Water Quality and Phytoplankton Communities in Newly Created Fishponds

Abstract

During the growing season of the year 2012 and 2013 (April–November) hydrobiological and hydrochemical monitoring of newly created fishponds inhered in Northern Moravia was carried out. Water temperature, dissolved oxygen content, pH, conductivity and water transparency were monitored directly at the sampling place. At the same time, water samples for taxonomical identification of phytoplankton were taken. Chemical parameters stabilization occurred in the second year after flooding. Chemism of fishponds was influenced by higher ration of organic matter in fishponds sediment and by fertilizing and liming. Water saturation by dissolved oxygen, pH, transparency and chlorophyll–a values fluctuated in the wide range due the growth of planktonic communities and composition of the fish stock. Hydrochemical parameters stabilized in the second year after the first flooding. The phytoplanktonic community of fishponds during the much of the growing season was formed by the representatives of green algae. Golden–brown algae were dominant during the spring season, in some cases euglenas as well. Diatoms were present in fishponds from spring to autumn but only to limited degree. The cyanobacteria formed only minor part of phytoplanktonic community, except the fishpond P1 where they formed dominant group.