Cyanobacterial community patterns as water quality Bioindicators



 The main goal of this
study was to examine the use of cyanobacteria for evaluating the
quality of running water. Accordingly epilithic cyanobacterial communities were
collected in Dez River and Ojeyreb drain in south of Iran. Samples were
collected in two seasons: autumn and spring. Effective physical and chemical
factors on the structure of cyanobacterial communities and the dispersion of
the species in relation with them were determined using PCA and CCA analyses. The
Shannon-wiener biodiversity index was used to define the species diversity. The
concentration of Nitrate as main nutrient had significant increase in Drain
stations. A decline in species richness was observed associated with these
increases in nutrient load in both seasons in different cyanobacterial
community structure.  The results
indicated that order Oscillatoriales had higher proportion of cyanobacteria
species at Drain. The species Oscillatoria
chlorina, Chroococcus minor, Phormidium
tenue and Lyngbya kuetzingii S
had the most positive correlation with nutrient factor. Species Lyngbya infixa and Lyngbya mesotrichia had the most negative correlation with nitrate. Our
results confirm the using of cyanobacteria species as indicators for monitoring
eutrophication in rivers and define them as water eutrophication bioindicators.