Levees Against the Rising Tide: Protecting Underwater Cultural Heritage From Climate Change Threats

The term “underwater cultural heritage,” or “UCH,” may call to mind sunken temple ruins or an ancient shipwreck languishing on the ocean floor. Although some UCH artifacts have been removed from the ocean, most UCH remains in situ, or in its original place. As such, UCH is very vulnerable to the effects of climate change, namely increased ocean temperatures, ocean acidification, sea level rise, and extreme weather. Thus, in order to protect UCH to the level that conservationists hope to achieve, it is necessary to protect the underwater environments in which UCH is preserved from the worst effects of climate change.
The first chapter of this paper explores the significant threats that climate change poses to in situ UCH. In underwater environments, various physical, chemical, and biological deteriorative agents cause the degradation of common UCH materials (i.e., wood, metal, and stone) over time. Although all of these modes of degradation are normal for materials preserved underwater, climate change will exacerbate the rate and intensity of this deterioration. This is because the effects of climate change on marine environments (i.e., sea surface temperature increase, ocean acidification, and increased storm severity) will disturb the equilibrium of preserved materials with their surrounding environment in various ways.
Luckily, a variety of U.S. federal laws exist for the protection of UCH. Thus, the second chapter of this paper examines the most prominent and substantive of these laws, namely, the National Marine Sanctuaries Act and the Antiquities Act. However, while the laws discussed herein do have the capacity to protect both UCH and the large marine areas in which they are preserved from certain effects of climate change (namely, agricultural-runoff-driven ocean acidification), they are currently unable to do so. Accordingly, this paper concludes by offering several specific recommendations on how existing U.S. legal frameworks can be extended to enhance UCH resilience and mitigate degradation due to the acidification of the surrounding marine environment.