…stealing sea cucumbers
If you’ve been snorkeling over a sand or mud bottom, you’ve probably seen something that looked like a small moldy loaf of bread. That was a sea cucumber, and it’s not a vegetable. These interesting and useful creatures, part of the same large family that includes starfish and sea urchins, are found almost everywhere in the world’s oceans.
The basic sea cucumber design is simple. It’s a gut with a mouth at one end and an anus at the other, surrounded by a sausage of muscle. The cucumber breathes by opening and closing the anus to pump water over a pair of “respiratory trees” (much like the inner workings of human lungs) that take oxygen from the water and put back carbon dioxide and other waste gases. There’s no real brain, though cucumbers can smell (or taste) food and can feel pressure, vibrations and changes in water currents.
Between the inner and outer skin layers, there are a lot of tiny bony plates that help to hold the animal’s shape, surrounded by collagen fibers that can be stretched or shortened to move the body. The outer skin has hundreds of little bumps. The ones on the bottom have developed into tube feet that help to move the cucumber along the sea floor, and the ones at the front have grown into tentacles that find and gather food.
Adult sea cucumbers have few natural enemies. Their primary defense against predators is camouflage and their thick leathery skins. Crabs, lobsters and a few large fish will eat them, but only if there is nothing else. They taste horrible because they contain a toxin (Holothurin) that acts like soap. They can also push out sticky strands of digestive tissue to tangle smaller predators.
There are sixteen different kinds of sea cucumber in the waters around Jamaica, of which six are considered commercially important. For a long time they survived almost unmolested. Pollution and habitat destruction took a toll on their numbers but they escaped the worst of the overfishing that helped to wipe out most of the nation’s other marine life.
In recent years, however, some species of cucumbers have become a target. For centuries, sea cucumbers have been a staple ingredient in Oriental cooking and traditional medicine.
Increasing numbers of Chinese coming to work in Jamaica wanted them, and the prospect of new domestic demand and export markets got at least two major fishing companies excited. In 2015, before things got too badly out of hand, the Ministry of Agriculture and Fisheries closed down the harvesting of sea cucumbers until a “species management plan” could be put in place.
The UN’s Food and Agriculture Organization (FAO) provided assistance and US$30 million of funding for a major study of the sea cucumber population – how many, what kinds, where are they, and most important, how many can be harvested every year before they also are wiped out.
The study concluded that a sustainable sea cucumber fishery needed tight regulation, including special licenses, minimum size rules and annual catch quotas. Mariculture (“farming” cucumbers at sea) could also help. Stakeholder consultations were held last December, and the management plan is to be rolled out this year.
In the meantime, illegal fishing continues to supply what Marine Police describe as a growing black market. Two weeks ago, five persons were arrested at Welcome Beach in Clarendon with 300 pounds of illegal sea cucumbers. All are on their way to court, and face fines or jail time.
Sea cucumbers aren’t pretty but they’re useful. In the reef, they pick up, break down and digest bits of dead plant and animal material from the sea floor. They’re not quick but they’re not fussy and they appear to feed 24 hours a day. In fact, there’s a study being done in the U.K. to see whether cucumbers might be used to clean up some of the waste from fish farming.
They also have medicinal potential. So far, Caribbean sea cucumbers have produced an arthritis supplement and at least one effective chemotherapy drug. Other medical and scientific uses are still being explored. It’s worth saving what’s left and growing more.