Cambodia’s Mekong River dolphin population in Kratie province is on the brink of extinction due to the threat of water pollution, the World Wide Fund For Nature warned Wednesday, saying laboratory tests on dead dolphins had found toxic levels of various pollutants.
Government fishing officials, however, questioned WWF’s research results.
Between 64 and 76 dolphins remain in the Mekong River section in Kratie province, according to WWF estimates, and 88 animals have died since 2003, 60 percent of which were calves under two weeks old.
Laboratory tests on 11 dead dolphins at the Pasteur Institute in Phnom Penh in 2007 found that they had died from bacterial diseases, the WWF report said.
“This [bacterial] disease would not be fatal unless the dolphin’s immune systems were suppres-
sed, as they were in these cases, by environmental contaminants,” Verne Dove, the report’s author and veterinarian with WWF Cambodia said in a news release.
Toxic levels of pesticides such as DDT and environmental contaminants such as Polychlorinated biphenyls (PCBs) as well as high levels of mercury were found during tests, conducted in the US and Canada, on samples of 21 dead dolphins sent abroad from Cambodia between 2004 and 2006, WWF said.
“These pollutants are widely distributed in the environment, and so the source of this pollution may involve several countries through which the Mekong River flows; Ms Dove said, adding that WWF is investigating the sources of pollution.
The research also suggests limited genetic diversity due to in-
breeding was another factor in the dolphins’ decline.
WWF Country Director Seng Teak said by telephone that a trans-boundary conservation program was now urgently needed to protect the Mekong River dolphins in Kratie and another dolphin group just up river in South-
ern Laos.
“This is the way to go now to protect the dolphins. We are working with the Fisheries Depa-
rtment to come up with a recovery plan,” he said.
Mr Teak said that such a project could include health monitoring and treatment of the dolphins and captive breeding, but he added that it would take several years to find the best model to preserve the already precarious dolphin population.
Touch Seang Tana, Chairman of the Commission for Mekong River Dolphin Conservation and Ecotourism Development, questioned WWF’s research and its findings that pollutants had affected the dolphins, adding that he would like to see details of the research before accepting the conclusions of the group.
“I want to see the results, the details of the tests and which laboratory conducted them,” Mr Tana said, adding that he had conducted similar tests with Japanese scientists in 2001 that found no contaminants.
Mr Tana also questioned the WWF’s dolphin population estimate, saying he thought there could be more than 100 dolphins in Kratie. According to Mr Tana, gill nets, in which dolphins get entangled, are the main threat to the species in Cambodia.
“The whole methodology has been well documented and people can look at the report and detailed lab results,” Mr Teak said in a reply to Mr Tana’s comments.
The Mekong River Irrawaddy dolphin has been listed as critically endangered on the IUCN Red List of Threatened Species since 2004.
