Evaluation of in situ preservation methods of underwater cultural heritage

The UNESCO Convention on the Protection of the Underwater Cultural Heritage, adopted in 2001, presents in situ preservation of the underwater cultural heritage as the first planned activity. In situ preservation is preferred by the countries with an extensive underwater heritage like Turkey due to the reasons such as the long duration of conservation practices and the high cost of excavation and conservation process. The underwater area containing cultural heritage must firstly be documented in order to decide whether it is appropriate for in situ preservation or not. During the documentation process in which both modern and traditional methods are used, physical, chemical, and biological properties of the seawater and the sediment surrounding cultural heritage are recorded. Also, the geological structure of the region, the deterioration level of the cultural heritage, and human risk factors affecting the area should be considered during the documentation process. In this way, the most effective protection method to be applied in the area is determined. It is important since the methods used can provide longer-term protection for different types of materials under different environmental conditions. In this study, the risk factors for in situ preservation of underwater cultural heritage and the effects of these risk factors on cultural properties are examined by exemplifying international projects carried out between 2000 and 2022. Application techniques and current data of the projects were examined by using the descriptive survey method. During the examinations, studies were carried out on cultural heritage found in seawater. Cultural heritage found in fresh water and brackish water was not included in the scope of the thesis. A cultural heritage that remained underwater for natural reasons, and not a cultural heritage that has remained underwater due to human influence, such as dams, have been studied.