Conservation Needs of the Dugong Dugong Dugon in Cambodia and Phu Quoc Island, Vietnam
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Oryx Vol 42 No 1 January 2008 Conservation needs of the dugong Dugong dugon in Cambodia and Phu Quoc Island, Vietnam Ellen Hines, Kanjana Adulyanukosol, Phay Somany, Leng Sam Ath, Nick Cox, Potchana Boonyanate and Nguyen Xuan Hoa Abstract This research was conducted to assess the species be strengthened and enforced. In collaboration location of population groups and conservation issues with the Cambodian and Vietnamese governments and affecting dugongs Dugong dugon along the eastern Gulf NGOs, we propose the exploration of alternative non- of Thailand off Cambodia and Phu Quoc Island, Vietnam. destructive fishing methods and the initiation of an Interviews in fishing communities in 2002 and 2004 education campaign based on conservation of marine along the Cambodian coast revealed that dugongs are wildlife and the nearshore environment. National and sporadically found in fishing nets and their body parts transboundary management and community-based con- are sold for a relatively large profit. During 4 days of servation are required in conjunction with strategies to aerial surveys in Cambodia in 2004 we saw no dugongs. address overfishing and poverty. We interviewed villagers in Phu Quoc Island, Vietnam, in 2002 and learnt that dugongs are regularly found and hunted, again for high profits. In both countries Keywords Cambodia, Dugong dugon, Phu Quoc Island, we recommend that legislation addressing threatened marine mammal, Vietnam. Introduction of dugongs near Phu Quoc Island (Perrin et al., 1995). In the Gulf of Thailand there are small numbers of dugongs The dugong Dugong dugon is categorized as Vulnerable in eastern Thailand close to the border with Cambodia on the IUCN Red List because of population declines, (Hines et al., 2003, 2004). habitat loss and degradation, and human exploitation There is a recently enacted law in Cambodia that (IUCN, 2007). In Cambodia and southern Vietnam no designates aquatic mammals as a fishery resource. This recent research has been conducted on the dugong legislation, signed by the King of Cambodia on 21 May (Marsh et al., 2002). In Cambodia, the dugong was 2006, was proposed by the Ministry of Agriculture, believed to be extinct near the Thailand border, although Forestry and Fisheries (MAFF) to establish a Fisheries rumoured to be present along the south-east coast near Administration with provisions to manage, protect, and Vietnam (Fig. 1). In Vietnam, near the border with conserve aquatic mammals and their habitat (MAFF, Cambodia, there are unconfirmed sightings of groups 2006). The law also prohibits catching, selling, buying and transporting fisheries resources that are designated endangered by MAFF. Ellen Hines (Corresponding author) Department of Geography and Human In Vietnam, legislation protecting the dugong and its Environmental Studies, San Francisco State University, 1600 Holloway Avenue, habitat from exploitation and destruction has been in San Francisco, CA 94132, USA. E-mail [email protected] place since 1989. There are several laws that address the Kanjana Adulyanukosol Marine Endangered Species Unit, Phuket Marine dugong as a fisheries resource, including Group 1B Biological Center, Phuket, 83000, Thailand. under Decree 18 (1992, updated in 2002 with Decree 48). Phay Somany and Leng Sam Ath Department of Fisheries, Ministry of Under this law species are protected against hunting, Agriculture, Forestry and Fisheries, # 186, Norodom Blvd, Phnom Penh, trade, confiscation, captive breeding, and import and Cambodia. export unless permission is granted by the Prime Nick Cox WWF Greater Mekong, P.O. Box 2467, Phnom Penh, Cambodia. Minister. The dugong is categorized as Endangered in Potchana Boonyanate Eastern Marine and Coastal Resources Center, the Red Data Book of Vietnam, last updated in 1994 Rayong, Thailand. (Cox et al., 2003). A new Fisheries Department law Nguyen Xuan Hoa Nha Trang Institute of Oceanography, 01 Cau Da, Nha mentioning aquatic mammal protection was ratified by Trang City, Khanh Hoa Province, Vietnam. the Vietnamese National Assembly in November 2003 Received 5 June 2006. Revision requested 22 September 2006. and came into effect in July 2004 (K. Symington, pers. Accepted 17 November 2006. First published online 14 January 2008. comm.). 