Japanese Potentially Polluting Wrecks in the Pacific Ocean By Ryo Sato 1. Executive Summary This paper assesses the location and potential dangers of contaminant associated with Japanese sunken ships and the possible contaminants, including oil and chemical weapons, leaking from the sunken ships in the Pacific Ocean. Many countries dumped chemical agents into the ocean; some agents, including chemical weapons (CWs), were dumped intentionally and others accidentally into the ocean. In either case, marine disposal of chemicals of all kinds threatens human and environmental life. 2. Japanese Commercial Sunken Ships During the Second World War (WWII), 7,240 Japanese commercial ships, including fishing boats were sunk1 -- most of them in the Pacific Ocean. In the South Pacific 3,800 vessels were sunk, over 85% of them under the Japanese flag, according to Sea Australia, an Australian based business providing environmental/marine pollution solutions.2 While this paper focuses on Japan, the geographic dispersal of sunken ships during WWII shows concentrations both around the north Atlantic and Pacific Oceans, as shown in the map below. World War II sunken vessels combining the Atlantic, Mediterranean and Indian Ocean (AMIO) and Secretariat of the Pacific Regional Environment Program (SPREP) databases Source: The Global Risk of Marine Pollution from WWII Shipwrecks (R. Monfils 2004) 0
A Japanese researcher put the number of people who died from Japanese ships sinking during WWII, including civilians, crewmen, soldiers and war prisoners, at 232,000. 3 This number included 59,200 civilians who died during Japanese ocean transportation mainly in the West Pacific Ocean. 4 Ships and vessels did not have enough naval escorts and were targeted from the Allied Forces, mainly from the United States, but the Japanese government and private companies continued the shipping activities. 5 The ocean transportation system was vital for Japan to transport natural resources, commercial goods, and passengers at that time, adding to the deaths of Japanese and the number of sunken ships in the Pacific Ocean. The figure below shows the distances of major Japanese shipping lanes during WWII. Since the average speed of Japanese ships was 10 knots (nautical miles/hour), the voyage between the islands was a long journey. 6 This was one of the main reasons that the Japanese commercial ships were easily targeted by the U.S. Navy, including submarines. Source: Loss of Commercial Ships During/After WWII 1
3.LocationofSunkenShips The figures below show that 2,588 Japanese ships over 100 metric tons were sunk during the Pacific War from 1941 to 1945. The alphabet letters in the table and map below refer to sea areas, and the numbers next to the letters refer to the number of sunken ships in each area, with the totals reflected in each geographic area in the chart. After 1942, the number of the Japanese sunken ships increased suddenly. Almost all the ships were sunk between 1942 and 1945. This is because the Japanese navy lost their main fleet in 1942 and lost the command of the seas in the West Pacific Ocean, leading to greater incursions of the US Navy into the area, as well as increased use of commandeered private vessels, which did not have the capability to defend themselves. Source: Association of War Ship Records (Senbotsu sen o kiroku suru kai) http://www.ric.hi-ho.ne.jp/senbotusen/siryo-deta/kaiikibetu.htm 2
Several shipping lines linked Japanese supply bases during WWII. The ships and vessels moved from base to base carrying passengers and goods. The first figure below shows the supply bases (the names of the bases are not placed in their geographic location), and the second figure depicts the major sea transportation routes between the supply bases. To reach the sea areas around Indonesia, the Japanese ships and vessels needed to stop at several ports. Most of the ships were attacked by the U.S. Navy on the way to these ports. In other words, most of the sunken ships are on the ocean bed along those shipping lines. 3
