Sea-level rise is a threat to historic buildings and structures along our coastlines, but shipwrecks and submerged sites are already underwater…so they’re safe, right? Maybe not. Ship hulls, prehistoric settlements, and the stone boundaries of ancient ports (among other heritage artifacts) are already submerged, but still affected by fluctuations in sea level and other climate change events. Increasingly intense storms scatter artifacts, changing water acidity affects the rate of wood or metal decay, and warming waters allow boring shipworms to expand their range.
Underwater cultural heritage sites are just as vulnerable as archaeological sites on land, and damage to these sites will impact our ability to learn about our human past. Sea level rise also affected Stone Age coastal societies, including Doggerland, and we may be able to learn from some of their adaptation strategies and mistakes. In the more recent past, Spanish colonial shipwrecks in the Caribbean can teach us about the pattern and severity of hurricanes. By comparing these shipwrecks with tree ring weather data, we can decipher which weather conditions were associated with increased hurricane activity and the extent of the area affected. With the clues to place-based weather patterns quickly disappearing, archaeologists are stretched thin to excavate more sites requiring immediate artifact removal and conservation.
Underwater heritage also contributes to modern economies in places with nearby or accessible sites. Deterioration of underwater heritage sites may impact employment opportunities for museums, tour companies, dive shops, and numerous supporting industries.
Are there any upsides to this gloomy picture? One silver lining may be that as the Arctic becomes more blue, ice melt may reveal underwater cultural heritage…
Want to learn more and join the conversation? Follow @USICOMOS and @US/ICOMOSClimate to stay up to date on what the global community is doing to protect cultural heritage from climate change at COP-22 in Marrakech!