Squid invasions signal changes in the Pacific Ocean
Some Fish Stock Decline as Jumbo Squid Migrate to New Waters
By MOISES VELASQUEZ-MANOFF
Dec. 19, 2009 When large numbers of jumbo squid first showed up in California’s Monterey Bay in 1997, scientists weren’t sure what had brought the cephalopod that far north. An unusually strong El Niño event had warmed the eastern Pacific. But the squid, dubbed el diablo rojo – the red devil – in its native waters off the coast of Mexico, didn’t typically venture farther north than Baja California. And indeed, within two years, the Humboldt squid – Dosidicus gigas – had disappeared from central California waters. But in 2002 – another El Niño year – they reappeared. This time, they took up permanent residence and pushed even farther north – past Oregon, Washington, and British Columbia, until, by 2004, fishermen near Sitka, Alaska, were hauling them in. When scientists dug through historical records, they discovered that the squid’s northward advance wasn’t entirely unprecedented. There were accounts from the 1930s of the creatures in Monterey Bay. But never in numbers comparable to what scientists observed now – schools many hundreds strong. And no one had ever seen them as far north as Alaska. “This occurrence has gotten weird enough to not really make it into the realm of ‘normal,’ ” says John Field, a fisheries biologist with the National Oceanic and Atmospheric Administration in Santa Cruz, California. Fishermen worry that the squid, a voracious predator weighing up to 110 pounds and reaching more than six feet in length, will diminish valuable fish stocks. Hake, for example, a major Pacific fishery, has declined since the squid arrived. …
