Sönmez Girgin

Relationship between aquatic insects and heavy metals in an urban stream using multivariate techniques

In the study, the relationship between some aquatic insect species (Ephemeroptera, Plecoptera, Trichoptera and Odonata) and some heavy metals (cadmium, lead, copper, zinc, nickel, iron and manganese) and boron were assessed using data obtained from the Ankara Stream, which flows through Ankara, the capital city of Turkey and receives high organic and industrial wastes. Sampling was carried out monthly along the Ankara Stream in 1991. environmental data were used to explain biological variation using multivariate techniques provided by the program canonical correspondence analysis ordination. The ordination method canonical correspondence analysis was applied to evaluate the relationships between environmental variables and distribution of aquatic insect larvae. Data sets were classified by two way indicator species analysis. In this study, aquatic insecta communities have been shown by canonical correspondence analysis ordination as related to total hardness, pH, cadmium, lead, copper, zinc, nickel, iron, manganese and boron. Cadmium, lead, copper and boron exceeded limits of the United States Environmental Protection Agency criteria for aquatic life. Trichopteran, Dinarthrum iranicum was an indicator of two way indicator species analysis and was placed close to the arrow representing copper. Odonate, Aeschna juncea was an indicator of two way indicator species analysis in site 10 and was placed close to the arrows representing manganese, lead, and nickel. Trichopteran, Cheumatopsyche lepida and odonate, Platycnemis pennipes were indicators of two way indicator species analysis for sites 6, 7, 11, 14, 15, 18 and were placed close to the arrows representing cadmium, boron, iron and total hardness.

Evaluation of the benthic macroinvertebrate distribution in a stream environment during summer using biotic index

The purpose of this study is to evaluate the benthic macroinvertebrate distribution in the Keşap Stream (in the Eastern Black Sea Region of Turkey) for the summer period using biotic index. The water quality was assessed through the application of the Belgian biotic index. For this purpose, benthic macroinvertebrate sampling was performed in six sites along the Keşap Stream in the summer period, in July 2007. The distribution of dominant genera of the sites was evaluated according to water quality. According to the Belgian biotic index, II, III and IV water quality classes (slightly, moderately and heavily polluted, respectively) were determined in the stream. In addition, diversities of benthic macroinvertebrates in six sites were calculated. The biotic index values are found also consistent with the diversity values. Especially, in areas of the stream after industrial facilities water quality decreased. However, very heavy pollution was not observed accord to the biotic index values. It was found that Ephemeroptera was the dominant major taxon in all sampling sites. As a result of this biological evaluation, Ephemeroptera were concluded to be the most common taxa in the stream and the ephemeropterans, Potamanthus, Baetis and Ephemerella were dominant genera in the conditions of slightly, moderately and heavily polluted.