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Underwater Cultural Heritage As A Potential Environmental Time Bomb

Small tank on the Nippo Maru. Sunk during World War II. Federated States of Micronesia, Chuuk. Photographer: Dr. Dwayne Meadows, NOAA/NMFS/OPR.
Small tank on the Nippo Maru. Sunk during World War II. Federated States of Micronesia, Chuuk. Photographer: Dr. Dwayne Meadows, NOAA/NMFS/OPR.

In the area known as the Pacific theater of World War II, there are about “3800 underwater wrecks—submarines, airplanes, ship, and other remnants of hard fought battles.  And, that war produced 7800 such wrecks worldwide from all of the participating nations.  Beyond their solemn history (and possible continuing service as watery human gravesites), there are emerging issues that need to be addressed for the health of our ocean today.  These World War II shipwrecks account for 75% of the known sporadic or continuous leakages of oil and other hazardous materials from vessels on the seafloor.  And, it is said that all of the World War II and other wrecks in the ocean may contain as much as 140 million barrels of oil.  As conservationists we want to look proactively at preventing catastrophic oil spills from potentially polluting shipwrecks. We are certain that the risk is growing yearly, as are the potential costs from harm that may result.

Sixty years later, we are particularly concerned that these wrecks are experiencing metal fatigue, failure and collapse, resulting in leakage of oil, fuel, unexploded ordnance, and toxic chemicals.  There are many observed causes for the weakening of these vessels that include corrosion, storm damage, harm from dynamite fishing, damage from anchors and bottom trawling gear, earthquakes, looting (treasure hunting), as well as intrusive exploration of the underwater cultural heritage (by well meaning archeologists).  Obviously, numerous sites have experienced more than one of these.  In the event of a serious leak from these vessels, we can expect habitat damage at the site, as well as for all the surrounding ecosystems including reefs, beaches, mangroves, and nearshore waters—which in turn may harm the plants and animals that live there.

NOAA has done an assessment of the wrecks in US waters and developed a hierarchy of threats, but doing the entire Pacific theater is not yet on the horizon.  We will need to assess the wrecks in the Pacific, prioritize which ones are threats to the environment and then work on solutions. The wrecks include tanker ships loaded bunker fuel, oil and aviation gas.  These tankers and many other ships were also powered by bunker fuel, which is considered a “dirty” fuel and is slow to break down in the ocean.  Add to these problems the unexploded ordnance, toxic chemicals and in some cases toxic metals and alloys and we have a lot of potential problems to identify, assess, and mitigate.

Coral encrusted gun on Da Na Hino Maru. - sunk during World War II. Federated States of Micronesia, Chuuk. Photographer: David Burdick.
Coral encrusted gun on Da Na Hino Maru. – sunk during World War II. Federated States of Micronesia, Chuuk. Photographer: David Burdick.

We also need to recognize that many of the wrecks have become thriving habitat as algae and sessile animals colonize them. These artificial reef habitats attract sedentary fish and then predators, building a full complex living network over decades.  This means that any proposed solutions should strive to minimize disturbing or harming the sealife and the structure that supports them.

Are there solutions?  In our toolbox of solutions, we can include in-situ bio-remediation (bacteria to break down oil), stabilizing metals by using anodes (a positively charged electrode), and hot tapping the ships to remove their oils and fuels.  There may also be options for oil containment and diversion.  However, all of these solutions are expensive and may not be a priority for those responsible, nor for island nations who are more concerned about the effects of climate change and the costs of adaptation, than finding the funds to assess and address the problems caused by these wrecks.

Who is responsible legally and financially? It is generally agreed at this point (thanks to international treaties and domestic legislation) that the flag of the vessel sunk, particularly for military vessels, gives continuing sovereignty for that flag country over the vessel.  This means that the shipwreck has sovereign immunity, which prevents other nations from claiming jurisdiction over it, and it means that the wreck is not considered abandoned, and thus is protected in place from salvage or looting as well.

Does this sovereign immunity also extend to immunity for environmental harm from leaks? And/or does it create an obligation or responsibility for clean up before a leak occurs?  The flip side of this set of questions is whether countries can protect their own fisheries and natural resources, regardless of who owns the wrecks that are causing or may cause harm?

Our international treaties on underwater cultural heritage create an obligation for all nations to protect each underwater cultural heritage site (which many of these wrecks are).   We need to know whether this protection obligation prevents action by country that feels the need to protect its resources by preventing environmental harm from leaking or potentially leaking World War II shipwrecks.

In the end, we have to seek balance in resolving these responsibility questions. We need our policies regarding underwater cultural heritage as well as our environmental policies to take into consideration tourism, marine protection, scientific or historical research, as well as war gravesites (and sensitivity to them).  We want those who are concerned with protection of underwater cultural heritage to also be concerned about potential environmental harm from leaking shipwrecks. In the same breath, we need those who are concerned about environmental conservation to understand that protection of cultural heritage is as important to many people as well.

Diver carefully inspecting World War II mine that drifted to Pearl and Hermes Reef. Hawaii, Northwest Hawaiian Islands. Photographer: Dr. Dwayne Meadows, NOAA/NMFS/OPR.
Diver carefully inspecting World War II mine that drifted to Pearl and Hermes Reef. Hawaii, Northwest Hawaiian Islands. Photographer: Dr. Dwayne Meadows, NOAA/NMFS/OPR.

Our work to protect and manage underwater cultural heritage should always avoid harm to natural resources on the wreck, or anywhere in the countries where the wrecks are situated.  We can ensure that underwater cultural heritage protections address our environmental concerns pursuant to UN Convention on the Law of the Sea as well as federal environmental laws, all in concert with historic preservation laws. We can encourage benign tourism and historical/archaeological study. We can clean wreck sites of trash and promote “leave no trace” (take photos only) visitation.  At the same time we can work to both rid potentially polluting shipwrecks of oil and preserve those wrecks in-situ (as is the international priority under the UNESCO Convention on Underwater Cultural Heritage).

The problems exist.  The solutions exist.  There remains one question.  What will it take to produce the political will to be proactive and mitigate the risk of leaks and spills before it creates substantial environmental and socioeconomic damages for the countries in which these wrecks exist?