About one-third of the world’s reef-building corals are at risk of extinction, according to the first extensive global evaluation of their conservation status. That’s bad news but the good news is: there are various methods available for their restoration, albeit not to their previous states of abundance.
During an International Coral Reef Symposium that took place in Fort Lauderdale, Florida several years ago, Dr. Baruch Rinkevich, a senior scientist at the Israel Oceanographic and Limnological Research, discussed the concept of “gardening coral reefs.” This approach is inspired by guidelines for forest restoration.
The method entails cultivating and nurturing substantial quantities of new coral colonies in a floating nursery, which is situated away from predators and other disruptive factors. After approximately one year, these corals are relocated to areas that have suffered degradation.
“In past efforts, we have taken coral colonies from healthy localities and transplanted them into denuded areas,” Dr. Rinkevich said. “This method resulted in low survival rates and inflicted stress on donor coral colonies.”
In their study, they selected five denuded knolls somewhere in Eilat’s Reef in the Red Sea. “Eilat’s coral reef is the world’s most northern reef,” said Yael Horoszowski, who did the study. “This reef, which was classified in the past among the richest and most biodiversed reefs, has been in decline for the past forty years.”
The researchers transplanted 550 nursery-grown colonies of two branching coral species. Three-hundred more colonies were transplanted two years later.
During the first two years of monitoring, they observed that few of these transplanted corals died. “We also found out that there was an increase of marine species like fish and crabs as we literally brought new ‘homes’ to them,” said Horoszowski.
In Indonesia, Dr. Helen Fox tried to restore degraded reefs caused by destructive fishing with explosives (dynamite or homemade bombs). The work was done in Komodo National Park. Sustained by rushing currents where the Indian and Pacific Oceans meet, the park is home to a staggering marine biodiversity. To the north, coral reefs sparkle. To the south, manta rays and filter-feeding whales glide through choppy, nutrient-rich waters.
“Blast fishing causes widespread and devastating damage to coral reefs,” said Dr. Fox, whose work was funded by the World Wildlife Fund for Nature. “Despite being illegal, blast fishing continues to be a threat to reefs in the national park.”
In restoring the degraded reefs, Dr. Fox and her team used rock piles as “a low-tech, locally-available reef rehabilitation method.” They installed four different configurations of rock piles at four sites.
The team observed that the rock piles were able to stabilize the rubble caused by explosives. It also attenuated the water currents, recreated “the three-dimensional structure” of an intact reef, and provided surfaces for coral recruitment and refuges for other marine species.
Although these two methods are very successful in restoring degraded reefs, Dr. Fox reiterated that it is “cheaper and more efficient to prevent the damage (of coral reefs) in the first place.”
Here, in the Philippines, British marine biologist Alexandra Hill headed a study looking at reef regeneration in the island province of Camiguin. The reef-rescue team employed a technology that involves the process of micro-fragmentation and colony fusion of coral fragments.
“In this technique, the massive corals – which normally have a slow growth rate – are fragmented or broken up using special equipment,” explained Hill, “and the corals exhibit a faster growth rate when fragmented,” she added. “Furthermore, fragments from the same donor colony have the ability to fuse together when physically joined which increases their overall surface area and their chances of survival.”
The quick-growth fragmenting approach was pioneered by Dr. David E. Vaughan, a researcher at the Mote Marine Laboratory in Florida.
“Years back I was working on breeding tropical saltwater fish, and I said let’s grow some coral for the aquarium trade so people don’t have to take coral from reefs,” he explained. “Then Jaques Cousteau’s grandson visited and told me I was totally missing the point, only growing corals for aquariums.”
Vaughan became so successful at growing corals for ocean transplanting that he left his fish-based job and dedicated his efforts to growing reef corals for areas that had seen extensive die-back for various reasons.
Perhaps some if not all of these methods could be employed in the degraded coral reefs impacted by the construction of the controversial Samal Island-Davao City (SIDC) connector bridge.
John Lacson, a marine biologist who was among those who took legal action to halt the construction of the SIDC at its present site, stated that the majority of the corals in the affected regions “were already dead” and approximately one-third of the Paradise Reef, a flourishing coral formation, has been lost.
“Further north, there’s still an intact reef, but one-third of Paradise Reef is already dead. If you kill the rest of it, you will be damaging a vital source of genes for fish and corals and the rest of the marine life in the area,” Lacson was quoted in an Inquirer report.
Coral reefs are the most threatened species on the planet, according to the World Conservation Union (IUCN). “The results are very disconcerting,” said Dr. Kent Carpenter, who headed the global coral reef assessment. “When corals die off, so do the other plants and animals that depend for food and shelter, and this can lead to the collapse of entire ecosystems.”
Coral reefs can be found in most parts of the world. But the diversity is far greater in the Indo-Pacific, particularly around Indonesia, the Philippines, and Papua New Guinea. Their loss will have profound implications for millions of people who depend on coral reefs for their livelihoods.
For Filipinos, the deterioration of coral reefs means less fish, their main source of protein. Touted to be “the rainforests of the ocean,” coral reefs are one of the greatest natural treasures. “A single reef may contain 3,000 species of corals, fish, and shellfish,” said the late Dr. Miguel D. Fortes, a noted Filipino marine biologist.
More than 40 million Filipinos live on the coast within 30 kilometers of coral reef. Some two million people depend on fisheries for employment, with about one million small-scale fishermen directly dependent on reef fisheries.
An estimated 10% to 15% of the total fisheries in the country come from coral reefs. About 80% to 90% of the income of small island communities come from fisheries. “Coral reef fish yields range from 20-25 metric tons per square kilometer per year for healthy reefs,” said Dr. Angel C. Alcala, a recipient of the Ramon Magsaysay Award.
Coral reefs are among the important economic assets of the country. “(But) many local, coastal communities do not understand or know what a coral reef actually is, how its ecosystem interacts with them, and why it is so important for their villages to preserve and conserve it,” said the Southeast Asian Center of Excellence in a statement.
The Philippine government has enacted and implemented numerous laws aimed at safeguarding the natural environment of the islands and the national territorial waters, including coral reefs. However, the government cannot achieve this objective alone; assistance from other people is also essential to prevent the reefs from total annihilation.
“We are the stewards of our nation’s resources,” said Dr. Rafael D. Guerrero III, an academician at the National Academy of Science and Technology, “we should take care of our national heritage so that future generations can enjoy them. Let’s do our best to save our coral reefs. Our children’s children will thank us for the effort.”
