Abundance, Distribution and Conservation Status of the Irrawaddy Dolphin in Riverine and Coastal Waters of Cambodia Dolphin from Prek Anchung, 40 km north of Phnom Penh.
Previous to 2001, no research had been undertaken on coastal cetaceans in Cambodia and minimal research had been conducted on the riverine Irrawaddy dolphin population. The aim of this research is to initiate a detailed assessment on the current status of the Irrawaddy dolphin which inhabits the Mekong River and coastal waters of Cambodia. The primary objectives are to:
investigate abundance, distribution and habitat preferences,
assess threats to both the riverine and coastal populations,
investigate public perceptions towards Irrawaddy dolphins and conservation in Cambodia,
initiate community-based education and management programs, and
conduct training programs and workshops to increase capacity of local Cambodians to undertake marine mammal research.
Preliminary research on cetaceans in Cambodia has been conducted during 2001, however, further preliminary research is essential in order to formulate a larger scale project to be initiated in 2003.
Project Update: August 2002 Dolphin from Prek Anchung, 40 km north of Phnom Penh.
Fieldwork began in May 2002, with boat and interview surveys throughout the upper Cambodia Mekong. Two continuous boat surveys (each of 7-8 days duration) were undertaken from Kratie to the Lao/Cambodian border - the most northerly extent of the dolphin's distribution in the dry season. A total of 785 km of survey effort over 67 hours were undertaken.Direct counts were used to estimate abundance, with a best estimate of 56 (range 47-73) dolphins sighted. These results were similar to those obtained during surveys in 2001 and indicate that the population is small and under severe threat of extirpation in the Mekong River.
In addition to boat surveys, a total of 45 hours were dedicated to photo-identification.Photo-identification during 2001 identified only two individuals. During 2002, more time was dedicated to photo-id and at least 20 individuals have been identified (with much of the data still to be analysed). This success is encouraging and will provide an effective method of studying minimum abundance, movements and association patters of the Mekong River Irrawaddy dolphin population.
A total of three Irrawaddy dolphins from the Cambodian Mekong River were recovered during 2002.Two of the three died as a direct result of accidental entanglement in gill-nets.By-catch in gill-nets is the most significant threat to the survival of the dolphins in the river.Additional threats include habitat degradation and pollution, vessel disturbance and harassment and potential dam and waterway constructions.
Preliminary surveys indicate that the population is small (perhaps numbering no more than 150 individuals), restricted in range and is in urgent need of biologically sound and socially acceptable conservation and protection measures.
Project Update: January 2003 We have now conducted a total of 3,116.69 km of boat survey over 269 hours throughout the upper reaches of the Mekong River. Boat surveys were undertaken in May 2002 – at the height of the dry season and January 2003. It is hoped that boat surveys will continue every month until May – the height of the dry season. In addition, interviews with local communities, photo-identification and capacity building amongst local Department of Fisheries officials have continued during the wet season (June-December) when boat surveys are logistically infeasible.
The Total Mekong River Irrawaddy dolphin population has now found to be even smaller than previously thought, with population estimates as low as 70-100 individuals. Accidental catch in gillnets in the primary cause of dolphin mortality in the river. During the past five months (as of January 2003) a total of four Irrawaddy dolphin carcasses had been recovered. Two were a direct result of by-catch and two were unknown causes (probably also by-catch). The situation is now critical for the Mekong River population, where the population is almost certainly facing extinction in the near future if conservation and management initiatives are not put in place immediately.
One of the posters produced and distributed for the education and awareness component of the project
An additional primary aim of the project has also been to encourage capacity building of local Cambodian Department of Fisheries officials. One full time Department of Fisheries Counterpart and eight part-time counterparts have been trained in survey techniques and methodology and regularly assist with surveys, interviews and community discussions.
Although the future of the Mekong River Irrawaddy dolphin is precarious, thanks to support from funding agencies (primarily the Rufford Foundation), the logistical assistance of Wildlife Conservation Society – Cambodia program and support from Department of Fisheries, local government officials and local communities, there is still a good chance that the population can be conserved and managed for their long-term survival in the Mekong River.
Final Report Read about the activities undertaken and findings of this project in the final report below.
