By Maria Cooper
Source: International Union for Conservation of Nature (IUCN)
Globally, there are approximately 3 million sunken and abandoned vessels. Over 8,500 of these contain harmful substances which are leaking into our seas and oceans. This map depicts the known wreckage sites of these ‘potentially polluting’ ships. It highlights a vast number of known shipwreck sites worldwide, marked by black dots. The density of these wrecks appears greatest in heavily trafficked maritime regions, such as the North Atlantic, Mediterranean Sea, European coastlines, the waters around Southeast Asia, and near coasts of North America.
It is estimated that between them, these wrecks contain between 2.5 and 20 million tonnes of heavy fuel oil. This figure is 545 times more than the Exxon Valdez oil spill in 1989, which had profound and long lasting environmental consequences. More shockingly, it is 30 times more oil than the Deepwater Horizon disaster in 2010, the most damaging accidental spill in history. They also hold unknown amounts of harmful chemical pollutants and unexploded munitions.
Many of these ships sank during World War I and II (WWI, WWII), and have yet to be recovered or cleaned up. The financial cost is prohibitively expensive for many nations, especially developing ones. Crucially, there is a question of responsibility: many countries affected by these shipwrecks were not participants in WWI or WWII, and under the principle of sovereign immunity, ships sunk during wartime remain the property of their home country. Internationally, there is a lack of cooperation and data on how to effectively manage wreckage pollution. Many governments are not equipped to proactively prevent leaks, or clean-up when they happen.
Marine pollution from these wrecks is projected to reach its highest level during this decade. This is due to a combination of time, and climate change. After more than 75 years in the water, vessels have corroded and broken down to release the harmful substances they carry. Severe weather events and warmer ocean temperatures are likely to speed up these processes of erosion. Pollution from sunken ships is a worldwide, transnational problem, impacting environments, people, and economies across the globe. Oil and hazardous chemicals cause persistent damage to marine biodiversity and habitats. These pollutants degrade critical ecosystems, including coral reefs and fisheries, leading to substantial economic costs in clean-up, fisheries, and tourism. Consequently, this issue directly hinders progress toward achieving Sustainable Development Goal 14 (Life Below Water), which emphasizes protecting marine ecosystems and reducing ocean pollution. The Sustainable Development Goals (SDGs) are 17 interconnected global goals set by the United Nations in 2015, intended to guide international efforts towards sustainability, equality, and prosperity by 2030. You can read more about SDG 14 here: https://www.globalgoals.org/goals/14-life-below-water/.
Sources:
IUCN (2023) ‘Marine pollution from sunken vessels’, International Union for Conservation of Nature, April. Available at: https://iucn.org/resources/issues-brief/marine-pollution-sunken-vessels (Accessed: 9 April, 2025).
Monfils, R., Gilbert, T. and Nawadra, S. (2006) ‘Sunken WWII shipwrecks of the Pacific and East Asia: The need for regional collaboration to address the potential marine pollution threat’, Ocean & Coastal Management, 49(9-10), pp.779-788.
van Dijk, L. (2023) ‘Sunken Shipwrecks Pose Unprecedented Threat of Marine Pollution’, Climate Court, 27 December. Available: https://www.climate-court.com/post/sunken-shipwrecks-pose-unprecedented-threat-of-marine-pollution#:~:text=Shipwrecks%2C%20particularly%20those%20from%20World%20War%20I%20and,and%20billions%20of%20gallons%20of%20heavy%20fuel%20oil (Accessed: 9 April, 2025).