China Releases Two Reports on South China Sea Ecosystem Amid Disputes

Two Repots Issued by Ministry of Natural Resources and Minsitry of Ecology and Environment

A Survey Report on the Damage to Coral Reef Ecosystem by Illegally Grounded Military Vessel at Ren’ai Jiao

Recently, two Chinese departments published their reports regarding the disputed South China Sea ecosystem. One regards the eco damage caused by the Fhillipeen grounding vessel, named “A Survey Report on the Damage to Coral Reef Ecosystem by Illegally Grounded Military Vessel at Ren’ai Jiao. “ published by the Ministry of Natural Resources.

China and the Philippines have been disputed for a long time regarding responsibility for damaging the reef's ecosystem; we finally have access to data and pictures of the seabed in the disputed area. The report is based on satellite remote sensing and on-site survey data and provides access to the coral reef ecosystem's status at Ren'ai Jiao for the first time.

Source:https://scs.mnr.gov.cn/scsb/shyw/202407/cc0646d175d14722b740bc318dad84bb.shtml

This report has the official English ver, so I’ll just bring some key takes of the report:

• The area of reef-building coral coverage on the reef flat and lagoon slope has significantly decreased, with the decline being particularly evident around the grounded vessel.

• Large amounts of coral reef fragments and dead corals were found near the vessel.

• The number of reef-building coral species and their coverage on the lagoon slope are lower than on the seaward slope.

• The population structure of large benthic invertebrates in the reef area is unbalanced, especially around the vessel.

• The content of heavy metals, oils, and active phosphates in the reef area's seawater is higher than in historical records.

• Various types of discarded objects, such as fishing nets, are scattered throughout the reef area.

  The report suggests that the main factors causing the damage to the coral reef ecosystem at Ren'ai Jiao are the grounding of the Philippine vessel and its associated human activities. These include the initial impact of the grounding, the long-term suppressive effect on coral growth and recovery, the leaching of heavy metals due to the vessel's corrosion, the discharge of waste and sewage from the vessel's personnel, and the discarding of fishing gear by Philippine fishing boats and vessel personnel.

A buoy is pictured near the grounded Philippine warship BRP Sierra Madre

Survey Report on the Ecological Environment Status of the Waters around Huangyan Island

The other report was issued by the Ministry of Ecology and Environment. This marks the first investigative report focusing on the ecological environment near Huangyan Island (called Scarborough Shoal in Philippine).

It is worth noting that during the 2016 arbitration case between the Philippines and China concerning the South China Sea, in which China neither participated nor acknowledged its legitimacy, the tribunal criticized China for causing "severe harm to the coral reef environment.” However, the tribunal failed to provide evidence to support this claim. The report today rejected that kind of accusation.

The report based on the on-site joint survey of various Chinese departments carried out from May to June 2024. The survey content covered seawater quality, sediment quality, biological quality, marine debris, as well as coral communities, reef-dwelling fish, and typical biological groups.

A total of more than 600 samples of various types were collected, and 289 GB of survey image data was obtained. In collaboration with the Guangxi South China Sea Coral Reef Research Key Laboratory of Guangxi University, the Resources and Ecology Key Laboratory of the South China Sea Institute of Oceanology, Chinese Academy of Sciences, and others, a comprehensive analysis and assessment of the relevant scientific investigation and research results, as well as satellite remote sensing survey results, of the waters around Huangyan Island over the years was conducted."

Here are some key points:

• The environmental quality of the waters around Huangyan Island is excellent, with Grade I seawater and marine sediment quality.

• Pollutant residues in fish samples are below standard limits, and no cyanide was detected in seawater, sediment, or fish samples.

• The density of floating garbage on the sea surface is relatively low.

• The coral reef ecosystem is healthy, with a rich diversity of reef-building corals (109 species) and a high average coverage of live corals (28.6%).

• Coral reef biodiversity is rich, with 125 species of reef-dwelling fish and various other key ecological groups recorded.

• No phase shift from corals to macroalgae or coral reef diseases were observed, and the quantity of enemy organisms is low.

• The reef-building coral communities show good resistance and tolerance to rising seawater temperatures, making Huangyan Island an important habitat and shelter for corals and related species in the South China Sea, especially in the context of global warming.

More details:

Source:https://www.mee.gov.cn/ywgz/hysthjbh/hystbhhhjzlgl/202407/U020240710397610658175.pdf

https://www.mee.gov.cn/ywdt/xwfb/202407/t20240710_1081267.shtml

Environmental Quality Status of the Waters around Huangyan Island

(1) Seawater Quality
The survey results from May to June 2024 show that the seawater quality in the waters around Huangyan Island is classified as Grade I. No cyanide, copper, lead, cadmium, total chromium, mercury, or arsenic were detected in the seawater at any of the survey sites. The concentrations of suspended solids, chemical oxygen demand, inorganic nitrogen, active phosphates, zinc, and petroleum in the seawater were all lower than the standard limits for Grade I seawater quality and also met the water quality requirements for coral growth in China's South China Sea.

The seawater eutrophication index at each survey site was less than 1, indicating no eutrophication of the water body. Compared with the survey results from May 2015, the concentration of inorganic nitrogen in the seawater around Huangyan Island has further decreased, while the concentration of active phosphates has remained basically the same, both far below the standard limits for Grade I seawater quality.

