Conservation Biologist: More Information Needed to Protect Marine Mammals

Conservation Biologist: More Information Needed to Protect Marine Mammals

Marine mammals (like dolphins and whales) are being threatened by growing sea traffic, changes in their habitat, bycatch, pollution and disease.

This was revealed by Angelico Jose Tiongson, a conservation biologist who had studied Marine Biology at Silliman University, in a lecture to young leaders at an environmental camp held in Lake Balanan, Siaton, Negros Oriental.

The camp was named SEA Camp, or Sea and Earth Advocates Camp, organized by the environmental advocacy group Save the Philippine Seas and supported by the US Embassy in Manila.

Tiongson is a lead researcher of the Dolphin Conservation Ecology Project in the Tañon Strait. He is currently working as a research assistant at the Cetacean Ecology Lab, Swire Institute of Marine Science, University of Hong Kong.

Tañon Strait is the 220 km long body of water between Negros and Cebu islands. It is narrow in width (27 km and 5 km at different parts) and deep (more than 500 meters), and home to 14 out of the 26 species of whales and dolphins found in the Philippines.

It also provides safe passage for whale sharks and other giant marine species that travel between Visayan Sea in the north and Bohol Sea in the south. It is one of the ten richest fishing grounds in the Philippines and a source of food and income for people in Negros and Cebu.

Tañon Strait was declared a Protected Seascape in 1998, the largest marine protected area in the Philippines, covering 5,182 square kilometers (more than three times the area of the TubbatahaReefsNational Park in the Sulu Sea).

“Now that we are moving so fast in terms of globalization and technology development, our seas will get busier and busier. The number of boats sailing will increase many-fold in just a couple of years. This spells disaster for these animals. They depend a lot on their communication skills to get around,” Tiongson said.

Since many people live along the coast, Tiongson said another threat to marine mammals is habitat modification. “We are continually developing our coastlines, thus getting closer and closer to the marine mammals’ habitat. We don’t know how this will affect these animals.”

Bycatch (or being caught during commercial fishing for a different species), is another problem. Studies showed that dolphin meat was ordinary fare in the local market before legal protection was enacted in 1991. More than 2,000 dolphins were being caught every year and sold to various markets in Central Visayas and Northern Mindanao.

In 1991 government declared protection for dugongs, in 1992 this was extended to all dolphin species, and in 1997 to all whale species. But the studies showed that the by-catch of marine mammals was “extremely beyond the sustainable take of the marine mammal population,”Tiongson said.


A survey in Eastern Sulu Sea, for instance, found that only 1% to 2% would be the sustainable take, “meaning that’s the number of individuals you can take from the population without negatively affecting the viability of the population.” But in reality, people were catching four to eight times the population of spinner dolphins and even more for other species, he said.

Pollution also threatens the lives of the species. Last year they found that 31% of the known Indo-Pacific bottlenose dolphins in the Tañon Strait had some type of abnormal skin conditions.

“We are continuing our study if these conditions are progressing or not. That’s 31%. That’s very high in terms of this species where they are distributed. We are trying to monitor that.

“We are also documenting cases of line entanglements especially among spinner dolphins. Last year we found five cases of spinner dolphins entangled in a sort of trash line, fishing gear line. Because dolphins never stop swimming, these lines will cut through their tails and they can no longer swim and eventually die.”

Tiongson said to protect marine mammals in the Philippines, there is still a lot of work to do in data gathering. “There are 26 species of marine mammals, but only six species have enough data to classify them on the International Union for the Conservation of Nature Red List (the global inventory of the conservation status of species).The rest are data deficient, so that’s a lot of information missing for our marine mammals.”

Part of the work in the Tañon Strait project is to look for several species of dolphins and focus on their “population ecology, population structure, social structure, spatial and habitat dynamics.”

Conservation biologists also work to determine which populations are at risk, identify the reason for decline, develop potential mitigation measures, assess effectiveness, and document recovery.

“We’ve done most of this, but we’ve done a small portion of it in the Philippines. It’s difficult to do a large-scale research especially because the Philippines is an archipelagic country.”

They are also looking at the effects of climate change. “A lot of scientists are now realigning their thoughts from just pure ecological aspect of research to conservation. The multiple effects of climate change, these cannot be ignored now.”

He said young people can do something through volunteerism. “Join research work and volunteer on various NGOs. Develop projects. Produce research projects. SEA Camp is the best way to learn about our marine environment. There is still a huge gap in terms of our knowledge about the marine mammals of the Philippines.” (SU Research and Environmental News Service; Nova Veraley V. Grafe and Ms Celia E. Acedo)