Possible effects sea bream and sea bass farming in net cages on water and sediment: A case study of Mersin Silifke

-Türköz M. Aydın Adnan Menderes University, Institute of Natural Sciences, Department of Aquaculture Engineering, Master's Thesis, Advisor: Prof. Dr. Deniz Çoban, Aydın, 2024. Objective: In this study, the Aquaculture Production Site located in Silifke district, Mersin Province (T.C. It is aimed to reveal the temporal and spatial distributions of the activities of (designated as "Potential Aquaculture Production Site No. 1" by the Ministry of Agriculture and Forestry), their possible effects on water and sediment. In addition, the carrying capacity of the region where the cultivation operations are carried out has been determined and the relationship between the environmental indicators and the production capacity of the enterprises in the region within the scope of the environmental legislation has been studied. Material and Methods: Increasing environmental awareness and tourism lobbying activities in our country resulted in the relocation of bream and sea bass breeding in bays and bays to offshore areas in 2008. since 2010, this process has accelerated. For the fish farms to be established on the Turkish coastline related to this; Together with the Aquaculture Law No. 1380 and the regulations and circulars published in accordance with this law, T.C. The process is carried out by the Ministry of Environment, Urbanism and Climate Change in accordance with Environmental Law No. 2872 and the "Communiqué on the Determination of Closed Bays and Bay Areas that are Sensitive Areas where Fish Farms Cannot be Established in the Seas" published in the Official Gazette No. 26413 dated 24.01.2007. In addition, according to the relevant provisions of the Environmental Law No. 2872 dated 09.08.1983 and Article 54 of the Water Pollution Control Regulation published in the Official Gazette No. 25687 dated 31.12.2004, "Communiqué on Monitoring Fish Farming Facilities Established in the Seas", fish farms are also monitored in terms of their environmental impacts and the final reports of the samples taken T.C. It is submitted to the Ministry of Environment, Urbanism and Climate Change. Especially in addition to Muğla and Izmir provinces where aquaculture is carried out, new aquaculture sites have been identified in Mersin and Aydın provinces. Studies on the effects of aquaculture sites on water and sediment, even in the open sea, are necessary to protect the environment and for the sustainability of aquaculture activities. 14 separate enterprises have been established on an area of 2850.43 hectares predetermined by the authorized ministry in Dana Island, Silifke district, Mersin province, subject of the thesis, and sea bream perch breeding with a capacity of 41,700 tons/year has been carried out in these enterprises. Some important water and sediment analyses in this field were evaluated with oceanographic data and a model was created. In the creation of this model, the Ocean Data View program was used. With this model, it was applied again before the cultivation activity was carried out on the site determined by this model and 2 years after the cultivation activities started. Results: In the study where the surface, middle water, and bottom sediment residues of the potential aquaculture area were examined, it was determined that the total amount of organic carbon of 14 facilities located in the aquaculture area was in the December range of 1.938% to 4.707%. It has been observed that the nitrogen and phosphorus amounts of the facilities located in the region are below the reference values. it has been determined that 14 facilities are suitable for the carrying capacity. In addition, in the study where the risk of eutrophication in the region was examined, it was determined that the eutrophication value was below the threshold value. It has been observed that the cultivation area of the region does not cause an environmental threat. Conclusion: Various parameters of the region (water column, accumulation of substances in the sediment, etc.) before the start of the operation of the cultivation area.) were evaluated and determined to be suitable for the field of cultivation. It has been observed that after a period of two years in this region, where cultivation has started, no changes have been observed that could put the environment at risk. It is of great importance because it is the first study in which environmental factors are evaluated before starting production activities. In addition, when the data obtained were evaluated, it was determined that the production capacity in the region was suitable for increasing gradually and that it was not necessary to move the area towards the open areas of the sea. For this reason, this study the found to be of great importance in terms of determining the cultivation areas and evaluating the environmental factors.