Mysteries of the sea (cucumber)

A little-known Southeast Alaska treasure

Posted: Wednesday, October 22, 2008

Erik Satie described the sea cucumber, or holothurian, in his 1913 score for "Dried-out embryos," ostensibly to help the pianist play more convincingly:

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David Sheakley / Juneau Empire
David Sheakley / Juneau Empire

The Holothurian crawls

across boulders and rocky

surfaces.

This sea-animal purrs like a

cat; also, it produces

disgusting silky threads.

Light appears to have an

incommodating effect on it.

Even more inconvenient than light, for sea cucumbers, are Southeast Alaska divers, who at this time of year harvest thousands of cucumbers from their benthic homes, mostly near Ketchikan.

Just one species is harvested: Parastichopus californicus, a warty, sometimes spotted, reddish, forearm-long fellow with meaty muscles that run down the length of its five-way radially symmetric body. The skins are boiled and salted until black and shriveled; the meat is frozen in chicken-breast-like packets.

Asian buyers ordered extra this year to prepare for the Olympics, according to one diver.

At an estimated $3.8 million a year, the value of last year's cucumber harvest was one-fifth of 1 percent of the $1.7 billion total for all Alaska fisheries. That may explain why sea cucumber research isn't exactly flush. So despite how plentiful they are, these creatures are still mysterious.

"The ocean floor swarms with vast herds of holothurians," says a University of California Museum of Paleontology Web page on the tube-shaped bags of water.

"One way to think of a holothurian," it says, "is as a sea urchin that is lying on its side, stretched out, and missing much of its skeleton!"

"People just don't even know these critters exist," said Marc Pritchett of the Alaska Department of Fish and Game, manager of what the department calls its "miscellaneous dive fisheries."

Known unknowns

For instance, nobody knows how long sea cucumbers live, how to age them or when they reproduce.

This sort of information would help out sea cucumber harvest managers, said Pritchett, who spends his summers counting sea cucumbers, sea urchins and geoducks. For instance, one could estimate how long it takes depleted populations to grow back.

State biologists' management strategy boils down to this: Count the sea cucumbers in an area; allow divers to harvest a certain proportion; and be conservative about it, given the dearth of knowledge.

The law says you have to survey each area before allowing harvest, and the department doesn't have the resources to survey each fishery each year. So biologists rotate the roughly 20 fishing grounds. Each is surveyed every three years, and only opened if enough are found.

In some areas cucumbers live like urbanites, "elbow to elbow," Pritchett said. In other, more rural parts, he'll see one or two every square meter.

A sharp reduction in the number of sea cucumbers in certain areas this year was not definitively explained by researchers.

But Pritchett said he suspects sea otters are partly to blame for the sudden disappearances of once-bountiful geoducks, sea urchins and sea cucumbers in a few places. The sight of a raft of 100-plus sea otters elicits no magical-moment-in-Alaska coo from him.

"I get a sinking feeling when I see that," he said. "You can get down on the bottom, and it looks like it was carpet-bombed where they dug the bottom out."

Letting it all hang out

We return to Satie's text. It's unclear whether scientists have substantiated the purring. But the "disgusting silky threads" are an oft-used, multipurpose sea cucumber strategy, well known to those who have disturbed the sea cucumber or poked it with a sea star.

In an annual fall cleaning, the sea cucumber expels its own guts. Its ridding itself of parasites after spending all summer vacuuming up whatever's in the mud, including nasty little worms that would feed on the cucumber from the inside. The guts grow back in two to four weeks.

Contents of the guts vary.

"Sometimes it's gonads," or other miscellaneous viscera, said Kristin Cieciel, who studies jellyfish for the National Oceanic and Atmospheric Administration in Juneau but did her master's on sea cucumbers. "But usually it's the digestive tract."

The sea cucumber also may self-eviscerate, as scientists say, to reduce its metabolic costs in hard times, such as when the temperature or salinity changes.

Under attack, a sea cucumber will self-eviscerate, in an attempt to distract a predator into eating the guts while it makes a speedy sea-cucumber getaway.

Speedy is relative. A sea cucumber gyrates its tubular torso, thrusting itself into the water column. Cieciel tagged her subjects (a challenge, because when you punch a hole in a sea cucumber it leaks, and that likely affects its motion - the tags are similar to those that attach price tags to clothing) and followed them on their day. A few traveled up to 25 meters in a day.

"We had some cheetahs," she said.

The dangers of cuke-picking

Though the prey is slow, sea-cucumber divers have to work fast.

"Once you go into water, you work like a dog. A mad dog," said diver Janusz Kunat of Gustavus. "You swing, and one eye is looking left while the other eye is picking cucumbers, nonstop."

Sea cucumber diving is still managed in the old derby style, as halibut once was. During the season, when an area opens, a diver has seven hours on Monday and four hours on Tuesday to collect his daily bag limit of 2,000 pounds.

One sea cucumber weighs a half-pound or less. Thus a day's work might be 4,000 cucumbers, piled up in the boat. And a diver isn't down that whole time, but spends about an hour at 50 feet, then must decompress.

Kunat has dived since the 1990s. He has been out in hurricane-force winds; when he was sick but fortified on NyQuil ("People do this all the time"); and sometimes, as neither he nor anyone else recommends, alone. Injuries are common, according to Kunat. Last year a Southeast diver died.

"Don't write about this like it's a super sport," he said. "It's a really stupid fishery. A lot of divers dive alone. You anchor the boat, and go down, and go up, and hope the boat's still there."

Last year Fish and Game counted 179 sea-cucumber divers, well below the authorized maximum of 389 in this limited-entry fishery and the all-time high of 424 divers in 1995, which was a year following high prices.

Kunat said the dive fishery is difficult and uneconomical, given current fuel prices.

"When we die, it's going to be the end of the fishery ... You'd have to be crazy to do this anyway."

• Contact reporter Kate Golden at 523-2276 or kate.golden@juneauempire.com.



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