CORRELATIONS BETWEEN THE ENVIRONMENTAL FACTORS AND PHYTOPLANKTON IN KARDZHALI AND DOSPAT RESERVOIRS

K. Dochin, V. Kuneva, L. Hadjinikolova, I. Iliev

Abstract: The aim of the present study was to analyze the correlation dependences between the quantitative indicators of phytoplankton and some environmental abiotic factors in Kardzhali and Dospat reservoirs for the period May 2009-April 2012. A Pearson (r) correlation coefficient was used for the analysis. In Kardzhali reservoir the results showed a very high correlation between the abundance and biomass of the phytoplankton (r=0.98, P<0.01), significant correlation between the phytoplankton abundance and pH (r=0.39, P<0.01) oxygen saturation (r=0.37, P<0.01), and a significant negative correlation with the transparency of the water (r= -0.36, P<0.01). The transparency of the water showed high level of correlation with the water conductivity (r=0.67, P<0.01) and significant with water temperature (r= 0.40, P<0.01). There was negative relationship between water temperature concentration of nitrates (r= -0.87,P<0.01), total nitrogen (r= -0.87, P<0.01) and phosphates (r= -0.37, P<0.01). The data from Dospat reservoir showed a very high correlation between the abundance and biomass of the phytoplankton (r=0.98, P<0.01). The phytoplankton abundance correlates significantly negatively with water transparency (r= -0.41, P<0.01), and correlated o the positive with dissolved oxygen levels (r=0.27, p<0.05)and oxygen saturation (r=0.25, P<0.05). Significant correlation between transparency of the water and temperature (r=0.52, P<0.01) was observed, along with significant negative correlation between water temperature and nitrate forms of nitrogen (r= -0.54, P<0.01) and total nitrogen (r= -0.54, P<0.01).

Keywords: abiotic factors; biotic factors; correlation coefficient of Pearson (r); phytoplankton; reservoirs

Date published: 2017-03-14