Avaliação de parâmetros de produção na Estação de Piscicultura Continental Johei Koike, UFRPE

Abstract

An aquatic environment for rational fish farming has its own complex ecology, where the dynamics of biological and physical-chemical processes determine water quality conditions. Planktonic communities represent a sensitive tool to monitor environmental variations, as indicators of water quality, levels of pollution and eutrophication, as well as important food sources for the trophic chain. The present work aims to evaluate the quality of water and plankton composition, as a management tool in fish farming at the Continental Pisciculture Station Johei Koike, UFRPE. The total volume of the ponds and the flow rate of the supply channel were calculated, and water was collected for five consecutive weeks in nine active fish ponds at the station, located on the main campus of the Federal Rural University of Pernambuco (UFRPE). In each pond a surface horizontal trawl was carried out with a plankton net (mesh opening of 64 μm). Plankton samples were preserved in 70% alcohol and analyzed at the Zooplankton Laboratory of the Department of Oceanography at UFPE. The identification took place at the taxonomic level of large groups. For the nine ponds the water transparency was always less than 25 cm, and in general the temperature was always between 28 and 29°C. Thus, a low variety of plankton species was observed in the ponds. Phytoplankton populations did not show large variations. In the nine ponds, the phylum Chlorophyta was the group of algae with the highest number of cells. As for zooplankton it varied between the nurseries according to the type of fish cultivated and the trophic conditions. The phylum Rotifera was in greater numbers in the nurseries. However, total phytoplankton and zooplankton densities point to three different pond groups, where pond size and type as well as uses and management seem to significantly affect populations of these organisms.