Plankton dynamics of Milicz Ponds: indicators of sustainability and anthropogenic driven threats

Abstract

AbstractStawy Milickie (Milicz Ponds) is a natural reserve that has a great ecological importance as a Ramsar site and economic importance as one of the largest carp breeding centres in Europe. Continuous anthropogenic pressure on these large ecosystems can lead to a high disturbance on its natural ecology and sustainability. Phytoplankton, one of the most important indicators of any anthropogenic load, especially organic pollution have been studied in the present study. This is the first work ever from Milicz ponds, wherein the diversity, community structure and seasonal variability of phytoplankton with respect to changes in physicochemical parameters and trace metals have been studied. Periodic samples of water and phytoplankton were collected from four selected ponds of various sizes from October 2018 to September 2019. Of the four selected ponds one was unused for carp cultivation. The study reports the presence of 147 phytoplankton species in nine distinct taxonomic groups. The Genera based Algal pollution index indicated presence of organic pollution in both noncultured pond and carp-cultured pond. The heavy metals detected in the concentration order of Cd>Mn>Fe>Zn>Cu>Pb remained much higher than the safe limits of freshwater aquaculture ponds. The probable sources of these pollutants were identified as artificial feed used in the cultivation of carp and inundation from the river basin. This study emphasizes the urgent need for continuous qualitative and quantitative assessment and monitoring of water parameters, including plankton, in these ponds. It strongly advocates for the implementation of sustainable measures to safeguard this vital ecosystem.