Degradation of coastal ecosystem services in southern Black Sea: A case study of Trabzon city

Coasts are extremely important areas for human beings. Tshis importance stems from the excess of social and economic opportunities they offer. However, human pressure on the coasts has disturbed the ecological balance of these areas in the last century. People obtain benefits from the coasts by using various ecosystem services (ES). These are provisioning, regulating, supporting and cultural services. Sustainability is an issue of high priority for ES supply. Conservation, use and management should be given necessary importance in order to ensure sustainability of the coastal areas. The quality and health of ecosystems depend on ES supply and continuity. Therefore, long-term changes of ES supply in the Ortahisar District of Trabzon city is a focus of the current study. In this study, temporal variation of the benefits provided by ES on the coastal zone of the city was investigated. For this purpose, the old and new state of the city have been researched and compared in terms of ES supply by focusing on cultural ES using survey methods and expert judgments. Moreover, in order to support the research, temporal change of Land Use/Land Cover (LULC) classes between 1985 and 2014 was revealed by using Remote Sensing (RS) and Geographic Information System (GIS) techniques. As a result of the study, a substantial decrease in ES supply and quality was observed in Trabzon City coastal zone in the last decades. In 30 years' time span, the loss of vegetation is about 20 % of total cover and a sharp increase of impervious surface is witnessed. This figure reached roughly 10 % of total 175.70 km2. Based on survey results, degradation rate of ES supply can reach 58 % in edible products, 82 % in air quality and 80 % in habitat availability. In addition, cultural ES have found to be dominating and representing the landscape value of the city by offering many benefits for local people and visitors. Finally, recommendations have been made for the protection and usage balance of coastal ecosystems.