Extinction Warning: only 85 endangerred Irrawaddy dolphins on the Mekong

By Amy Lou Jenkins

Today the World Wildlife Fund revealed that its research has confirmed that the critically endangered Irrawaddy dolphin population in the Mekong River numbers just 85. Complicating these dismal numbers was the finding that calf survival was found to be very low, leading researchers to conclude that the small population is declining and at high risk of extinction.

With the steep decline in populations of many animal species, from frogs,fish and dolphins to tigers, some scientists have warned that Earth is on the brink of a mass extinction like those that occurred only five times before during the past 540 million years.

Anthony D. Barnosky, UC Berkeley professor of integrative biology, a curator in the Museum of Paleontology and a research paleontologist in the Museum of Vertebrate Zoology, reported in the 2011 Science Daily:

"If currently threatened species -- those officially classed as critically endangered, endangered and vulnerable -- actually went extinct, and that rate of extinction continued, the sixth mass extinction could arrive within as little as 3 to 22 centuries. Nevertheless, it's not too late to save these critically endangered mammals and other such species and stop short of the tipping point. That would require dealing with a perfect storm of threats, including habitat fragmentation, invasive species, disease and global warming."

Each extinction accerates the threat of extinction to other species. Humans are a species.The WWF and scientist recognize human impact, development/ and climate change as a caustivative factors in the accerated extinction rates. Humans can also act to prevent mass extinctions, and the WWF is today calling for world wide effort on behalf of the Irrawaddy.

According to Dr. Li Lifeng, Director of WWF’s Freshwater Programme, the research is based on photographic identification of dolphins through individually unique features of their dorsal fins. “Most of the dolphins can be identified, and we use that information to estimate the population size.”Although this population estimate is slightly higher than the previous estimate, the researchers were quick to note that the population had not increased over the last few years.

“With a larger dataset and recent analytical advances, previously unidentifiable dolphins which had few marks on their dorsal fins have been included,” Dr. Li said. However, surveys conducted from 2007 to 2010 show the population slowly declining.

“Evidence is strong that very few young animals survive to adulthood, as older dolphins die off and are not replaced,” Dr. Li explained.The population is ranked as critically endangered on the IUCN Red List, the highest international threat ranking for endangered species, and Irrawaddy dolphins are fully protected under the highest level of Fishery Law in Cambodia and Lao PDR. Dolphins in the Mekong continue to be threatened by gill net entanglement and the causes of calf mortality remain unclear.

“This tiny population is at high risk by its small size alone. With the added pressures of gill net entanglement and high calf mortality we are really worried for the future of dolphins,” Dr. Li said. The research (research reports available for download) also indicates that the small population resident in the transboundary pool on the Cambodia – Lao PDR border may number as few as 7-8 individuals. This is the only area in Lao PDR where dolphins remain. WWF is working to coordinate transboundary management with government agencies and local communities in Cambodia and Lao PDR at this most critical dolphin site.

“Our best chance of saving this iconic species from extinction in the Mekong River is through joint conservation action,” said Dr. Li. “WWF is committed to working with the Fisheries Administration, the Dolphin Commission, and communities all along the river to reverse the decline and ensure the survival of this beautiful species in the Mekong.”WWF is asking the government of Cambodia to establish a clear legislative framework to protect dolphins in Cambodia. This should include the designation of dolphin conservation zones and should allow a ban or limit on the use of gillnets where needed. Doing so will require formalizing special legislation to protect dolphins or amendments to existing Fishery Law.