Stranding records of dugong (Dugong dugon) in Thailand

December 15-17, 2007, Royal Phuket City Hotel, Phuket, ThailandThe information of stranded dugongs (Dugong dugon) has been recorded by the Phuket Marine Biological Center from the Andaman Sea coast and the Gulf of Thailand. The data were obtained from the records of fishermen, stranded dugongs, and specimens preserved in the museums, temples or institutions. Two hundred and eighty two records of stranded dugong were recovered from 1962 through February 2008. Of these 71.6% of the records were from the Andaman Sea, 25.8% of the records from the Gulf and 2.6% of the records had no information of the stranding place. Some 22.7% of the records were male, 22.3% female and 55.0 % of unidentified sex. The highest record of stranded dugong per year was in 1996 and the place where most stranding was found was in Trang province. The mean length of stranded mature dugong was 2.52±0.18 m in male (n=12) and 2.5±0.16 in female (n=19) while the maximum length was 2.94 m. The smallest calf was 0.97 m in length and 14 kg in weight. The maximum weight of 310 kg was recorded in a male dugong with 2.75 m in body length. The number of stranding sizes of the dugong ranging from 0-1.5 m long, >1.5-2.0 m long and >2.0-3.0 m long was 20.8%, 31.7% and 47.5%, respectively (n=101). The body length (m) and body weight (kg) relationship equation was Y = 19.108 x 2.8103 and R = 0.945 (n=65). Most dugongs died by unidentified cause. However a generally high proportion of deaths was from gillnets among identified causes of the stranding

Development of detection device for dugong calls

December 15-17, 2007, Royal Phuket City Hotel, Phuket, ThailandAn acoustical approach for research on marine mammals has been a very active research method in recent years. Dugong (Dugong dugon) is one of the highly endangered species, which are strictly-marine herbivorous and mainly inhabit coastal areas. In order to detect dugong calls from recorded data, several algorithms have been adapted by researchers in the analyzing process. However, the number of misses in the detection is still non-zero. The sound of snapping shrimp recorded in a wide range (2-300 kHz) is one of the main background noises that makes the detection of dugong calls difficult in warm shallow waters. Impulse elimination was employed in the system to get rid of the snapping shrimp noise. In order to improve the performance of the detection system by increasing the detection rate and decreasing the number of misses, two new algorithms were tested in the experiment. The experimental results for the new algorithms including impulse elimination and the cepstrum method are presented in this paper

A low-cost solution for documenting distribution and abundance of endangered marine fauna and impacts from fisheries

Fisheries bycatch is a widespread and serious issue that leads to declines of many important and threatened marine species. However, documenting the distribution, abundance, population trends and threats to sparse populations of marine species is often beyond the capacity of developing countries because such work is complex, time consuming and often extremely expensive. We have developed a flexible tool to document spatial distribution and population trends for dugongs and other marine species in the form of an interview questionnaire supported by a structured data upload sheet and a comprehensive project manual. Recognising the effort invested in getting interviewers to remote locations, the questionnaire is comprehensive, but low cost. The questionnaire has already been deployed in 18 countries across the Indo-Pacific region. Project teams spent an average of USD 5,000 per country and obtained large data sets on dugong distribution, trends, catch and bycatch, and threat overlaps. Findings indicated that >50% of respondents had never seen dugongs and that 20% had seen a single dugong in their lifetimes despite living and fishing in areas of known or suspected dugong habitat, suggesting that dugongs occurred in low numbers. Only 3% of respondents had seen mother and calf pairs, indicative of low reproductive output. Dugong hunting was still common in several countries. Gillnets and hook and line were the most common fishing gears, with the greatest mortality caused by gillnets. The questionnaire has also been used to study manatees in the Caribbean, coastal cetaceans along the eastern Gulf of Thailand and western Peninsular Malaysia, and river dolphins in Peru. This questionnaire is a powerful tool for studying distribution and relative abundance for marine species and fishery pressures, and determining potential conservation hotspot areas. We provide the questionnaire and supporting documents for open-access use by the scientific and conservation communities

