Gölcük Gölü (İzmir, Türkiye) sedimentinin Desmodesmus (=Scenedesmus) dimorphus üzerine fitotoksistesi

Abstract

Gölcük Lake (Bozdağ-İzmir) is polluted by the touristic activities and agricultural and domestic sources. Gölcük Lake also adversely impacts human health as the lake water is used for irrigation in agriculture, and the fish caught from the lake is used for nutrition by the community around it. For this purpose, “OECD 201 Algal Growth Inhibition Test”, the standard test protocol was evaluated with cultures of green algae Desmodesmus dimorphus as the representative of the first trophic level. This test was used to assess the toxicity of sediment samples collected from five sampling sites in Gölcük Lake. Extracts of sediment samples were assayed in four different concentrations (20, 40, 100, and 200 mg/ml). The effects on the growth of D. dimorphus were examined by scoring cell numbers under the light microscope with a Neubauer haemocytometer counting chamber. According to the results, all extracts, except those from Station 3, inhibited growth of D. dimorphus in increasing concentrations of sediment samples, and inhibition was observed in the following order of stations: 2>5>4>1. Additionally, an increase in the number of algae (hormesis) was observed in the Station 3, depending on time and concentrations.