Global Green USA The figure below shows major sea battles and the accidents of oil spilling in the South West Pacific Ocean. Japanese and U.S. sunken battle ships are mainly around the battle area. For example, five aircraft carriers, one heavy cruiser and one destroyer were sunk in the battle of Midway.7 4. Chemical Munitions and Sunken Ships On January 29th, 1944, the Japanese Army announced the outline of chemical war preparation against the United States. This document outlined retaliation against the U.S. by using chemical weapons per chance the U.S. Army first used chemical weapons. The locations of stockpiles were decided by the Japanese government to be in Shanghai, Manila, Singapore, Truck Lagoon and Sapporo, and Ujina. The precise amount of chemical weapons that came from each of these stockpile locations is unknown, except in the case of Ujina, where the amount has been specified.8 This raises the possibility that chemical weapons might have been inside Japanese sunken ships. Furthermore, statistical data also shows the possible existence of chemical weapons in other Asian countries. According to Yoshiaki Yoshimi, a professor at Chuo University, 6,616 tons of chemical weapons were produced in Ohkuno-island. However, only 3,647 tons have been found since the 4
Photo by Rod Klein http://www.scubadiving.com/travel/2007/07/worlds-best-wrecks end of the Second World War. This implies that nearly 3,000 tons were somehow disposed of in other Asian and Pacific countries, in order to fight the Allied Forces. 9 The picture to the left shows a gas mask resting near the Japanese sunken ship, Nippo Maru, in Truk Lagoon. Truk Lagoon is located in the central Pacific Ocean. 5.OilleakingfromJapaneseSunkenShips Another problem is the issue of sunken ships leaking oil. These shipwrecks could bring about massive disasters from leaking oil in the future. 10 For instance, in 1944 an American bomb sank the Japanese oil tanker Hoyo-Maru, which now rests on the seabed. The tanker contained 2,000,000 gallons of fuel oil which could leak into the ocean. The Australian underwater archaeologist Jeffery Bill has reason to believe that bunker oil is leaking from the Hoyo-Maru and states that of the 52 shipwrecks located in Chuuk Lagoon, three are oil tankers (Hoyo-Maru, Shinkoku-Maru and Fujisan-Maru). Combined these vessels have the potential to carried up to 32,000 tons of oil (approximately 32,000,000 liters or 7,620,000 gallons). 11 Sunken ships have the potential to harm human health and the marine environment. A number of environmentalists worry about these wrecks, which are vulnerable to improper anchoring, dynamite fishing, and storms. Researchers are also concerned about the corrosion and possibility of leakage from these wrecks, since many have already been submerged for more than 60 years. 12 Photo above: Bubbles from the wreck. Photo by Bill Jeffery 6.Conclusion The negative legacy of the Second World War includes the danger of bunker oil leakages from the 7,240 Japanese ships, as well as those of other nations, sunk in the Pacific Ocean. Furthermore there is a possibility that some sunken ships contain chemical agents and unexploded ordnance. Since most of the ships and vessels have not been definitively located, it is important to conduct thorough research in order to establish a database before further investigation can be made of the dangers posed by these sunken ships both to humans and the environment. Major shipping lanes will be one of the primary clues to locate Japanese and other sunken ships. Because of the 5
potential risks these pollutants pose both to the environment and local communities in the Pacific Ocean, further research and action is needed. Endnotes 1 Takashi Oida. Loss of Commercial ships during/after the War. Resource Center of Sunken ships and Crews in Battle. (Accessed on March 16 th, 2010) 2 Rean Monfils. The Global Risk of Marine Pollution from WWII Shipwrecks: Examples from the Seven Seas. Sea Australia. 3 Takashi Oida. Loss of Commercial ships during/after the War. Resource Center for Sunken 4 Takashi Oida. Loss of Commercial ships during/after the War. Resource Center for Sunken 5 Takashi Oida. Loss of Commercial ships during/after the War. Resource Center for Sunken 6 Takashi Oida. Loss of Commercial ships during/after the War. Resource Center for Sunken 7 Atsushi Aizawa. An Announcement from the Imperial Headquarters and the Battle of Midway. http://www.nids.go.jp/publication/senshi/pdf/200403/10.pdf 8 Yoshiaki Yoshimi. Chemical gasses use by the Japanese Army. The Report from Okuno shima. 9 Yoshiaki Yoshimi. Dokulekiken-Kaihou.2. 10 Tali Woodward.Pacific. World War 2 Wrecks Pose Risk of Toxic Leaks. Ocean Conserve News Archive. December 9, 2008. http://www.oceanconserve.org/shared/reader/welcome.aspx?linkid=112882&keybold=oil%20an D%20%20spill%20AND%20%20ship (Accessed on March 16 th, 2010) 11 Bill Jeffery. Report on Oil/Diesel leaking from shipwrecks in Chuuk Lagoon. August 17 th, 2008 12 Tali Woodward.Pacific. World War 2 Wrecks Pose Risk of Toxic Leaks. Ocean Conserve News Archive. December 9, 2008. http://www.oceanconserve.org/shared/reader/welcome.aspx?linkid=112882&keybold=oil%20an D%20%20spill%20AND%20%20ship (Accessed on March 18 th, 2010) 6