SEATTLE – Scientists suspect that rising ocean temperatures and dwindling plankton populations are behind a growing number of seabird deaths, reports of fewer salmon and other anomalies along the West Coast.
Coastal ocean temperatures are 2 to 5 degrees above normal, apparently caused by a lack of upwelling – a process that brings cold, nutrient-rich water to the surface and jump-starts the marine food chain.
Upwelling fuels algae and shrimplike krill populations that feed small fish, which provide an important food source for a variety of sea life, from salmon to sea birds and marine mammals.
“Something big is going on out there,” said Julia Parrish, an associate professor in the School of Aquatic Fisheries and Sciences at the University of Washington. “I’m left with no obvious smoking gun, but birds are a good signal because they feed high up on the food chain.”
“In 50 years, this has never happened,” said Bill Peterson, an oceanographer with the National Oceanic and Atmospheric Administration (NOAA) in Newport, Ore. “If this continues, we will have a food chain that is basically impoverished from the very lowest levels.”
This spring, scientists began tracking anomalies along Washington’s coast, from the appearance of warm-water plankton species to scores of jellyfish piling up on beaches. A Guadalupe fur seal, native to South America, was found dead in Ocean Shores.
Parrish is documenting unusual breeding behavior among common murres on Tatoosh Island off the Olympic Peninsula. In 15 years of monitoring the murre colony, this is the latest the birds have initiated breeding.
“They are starting very, very late and then just giving up,” she said.
The trend toward warmer temperatures began in fall 2002, said Peterson, the NOAA oceanographer. No one is pointing to one direct cause for the warmer waters, but many scientists suspect climate change may be involved.
While Peterson is concerned about the unusual ocean conditions, he is more worried that people will not take notice.
“People have to realize that things are connected – the state of coastal temperatures and plankton populations are connected to larger issues like Pacific salmon populations,” he said.