The use of malacostraca (Crustacea) class in biomonitoring studies in accordance with water framework directive and ecological evaluation: The case of Ceyhan and Seyhan basins

In this thesis, 72 stations were sampled from the Ceyhan and Seyhan basins between 2014 and 2019, once each in the spring, summer and fall seasons. As a result of the study, 16669 individuals were examined. As a result of the species identification, 18 species belonging to three orders (Amphipoda, Decapoda and Isopoda), six families (Asellidae, Athyidae, Gammaridae, Niphargidae, Paleomonidae and Potamidae) and seven genera belonging to the class Malacostraca were identified. It was determined that Gammarus pseudanatoliensis was the most dominant species with 8345 individuals in Ceyhan basin and Gammarus goedmakersae was the most dominant species with 2039 individuals in Seyhan basin. Within the scope of the study, five of the 13 species identified in the Ceyhan basin (Gammarus lacustris, G. effultus, G. agrarius, Echinogammarus ischnus ve Potamon ibericum) and four of the 10 species in the Seyhan basin (Gammarus mladeni, G. pseudanatoliensis, Potamon potamios ve Echinogammarus ischnus) are new records for the region. The final quality classes of the average values of the physicochemical parameters measured at the stations were evaluated according to the Regulation on Surface Water Quality Management. In Ceyhan Basin, three stations were found to be in moderately polluted water quality (Class III), 15 stations in slightly polluted water (Class II) and 31 stations in high quality water (Class I). In Seyhan Basin, 12 stations were classified as slightly polluted water (Class II) and 11 stations were classified as high quality water (Class I). If a general evaluation is made for the basins by using biotic indices, eight stations in Ceyhan Basin and two stations in Seyhan Basin were observed as polluted or under the influence of pollution, while the other stations were relatively free from pollution pressure and in good quality (medium, good, high quality).