Thousands of sea cucumbers were washed up on the beach of Phu Quoc Island over the weekend, raising concern among experts that the ecosystem of the famous Vietnamese tourist destination is at risk of severe pollution.
On Saturday, locals and visitors were surprised to see thousands of the marine animals pushed ashore and fill the beach on Phu Quoc, a district administered by the Mekong Delta province of Kien Giang.
With sea cucumbers usually traded as valuable seafood, local residents immediately rushed to collect the creatures for sale, even though they were all dead. The echinoderms fetch around VND70,000 (US$3.13) a kg.
The operators of nearby hotels, in the meantime, had to have their employees clear the dead sea cucumbers around their premises to prevent pollution.
There could be as much as two tons of sea cucumbers stranded on Phu Quoc, Nguyen Van Long, a local fisherman, told Tuoi Tre (Youth) newspaper on Sunday.
Long and his family members collected around 100kg of the animals.
There used to be an abundant supply of sea cucumbers along the Phu Quoc beach, but fishermen now have to sail far offshore to find the creatures due to excessive catching, according to Nguyen Van Thuong, a seasoned diver.
“This is the first time I have seen sea cucumbers washed ashore by waves,” he said.
Most senior citizens on the island said the phenomenon was unprecedented and unusual, whereas experts and scientists pointed the finger at the increasingly polluted ecosystem of Phu Quoc.
Sea cucumbers are found in nearly every marine environment, but are most diverse on tropical shallow-water coral reefs, according to biologists.
“But the coral reefs and sea floor around Phu Quoc have been severely damaged by tourism and fishing activities,” Dr. Vu Ngoc Long, head of the Southern Institute of Ecology, commented.
Such methods as blast fishing or fishing dredge have destroyed the habitat of sea cucumbers, and the animals would thus be washed up on the shore easily by rough seas, he elaborated.
Blast fishing or dynamite fishing is the practice of using explosives to stun or kill schools of fish for easy collection, whereas fishing dredge is a kind of dredge which is towed along the bottom of the sea by a fishing boat in order to collect seafood.
Long’s explanation was echoed by Dr. Do Van Tu, from the Institute of Ecology and Biological Resources, who said the habitat of sea cucumbers might have been hurt by the practice of fishing with chemicals.
“These fishing methods make sea cucumbers weak and destroy their homes, which leads to the stranding phenomenon,” he said.
Professor Dang Huy Huynh, deputy chairman of the Vietnam Association for Conservation of Nature and Environment, urged authorities on Phu Quoc Island to pay special attention to the waste issue, with a huge amount of tourism trash currently dumped into the sea.
“If the sea continues to be polluted with garbage, more bad consequences will come,” he warned.
Most sea cucumbers, as their name suggests, have a soft and cylindrical body, more or less lengthened, rounded off and occasionally fat in the extremities, and generally without solid appendages.
They are used in fresh or dried form in various cuisines, and are thought to have medicinal properties in some countries.
Most cultures in East and Southeast Asia regard sea cucumbers as a delicacy. A number of dishes are made with sea cucumbers, and in most dishes the creatures have a slippery texture.
But Dr. Long, from the Southern Institute of Ecology, warned that people should not eat dead sea cucumbers as their flesh might have changed, and the animals may contain toxic seaweeds that are not safe for consuming.