Seasonal variation of the water quality of rivers and streams of eastern Mediterranean

M Lazaridou-Dimitriadou

doi:10.5194/we-3-20-2002

Abstract

Abstract. Biotic and abiotic data on undisturbed or moderately disturbed lotic sites from a number of studies carried out in northern Greece showed that large rivers differ from small rivers, streams or creeks in terms of diversity, dominant groups and the kind of taxa (concerning the sensitivity of the taxa according to Biological Monitoring Working Party (BMWP) biotic scores). This is mainly due to the differences in their physical characteristics. Correlation of the environmental variables using MDA (multiple discriminant analysis) showed that the chief differentiating factors among the above water bodies are substrate, total suspended solids (TSS), conductivity, slope and temperature. Additionally, there is no clear phenological seasonality in the majority of the dominant benthic macroinvertebrate groups when undisturbed or moderately disturbed sites of mountainous creeks and small rivers are examined. By contrast, in downstream sites of long rivers, seasonality characterizes the dominant benthic macroinvertebrate groups, as it does for other Mediterranean animals.

Highlights

Biotic and abiotic data on undisturbed or moderately disturbed lotic sites from a number of studies carried out in northern Greece showed that large rivers differ from small rivers, streams or creeks in terms of diversity, dominant groups and the kind of taxa (concerning the sensitivity of the taxa according to Biological Monitoring Working Party (BMWP) biotic scores)
In all the Greek rivers and creeks, mainly because of reduced river vegetation, total suspended solids increase (Bobori and Mourelatos 1999) after a rainy season or after snow melting or both (Tables 5 and 6)
Concerning the studied sites, the results suggest that the substrate and total suspended solids (TSS) were found to be the most important in the studied sites in determining community structure

Summary

Introduction

Biotic and abiotic data on undisturbed or moderately disturbed lotic sites from a number of studies carried out in northern Greece showed that large rivers differ from small rivers, streams or creeks in terms of diversity, dominant groups and the kind of taxa (concerning the sensitivity of the taxa according to Biological Monitoring Working Party (BMWP) biotic scores). The use of changes in community structure for monitoring freshwater pollution, commonly involves benthic macroinvertebrates, because this group is considered as the most appropriate biological indicator of water quality in EU countries (Metcalfe 1989) including Greece (Anagnostopoulou 1992, Anagnostopoulou et al 1994).

Methods

Results

Conclusion