A ray of hope shines upon the polluted Manila Bay with the discovery of sturdy coral species, remnants of what was once considered the vast tropical rainforest of the sea.
The corals managed to survive the odds, despite the poor living conditions caused by decades of environmental degradation that continue to kill marine life and other organisms in the pollution-challenged water body.
This development was documented by a team of from the Ecosystems Research Development Bureau (ERDB) of the Department of Environment and Natural Resources (DENR) that was sent out to conduct a vulnerability assessment of coral reefs in Manila Bay last month.
The discovery adds more reasons for the conduct of a more comprehensive environmental impact assessment relevant to the various Manila Bay development projects to ensure that a science-based policy on how to best rehabilitate—and manage—the still undiscovered biodiversity sitting beneath the waters of Manila Bay is put in place.
Conservation
Initial findings of a team of the ERDB-DENR revealed that even under the worst conditions when and where others perish, several sturdy coral species manage to survive by adapting to even the poorest living conditions.
The research arm of the DENR, the ERDB is currently gathering data to assess the vulnerability of the bay to climate-change impacts.
The project is being implemented by a team of science practitioners of various disciplines seeking significant, research-driven information on the factors influencing the present state of the bay and its vulnerability to different hazards.
The project components include terrestrial, coastal, freshwater, air and water quality, social and solid-waste management.
Ridge-to-reef study
In a news statement released in the first week of April to highlight the vulnerability assessment being conducted by the ERDB, Director Sofio B. Quintana said the coverage of the research encompasses terrestrial and marine ecosystems.
“In this ridge-to-reef research on the Manila Bay Area, we are seeking for a definite connection among risk factors. Right now, we are trying to explore more data on informal-settler families, air and water quality, and habitat to make scientific studies relevant for future projects.”
According to Quintana, the bureau is trying to come up with a unified framework for these projects. Consolidated properly, these could make an inference on the status of the Manila Bay area.
Major threats
According to the DENR, a total of 17 major river systems in nearby cities and provinces drain to Manila Bay.
Incidentally, most of the wastes from households and industries from these estuaries pose the most apparent threat to the bay.
The DENR data showed that only 15 percent, or an estimate of 2.4 million out of 16.3 million, of the water-served population of the National Capital Region, are connected to a sewerage system.
Also, the poor solid-waste management remains a bigger challenge as aftermaths of strong typhoons would later reveal the tons of uncollected garbage washed back along the shores of Manila Bay every now and then.
The Manila Bay area is also vulnerable to the dangers of noise pollution, the presence of invasive species brought by international cargo ships and illegal fishing activities.
Coral inventory
As part of the coastal component, a team led by ERDB’s Supervising Science Research Specialist Jose Isidro Michael T. Padin conducted an inventory of coral communities in the provinces of Bataan and Cavite.
Of the Manila Bay’s total reef area of 293.68 hectares, nearly 72 percent are found in Cavite.
Padin reported that the reef sites in Maragondon, Cavite, and few stations on Corregidor in Bataan and Caballo Islands in Manila Bay had fair to good live coral cover.
However, he said the reefs are continually threatened by sedimentation, nutrient contamination, reduced water clarity and high fishing pressure.
According to Padin, runoff of sediments and nutrients had been documented to cause coral mortality by smothering and burial, low coral recruitment, reduced coral diversity, change in community structure, macro-algal abundance, reduced calcification and reduced live coral cover in many reef ecosystems around the world.
Adapting to worse conditions
In a telephone interview with the BusinessMirror on April 8, Padin expressed amazement on how corals managed to survive under such poor living conditions.
In terms of diversity, Padin said the corals they found are not as diverse as in other areas, because those that remain are the sturdy corals.
“The community of corals has changed. There is a shift in the type of corals there [Manila Bay]. The form and the morphology are different from the corals that can be found in Batangas or other areas,” he said.
He said it could be concluded that the corals found in the Manila Bay area, particularly in the study sites they visited, are adapting to survive their current environment.
“When we conducted the dive, there was poor visibility. I can’t even see my own body. The water quality is no longer good,” he said in mixed English and Filipino.
He explained that it was caused by the altered water circulation because of sedimentation and siltation that occur in estuaries and in some portion of the bay.
Lifeline: Good water circulation
Despite the high level of pollution that threatens living organisms in Manila Bay, relatively good water circulation keeps hope alive.
“The remaining reefs in the bay are located proximate or near to the mouth of Manila Bay, where water circulation is relatively strong. Strong water current can reduce stress on corals by limiting sediment deposition at the bottom and on coral colonies,” he explained
Good water circulation facilitates transport of fresh supply of plankton and improves water clarity by flushing land-based materials out of the bay, he added.
Moreover, he explained that corals filter organisms in the water as they feed on plankton.
“Corals also need light to support the photosynthetic activity of symbiotic algae living in their tissues,” he said.
According to Padin, land-reclamation projects should be backed by an environmental impact study (EIS) as mandated by law, to ensure that the impact to the coastal and marine ecosystem or the area targeted by the project, would be minimal.
The EIS, he said, would help determine what kind of intervention is best for an area to be rehabilitated.
“Whether the intervention requires soft engineering or hard engineering, it should be determined by a study and conduct of EIS,” he said.
Moreover, he said dredging to remove silts and allow the free flow of water from rivers would positively impact and help revive Manila Bay.
More importantly, however, a ridge-to-reef approach to rehabilitation, where everything starts from the upland areas—the watershed areas down to rivers down and the reefs—should be observed.
New discovery, a new hope
According to Padin, surprisingly, corals have been discovered in areas where there is no previous record of corals, referring to two seagrass sites where corals were sighted by the team.
Based on the National Mapping and Resource Information Authority (Namria) coastal resource map, in Cavite, Corregidor and Caballo, the reef area spans to 293.68 hectares.
The reef in Mariveles, Bataan, is not yet included, since the Namria map has no record of corals there, he said.
However, Padin said that when the team checked two of the purported seagrass sites using scuba gears, some corals were surprisingly spotted.
In the end, both Padin and Quintana said there is always hope in saving Manila Bay.
“What we only see from above is the surface of another living world underneath us. People should understand that Manila Bay is home to other life forms. Despite its rapid deterioration, there remains hope in Manila Bay. It is not yet too late to revive the life out of its troubled waters,” Quintana said.