SCIENCE: Davao gulf’s coral reefs on the brink

(First of Two Parts)

“When trees are cut and human beings are affected as a result of flashfloods, people rallied against deforestation. But like forests, coral reefs are also suffering the same magnitude of destruction.” – Dr. Bernhard Riegel, associate director of the US National Coral Reef Institute

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“Large areas were found with very high live coral cover, up to nearly 100 percent in places, but live coral coverage would have been much higher had there not been heavy dynamite fishing damage in many areas in the past.”

This was part of the submitted written report of Dr. Thomas J. Goreau after he and his team assessed the coral reefs in and around the Tubalan Cove of Malita in Davao Occidental some years back.

“Fish populations were very poor except around promontories with higher water flow,” wrote Dr. Goreau, the president of the Global Coral Reef Alliance, a non-profit international organization founded in 1994 working exclusively to save coral reefs. “The area has a mix of prime dive sites suitable for ecotourism, as well as extensively damaged areas badly in need of restoration as fisheries habitat.”

But what really caught the attention of the team was the discovery of seeing almost the entire sea bed within the cove to be almost covered with only one species of the ecologically-fragile cabbage corals.

“This is unique,” British diver Andrew MacDonald and his wife Jane Widdison commented. “We have only seen one species dominate an individual offshore reef before but have never seen any other ancient coral colonies like this which cover such a large area. It appears that this colony covers an area of several hundred hectares and it is likely that these corals have taken centuries to form like this.”

Before they joined the survey team, the couple has lived and dived in some parts of Mindanao for four years. According to them, the presence of the ancient cabbage coral colony alone makes Tubalan Cove as “one of the most special and unique places in the world for marine biologists and recreational divers alike.”

“The corals are very varied and colorful – a mixture of soft and hard corals – just what dive tourists like to see,” the husband and wife divers said in their report. “The corals are better in condition and coverage the closer you are to the open sea.”

There’s even more: “Diving amongst the corals of Tubalan cove offers great opportunities for macro (small marine creature) spotting and photography as good as anywhere in the world,” the two British divers reported. “We saw several species of small animals that are highly prized by dive photographers.”

Two provinces away from Davao Occidental is Compostela Valley. The province is known for its highlands as it is located in the upper portion of Davao Region. But it has two towns located near the sea: Maco and Mabini.

Interestingly, a new study found out that of the 72 known genera of Scleractinian or “stony” corals identified in the Philippines, about 46 of them can be found in the pristine waters of Mabini. (Around the world, only 110 genera of Scleractinian corals have been identified so far.)

The discovery was among the initial findings of a study – “Mapping and Assessment of Mabini Protected Landscape and Seascape’s Coral Reef Ecosystem and Associated Reef Fish Community” – conducted by the regional office of the Department of Environment and Natural Resources (DENR).

“We have more Scleractinian corals compared to those found in the Island Garden City of Samal and in Davao Oriental,” pointed out Christine T. Dompor, the provincial tourism officer. “There is also one type of coral which the researchers could not identify since it is not found in their list of classification.”

“The (discovery) just shows there is a dearth of information out there and it is becoming a race to get this knowledge before more and more of the marine environment gets destroyed,” deplores Dr. Arnel “AA” Yaptinchay, founder and director of the Marine Wildlife Watch of the Philippines. “It also confirms again and again, the importance of our country in marine biodiversity.”

Scleractinia, also called stony corals, are marine corals that generate a hard skeleton. They first appeared in the Middle Triassic and descended from the tabulate and rugose corals that barely survived the end of the Permian. Much of the framework of modern coral reefs is formed by Scleractinians.

Both discoveries are located in areas which are part of the Davao Gulf, a key biodiversity area in the Philippines. The World Wildlife Fund considers Davao Gulf as one of the most diverse marine ecosystems in the world. It is the feeding ground for 11 species of cetaceans, which include sperm whales, killer whales, and bottle-nose dolphins. Not only that, it also serves as the nursing ground for endangered marine turtles.

The regional office of the Bureau of Fisheries and Aquatic Resources (BFAR), a line agency of the Department of Agriculture, listed Davao Gulf – which has an area of 308,000 hectares that cuts into the island of Mindanao from Philippine Sea – as one of the biodiversity hotspots in the world.

Over 80% of Davao Gulf’s coral reefs are already degraded, the regional technical director of the environment department reported in 2006. “The coral reefs in almost all areas of Davao Gulf are in bad condition,” the official said.

Only one-fourth of the coral cover was live, manta tow surveys covering 33.8 kilometers of reefs in the gulf showed. Of the 19 areas surveyed, only the corals in Tubalan were in very good condition. Areas with poor values of 10% and below were found in Agdao, Malita and Valez (Toril) in Davao City.

The coastlines of the cities of Panabo and Tagum – which contain “the most dense concentrations of fish larvae in the entire gulf” – are no better. “The coral reefs, which used to be extremely rich, are already buried,” said Harry D. Morris, a British-Filipino marine biologist. “What’s left behind are mostly coral skeletons and small patches still struggling to survive.” (To be concluded)