Sea cucumbers are marine animals resembling worms. They live on sea floors all over the world, but they are particularly dense in the Pacific Ocean. Despite their humble appearance, they are extremely valuable, at over $3,000 a kilo. They are a delicacy with plenty of potential health benefits. As a result, many people embark on the risky dive to try to gather them.
Sea Cucumbers are Expensive Delicacy
They have been considered a luxurious treat in Asia for centuries but demand increased in the 1980s when more people became able to afford them. Today, these animals are often served dried and given as gifts.
“They’re quite strange animals,” said Steven Purcell, one of the foremost experts on sea cucumbers. “They don’t have any limbs, they don’t have any eyes. They have a mouth and they have an anus and a whole bunch of organs in between.” 
Plus, the stranger-looking the cucumber, the more expensive it is. There are actually 1,250 different species of sea cucumber all around the globe. But the oddest-looking one is the Japanese sea cucumber, which resembles a slug covered in pointed spikes like a club. They can cost up to $3,500 a kilo.
Sea cucumber is not only a popular dish, it’s a common medicinal ingredient. They contain high levels of a chemical called fucosylated glycosaminoglycan and many people in Asia use it to treat joint issues like arthritis. In Europe, people have begun using the food to reduce blood clots and treat different kinds of cancer. Overall, demand has increased around the world, which is why many divers joined the risky hunt for sea cucumber.
An Endangered Species
But as the species become more harvested, they couldn’t reproduce to keep up with the demand, making them even more rare and expensive. Their prices increased almost 17% between 2011 and 2016. And as the sea cucumbers become rarer, divers must swim into deeper and more dangerous waters to find them.
“Some countries, they’re doing that without a lot of training,” said Purcell. “In some of the tropical countries, you’re getting a lot of people either becoming paralyzed through decompression sickness.”
To make matters worse, at least 40 Yucatan divers have died on a mission to gather sea cucumbers. And the species is becoming dangerously rare. Seven of the species are now classified as endangered. However, an endangered species also means an endangered environment. In this case, sea cucumbers play a significant role in their ecosystem. They are essentially filters as they eat on organic matter and microalgae while they excrete “clean” sand. They also help maintain oxygen levels and the pH of the surrounding water.
Unfortunately, China, the largest worldwide market for this delicacy, has no more natural sea cucumber populations, according to marine biologist and sea cucumber expert Dr. Mercedes Wanguemert. However, the population in other parts of the world is not known.
Still, Wanguemert warns that harvesting too many could negatively affect their habitat in a chain reaction, first lowering the population of algae, which would limit food for smaller fish, which would cause food scarcity for larger fish. 
Additionally, there’s the effect of overfishing on the human population. For instance, in Sri Lanka, over 10,000 fishing families worry about the future of their trade, especially as smugglers and poachers encroach on their business.
“Populations are declining due to overfishing. It affects biodiversity, and it also affects the livelihood of the coastal fishers who depend on this activity,” says Chamari Dissanayake, a senior lecturer of zoology at Sri Lanka’s University of Sri Jayewardenepura.