Starfish attack corals in Southern Leyte
MAASIN CITY—Fisherman Felix Rosalijos can only scratch his head in frustration.
He and fishnet owner Paul Balorio had been at sea for a long time but they hardly caught any fish.
Others are also complaining of dwindling fish catch, and they cite as reason an outbreak of crown-of-thorns, a giant starfish that feeds on corals, in Maasin City and in almost 18 towns in Southern Leyte.
Only three of the 19 coastal villages in Maasin were not affected, agricultural technician Precy Torres said. She said her office had yet to determine the extent of the damage caused by the crowns-of-thorns on the corals.
Among the affected villages, only Mantahan had initiated a campaign to extract the starfish. So far, barangay officials and residents had removed more than 10,000 crowns-of-thorns in four days starting on March 3.
Torres said the outbreak was not related to the dwindling fish catch, though the starfish would attack the corals to their eventual death.
But Rosalijos said he noticed that fish started to become scarce in February when the crowns-of-thorns appeared.
Fish scarcity
The fisherman pointed out that he used to bring home more than
2 kilograms of fish after laying out a fishnet at the sea bottom for an hour or so, about 200 meters from the shoreline. In February, he caught less than a kilo of fish, including two thorny starfish.
A week later, he and Balorio caught not a single fish but 30 starfish.
The crown-of-thorns, which got its name from thorn-like spine, can grow to over a foot across and has 10 to 21 arms. It is known for its voracious appetite of live hard corals. According to www.divegallery.com, the destructive starfish has been blamed for killing large portions of the reefs in parts of the Pacific Ocean, including a sizeable portion of the Great Barrier Reef of Australia during the 1960s.
The structure built by corals over thousands of years provides complex refuges in which animals can hide from predators. When corals die, the abundance of reef fish quickly decreases, mainly due to the lack of places for larval fish to settle as they leave the open water and settle on the reef where they will spend their adult lives, according to The Encyclopedia of Earth website (www.eoearth.org/article/Coral_reefs_and_climate_change).
Coral destruction
Southern Leyte environment officer Armand Gaviola said the crowns-of-thorns had so far affected around 70 percent of the 6-hectare coral area off Barangay Mantahan.
Just like the fishermen in Maasin, their counterparts in Padre Burgos town, 25 kilometers away, have experienced low fish catch.
“All 11 coastal barangays have been attacked (by the crowns-of-thorns) causing around 85 percent damage to the town’s coral reefs,” Padre Burgos municipal agriculturist Juliet Crisostomo said.
The proliferation of the marine predators does not only affect the town’s fishing industry but also the tourism industry.
Padre Burgos, known for its dive sites, has at least 10 dive resorts operated by foreigners, mostly Europeans. Mayor Ricardo Borces said the town was earning more than P300,000 in fees and taxes from the resorts.
“It’s so many already that they have gone near the shoreline to get their food,” Crisostomo said.
She pointed out that more than 50,000 crowns-of-thorns had been extracted off coastal barangays of Padre Burgos.
Volunteers needed
She, however, observed difficulty in getting more volunteers to dive and extract the starfish. Many of the town’s fishermen have gone to other coastal municipalities to fish there.
“There are so many (crowns-of-thorns) to be extracted and if we don’t move now, our dive sites will be gone. It’s good that dive site resorts owners have joined us in the extraction,” Crisostomo said.
A Coral Cay Marine Expedition volunteer scientist said the starfish was preying “on hard corals and multiplies (so) fast that when one lays eggs, it can burst up to one million eggs.”
“Although only about 3 percent would survive, it’s already a huge number,” said Joe Wilkinson, Coral Cay scientist who has a doctorate in marine chemistry.
Wilkinson said the crowns-of-thorns proliferated because its natural prey, such as the trumpet shellfish, had disappeared due to overharvesting.
The crown-of-thorns could be extracted using a stick, he explained.
Special guns
But Wilkinson said a special gun could be used to kill the starfish. “You put sodium bisulfate into the syringe attached to the gun then shoot them. (And) there’s no problem with the chemical because it would not harm the fish or the corals,” he added.
The scientist said the starfish should be handled carefully since the long, sharp spines are venomous and could inflict real painful wounds that are slow to heal.
Eva Abad, a marine specialist of the provincial environment and natural resources management officer, said the provincial government needed around 30 guns to kill the starfish.
She said her office had already requested funds to purchase
30 guns, which cost more than P7,000 each, including paraphernalia and handling. Total cost would reach P210,000, excluding the chemicals to be used, she said.
The provincial board has set aside P300,000 to buy the equipment. In the meantime, the fishermen are scouring other seas while crowns-of-thorns eat on the corals of Southern Leyte.
