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In this study, characteristics of effluents from three flow-through rainbow trout farms in Turkey and their impact on water quality and epilithic algal communities of the receiving stream were investigated. Water samples were taken monthly from both inlets and outlets of three fish farms, while both water and epilithic algae samples were collected from two stations (upstream and downstream) in the stream. A significant increase from inlets to outlets was observed for chemical oxygen demand (COD), soluble reactive phosphorus (SRP), total suspended solids (TSS), NH4-N and total phosphorus (TP) (p < 0.05) due to no effluent treatment processes and high FCR at the fish farms. The daily average total nitrogen (TN) and TP fluxes of the fish farms predicted with the nutritional method were found close to those measured with the hydrological method. Although there were significant increases in COD, TSS, NH4-N, TN, NO3-N, NO2-N, TP and SRP concentrations at the downstream station compared to the upstream station of the receiving stream (p < 0.05), water quality of the downstream station remained in Class I in terms of examined parameters. Trophic Diatomic Index and Biological Diatom Index values indicated that the upstream station had a better water quality than the downstream station. Also, filamentous algae such as Cladophora glomerata, Ulothrix zonata and Stigeoclonium lubricum were observed at the downstream station. In view of the above findings, several suggestions were put forward to protect the water quality of the receiving stream. (C) 2020 Elsevier Ltd. All rights reserved.

Keban Dam Reservoir (KDR), located on the Euphrates River (Turkey), is an internationally important reservoir. In this study, levels of ten metals in 220 muscle samples of five fish species (mangar, common carp, Tigris scraper, Euphrates barbell and trout barb) taken from 11 sampling sites in the KDR were determined and compared with the results of previous studies carried out in other countries and Turkey. In addition, multiple approaches were used to assess human health risks from fish consumption. The significant spatial differences in concentrations of studied metals except As and Ni in Euphrates barbell were not found. However, concentrations of all metals except Cd showed significant seasonal differences. The concentrations of ten metals in fish species were lower than or comparable to those in fish species from other freshwater bodies. The metal concentrations in all fish species were found below the maximum permissible concentrations. No health risks of studied heavy metals on human were found by daily fish intake. The target hazard quotient (THQ) and total THQ values were below 1, which suggests there are no significant non-carcinogenic health risks for fish consumers. The cancer risk values calculated for inorganic arsenic in all fish species except Euphrates barbell did not exceed the 10-6 threshold. The allowable number of fish meals per month can be categorized as safe fish consumption. The results of this study revealed that the consumption of the examined fish species does not pose a significant risk to human health. (C) 2018 Elsevier B.V. All rights reserved.

Phytoplankton samples were collected from four different water bodies in the Tigris River basin in 2008. Nine Euglenophyceae taxa at specific and infraspecific level are reported for the first time on Turkish freshwater algal flora. New records come from six sampling sites in the study area. These taxa consist of one Euglena Ehrenberg (E. sociabilis), two Strombomonas Deflandre (S. planctonica and S. pascheriana), four Trachelomonas Ehrenberg (T. nigra, T. aspera, T. borodiniana and T. scabra var. labiata) and two Phacus Dujardin (P. inflexus and P. ovalis). Identification keys and general information on the morphology and taxonomy of the species are briefly described in this paper, with original illustrations.