INVASIVE CORALS ARE PUTTING PHU QUOC CORAL REEFS UNDER THREATS | FIGHTING HARMFUL CORALS

We have discovered a type of invasive coral that is a real “coral killer” and is currently one of the biggest dangers to Phu Quoc’s coral reefs, based on observations that OnBird has made about the reefs over the previous five years.

Corals called button polyps and other Zoanthid species spread quickly, grow out of control and invade other coral species to form densely packed, hard-to-trim colonies.

Button polyps known as Moon Polyps, Encrusting Anemones, or Sea Mats, corals are colonial creatures with numerous individual polyps clinging to a fragment of live rock or coral rubble.

With optimal conditions, Button Polyp Corals will expand out, producing new colonies and eventually forming a mat or carpet-like appearance. The abundance of Button Polyps Coral has recently expanded substantially, and it currently controls hundreds, if not thousands, of meters of coral reefs on Phu Quoc Island, displacing hard corals and other traditionally dominating biota. This rapid growth is a cause of coral reef destruction, as the Button Polyps Coral has blanketed many portions of Phu Quoc’s coral reefs, regardless of whether the corals are alive or dead, squeezing out all other sessile invertebrates. 

The photosynthesis process, which produces sugars, lipids (fats), and oxygen, is not possible for the zooxanthellae cells. This causes the coral to starve to death and lose its ability to develop and perform cellular respiration.

Now spreading throughout Phu Quoc, button polyp coral is a type of harmful coral that is endangering the reefs without giving them a chance to recover. It will gradually encroach and cover any area, including dead and damaged coral areas, which are meant to serve as new sites for young coral larvae to attach themselves to to regrow. Button-plastic corals are fast-growing and will push away their neighbors, other corals, and any other sessile species. Hard corals will eventually die off and become incapable of reproducing once they have taken over the coral reef community.

Many coral reefs are currently in a very serious situation because they have few opportunities to reproduce and regrow. For instance, the coral reefs at Dam Ngang Island, May Rut, Mong Tay, and Hon Xuong are currently experiencing a fast-growing area of Button Polyp Corals, which cover every surface of underwater objects, meaning that healthy coral areas will eventually disappear forever.

3. RESCUING CORAL IN PHU QUOC FROM THE INVASIVE & HARMFUL CORALS

The OnBird Phu Quoc team has been working to eradicate hazardous or invasive coral from the coral reefs on Phu Quoc Island to preserve the hard coral areas that are currently in danger due to the growth of button polyps coral. With the right equipment (a wetsuit, gloves, and knife), “OnBird underwater warriors” can remove these dangerous corals from both dead and living coral patches, which are the places where new corals can grow and attach. We typically clean the reefs during our snorkeling excursions, provided that the water conditions are favorable.