for National Geographic News
Flotillas of jumbo squid are invading the length of the eastern Pacific Ocean, and the voracious predators may be upsetting ocean ecosystems and threatening fisheries, scientists warn.
At their largest, jumbo, or Humboldt, squid (Dosidicus gigas) can extend to six feet (two meters) in length and weigh more than 100 pounds (45 kilograms) each.
The squid have earned the nickname "red devils" for their powerful arms and tentacles, razor-sharp beaks, and insatiable appetites. (Related: "Researchers Shed Light on Mysterious Jumbo Squid" [July 18, 2003].)
The animals were already known to exist in large concentrations in Mexico's Sea of Cortez, or Gulf of California (see Mexico map). Scientists estimate that more than ten million squid may be living in a 25-square-mile (65-square-kilometer) area near the town of Santa Rosalia.
But now the squid also seem to have entrenched themselves in the waters along California's coast.
Scientists say the growing numbers of squid are playing an increasingly significant role in the ocean's ecosystems.
Voracious and opportunistic predators, the squid move in schools of more than a thousand and consume vast quantities of fish. At the same time, the squid serve as prey for sperm whales, mako sharks, and other top predators. (Related story: "Jumbo Squid, Sperm Whale Study Reveals How the Giant Creatures Feed, Hunt" [March 12, 2007].)
"Anything that is so abundant and eats so much is bound to have an impact" on its environment, said William Gilly, a biologist at Stanford University's Hopkins Marine Station in Pacific Grove, California. Gilly has studied the squid for decades.
The large number of squid seen today off the California coast isn't unprecedented. The squid were abundant there in the 1930s before mysteriously vanishing. They reappeared in the 1970s and were seen in great numbers again in the 1990s.
But in the past few years the predators have spread to entirely new areas. Jumbo squid now clog waters off Oregon, Washington State, and Alaska to the north and have been spotted near the southern tip of South America.
SOURCES AND RELATED WEB SITES