Humanities › Geography Seas of the Pacific Ocean List of the 12 Marginal Seas Surrounding the Pacific Share Flipboard Email Print Australia, Great Barrier Reef. Grant Faint/Getty Images Geography Physical Geography Basics Political Geography Population Country Information Key Figures & Milestones Maps Urban Geography By Amanda Briney Geography Expert M.A., Geography, California State University - East Bay B.A., English and Geography, California State University - Sacramento Amanda Briney, M.A., is a professional geographer. She holds a Certificate of Advanced Study in Geographic Information Systems (GIS) from California State University. our editorial process Amanda Briney Updated March 01, 2019 The Pacific Ocean is the largest of the world's five oceans. It has a total area of 60.06 million square miles (155.557 million sq km) and it stretches from the Arctic Ocean in the north to the Southern Ocean in the south and has coastlines along the continents of Asia, Australia, North America, and South America. In addition, some areas of the Pacific Ocean feed into what is called a marginal sea instead of pushing right up against the coastlines of the aforementioned continents. By definition, a marginal sea is an area of water that is a "partially enclosed sea adjacent to or widely open to the open ocean". Confusingly a marginal sea is also sometimes referred to as a Mediterranean sea, which shouldn't be confused with the actual sea named the Mediterranean. Marginal Seas of the Pacific Ocean The Pacific Ocean shares its borders with 12 different marginal seas. The following is a list of those seas arranged by area. Philippine Sea Area: 2,000,000 square miles (5,180,000 sq km) Coral Sea Area: 1,850,000 square miles (4,791,500 sq km) The South China Sea Area: 1,350,000 square miles (3,496,500 sq km) Tasman Sea Area: 900,000 square miles (2,331,000 sq km) Bering Sea Area: 878,000 square miles (2,274,020 sq km) The East China Sea Area: 750,000 square miles (1,942,500 sq km) The Sea of Okhotsk Area: 611,000 square miles (1,582,490 sq km) The Sea of Japan Area: 377,600 square miles (977,984 sq km) Yellow Sea Area: 146,000 square miles (378,140 sq km) Celebes Sea Area: 110,000 square miles (284,900 sq km) Sulu Sea Area: 100,000 square miles (259,000 sq km) The Sea of Chiloé Area: Unknown The Great Barrier Reef The Coral Sea located in the Pacific Ocean is home to one of nature's greatest wonders, the Great Barrier Reef. It is the world largest coral reef system which is made up of almost 3,000 individual corals. Off the coast of Australia, the Great Barrier Reef is one of the nation's most popular tourist destinations. For the Aboriginal population of Australia, the reef is culturally and spiritually important. The reef is home to 400 types of coral animals and over 2,000 species of fish. Much of the marine life that calls the reef home, like sea turtles and several whale species. Unfortunately, climate change is killing the Great Barrier Reef. Rising ocean temperatures cause coral to release the algae that not only live in it but is the main source of food for the coral. Without its algae, the coral is still alive but is slowly starving to death. This release of algae is known as coral bleaching. By 2016 over 90 percent of the Reef had suffered from coral bleaching and 20 percent of the coral had died. As even humans depend upon coral reef ecosystems for food the loss of the world largest coral reef system would have devastating effects on the plant. Scientists hope they can stem the tide of climate change and preserve natural wonders like coral reefs.