Stanford Report, Dec. 3, 2003
Biological scientist goes to Sea of Cortez to unravel mysteries of Humboldt squid
BY MARK SHWARTZ
When John Steinbeck and Ed Ricketts sailed past Santa Rosalia on the Gulf of California, they were surprised to discover an industrial skyline in the midst of an otherwise isolated coast. "It is a fairly large town which has long been supported by copper mines," they wrote in 1940. "There were industrial works of large size visible, loading trestles, and piles of broken rock."
Broken-down trestles and dilapidated buildings are the only visible reminders of this once thriving industry. Today, many people in Santa Rosalia make their livelihoods fishing for squid -- not the small variety commonly sold in seafood markets in the United States, but the jumbo Humboldt squid, which can grow up to 7 feet long and weigh more than 100 pounds.
"The squid fishery in Santa Rosalia is fascinating," says biological
sciences Professor William Gilly, who conducts extensive fieldwork on
Humboldt squid in the Gulf of California. "Since copper ran out, squid
has become the new big industry in town. Men and boys do the fishing,
and the women work in the freezer plants and factories. Most of the squid
ends up in Korea and is resold worldwide."
The squid industry in Santa Rosalia is now one of Mexico's largest fisheries,
despite the fact that harvesting methods have changed very little since
1940. Fishermen still set out in small skiffs (called pangas),
drop lures overboard and pull up their catch by hand. During fishing season,
as many as 300 pangas will go out in the evening and return the
same night with up to 2,200 pounds of squid per boat.
Above, Ed Ricketts Jr.; Katherine
Rodger, a University of California-Davis graduate student; and Jon Christensen,
San Jose State University Steinbeck Fellow, look on as Stanford biological
sciences Professor William Gilly holds a squid he used to help explain
chromatogenic behavior, a term scientists coined to describe a the animals’
mysterious ability to generate and change color. Below, pangas, small
fishing skiffs, float in a harbor at Santa Rosalia. Photo:
L.A. Cicero
"You'd think with a primitive method like hand-lines you'd never fish
out the resource," Gilly says, "but the fact is, no one knows the actual
size of the squid population, so it's difficult to set limits on commercial
fishing."
For the past few years, Gilly has been working with local fishers and
Mexican scientists to learn more about the elusive Humboldt squid -- how
many there are, where they go and where they breed. Answering these basic
questions could protect the fishery and assure its sustainability for
many years, Gilly adds.
To track the squid's whereabouts, Gilly and his colleagues have begun
an electronic tagging program. Ninety-six squid were outfitted with archival
tags, which continuously collect data on diving and migration. Only one
tag was retrieved, but it contained an entire month's worth of data. The
researchers also outfitted three squid with satellite tags -- devices
that transmit data directly to satellites. One of the three satellite
tags successfully provided a week's worth of data, giving researchers
a rare glimpse of the life of a Humboldt squid.
"The tagging data showed us that, during the day, squid dive to depths
of about 1,000 feet and stay there all day," Gilly says. "The amazing
thing is that there is virtually no oxygen at that depth, so how do they
survive? At night, they prefer to stay at depths of around 210 feet."
Last month, Gilly returned to Santa Rosalia to catch live juvenile squid
in an attempt to keep them alive for observation in a portable holding
tank.
"We hired local fishermen to catch the smallest squid possible," he
says. "Our goal is to keep them alive in the lab and to conduct studies
on their respiration, physiology and neurophysiology. This has never been
done before with Humboldt squid."
Gilly also is interested in understanding the squid's strange color-
flashing behavior. He recently worked with an underwater photographer
who filmed an encounter between two squid whose bodies flashed back and
forth synchronously. "They seemed to be having some kind of dialogue with
one another, which may have had something to do with courtship or fighting,"
he says.
Gilly's fascination with squid seems to be shared by writers and filmmakers
around the world. His research in the gulf has been featured on National
Geographic television, Discover magazine and in other media.
"At first writers come here expecting to encounter some ferocious beast
with a giant beak that can bite your arm off," he says. "They expect you
to have to wear a chain mail suit or something like that, but I tell them
I've handled hundreds of squid and have never been bitten. Eventually,
they come around and learn to appreciate the animal as an intelligent
creature with remarkable attributes."
Our fear and fascination with giant sea creatures is nothing new, of
course. As Steinbeck and Ricketts observed 63 years ago in the Sea
of Cortez: "Men really need sea monsters in their personal oceans."
Professor
Gilly transfers a specimen to the holding area of the panga.
Photo: L.A. Cicero
Above, Bill Gilly,
a professor of biological sciences at Stanford, holds a Humboldt squid
beak, which resembles that of a parrot. The animals can grow up to 7 feet
long and weigh more than 100 pounds. Photo:
L.A. Cicero
