Coral Reef Assesment and Status Evaluation in Dongsha Atoll

Project Duration	2011-02-28 ~ 2011-12-29
Research Title	Coral Reef Assesment and Status Evaluation in Dongsha Atoll
Contracted Organization	Taiwan Coral Reef Society
Principal Investigator	Cheng Ming-Hsiu
Co-Principal Investigators	Tai Chang-Feng, Chen Cheng-Ping
Project Participants	Lin Hsin-Yu, Chen Teng-Sung, Tu Tzu-Hsuan, Chu Shu-Hui, Kuo Tao-Jen, Cheng An-Yi, Chin Chi-Hsiang, Huang Chien-Hua, Kuo Jen-Wei, Tsai Ming-Hsien, Yang Ching-Na
Keywords	Dongsha, Dongsha Atoll, coral reefs, ecological resources
Abstract	This project was conducted from March to December 2011. Four field surveys were carried out in April, June, July, and August, completing scuba investigations at 27 stations, including 17 stations on the outer atoll and 10 within the lagoon. Surveys covered coral assemblages, coral reef fishes, and large benthic invertebrates. A total of 286 coral species were recorded, including 231 scleractinian corals, 1 antipatharian coral, 48 octocorals, and 6 hydrocorals. Among these were 6 newly recorded genera and 20 newly recorded species. Coral reef fish surveys documented 408 species; of 30 newly recorded species, one (Nannosalarias nativitatis) was a new record for Taiwan, while the remaining 29 species were newly recorded for Dongsha waters. Large benthic invertebrates comprised 205 species from 70 families, dominated by mollusks (42 families, 137 species), followed by echinoderms (15 families, 28 species) and crustaceans (13 families, 40 species), including newly recorded families and species for the latter two groups. Regarding coral cover, the highest live coral coverage (92.5%) was recorded at a south-southeastern outer atoll station. Lagoon stations exhibited substantial spatial variability (5.5%–80.0%), indicating strong influence of localized environmental factors. No mass coral bleaching or crown-of-thorns starfish outbreaks were observed during the surveys. Compared with previous years, most stations showed slight increases in coral cover in 2011. Fish assemblages differed significantly among inner lagoon, outer atoll, and near-island areas, consistent with previous findings. Indicator fish assessments suggested that groupers and large commercially valuable fishes were under considerable fishing pressure. Surveys of large benthic invertebrates also showed increased species richness in 2011, with distinct assemblage differences between outer atoll and lagoon areas. Both fish and invertebrate results indicate that Dongsha Atoll continues to face harvesting pressure, particularly in outer atoll areas. Recommendations for future management of Dongsha Atoll National Park include: 1. Promote development toward marine education and ecotourism. 2. Encourage international academic collaboration to enhance global visibility. 3. Develop interpretive materials and establish a marine ecological guide system. 4. Implement routine ecological monitoring programs. 5. Plan for transportation vessels, research vessels, and pier facilities in anticipation of tourism. 6. Strictly review and supervise new infrastructure development on Dongsha Island. 7. Strengthen enforcement against illegal fishing in cooperation with the Coast Guard Administration and reinforce no-fishing zone regulations.