Tokyo Bay
Tokyo Bay sits at the heart of the most populated and heavily industrialized stretch of land in Japan. On a July morning in 1853, four American warships steamed into what was then called Edo Bay, and nothing about Japan would be the same again. The bay that Commodore Matthew Perry chose for that confrontation had already carried centuries of history on its waters. How did a sheltered inlet on the southern coast of Honshu become the fulcrum of an empire, a theater of war, and the engine of a modern industrial giant? Those are the questions that draw us into Tokyo Bay.
Long before Perry arrived, the Japanese had their own name for these waters. In ancient times the bay carried a name rooted in the local landscape. By the Azuchi-Momoyama period, spanning 1568 to 1600, the bay had taken on the name of the city of Edo that dominated its northern shore. The name Tokyo Bay came only after the Imperial court moved to Edo and renamed the city Tokyo in 1868. That single act of renaming rippled outward to the water itself, tying the bay permanently to the new capital's identity. The older Edo name is a reminder that the bay's importance predates the modern era by many centuries.
Cape Kannon on the Miura Peninsula to the west and Cape Futtsu on the Boso Peninsula to the east mark the bay's narrow inner boundary. In that confined definition, Tokyo Bay covers about 922 square kilometers. A broader reading includes the Uraga Channel, which stretches the area to roughly 1,100 square kilometers; combined with the channel, the total reaches 1,500 square kilometers. The bay's floor is relatively uncomplicated north of a shoal called Nakanose, where the depth sits at around 40 meters. Nakanose itself, stretching between Cape Futtsu and Cape Honmaku in Yokohama, is shallower at 20 meters. South of Nakanose, the seabed drops sharply as the water pushes toward the Pacific.
Sarushima, a tiny natural island of just 0.055 square kilometers off Yokosuka in Kanagawa Prefecture, holds the distinction of being the only natural island in Tokyo Bay. During the Bakumatsu period it was fitted with coastal artillery; later, in the Meiji period, it became part of the Tokyo Bay Fortress. The Imperial Japanese Navy kept a degaussing station on Sarushima until the end of World War II. Today the island is uninhabited and serves as a marine park. Odaiba tells a different story. One of six artificial islands built in 1853 to shield the Tokugawa shogunate at Edo, it was known as the Shinagawa Daiba before eventually being folded into Tokyo and rebuilt for commercial and recreational use after World War II. Yumenoshima was once drawn up as an airfield planned to be among the largest in the world. When the US military expanded Haneda Airport after the war, that plan collapsed. The island opened briefly as a public beach and then spent a decade, from 1957 to 1967, absorbing waste from the Tokyo Metropolitan Area. The reclaimed ground is now Yumenoshima Park. Hakkei Island, built in 1985 on what had been Landfill Number 14, covers 0.24 square kilometers and is home to Yokohama Hakkeijima Sea Paradise.
Land reclamation along Tokyo Bay dates back to the Meiji period. Wherever the water is shallower than 5 meters, landfill operations are most practical, and sand dredged from the bay floor supplies the raw material. By 2012, about 249 square kilometers of reclaimed land existed along the bay's edges, and ongoing projects continued to slowly shrink the bay's measured area of 922 square kilometers. Greater Tokyo produces waste on an enormous scale. Space for traditional disposal is scarce, so households sort waste rigorously. Much of it is converted to ash and then cycled back into landfill construction, linking the daily life of millions of residents to the physical reshaping of the bay. The reclamation effort has so thoroughly altered the shoreline that its modern outline bears little resemblance to how it looked in the pre-modern period.
Fishing and shellfish gathering were once central to life around Tokyo Bay, but industrialization in the early twentieth century pushed those industries aside. Construction of the Keihin and Keiyō industrial zones directly after World War II essentially ended the fishing economy that had existed there for generations. The Keihin Industrial Zone grew on reclaimed land in Kanagawa Prefecture to the west of Tokyo. The Keiyō zone expanded it into Chiba Prefecture along the bay's northern and eastern edges. Together they produced the largest industrialized area in Japan. The Port of Yokohama, the Port of Tokyo, the Port of Chiba, the Port of Kawasaki, the Port of Yokosuka, and the Port of Kisarazu all rank among the busiest in the Asia-Pacific region. That concentration of industry and shipping, however, brought significant air and water pollution to the coastal zone. The Port of Yokosuka is also where the Japan Maritime Self-Defense Force and United States Forces Japan maintain naval bases.
Commodore Matthew Perry, born in 1794 and died in 1858, sailed his four ships into Edo Bay on the 8th of July, 1853. Those vessels, famously called the Black Ships, carried the weight of American diplomatic pressure aimed at opening Japan to trade. The negotiations Perry began with the Tokugawa shogunate concluded in 1854 with a peace and trade treaty between the United States and Japan. Less than a century later, the bay became the site of a very different ceremony. On the 2nd of September, 1945, the Japanese Instrument of Surrender was signed aboard a warship anchored at 35 degrees 21 minutes 17 seconds north, 139 degrees 45 minutes 36 seconds east. A flag from one of Perry's original ships was flown in from the Naval Academy Museum and displayed at that surrender ceremony, connecting the moment of Japan's opening to the world with the moment that marked the end of a global war.
Common questions
Where is Tokyo Bay located in Japan?
Tokyo Bay is located in the southern Kanto region of Japan, spanning the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture on the southern coast of Honshu. It connects to the Pacific Ocean via the Uraga Channel.
How large is Tokyo Bay in square kilometers?
In the narrow sense, Tokyo Bay covers about 922 square kilometers. Including the Uraga Channel, the broader area reaches approximately 1,100 square kilometers, and the combined total with the channel is 1,500 square kilometers.
What is the only natural island in Tokyo Bay?
Sarushima, a 0.055 square kilometer island off Yokosuka in Kanagawa Prefecture, is the only natural island in Tokyo Bay. It served as a fortification site during the Bakumatsu and Meiji periods and is now an uninhabited marine park.
Why did Commodore Perry sail into Tokyo Bay in 1853?
Commodore Matthew Perry sailed his four Black Ships into Edo Bay on the 8th of July, 1853, to pressure the Tokugawa shogunate into opening Japan to American trade. The negotiations he began led to a peace and trade treaty between the United States and Japan in 1854.
Where was the Japanese Instrument of Surrender signed at the end of World War II?
The Japanese Instrument of Surrender was signed on the 2nd of September, 1945, aboard a warship anchored in Tokyo Bay at coordinates 35 degrees 21 minutes 17 seconds north, 139 degrees 45 minutes 36 seconds east. A flag from one of Commodore Perry's original ships was displayed at the ceremony.
How much reclaimed land does Tokyo Bay contain?
Tokyo Bay contained about 249 square kilometers of reclaimed land as of 2012. Land reclamation has been ongoing since the Meiji period, using sand dredged from the bay floor, and continues to gradually reduce the bay's area.
All sources
2 references cited across the entry
- 1encyclopediaTokyo BayShogakukan — 2012