Irrawaddy, One of the Rarest, Most Threatened Species of Dolphins
Posted on September 7, 2010 / 4,540 viewsRare dolphins in Bago, Pulupandan
The coastal waters of Bago City and Pulupandan in Negros Occidental are home to one of the rarest and most threatened species of dolphins, the Irrawaddy dolphin (Orcaella brevirostris), Dr. Louella Dolar, who heads a team of scientists documenting their presence, said yesterday.
Dolar, a marine biologist from the Tropical Marine Research for Conservation (TMRC) in San Diego, California, U.S.A., and a visiting scientist at the Institute of Environmental and Marine Sciences (IEMS) of Silliman University in Dumaguete City, told the DAILY STAR they have so far documented the presence of about 30 to 40 Irrawaddy dolphins in Bago and Pulupandan and their study is still ongoing.
She said they started the survey in April 2010, when they first documented the presence of the dolphins, and have returned this month to learn more about the dolphins.
They want to know how big the population is, how far they range and what is the importance of the Bago estuary to their continued existence, Dolar said.
The project is being funded by the National Geographic Conservation Trust and Ocean Park Conservation Foundation, Hong Kong and will continue for another year, she added.
The Bago-Pulupandan area is only the third locality in the Philippines where this species of dolphin has been documented to be present, she said.
For a while, it was thought that the Malampaya Sound in Palawan was the only place where this species was found, she added.
Then in 2005, Dr. Doris Bagarinao and Ellen Flor Doyola-Solis of SEAFDEC reported that an Irrawaddy dolphin got tangled in a fishing net in Iloilo Strait. And, in 2007, a population near Guimaras was found by chance while TMRC and IEMS researchers were conducting their survey on dugongs in Iloilo, she added.
The survey conducted in Iloilo and Guimaras in 2009 by TMRC and IEMS led to the discovery of another population in Bago and Pulupandan, Dolar added.
Irrawaddy dolphins are only found in the Indo-Pacific region. They are coastal animals and they prefer brackish, shallow and protected waters, she said.
Dolar said because the dolphins’ habitat overlaps with areas often used by people, their populations have drastically declined in recent years. With the exception of the newly discovered population of about 6,000 Irrawaddy dolphins in Bangladesh, Irrawaddy dolphins are often found in small patches of populations centered near estuaries and lagoons, she said.
The species has been declared by the World Conservation Union (IUCN Red List) as “Vulnerable”, and five subpopulations including the Malampaya Sound population comprising 77 dolphins have been declared “Critically Endangered”, she said.
The population size in Iloilo Strait and the Bago-Pulupandan area is also likely to be small, and is most likely to be endangered as well, she added.
The research team headed by Dolar of TMRC is composed of Edna Sabater of IEMS – research assistant, Manuel Eduardo de la Paz – an IEMS graduate student who will be studying the Irrawaddy dolphins of Bago for his master’s thesis, Teri Aquino – research associate, Mavic Matillano of the WWF-Phil – study leader of the Malampaya Sound Irrawaddy dolphin conservation project;
Joaquin Villegas – research assistant, Jean Utzurrum – IEMS volunteer graduate student, Tara Whitty of the Scripps Institute of Oceanography of the University of California San Diego, and Dr. William Perrin of the Southwest Fisheries Science Center, La Jolla, California – research collaborator.*CPGomez.
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