Environmental impact and climate change
Environmental changes, such as climate change, stronger erosion and current change can pose a threat to underwater cultural heritage sites. On the other hand underwater cultural heritage can however tell us a lot about historic climate change that once impacted the life of our ancestors.
Today, tsunamis, coastal erosion, and water warming threaten underwater cultural heritage sites.
Sea levels have been rising due to climate change since the end of the last glaciation during the late Pleistocene period. The relationship between rising sea levels and the vertical displacement of the earth’s crust lead to changes in the sea levels on the continental margin. Thus accounting for these changes is essential in planning and executing archaeological surveys on the continental shelf. Climate change can also lead to the destruction of many sites, due to a change in conservation patterns, change of currents and the introduction of new animal species in waters.
Biological environmental threats
A special example of the threat of climate change is to be observed in the Baltic Sea. Biological degradation of wooden wrecks occurs naturally. However, marine borers such as ship-worm provoke a quickening of this process. Wrecks in the Baltic sea have until now been well preserved due to the low salinity of the water and low temperatures, as well as its lack of marine borers. However, climate change has been cited as a factor contributing to the spread of marine borers (ship-worms) in the Baltic in recent years. The waters have warmed and the species has come into the region since.
The formation of bacteria structures, such as the rusticles formed by Halomonas titanicae, named after the wreck of the Titanic, where they were identified, can moreover accelerate the corrosion of structures of wrecks. Their development depends on the environment and changes, when it changes.
Underwater Cultural Heritage Research and Environment Preservation
Underwater Cultural Heritage Research has to respect the environment. This is regulated by the Rules annexed to the 2001 Convention.
Environmental studies can also contribute to underwater cultural heritage preservation. In cases such as the planning process for the North Stream pipeline, running through the Baltic, underwater cultural heritage preservation became a key issue with the discovery of some 50 shipwrecks.