Estimation of water quality of Bafa Lake by using benthic macroinvertebrate fauna

Ali TOMAY M.Sc. Thesis, Department of Fisheries and Aquaculture Supervisor: Assist. Prof. Dr. Semra KÜÇÜK 2020, 82 pages This study was conducted between February 2018 and December 2019 at 3 sites of Bafa Lake using both physicochemical parameters and macroinvertebrate diversity and to estimate water quality of lake. From each site, water and sediment samples were taken twice in every two months. Some of water parameters (temperature, pH, dissoved oxygen, salinity, electrical conductivity) were measured in the field. Some others (total nitrogen, total phosphate, hardness, chemical oxygen demand, and chlorophyll a) were graded in the laboratory with standard methods. Sediment samples were placed into the nylon bags labeled with location and time by taking with Ekman Grap. Samples bringing from field in the same day and they were saved in the + 4 °C until observation begin. After that, sapmles were transfered by sieves (4000-2000-500 µm mesh). Founded macroinvertebrates were identified according to families and recorded their both numbers and weight. Then they saved in the separated boxes containing 10% of formaldehyde and labeled for family names. Average of macroinvertebrates was 89369 individuals/m2. Total taxa (family) were 14. In the site of Serçin, the most abundant taxa was Nereididae (21.98%), Corophidae (20.48%), Tubificidae (14.32%), Gammaridae (11.98%), Chironomidae (11.96%) and others (19.282%); In the site of Mened island, Mytilidae (27.39%), Tubificidae (23.69%), Gammaridae (19.68%), Enchytracidae (13.59%) and others (15.65%); In the site 3 of Kapıkırı, Tubificidae (30.11%), Mytilidae (28.14%), Chironomidae (26.19%) and others (15.56) were mentioned. Macroinvertebrates found in all sites were pollution tolerant species. Three sites showed Bafa Lake were polluted. Similar senario was also seen on the BMWP (Biological Monitoring Working Part) and ASPT (Average Score Per Taxa) scores. Additionally, physicochemical classification result supported that the lake is polluted as well. Key Words: Bafa Gölü, Water quality, Macroinvertebrate fauna, BMWP, ASPT