In order to evaluate the macrozoobenthic fauna of Çıldır, Aktaş and Aygır lakes, 47 taxa were identified as a result of the samplings carried out in different periods in 2013, 2017 and 2019. 41 of 43 taxa identified at species level were new records for the study area. The dominant species of Lake Çıldır were Gyraulus (Armiger) crista (4.49%), Paratanytarsus lauterborni (3.90%) and Virgotanytarsus arduensis (3.80%). It was seen that the gammarid population was determined dominant among zoobenthos of Aktaş Lake. Gammarus pseudosyriacus was the dominant species with 15.24% dominance rate in Aktaş Lake, followed by Cricotopus (Isocladius) reversus with 7.53% and Gyraulus albus with 7.29%. Gammarid population was also high in Aygır Lake, but unlike Aktaş Lake, Gammarus balcanicus from this group with a dominance rate of 6.28%; it took the fourth place after Gyraulus albus (8%), Virgotanytarsus arduensis (6.92%) and Cricotopus (Isocladius) tricinctus (6.64%). In terms of macrozoobenthic fauna diversity, the highest Shannon and Margalef Index values were found in Lake Çıldır (Shannon Index H': between 1.73-2.23 (average 2.0), Margalef Index: between 1.89-2.06 (average 2.03)) while diversity indices were lower in Aktaş and Aygır lakes. The taxa detected in all three lakes are α and β mesotrophic species, and the high population density can be considered as a sign of the transition from the oligotrophic level to the mesotrophic level, especially for Lake Çıldır.

Caves are laboratories for many disciplines that work in natural sciences including mineralogy, biology, hydrogeology, and archaeology. In this study, bi-monthly samplings were carried out from three sampling locations within and around the Güvercinkaya Cave, a high-altitude cave located in northwestern Turkey, to evaluate the hydrochemical and microbiological properties and the aquatic macroinvertebrates of the cave stream. Some parameters of the water including pH, electrical conductivity, temperature, oxidation-reduction potential, and dissolved oxygen were measured in-situ, while elemental (70 in total) and ionic composition of water were analyzed in the laboratory. Microbiological analyses of the cave stream were examined through analyses of total bacteria, total coliforms, fecal coliforms, fecal Streptococcus, and Escherichia coli. According to the Piper diagram of hydrochemical data, the cave stream had mainly Ca-Mg-HCO3 character, on the other hand, the Schoeller diagram indicated a common water source in Güvercinkaya cave due to the similar components of the main ionic components of the water. As a result of microbiological analysis, fecal contamination was determined, indicating active wildlife in the cave. Additionally, several aquatic macroinvertebrates taxa, Rhynchelmis limosella, Dugesia sp., Gammarus uludagi which have non-troglobiont character were found in the cave stream. Rhynchelmis limosella detected in this study is the first record for the Turkish fauna.