Aspects of the Plankton Community from Sauípe Port Estuary, Bahia, Brazil

The estuary forms at the meeting of the river and the sea. It houses a fundamental microbiological community of plankton, which plays a role in the trophic network and the decomposition of organic matter. The uncontrolled expansion of human occupation in areas near mangroves has led to degradation, with alterations in physical, chemical, and biological characteristics. The present study investigates the ecological aspects of planktonic communities in the estuary waters and the identification of species that indicate the water quality of the Port of Sauípe estuary, state of Bahia, Brazil. Estuary water samples were collected to identify plankton, with random releases of a conical plankton net with a screw cup and stored in plastic containers with Transeau solution. The water samples were filtered, and the material retained in the filter was analyzed. All samples were examined under an optical microscope to identify phytoplankton, zooplankton, parasites, and other microinvertebrate species. Cyanobacteria predominated in the phytoplankton, while Copepoda was the most common in the zooplankton. Among the parasites, Ascaris lumbricoides had been recorded six years earlier, but Schistosoma haematobium and Entamoeba coli are being recorded for the first time in the area. The plankton data indicate poor environmental quality in the estuary, with toxin-producing species and sanitary hazard parasites used for fishing, shellfish harvesting, recreation, and tourism in a reference place on the North Coast of Bahia, Brazil.