In their survey of terrestrial biodiversity of islands in Ba Lua archipelago in June 2010, researchers from the Institute of Tropical Biology unveiled a skeleton of Irrawaddy dolphin on Hon Da Bac Island.
Last September, the group discovered more than 20 Irrawaddy dolphins in the sea around the Ba Lua archipelago. They also excavated two skulls of this species on the island.
Scientists do not have the accurate statistics of the community of Irrawaddy dolphins in Ba Lua, but over 20 is a large number in comparison with 7-10 dolphins discovered in other surveys in the Malamyapa Strait or in the Mekong River in the past.
The Center for Biodiversity and Development will cooperate with local and international organizations to preserve this species.
Vietnam has a little information about Irrawaddy dolphin.
Dr. Vu Ngoc Long, a member of the research group, said that the newly-discovered community of dolphin is separated from the recorded communities in Songkhla Lake of Thailand and the one in the upper region of the Mekong Delta.
Little research on the Irrawaddy dolphin has been conducted in Viet Nam and they are not listed in the country's Red Book of endangered species, Long said.
On January 12, the researchers will travel to Thailand to work with the International Union for Conservation of Nature (IUCN) to work out a detailed plant to protect the dolphins, he said. In the meantime, researchers have joined hands with local fishermen to track the population of dolphins in the Ba Lua Archipelago.
Five populations of Irrawaddy dolphin, whose scientific name is Orcaella brevirotis, were thought to be living in Vietnamese waters.
The Irrawaddy dolphin (Orcaella brevirostris) is a euryhaline species of oceanic dolphin found in discontinuous subpopulations near sea coasts and in estuaries and rivers in parts of the Bay of Bengal and Southeast Asia.
Entanglement in fishnets and degradation of habitats are the main threats to Irrawaddy dolphins. Conservation efforts are being made at international and national levels to alleviate these threats.
Some Irrawaddy dolphin populations are classified by the IUCN as critically endangered; in Lao PDR, Cambodia, Vietnam (Mekong River sub-population), Indonesia (Mahakam River sub-population, Borneo), Burma (Ayeyarwady/Irrawaddy River sub-population), the Philippines (Malampaya Sound sub-population), and Thailand (Songkhla Lake sub-population).
Irrawaddy dolphins in general however, are IUCN listed as a vulnerable species, which applies throughout their whole range. In 2004, CITES transferred the Irrawaddy dolphin from Appendix II to Appendix I, which forbids all commercial trade in species that are threatened with extinction