(2) Marine Sediment Quality
The quality of marine sediments inside the lagoon of Huangyan Island is classified as Grade I. No cyanide, sulfide, hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT), or polychlorinated biphenyls (PCBs) were detected in the sediments at any of the sites. The contents of total organic carbon, heavy metals, and petroleum in the sediments were all lower than the standard limits for Grade I marine sediment quality.

(3) Residual Levels of Pollutants in Marine Organisms
Fish samples, including the pennant coralfish (Heniochus acuminatus), dash-and-dot goatfish (Parupeneus barberinus), and convict surgeonfish (Acanthurus triostegus), were collected from the lagoon of Huangyan Island to test the residual levels of various pollutants in marine organisms. The results showed that no cyanide was detected in the fish samples, and the contents of copper, zinc, chromium, total mercury, cadmium, lead, total arsenic, and petroleum hydrocarbons were all lower than the standard limits specified in the guidelines for quality risk assessment of marine economic organisms.

(4) Distribution of Floating Garbage on the Sea Surface
The results of the survey using the surface water trawl method showed that the average density of floating garbage in the waters around Huangyan Island is 2.6 grams per square kilometer, and all of the garbage is plastic. Compared with the survey results of similar offshore waters globally, the density of floating garbage in the waters around Huangyan Island is at a relatively low level.

Footnote: The floating garbage surveyed by the trawl method refers to medium-sized (0.5 cm ≤ diameter < 2.5 cm) and large-sized (2.5 cm ≤ diameter < 1 m) garbage.

Status of the Coral Reef Ecosystem at Huangyan Island

(1) Status of Reef-Building Coral Communities
The survey conducted from May to June 2024 found that the reef-building coral communities of the coral reefs at Huangyan Island are in good condition.

The coverage of live reef-building corals is relatively high. The average coverage of live reef-building corals is 28.6%. In particular, the average coverage of live reef-building corals in the northeastern part of Huangyan Island reaches 37.1% (ranging from 25.4% to 52.2%), which is comparable to that of the Great Barrier Reef in Australia.

The replenishment of reef-building coral recruits is sufficient. This survey found that the replenishment of reef-building coral recruits at Huangyan Island is generally high (> 5 individuals/m²), mainly dominated by recruits from the families Pocilloporidae, Acroporidae, Agariciidae, and Poritidae, which account for 94%.

The species diversity of reef-building corals is rich. In this survey, a total of 109 species of reef-building corals belonging to 34 genera and 12 families were recorded. Compared with the survey results from May 2015, the number of reef-building coral species has increased by 45. All the reef-building coral species recorded in this survey are under second-class state protection in China. Among them, 41 species are listed as Near Threatened and 14 species as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. The dominant species mainly include Pocillopora verrucosa, Porites lutea, Pocillopora eydouxi, Porites lobata, Porites rus, Goniastrea retiformis, and Isopora palifera.

(2) Status of Key Ecological Groups in the Coral Reef

Reef-dwelling Fish

In this survey, based on the belt transect video method, a total of 125 species belonging to 23 families were recorded, with an average density of 165 individuals per 100 square meters. In addition to their significant economic value, reef fish play a crucial role in the material cycling and energy flow of coral reefs. Coral reef fish themselves are important nutrient reservoirs, and their excretions can enhance primary productivity, promote coral growth, and regulate the nutrient ratios in the ecosystem. Furthermore, coral reef fish can diagnose and protect degraded coral reefs through mechanisms such as top-down control within the food web.

Giant Clams

In this survey, a rich distribution of giant clams (Tridacna) was found in the lagoon of Huangyan Island, with an average density of 25 individuals per 100 square meters. Giant clams are the largest bivalve mollusks in the ocean, living attached to coral reefs. They are key protected wild animals in China and are listed on the IUCN Red List. Like reef-building corals, they mainly rely on the photosynthesis of symbiotic algae within their bodies to provide nutrition for their growth and development. Giant clams have the function of building and protecting coral reefs and play an important role in maintaining the ecological balance of the coral reef system and promoting the growth of coral reef structures.

Crustose Coralline Algae
Crustose coralline algae are another important group of reef-building organisms in coral reefs. This survey found that the coverage of crustose coralline algae in the coral reefs of Huangyan Island reached 23.5%, an increase of 5.6 percentage points compared to 2015, indicating the continued healthy development of the coral reef ecosystem at Huangyan Island. Crustose coralline algae are an important source of calcium carbonate in coral reef areas. They can integrate carbonate sediments and reef components, filling in the gaps and spaces in the reef rock, thereby stabilizing the structure of the coral reef. At the same time, coral larvae preferentially attach to the calcareous surface of crustose coralline algae, which plays a vital role in the growth and recovery of coral communities.

Other Typical Biological Groups
This survey found that the coverage of macroalgae in the coral reefs of Huangyan Island is generally low (< 1%). Macroalgae and coral communities coexist organically and mutually restrict each other. Macroalgae compete with and shade reef-building corals for light, physically squeeze them, and occupy their living space, thus stressing the reef-building corals and having a significant negative impact on their survival, reproduction, and population replenishment. The extremely low coverage of macroalgae found in this survey also indicates that the coral reef ecosystem of Huangyan Island is in a healthy state.