Dugong (Dugong dugon) and seagrass in Thailand: present status and future challenges

December 13-14, 2006, Siam City Hotel, Bangkok, ThailandDugong and seagrass research in Thailand has been principally conducted by Phuket Marine Biological Center (PMBC), Department of Marine and Coastal Resources (DMCR). The first stranded dugong was reported in 1979. The interview surveys with villagers and aerial surveys for dugong population were started in 1993 and 1997, respectively. Several research topics were documented on dugong, both the biological and chemical aspects, and including the management plan. Seagrass surveys had been originally conducted in 1988 particularly in the Andaman sea coast and seagrass surveys in the Gulf of Thailand have been recently performed. Seagrass data-based information of PMBC was officially available in 2004. Although, the diversity of only 12 seagrass species have been reported in Thai waters, the seagrass beds have been shown to play an important role as the nursery ground of economically important species. We have reviewed the recent status and future research of dugong and seagrass in Thailand according to the follo ing items: population, genetic divergence and threats; dugong behavior, feeding habit and acoustic survey; heavy metal and organotin compounds concentration; status of seagrass; marine organisms in seagrass beds; future challenges; and conservation and management

Research and conservation of dugong in Thailand

Southeast Asia Sea Turtle Cooperative Research (SEASTAR2000)ORGANISED BY KYOTO UNIVERSITY, JAPAN; THE UNEVERSITY OF TOKYO, JAPAN; PHUKET MARINE BIOLOGICAL CENTER, THAILAND; SEA TURTLE CONSERVATION STATION, THAILAND; MARINE FISHERIES DIVISION, DEPARTMENT OF FISHERIES, THAILANDKYOTO, Japan, 27-30. November 2007Dugongs are rarely seen in Thailand, although they have distributed along coastlines both in the Andaman Sea and the Gulf of Thailand. The most abundant area of dugong is at Talibong-Muk Islands, Trang Province. Aerial surveys of dugong population along the Andaman Sea coast in 1997 and 1999 have been conducted and 50 and 38 dugongs were observed, respectively. So far, age determination had been made on 12 dugongs and the range of their ages was 1-43 years. Recently stomach contents of 6 dugongs have been investigated and 9 species of seagrasses were found in their stomachs. The composition of seagrasses found in dugong stomachs may be affected by the composition of seagrasses presented in dugong's feeding ground. Dugongs were occasionally entangled in fishing gears. Among various types of fishing gears, gill nets were the main cause of the death of dugongs. The principal strategies to conserve the dugong in Thailand are : 1) to act of limiting or reducing some activities, which do harm dugong lives, such as the type of fishing gear, illegal fishing, speed boat, and tourism activity in seagrass beds and dugong habitats, 2) to promote the specific areas as national dugong sanctuaries, for instance, Talibong-Muk Islands in Trang Province, Sriboya-Cham-Pu Islands in Krabi Province, 3) to provide education and to increase public awareness on dugong and seagrass resources conservation, and 4) to promote a network of well-managed marine protected areas, which will conserve key dugong feedings sites through the both coastlines

Cultural significance of dugong to Thai villagers: Implications for conservation

March 5-6, 2009, Bangkok, ThailandDugongs (Dugong dugon) are seen in limited areas along both coastlines of Thailand, the Andaman Sea and the Gulf of Thailand. Thai researchers have been studying the dugong since 1979. Information on the history of dugongs, beliefs, and the previous use of dugong body parts in Thailand has been gathered from interviews with local people along both coastlines since 1994. Within Thailand various village names and other locations have been derived from the various names of the dugong in the Thai language. Currently, the local belief in magical properties of dugongs are not as strong as in the past, but items made of dugong body parts have been found, especially along the coast of the Andaman Sea. Scientists are making an effort to utilize traditional ecological knowledge on the conservation and management of dugong and other marine endangered animals. It is likely that traditional ecological knowledge would play an important role in conservation and management of dugong and biodiversity in Thailand in the future

