Application of Phytotoxkit Microbiotest for Hazard Assessment of Bottom Sediments in the Eutrophic Dam Reservoir

The aim of this study was to estimate ecotoxicity of the sediments from the shallow, eutrophic dam reservoir—Sulejowski. Research was carried out using Phytotoxkit microbiotests, which measure inhibition of seeds germination and roots growth retardation of the three species of plants (dicotyl Lepidium sativum, Sinapis alba, monocotyl Sorgum saccharatum). Tested plants gave different response to sediment samples, with decreasing sensitivity gradient: L. sativum, S. saccharatum, S. alba. The relationship of phytotoxicity of sediments with its water content was recorded (r = 0.63, p < 0.05). The results obtained showed spatial diversification along the reservoir, with the highest values in its opposite ends of the upper and lower parts (up to 87%), which are separated by a central area with the lowest toxicity (up to 45%). Possible reasons and implications of bottom sediments phytotoxicity are discussed.