While exploring an atlas, you will come across a number of seas spread across the globe. Earth has approximately 50 seas spread across its surface, all with their own ecological, social, and economic importance.

One such sea that has claimed significant importance in geopolitics is the China Sea, found in the West Pacific Ocean. Broken into the East China Sea and the South China Sea, this region is not only home to a unique marine environment but has long been the subject of maritime conflict.

Let’s take a deeper look at the China Seas, their characteristics, ecological importance, and an overview of the territorial conflict in the area.

The East China Sea

Quick Facts: 

  • Size: 482,000 square miles
  • Average depth: 1,145 feet
  • Max depth: 8,912 feet
  • Coordinates: 30.3953° N, 125.9152° E
The East China Sea is relatively shallow and consists mostly of the Okinawa Trench
The East China Sea is relatively shallow and consists mostly of the Okinawa Trench

The East China Sea is a marginal sea, meaning it borders a continent and is semi-isolated from the open ocean by an island arc or land ridge. It is located in the western Pacific Ocean. The East China Sea is bordered by China to the west, Japan to the east, Korea to the north, and Taiwan to the south.

This sea covers an area of approximately 482,000 square miles (1,249,00 square kilometers), which consists mostly of the Okinawa Trench. The East China Sea has an average depth of only 1,145 feet (350 meters) but reaches a max depth of 8,912 feet (2,716 meters) within the Okinawa Trench.

The South China Sea

Quick Facts: 

  • Size: 1,423,000 square miles
  • Average depth: 3,976 feet
  • Max depth:16,457 feet
  • Coordinates: 15.4881° N, 114.4048° E
The south China Sea is in constant dispute for its minerals
The South China Sea is in constant dispute for its minerals

The South China Sea is surrounded by several countries, including China to the north, Vietnam to the west, the Philippines to the east, Malaysia and Brunei to the south, and the Taiwan Strait, which borders to the northeast, and connects the South China Sea to the East China sea.

The South China Sea covers an area of approximately 1,423,000 square miles (3,685,000 square km) and has an average depth of 3,976 feet (1,212 meters), with a max depth of 16,457 feet (5,016 meters) in the Philippine Trench.

Ecology Of The China Sea

The China Sea (including both the South and East China Sea) is home to a wide variety of unique marine biodiversity that forms a tightly woven ecosystem that supports an abundance of life, both directly and indirectly, to the globe as a whole. 

Some of the most significant ecological factors of the China Sea include:


Rich biodiversity plays a major role in an ecosystem’s health. The China Sea is home to a wide range of marine species, such as coral reefs, sea turtles, dolphins, whales, and numerous invertebrates, as well as approximately 3,365 species of fish.

Many of these diverse species, such as the Harlequin Shrimp (Hymenocera elegans) and the Chinese White Dolphin (Sousa chinensis) are unique to the area and are found nowhere else on Earth.

Coral Reefs

Thanks to its shallow water basin, warm water, and extensive coastlines, the China Sea has become a significant breeding ground of hard and soft coral that supports a number of plant and animal life unique to the specific living conditions.

The china sea is home to a large variety of life, including coral reefs
The China Sea is home to a large variety of life, including coral reefs

Fisheries and Feeding Grounds

Both the East and South China Seas are vital to the global fishing industry. This region supplies a food source for local and international fishing communities and industries thanks to its high (yet falling) fish population. This fish population supports human life across the globe, as well as larger predators in the area.

Migration Routes

The China Sea serves as an important migratory gateway for a variety of marine species such as fish, sea birds, marine mammals, and reptiles such as sea turtles. The region provides an abundance of food, breeding grounds, and a connection to other parts of a species’ population.

Ecosystem Support

Thanks to the high diversity of coral reefs and plant life, the China Seas contribute widely to the global ecosystem by removing carbon dioxide, increasing oxygen content, filtering ocean water, and cycling nutrients.

Threats to The China Sea Ecosystem

As the China Sea holds such significance to humans, the overuse and abuse of the region and its resources by means such as overfishing have led to a decline in biodiversity, water quality, and the health of habitats. Although the depth of the level of human destruction is unclear, the China Sea faces ecological issues such as the following:

  • Overfishing: As the China Sea holds a large number of fish life, it has quickly become a go-to for the global fishing industry. Thanks to a lack of education, greed, and a blatant disregard for sustainable fishing practices, the fish stocks are quickly depleting, which in turn, is affecting a variety of marine life that these fish previously supported.
  • Destruction of habitats: Coastal development (think hotels and resorts for tourists), leisure activities such as SCUBA diving and motorboats, and destructive fishing methods such as dynamite fishing have laid waste to large areas of critical habitats. Seagrass, coral reefs, and mangrove forests that have previously supported a large variety of life are quickly disappearing, and with them, the life that once supported
  • Pollution: An increase in industrial production, tourism, and shipping create pollutants such as nutrient run-off, oil spills, chemical waste, and greenhouse gasses that are affecting the quality of life in the China Sea, which has begun to threaten its plant and animal populations
  • Climate change: Rising water levels, a change in ocean acidity, and warming seawater have led to coral bleaching, a reduction in marine organism calcification rates, and the destruction of life-supporting habitats
  • Invasive species: The introduction of non-native species, whether it be intentional or otherwise, can and does disrupt the natural balance of the China Sea ecosystem. Invasive species often out-compete natives, sometimes wiping them out entirely
  • Territorial disputes: The China Sea has been under constant dispute between the surrounding nations, each of them fighting for the right to use the waterway to their own benefit. This dispute has hindered cooperation for conservation efforts and sustainable fishing practices.
Overfishing in the China Sea is quickly destroying the natural habitat
Overfishing in the China Sea is quickly destroying the natural habitat

China Sea Conservation Efforts

Although a large amount of destruction is taking place in the China Sea, surrounding regions, as well as global organizations, have made a large push in the direction of conserving the environmentally significant area.

In 2016, China implemented a project that aimed at establishing red lines with regard to development in its coastal areas. This proposal was aimed at conserving the remaining habitats and restoring those that have degraded within the coastal ecosystem.

Marine nature reserves, a fishing limit, and coastal patrols have some of the ways that the China Sea is being regulated; however, due to the large number of fishing vessels and local fishing villages, these efforts are difficult to maintain.

Roughly 13% of China’s marine and coastal areas are protected by either MPAs (Marine Protected Areas ) or AGRs (Aquatic Germplasm Reserves). The China Sea includes approximately 326 sites, of which conservation efforts are taking place.


Why is there a territorial dispute in the China Sea?

Surrounding countries, including China, Vietnam, the Philippines, Malaysia, Taiwan, and Brunei, all have claims in the South China Sea. These claims are based on historical, geographical, and sometimes legal factors which often contradict each other, thus keeping the area in an unsettled dispute.

Are there endangered species in the China Sea ecosystem?

There are a number of endangered species that are found in the China Sea. Some of these include the Hawksbill turtle, which uses the China Sea and its many islands as a yearly nesting ground. Another species at risk is the dugong, which is threatened by a decreasing seagrass population.

How important are coral reefs in the China Sea for marine wildlife?

Coral reefs provide food, shelter, and breeding grounds for a wide array of species, as well as produce oxygen and remove carbon dioxide from the environment. Coral reefs support a large variety of life that can be found in no other conditions on Earth.

How does the loss of biodiversity in the China Sea impact the ecosystem?

A loss of biodiversity is catastrophic for any ecosystem. As the food web is a complex formulation of intricacies, removing a single part of the system can lead to the entire destruction of the ecosystem. For example, if one species dies out, predators will favor others, often leading to overfeeding on a particular species and a further reduction in biodiversity.

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