The South Pacific was not involved in the first stages of the war as before the bombing of Pearl Harbour (Hawaii) by the Japanese the 'global' war was predominantly confined to the European mainland, some minor colonial struggles in Africa and Asia, the battle for the Atlantic supply chains and Manchuria/China. However, after the American entry into the war the South Pacific became the site for the key battles of the Far Eastern theatre. Along with these large scale conflicts there developed an Atlantic-style form of submarine warfare as each side tried to derail the others logistical war effort by sinking their transports, oil tankers and warships.
Invariably this destruction of shipping had major environmental effects on areas of great marine biodiversity. To this day the governments of Pacific islands worry about the effects that oil discharges from long abandoned wrecks will have on sea birds, fish stocks and sea turtles. Some of the environmental issues involved can best be examined through a case study of the sinking and subsequent handling of the USS Mississinewa.
1) Environmental risks – Oil in submerged ships does not cease to be dangerous just because it has been down there for decades. A wide range of different types of fuel were used by WW2 era ships. Diesel, predominantly used by submarines, dissipates very quickly in Pacific waters but can still cause environmental damage if containers that have previously kept it from escaping are breached. Heavy fuel oil, generally carried by larger oil tankers and war ships, is more durable. While some elements of it quickly dissipate, others will spread widely where currents permit and can endanger birds, fauna and sea life over a wide area by smothering them in toxic oil. Even wrecks that seem to be secure can quickly become environmental crisis points as tropical storms are common in the Pacific and may cause breaches of previously sealed fuel tanks.
To take an example, the USS Mississinewa was carrying 3,780,000 US gallons of oil when it was sunk by a Japanese manned torpedo. SOPAC estimates that, after a tropical storm disturbed it in 2001, it was leaking 300-400 gallons of oil a day. They claim that 18-24,000 US gallons were dispersed before the clean up was complete, a serious amount of oil to release into a rich marine environment.
2) Responsibility for clean up – Obviously the nations with most reason to be concerned about potential oil spills are the island states of the South Pacific. It is their tourist industry and fishing activities that are endangered by pollution and they are responsible for protecting the local marine diversity. Their consciousness of this responsibility is shown by the development of the 'Regional Strategy' less than a year after the Mississinewa incident preparing for the management and safe handling of oil-carrying wrecks.
However, international law says that, unless a wreck was captured before sinking or is sold or granted to another party, it is still the property of the nation to which it belonged when it was in military service. This means that the nation in whose territorial waters the wreck ends up needs to ask permission before carrying out any salvaging or clean up operations. This means that responsibility for dealing with individual, high-risk wrecks generally extends beyond the nations of the South Pacific.
In the case of the Mississinewa the US SUPSALV organisation (contracted by the Navy for salvage, diving operations and environmental duties) took responsibility for the clean up of the oil spillage. They initially patched the leaks and pumped out the most unstable oil. However, in view of the high risk of further leaks, they decided to carry out a more comprehensive operation in February 2003. 'Hot tapping' through the hull was used to remove 2 million US gallons (virtually all the oil that remained on the wreck). This oil was separated from the sea water and sold to Singapore for reprocessing (showing just how resilient oil can be after decades of lying underwater in poorly sealed tanks!).
3) Difficulty of locating wrecks that were often lost in confusing war time conditions – While some wrecks have been known about for a long time (The USS Chehalis and the remains of its cargo of 400,000 gallons of petroleum were sold to American Samoa by the USA in 1955) others are still missing today.
Part of the regional strategy developed after the Mississinewa incident was a survey of the location of wartimes wrecks. 857 wrecks were located in the territorial waters of the participating countries and 35 of these were oil tankers. A risk evaluation was then carried out on these wrecks to work out what response was necessary in each case.
4) Aftermath – In the long term the regional strategy was abandoned in favour of bilateral negotiations between the nation owning the territorial waters and the nation owning the wreck. This was probably due to the positive response of the USA who assisted in the salvaging of both the USS Mississinewa and the later situation involving the USS Chehalis in 2009 (I don't know if the Japanese government or others that could conceivably be involved in wreck salvage operations show the same degree of responsibility). However, all in all this seems a good example of a strong regional approach to environmental damage caused by WW2. Vulnerable species have been protected and the potential for environmental catastrophes has been responsibly handled by international negotiation and agreements.
Sources -
-A Regional Strategy to Address Marine Pollution from WW2 Wrecks (July 2002), created by the South Pacific Applied Geo-Science Commission (SOPAC)
- South Pacific Regional Environment Programme website
-SUPSALV presentation on the USS Mississinewa situation.
-SUPSALV organisation website
- Wikipedia - USS Mississinewa, USS Chehalis