Population Estimate and Foraging Niche of Dugong (Dugong dugon) in Davao Gulf

Source: OAI

ABSTRACT The symposium took place in Bangkok, Thailand on March 5 and 6, 2009. This study focused on the seagrass habitat quality assessment and population estimate of dugong in Davao Gulf. It was carried out through interview/survey and a three-month dugong daily monitoring from an elevated facility set along the shoreline. Line transect quadrant method (LTQM) and SCUBA diving were employed to assess the seagrass beds in the study sites. Not less than 14 dugongs were counted in New Argao (12) and Talicud (2), mostly between 8AM-12NN and 1PM-4PM. Simultaneous occurrence of dugong in New Argao and Talicud was observed between November- December 2008. Of the 14 seagrass species found in Davao Gulf, the Halophila species was the most preferred food of dugong with a herbivory rate of 80%. Approximately, 1,705 sq. m were occupied by feeding trenches within the three-hectare seagrass bed having a potential biomass production (wet weight) of 164.32 grams/sq. m. A dugong consumes 18.68 kg (wet weight) of seagrass per day. Thus, the seagrass beds in New Argao can sufficiently sustain the food requirement of dugong in the area. Protecting the foraging niche of dugong is significant to address the declining population of dugong and to increase the chances of seeing them in the wild.

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    ABSTRACT: December 13-14, 2006 Siam City Hotel, Bangkok, Thailand To study feeding selectiveness of dugongs, community structure of seagrass meadows and distribution of dugong feeding trails were investigated around Talibong Island, Thailand, during the dry season 2005. The dominant species in this area were; Halophila ovalis, Cymodocea serrulata, Cymodocea rotundata, Enhalus acoroides. H. ovalis dominated in shallow areas mainly on tidelands and in deep areas, E. acoroides dominated areas that received the strongest influence of drift sand, such as shallow offshore sides of the seagrass meadows, or waterways. Along coastal sides of E. acoroides communities, the comparatively calm inner sides were dominated by C. serrulata and C. rotundata. Among those seagrass meadows, concentration of dugong feeding trails were observed at H. ovalis communities in tidelands, therefore dugongs selectively feed on H. ovalis at tidelands in this study site during dry season.
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  • Dugong Sighting and Occurrence in New Argao, Malita, Davao del Sur, Philippines in Support to Ecotourism. . 2005-02. SPAMAST Research Journal 2