Farklı İki Lagün Sisteminde (Samsun, Gıcı ve Karacabey, Dalyan ) Fizikokimyasal Parametrelere Bağlı Olarak Zooplankton Biyokütle Değişiminin İncelenmesi

Abstract

Within the scope of the thesis study carried out in 2 areas with different ecological characteristics and different salinity contents, the study was carried out in Dalyan Lagoon located in Susurluk Basin (Kocaçay Delta) and Gıcı Lake in Kızılırmak Basin. It was aimed to determine the difference in species composition and biomass depending on physicochemical parameters, and to reveal the variation depending on seasons and sampling stations. In this comparative study, it was also aimed to indicate in general terms how zooplankton biomass was affected by environmental factors, especially salinity and temperature, in lakes located in different geographical areas. During the study dates, a total of 45 taxa were identified in Lake Gıcı, 2 of which were Copepoda (1 at genus level), 5 were Cladocera (1 at genus level) and 38 were from Rotifera group (1 at genus level). In Dalyan Lagoon, a total of 19 taxa were identified, of which 4 were Copepoda (3 at genus level) and 15 species were from Rotifera group. Rotifera was the most dominant group in Lake Gıcı, followed by Copepoda and Cladocera groups, respectively. It was determined that 90.3% of zooplankton consisted of Rotifera in terms of numbers, and 0.3% Cladocera, 2.1% Copepoda, 3.9% Copepodite and 3.3% nauplius. According to the total numerical data in Dalyan Lagoon, it has been determined that 11.4% of the community consisted of Rotifera, 2.8% of Copepoda, 12.9% of Copepodite and 72.9% of nauplius. During the sampling dates, Brachionus calyciflorus was the species that contributed most to the total biomass in the stations in Lake Gıcı, while the lowest biomass value was for Synchaeta oblonga with 0.01 µg and 0.08%. According to the average biomass data in terms of µg/L in Lake Gıcı, the highest value was in September (2017) with a value of 1218.84 µg/L (23.84%) and the lowest value was 22.6 µg/L (0.09%) in March (2015). According to the average biomass values in Dalyan Lagoon, Diaptomus sp. type contributed a biomass value of 7.96 µg, at the same time it was determined that it provided the highest contribution to biomass. In the Rotifera group, Keratella cochlearis was represented with the lowest value in terms of biomass with a value of 0.09 µg. As a result of the statistical analysis, it was determined that Ascomorpha saltans, Brachionus angularis, Brachionus urceolaris, Filinia terminalis, Keratella cochlearis and Trichocerca longiseta species differed seasonally in Lake Gıcı. In Dalyan Lagoon, it was determined that copepodite and nauplius organisms differed seasonally. It was determined that the total biomass (µg) was related to temperature, salinity, saturated oxygen and pH in both Gıcı Lake and Dalyan Lagoon. The species diversity of zooplanktonic organisms in Lake Gıcı varied between 2.26 and 0.32. The average species diversity in Dalyan Lagoon was found between 1.16 and 0.44. In both lagoon systems, the average values below 2.5 during the sampling dates indicated that some species were dominant in the community. Average Pielou regularity value was calculated between 0.85 and 0.14 in Lake Gıcı, and between 0.49 and 0.21 in Lake Dalyan. The values of this parameter showed that the species were not evenly distributed in both communities.