Dongsha Islands
The Dongsha Islands, also known as the Pratas Islands, are a small group of three islands forming a coral atoll located in the South China Sea, approximately 211 miles southeast of Hong Kong. Governed by Taiwan, these islands are characterized by a circular atoll structure, with Dongsha Island being the only island above sea level, while the other two are submerged. The region is notable for its rich biodiversity, supporting a variety of flora and fauna, including numerous fish species, coral, and migratory birds like the Chinese Egret.
The islands face significant environmental challenges, such as overfishing, pollution, and climate change, which threaten their delicate ecosystems. Human activities, including past military control and commercial fishing, have exacerbated these pressures. In response to environmental concerns, the Dongsha Marine National Park was established to protect the marine habitat and the surrounding waters. Despite these conservation efforts, ongoing tensions between Taiwan and China, along with the impacts of global warming, continue to pose risks to the islands and their biodiversity. The Dongsha Islands represent a unique ecological area that highlights the interplay between natural beauty and human impact in the South China Sea.
Dongsha Islands
- Category: Marine and Oceanic Biomes.
- Geographic Location: South China Sea.
- Summary: The Dongsha Islands are a group of three islands forming an atoll in the South China Sea. They are threatened by development, climate change, and overfishing.
The Dongsha Islands (or Tungsha, literally meaning “east sand” in Chinese), formerly known as the Pratas, are a group of three islands located 211 miles (340 kilometers) southeast of Hong Kong in the northeastern South China Sea. Together, they comprise a circular coral atoll composed primarily of clastic coral and reef flats approximately 15 miles (24 kilometers) in diameter, enclosing a lagoon about 10 miles (16 kilometers) in diameter. The island group includes Dongsha Island, which is above sea level, about 1 mile (1.6 kilometers) long, and a little over 0.5 mile (0.8 kilometers) wide, and Northern Vereker and Southern Vereker atolls, both of which are below sea level.
Dongsha is governed by Taiwan, the Republic of China. The closest Taiwanese city is Kaohsiung, 276 miles (444 kilometers) to the northeast. Uniquely positioned along important trade routes, Dongsha has a human history that dates back to ancient times. Today, it faces numerous challenges, primarily from human activity, such as overfishing, pollution, and development.
Known as the Imperial Crown of the South China Sea, Dongsha Island rises 25 to 30 feet (eight to nine meters) above sea level; it is covered by coarse coral sand, shrubs, tropical vines, and low bushes. The area has a subtropical monsoon climate, with year-round temperatures averaging 79 degrees F (26 degrees C). The region is affected by typhoons, the northeast monsoon, and the East Asian rainy season, commonly called the plum rains.
Biota
The island supports a wide variety of reptiles, birds, mammals, fish, coral, and flora, including 168 plants, 250 corals, 140 birds, and more than 600 fish species. New discoveries are continuously being made. From 2018 to 2019, researchers recorded seventy-four new crustacean species on the islands. Already known flora include silver silk trees (genus Albizia), tung trees (Aleurites fordii), coconut trees, and marine plants. The majority of the bird species observed on Dongsha are waterfowl or migratory birds; they include little tern (Sternula albifrons), Chinese egret (Egretta eulophotes), turnstone (family Scolopacidae), and gull-billed tern (Gelochelidon nilotica).
The waters surrounding Dongsha support a variety of fish, such as grouper (subfamily Epinephelinae), parrotfish (subfamily Scarinae), and sea bream (family Sparidae), as well as a host of invertebrates such as mollusks, starfish, and crustaceans like mud crabs, hermit crabs, and rock lobsters. The beaches of Dongsha Island also provide an important nesting ground for marine turtles. In 2011, a newly recorded species of sea slug, Ercolania subviridis, was discovered at Dongsha, living in the chaetomorpha algae. The discovery of this tiny slug moved its known range of global distribution further south.
Human Interaction
Dongsha Island occupies a unique position between Taiwan, Hong Kong, and the Philippines; it has been an important location for sea travelers. Before becoming part of the Dongsha Marine National Park, the area was under military control, and today, the Dongsha Coast Guard Administration maintains a presence on the island. Once discovered during the ancient Han Dynasty, Dongsha Island became an important point along trade and fishing routes through the Taiwan Strait, which separates Taiwan from mainland China, and the Bashi Channel between Y'Ami Island of the Philippines and Orchid Island of Taiwan.
