Sea Of Japan (East Sea)

The Sea of Japan, also referred to as the East Sea, is a marginal sea located in the western Pacific Ocean. It covers an extensive area of 978,000 km2. Due to their proximity to land masses and human activities, marginal seas tend to be shallower compared to the open oceans. A marginal sea is specifically defined as a sea that is partially enclosed by islands, archipelagos, or peninsulas.


Do-dong port, Ulluendo island, South Korea, in the Sea of Japan.

The Sea of Japan is approximately 2,255 km in length and has a maximum width of 1,070 km. It consists of steep and high banks such as Banks Hakusan, Ridge Wakasa, Oki Ridge, Okujiri Ridge, and Sado Ridge. The coastline of the sea is weakly dissected and it is located in the southwest Basin Tsushima and southeast Basin Yamato, with the north Basin Japan. The mean depth of the sea is estimated to be 1,752 m, while its maximum depth is 3,742 m.

The warm and cold currents converge at the Sea of Japan, which acts as a meeting point for regions from the south and the north. Honshū Island in Japan, specifically Toyama and Wakasa, Ishikari in Hokkaidō Island, Sovetskaya Gavan, Vladimira Bay, Posyet Bay, Olga, Peter the Great, and East Korea Bay in North Korea are home to the largest bays in the Sea of Japan.

Rebun, Rishiri, Okushiri, Sado, Moneron, Ōshima, Okinoshima, Askold, Putyatin, and Russky islands form part of the archipelago. The remaining smaller islands are located along the eastern shoreline, with the exception of Ulleungdo, an island belonging to South Korea. The Sea of Japan does not have any significant landmasses.

Marine Life

King crab for sale in a market in Niigata, Japan.

The marine mammals found here include seals and whales, with echinoderms like trepangs (sea cucumbers), mollusks like oysters, scallops, mussels, squid, and cuttlefish, as well as crustaceans like shrimps and crabs residing in the waters of the Sea of Japan. Cod, Atka mackerel, and Alaskan pollack are among the demersal fish in the sea. Pelagic fish such as different salmon and trout species, herring, anchovies, sardines, saury, Jack mackerel, and mackerel are also found here. The Sea of Japan is home to 26 species of marine mammals, 900 crustacean species, and 1,000 fish species. The rich diversity of marine life supported by the Sea of Japan includes over 800 species of aquatic flora and 3,500 aquatic faunal species.

Sea of Japan map
Sea of Japan map

Where Is The Sea Of Japan?

Sea of Japan map
Map of the Sea of Japan.

The Japanese archipelago is connected to the East China Sea in the south by the islands of Kyūshū and Honshū, and to the east by the Sea of Japan. The Sea of Japan is also connected to the Okhotsk Sea in the north by the Tatar and La Perouse Straits. Japan’s Sea of Japan is connected to the Sea of Japan in the south via the Korea and Tsushima Straits. It is also connected to the Sea of Japan via the Kanmon Strait and the inland waters of Japan. The Sea of Japan is connected to the Pacific Ocean by the Tsugaru Strait and the East China Sea via the Tsushima Strait. The Sea of Japan is bounded by South Korea to the south and southwest, North Korea to the west, and Sakhalin Island and Russia to the north in Eastern Asia.

Naming Dispute

, Both the “Sea of Japan” and “East Sea” are commonly used to refer to this body of water, including in parentheses. However, some documents and maps often use either the name “Sea of Japan” or “East Sea.”


Niigata, Tsuruta, and Maizuru are notable ports in the Sea of Japan. Hamhung, Chongjin, and Wonsan are the prominent North Korean ports in the same area. Vladivostok, Sovetskaya Gavan, Nakhodka, Alexandrovsk-Sakhalinsky, and Kholmsk are the main Russian ports found in this sea. Fishing has been a long-standing pillar of the region’s economy for centuries. Mining for mineral deposits such as magnetite, natural gas, and petroleum constitutes some of the key economic activities conducted in the Sea of Japan.