Coral is seriously damaged by crown-of-thorns starfish (Photo courtesy of Nguyen Van Gioi)“Whendiving to look at coral reefs on Hon Tranh isle, wesaw crown-of-thorns starfish seriously devastate the coral reefs,” said Gioi,a tour guide on Phu Quy Island in the south-central coastal province.
Heand other tour guides on the larger island of Phu Quy decidedto set up a team "to catch these poisonous crown-of-thorns starfishto save coral."
Accordingto the Australian Institute of Marine Science, crown-of-thorns starfish aremarine invertebrates that feed on coral and occur naturally on reefs throughoutthe Indo-Pacific region, and when conditions are right, they can reach plagueproportions and devastate hard coral communities.
Theinstitute’s research has revealed that crown-of-thorns starfish are a majorcause of coral loss on the Great Barrier Reef.
Thesestarfish can grow to over 50 centimetres in diametre, and one individualcan consume over 13 square metres of coral reef per year, according to theNew Heaven Reef Conservation Programme’s team in Thailand.
WhenGioi and other members of the team have free time, they go to Hon Tranhisle to catch crown-of-thorns starfish.
“Inone day, we can catch nearly 500-700 starfish. We often catch them insummer because the water is warm for diving,” Gioi said.
Comparedto the past, more and more crown-of-thorns starfish are appearing because ofan imbalance in the marine ecosystem, he said, adding thatstarfish predators such as giant triton snail and sea urchins areoverfished on the island to serve tourism.
Seaurchins play a critical role in maintaining the balance between coral and algae.
NguyenTrong Tan, another member of the team, said: “Diving to see coral reefs onHon Tranh isle appeals to tourists. So when coral is lostby crown-of-thorns starfish, tourists will no longer like to come to theisland. His job as a tour guide also will be affected.”
Tanhas called on other tour guides to join his team to catchcrown-of-thorns starfish when they have free time.
Crown-of-thornsstarfish are very poisonous and dangerous for divers, he said. When theirspines accidentally hit a diver, it causes swelling and severeinflammation which could be life-threatening.
Gioisaid: “We're very careful when catching starfish. We are workingfor sustainable tourism development on the island.”
BinhThuan province’s Fisheries Division estimates that each 100 square metrescontains 50-60 crown-of-thorns starfish.
BinhThuan province has two marine reserves in Cu Lao Cau and Phu Quy islands.
PhuQuy Island is surrounded by a thick ring of coral reefs. Its deepest point is42 metres. The island has 72 species of seaweed, 134 species of stony coral and15 species of mollusks.
Accordingto the Fisheries Division, 10 years ago, the sea surrounding theisland was recognised as having the most beautiful coralreefs in the country. However, over the last several years, coral reefshave been devastated or lost.
Thatis why the province set up the marine reserve on the island.
Thedivision has been working with the Phu Quy People’s Committee to carry outa crown-of-thorns starfish monitor programme. Their staff dive tocatch and find them.
Ithas also asked for help from the Directorate of Fisheries and Institute ofOceanography in Khanh Hoa province’s Nha Trang city to provide the optimalmethods to kill them./.
VNA