Morphology and organ weight of dugongs (Dugong dugon) in Thai waters

February 23-25, 2010, Phuket, ThailandData were obtained from dugong specimens collected in Thai waters during 22 June 1979 to 31 October 2009. Length and weight of calves ranged from 0.97-1.31 and 14-50 kg (n = 14). The average length of mature male and female was 2.58 ± 0.18 m (SD) (n = 12) and 2.55 ± 0.17 m (n = 23). The average weight of mature male and female was 249.6 ± 40.6 kg (n = 7) and 251.2 ± 55.2 kg (n = 17). Meat was the main part of dugong followed by blubber, while bone and internal organs were of similar proportion (n = 44). Organ weight from maximum to minimum was; lung, liver, kidney and heart. Weights (kg) of lung: liver: kidney: heart in male were 2.99 ± 1.01: 2.52 ± 0.73: 0.88 ± 0.21: 0.53 ± 0.18 (n = 11) and those weights (kg) in female were 3.35 ± 0.94: 3.09 ± 1.00: 1.26 ± 0.50: 0.53±0.19 (n = 7). Brain was very small, only 0.1% of body weight. Food contents in the stomachs of male and female were 1.92 ± 0.99% and 2.8 ± 1.13% of their body weight (n = 45). The maximum length of intestine was 12.04 ± 2.1 times of the body length (n = 44)

Analysis of stomach contents of dugongs (Dugong dugon) from Gulf of Thailand

Organized by Graduate School of Informatics, Kyoto University ; JSPS Bangkok Liaison Office ; Japanese Society of Bio-logging Science ; Informatics Research Center for Development of Knowledge Society InfrastructureDecember 13-15, 2004, Imperial Tara Hotel, Bangkok, ThailandDuring October 1994-March 2001, six stomach samples of stranded dugongs were collected from 4 provinces in the Gulf of Thailand - 3 from Rayong Province, 1 from Chonburi province, 1 from Chumporn Province and 1 from Surat Thani Province. Based on the inspection of physio/morphological characters of leaves and epidermal cells, seagrass fragments were identified down to genus/species under stereo-and compound-microscopes. Five species of seagrass were found in the dugong stomachs, their biomass were determined in terms of dry weight. The percentage of dry weight of each genus/species found in the stomach contents was as follows : Halophila (H. ovalis and H. decipiens) 9.97-55.43%, Halodule uninervis 0-37.43%, Thalassia hemprichii 0-2.25%, and Enhalus acoroides 0-13.74%. The frequency of occurrence of seagrasses in the stomachs ranged from the maximum to the minimum as follow : Halophila, Halodule, Enhalus and Thalassia. In addition, rhizome (13.99-45.49%) and algae (3.33-16.41%) were found in all stomach samples

Records of killer whales (Orcinus orca) in Thai waters

March 5-6, 2009, Bangkok, ThailandKiller whales (Orcinus orca) are found in all oceans and seas, in both hemispheres. Recent genetic, morphological, coloration and ecological evidences suggested that there are several geographic forms of killer whale i.e. Type A resident, Type A transient, Type B, Type C, and Type D. This paper provides killer whale records in Thailand since 1993 to 2008. There were 11 records of killer whale sightings in Thai waters; 10 records were from the Andaman Sea and 1 record was from the Gulf of Thailand. All sightings were from coastal areas of 3 provinces; Phang-nga, Phuket and Surat Thani and most of them were concessionary recorded by tourists. The sighted pods were around 2-30 individuals. Among all records, the photographs were available for type identification from 2 records in 2006-2007. The closed saddle patch that extends forward and the more pointed dorsal fin tip indicated that they were Type A transient killer whale. Additionally, killer whales in the Andaman Sea were reported to prey upon mantas