The world’s oceans contain more than 8,500 shipwrecks classified as potentially polluting wrecks, which experts estimate could harbor up to 20.4 million metric tons of oil and hazardous materials. This environmental threat has largely remained unaddressed despite its significant implications for marine ecosystems and coastal communities worldwide.
Visual Capitalist’s Cody Good, working alongside Lloyd’s Register Foundation, has created a comprehensive visualization mapping the concentration of World War II-era wrecks globally. The data draws from Paul Heersink’s extensive Sunken Ships of the Second World War database, combined with oil quantity estimates presented by Michel et al. at the 2005 International Oil Spill Conference.
The geographic distribution of these underwater hazards reveals concerning patterns. More than three-quarters of potentially polluting wrecks resulted from World War II naval engagements, creating significant concentrations in specific maritime regions. The South Pacific holds the largest share, accounting for 32 percent of all potentially polluting wrecks and containing approximately 25 percent of the total estimated oil volume. Meanwhile, the North Atlantic region contains 25 percent of these hazardous vessels but holds a disproportionately large 38 percent of the total oil content, indicating that wrecks in this area tend to be larger vessels or carried more substantial fuel quantities.
The legal framework surrounding these submerged vessels creates additional complications. Original flag states retain ownership of their sunken warships and merchant vessels, yet face no legal requirement to take action regarding potential environmental hazards. This absence of mandatory intervention necessitates voluntary international collaboration to address mounting risks.
The environmental implications prove particularly severe for small island nations whose economies depend heavily on marine resources, fishing industries, and tourism. Even relatively minor petroleum releases in ecologically sensitive waters can trigger catastrophic consequences for these vulnerable regions. Analysis of countries with the highest concentrations of potentially polluting wrecks within their exclusive economic zones, when ranked by gross domestic product, reveals that many affected nations possess limited financial resources to mount effective responses.
Data compiled from Paul Heersink’s research in 2025, combined with exclusive economic zone boundaries defined by the Flanders Marine Institute in 2023, identifies the top ten countries facing the greatest exposure to these underwater threats within their territorial waters. These nations frequently lack the technical expertise, equipment, and funding necessary to monitor deteriorating wrecks or respond to leaks, leaving them exceptionally vulnerable to
environmental disasters.
Addressing this overlooked legacy of historical conflict requires coordinated international action. Project Tangaroa has introduced the Malta Manifesto, proposing a comprehensive global framework
specifically designed to tackle the potentially polluting wreck challenge. This initiative emphasizes several critical priorities, including systematic identification of highest-risk vessels, development of standardized assessment protocols, and provision of support to coastal states with insufficient capacity to independently manage these threats.
The Manifesto operates on the principle that location matters critically when evaluating risk. A single leak occurring in an environmentally sensitive area or near economically dependent coastal communities can generate impacts far exceeding what vessel size or oil quantity alone might suggest. This recognition drives the call for equitable solutions grounded in scientific evidence rather than purely economic considerations.
The proposed framework seeks to establish mechanisms for international cooperation that acknowledge historical responsibility while providing practical assistance to nations currently bearing environmental risks from conflicts they may not have directly participated in. By treating these wrecks as a shared global challenge rather than isolated national problems, the initiative aims to mobilize resources and expertise where they are most urgently needed.
The Malta Manifesto represents an important step toward systematic management of an environmental threat that has been largely ignored for decades. As these vessels continue deteriorating after eight decades underwater, the urgency of coordinated action only increases. Without proactive international engagement, the question becomes not whether these aging wrecks will release their toxic contents, but when and where the most damaging releases will occur.