Lying on a direct route between Manila and Hong Kong, Dongsha is the site of many shipwrecks, particularly on its southeast side, which is covered by a thick fog during the northeast monsoon, which occurs annually around September. To increase maritime safety in the region, a lighthouse, radio station, and meteorological observatory were built on Dongsha in the early 1900s. During its wartime occupation by Japan, Dongsha was a site of significant hunting and phosphorous mining, activities that negatively affected bird populations.
Environmental Threats and Response
Ongoing threats to the Dongsha Atoll include climate change, coral bleaching, and pollution. While Dongsha Island is biodiverse, the numerical population of each species is relatively low, due primarily to human pressures in the form of development, mining, hunting, overfishing, pollution, and the introduction of invasive species.
Concerns about the health of this rich environment led to the 2004 formation of the Dongsha International Research Station by the Kaohsiung municipal government, followed three years later by the creation of Dongsha Marine National Park, the seventh and latest national park of Taiwan. Managed by the Ministry of the Interior, the park comprises 1,365 square miles (3,535 square kilometers) of mostly open water, with Dongsha Island representing the terrestrial portion. After Kenting National Park, it is the second marine ecological protection area in Taiwan, and represents the first area in the nation dedicated exclusively to the protection of a marine environment.
Rising tensions between China and Taiwan and the presence of Chinese military forces near the island is another unknown threat. China-Taiwan relations remain at odds with the international community worrying about the possibility of a military conflict. Such an outcome could have devastating consequences for the island and marine life. However, as of 2024, the two countries have had no direct engagements. Observers continue to monitor the situation and report on military presence.
The effects of global warming are a growing concern here. Rising sea level and increased likelihood of more severe typhoon events mean that coral, intertidal, and shoreline habitats could suffer repeated and lasting damage, both from outright battering and flooding, and from salt intrusion. Seawater-temperature rise will also jeopardize the coral, as coral bleaching is directly associated with higher temperatures. Unpredictable changes in marine species balance are also projected, as several fish types have already been recorded as migrating farther north across the South China Sea, presumably fleeing from higher average seawater temperatures near the equator.
Overfishing, in particular, has taken a heavy toll on Dongsha. Surveys conducted between 1994 and 1998 revealed that almost 8,000 fishing vessels from China, Hong Kong, Vietnam, and the Philippines were observed fishing near Dongsha, using destructive methods such as gill nets, longlines, purse seine nets, dynamite, and cyanide. Some estimates show that around 1 ton (0.9 metric tons) of dynamite, 9 tons (8 metric tons) of mercury and batteries, and 50 tons (45 metric tons) of cyanide are dumped in the waters around Dongsha every year.
Attention to these issues, and higher-visibility conservation efforts, may help to turn the tide. The endangered green sea turtle (Chelonia mydas), which had previously disappeared from the island, was spotted in 2011 laying eggs during the breeding season, indicating the success of Taiwan's “blue sea ad hoc” conservation program, which prevents foreign ships from operating near Dongsha.
Bibliography
Chen, Rogge, et al. "Endangered Sea Turtle Reappears on Dongsha Island." Taiwan News, 13 Dec. 2011, pp. 3-4.
Collingwood, Cuthbert. "The Natural History of Pratas Island in the China Sea." Quarterly Journal of Science, vol. 4, no. 1, 1867, pp. 1-8.
"Conservation Efforts in Dongsha See Results: 5 Newly Recorded Species in Taiwan." Taiwan National Park Service, 27 May 2020, www.taiwan.nps.gov.tw/news/274-english/news/dongsha/10489-conservation-efforts-dongsha-see-results. Accessed 8 Nov. 2024.
Lee, Ling-ling, editor. "Dongsha Marine National Park." Society for Wildlife and Nature International Conservation Newsletter, vol. 15, no. 1, 2007, pp. 12-15.
Liu, Shang Yin Vanson, et al. "Dongsha Atoll Is an Important Stepping-Stone That Promotes Regional Genetic Connectivity in the South China Sea." Aquatic Biology, 31 Aug. 2021, doi.org/10.7717/peerj.12063. Accessed 8 Nov. 2024.
Ting-hung, Hung. "Number of Sea Turtles Increasing across Taiwan." Taipei Times, 14 Sept. 2020, www.taipeitimes.com/News/front/archives/2020/09/14/2003743376. Accessed 8 Nov. 2024.