Evaluating the environmental impact of leaking WW2 shipwrecks: A closer look at the VRAKA and AmuCad decision support tools

Of the thousands of shipwrecks originating from WW2, many still contain munitions or chemical warfare agents that still pose a substantial risk to the environment and societal safety. Initially, it was believed that the ammunition would slowly become harmless over time, leading post-war governments to dispose of millions of tonnes of surplus ordnance by dumping it at sea or loaded onto derelict vessels and scuttled in designated areas. However, this assumption has long been disproven. As the wrecks and their cargo deteriorate, they release toxic substances into marine environments, being taken up by exposed organisms causing contamination of impacted sites. Some of the chemicals contained herein are carcinogenic and highly toxic, thus posing long-term risks to ecosystems and human health. Here, one of the biggest threats lies in the potential of a sudden release of harmful substances due to the collapse of corroding shipwrecks. The collapse rate, influenced by factors such as corrosion, natural forces, and human activities, is poorly understood, especially for deep-sea wrecks. To address these risks, this study evaluates decision-support tools developed for assessing the environmental impact of underwater munitions. It compares the VRAKA and AmuCad tools under varying conditions to prioritize wrecks that pose the greatest environmental threat and determine the urgency of remedial actions. This paper highlights the need for improved risk assessment tools to model wreck deterioration and the associated release of hazardous substances, ultimately contributing to informed decision-making for mitigating the ongoing impacts of wartime shipwrecks.