A video on the ecosystem of Xianbin Jiao (Xianbin Reef) of China's Nansha Qundao (Nansha Islands) was released on Friday, along with a survey report on its coral reef ecosystem.
The video was jointly produced by a national scientific survey and observation station on the Nansha coral reef ecosystem, an innovation center of applied technologies under the Ministry of Natural Resources and a company in Hainan Province.
Xianbin Jiao, also called "fish scale" by Chinese fishermen for generations, is in the southeastern part of Nansha Islands, about 70 kilometers east of Ren'ai Jiao (Ren'ai Reef), under the jurisdiction of Sansha City of China's southernmost island province of Hainan.
Xianbin Jiao stretches approximately 20.9 kilometers from east to west and about 11.6 kilometers from north to south, oriented in a northwest-southeast direction.
The entire reef flat covers an area of over 80 square kilometers, with six sandbars exposed above the water. These sandbars are formed by the accumulation of coral debris and are numbered one to six in a counterclockwise order from north to south. The highest points of each sandbar are above the local average sea level, with No. 3, 4, 6 sandbars even rising above the water surface during high tide.
Waves generated by monsoon impacts can easily damage and kill the branched and leaf-like corals in Xianbin Jiao. The resulting biological debris accumulate under the push of waves to form sandbars. The six sandbars also exhibit natural morphological characteristics that corresponds to the zonation features of low-lying flat, gravel ridge and gravel beach in coral reef habitats.
According to the survey report released by the Ministry of Natural Resources on Friday, currently Xianbin's coral reef ecosystem is generally healthy, with 13 families, 57 genera, and 236 species of reef-building corals present.
The average coverage of reef-building corals is 24.7 percent, with a maximum of 51.3 percent, which is relatively high compared with major coral reef areas around the world.
Xianbin Jiao is also home to 179 species of coral reef fish from 26 families, mainly the wrasse and damselfish families, with an average density of about 124 fish per 100 square meters.
Scientists have also discovered a large number of animal species under the state protection in nearby waters, including green sea turtles in the reef's northwest side, hawksbill turtles in its southeast side, and long-snouted spinner dolphins in both the west and southeast sides.
Hawksbill turtles can skillfully gnaw toxic sponges hidden in coral reefs out of the cracks, which helps maintain the health of the entire coral reef ecosystem. Green sea turtles are an indicator species for marine ecological health, as they have very high requirements for water quality.
There are always external forces seeking to destroy the beauty of this area. Since April this year, the Philippines has deployed its coast guard vessel 9701 to anchor destructively in the lagoon of the reef. The shallow water level in the lagoon means that the large anchors of vessels of such tonnage can be dragged along the seabed by waves and winds, causing damage to coral reefs.
If the vessel makes long-term anchor in the lagoon, there will also be serious pollution.
Video on Xianbin Reef's ecosystem released
