. This year, it was 80.”
”We annually survey [juvenile rockfish] from San Diego to Cape Mendocino, and this is the lowest catch we’ve recorded in the 23 years we’ve been doing it,” said Stephen Ralston, a supervising research biologist at the Santa Cruz office for the National Marine Fisheries Service, the federal agency that oversees fisheries in federal waters.
The report quoted a recent Canadian government study that found that 2004’s spring and summer ocean surface temperatures in the Gulf of Alaska and off British Columbia were the warmest in 50 years, due largely to the ”general warming of global lands and oceans”. ‒ Sapa-DPA