Jumbo squid invade California waters

MONTEREY, Calif. — Jumbo squid that can grow up to 7
feet long and weigh more than 110 pounds are invading
central California waters and preying on local anchovy,
hake and other commercial fish populations, according to a new study.

An aggressive predator, the Humboldt squid — or
Dosidicus gigas — can change its eating habits to consume
the food supply favored by tuna and sharks, its closest
competitors, according to an article published Tuesday
in the Proceedings of the National Academy of Sciences.

"Having a new, voracious predator set up shop here in
California may be yet another thing for fishermen
to compete with," said the study's co-author, Stanford University
researcher Louis Zeidberg. "That said, if a squid saw a human,
they would jet the other way."

The jumbo squid used to be found only in the
Pacific Ocean's warmest stretches near the equator.
In the past 16 years, it has expanded its territory throughout
California waters, and squid have even been found in
the icy waters off Alaska, Zeidberg said.

Zeidberg's co-author, Monterey Bay Aquarium
Research Institute senior scientist Bruce Robison,
first spotted the jumbo squid here in 1997,
when one swam past the lens of a camera mounted on a
submersible thousands of feet below the ocean's surface.

More were observed through 1999, but the squid
weren't seen again locally until the fall of 2002.
Since their return, scientists have noted a
corresponding drop in the population of Pacific hake,
a whitefish the squid feeds on that is often used in
fish sticks, Zeidberg said. "As they've come and gone,
the hake have dropped off," Zeidberg said.
"We're just beginning to figure out how the pieces fit together,
but this is most likely going to shake things up."

Before the 1970s, the giant squid were typically
found in the Eastern Pacific, and in coastal waters
spanning from Peru to Costa Rica.
But as the populations of its natural predators
— like large tuna, sharks and swordfish —
declined because of fishing, the squids moved northward and started
eating different species that thrive in colder waters.

Local marine mammals needn't worry about the squid's
arrival since they're higher up on the food chain — but lanternfish,
krill, anchovies and rockfish are all fair game, Zeidberg said.

A fishermen's organization said Tuesday they were
monitoring the squid's impact on commercial fisheries.
"In years of high upwellings, when the ocean is just
bountiful, it probably wouldn't do anything," Zeke Grader,
the executive director of thePacific Coast Federation of Fishermen's Associations.
"But in bad years it could be a problem to have a new
predator competing at the top of the food chain.