113 ª 2008 FFI, Oryx, 42(1), 113–121 doi:10.1017/S0030605308000094 Printed in the United Kingdom Downloaded from https://www.cambridge.org/core. IP address: 170.106.33.42, on 26 Sep 2021 at 15:31:09, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605308000094 114 E. Hines et al. Fig. 1 (a) Location of the study area in Cambodia and Vietnam. (b) The three areas studied along the Cambodian coast, and Phu Quoc Island, Vietnam, in 2002 and 2004. (c) Aerial tracks surveyed along the Cambodian coast in January 2004. The aims of this research were to assess the distribu- Aerial surveys tion and population of the dugong and its habitat along Aerial surveys in Cambodia in January 2004 were flown the Cambodian coast and Phu Quoc Island in Vietnam, using a Cessna 206 aircraft flying at an average height and provide recommendations for management and and speed of 152 m and 92.6 km hÀ1, respectively. The conservation. surveys were flown using strip (i.e. fixed-width) trans- ects (Hines, 2002; Hines et al., 2005a), which is the most Methods commonly recommended survey method for the du- In 2000 and 2001 Hines (2002) and Hines et al. (2005a, b) gong (Marsh, 1995; Pollock et al., 2006) and has been created and implemented repeatable and practical field shown to be an efficient way to cover the most area protocols to provide baseline information and monitor with the least time and expense (Hines et al., 2005a). populations of dugongs along the Andaman coast of We designed a zigzag pattern to equalize the effort on Thailand. We applied these methods here, using aerial all parts of the transect line, and transects were flown at surveys to find and assess the numbers of dugong along predefined intervals of 400-500 m apart, based on an the Cambodian coast, and intertidal and boat-based estimate of 200 m visibility from each side of the aircraft, surveys of seagrass areas. We conducted interviews in perpendicular to shore (Hines et al., 2005a). Tide tables fishing communities close to potential dugong habitat in were not available but tidal amplitude is negligible Cambodia and Phu Quoc Island, Vietnam, to enquire along this coast and did not influence the timing of about people’s history of association with the dugong, surveys. We generally flew surveys in the morning to locations of dugong populations, and people’s opinions avoid afternoon winds and glare. All survey areas were on dugong and seagrass conservation. either near villages or in unpopulated areas. We planned ª 2008 FFI, Oryx, 42(1), 113–121 Downloaded from https://www.cambridge.org/core. IP address: 170.106.33.42, on 26 Sep 2021 at 15:31:09, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605308000094 Dugongs in Cambodia and Vietnam 115 our survey and transect areas based on our previous a snowball sampling technique, the chief then recom- interviews in Cambodia in 2002, boat surveys as re- mended other people to interview (Broadfoot, 2000). We ported in Beasley et al. (2002), and consultations with went to stores and restaurants where people gather, and researchers at the Department of Fisheries in Phnom walked through villages and stopped at houses with Penh and Koh Kong. nets outside. We tried to mix ages and sexes when On 16-17 January 2004 we flew over the western coast choosing interview respondents. In Vietnam, because of of Cambodia, south of the Thai border, with flights time constraints, we spoke to meat sellers in local originating out of Koh Kong (Fig. 1). On 16 January markets but in villages interviewed only key respond- we flew south to the island of Koh Rung. On 17 January ents and deliberately chose to question fishers who were we flew south-east to the eastern shore of Kampong Som identified by other villagers or fish sellers as dugong Bay, and the southern coast of Thma Sa. On 19-20 hunters. January we flew out of Phnom Penh and surveyed the eastern Cambodian coast to the Vietnamese border, concentrating on the coast and near-shore islands in Results Kep and Kampot provinces (Fig. 1). Aerial and seagrass surveys No dugongs or feeding trails were seen during the aerial Seagrass surveys surveys in Cambodia. Water clarity was high, Beaufort To determine the general boundaries and species of Sea State was #2 and 1,102 km of transects were flown seagrass beds we consulted with seagrass scientists at over 4 days. Based on observations from the aerial the Department of Fisheries in Phnom Penh about the surveys we extended the boundaries of seagrass beds location of seagrass beds along the coast. Intertidal land- previously mapped by Cambodian seagrass scientists based surveys to determine seagrass species were car- (Fig. 2). We saw eight species of seagrass during inter- ried out in eastern Cambodia in 2002. In 2004 we used tidal surveys in eastern Cambodia in 2002. During the the aerial surveys to sight seagrass areas, and conducted 2004 boat-based surveys we found sparse beds of a boat survey near Koh Kong Island in western Cambodia Halodule pinifolia near Koh Kong in western Cambodia to determine species, depth and substrate in seagrass at depths of ,1-1.3m in sandy mud (Table 1, Fig. 2). In areas. both eastern and western Cambodia the seagrass we saw had a dense (.60%) cover. In eastern Cambodia, along the coast of Kampot province, there was extensive Interview surveys seaweed farming (Fig. 2). Hoa (2003) has documented Hines et al.