Qualidade da água e comunidade fitoplanctônica, Praia do Ideal, Fortaleza/CE

Abstract

The phytoplankton forms a community mainly composed of unicellular algae, playing a fundamental role in the food chain, in balancing the carbon cycle, and in preserving water quality. Thus, the work aimed to verify the water quality and the composition of the phytoplankton community and its bioindicators in the Ideal Beach. Monthly collections were conducted between February and October 2023, filtering 100 liters of water in each sample using a mesh aperture of 25 μm and a mouth diameter of 25 cm. The collected material was concentrated to 10 mL, fixed in 4% formaldehyde at a 1:1 ratio, and 10 subsamples of 0.1 mL were analyzed using a Callmex® microscope. In situ data on water temperature, transparency, salinity, pH, dissolved oxygen, ammonia content, and phosphate were obtained. The results showed water of good quality and a phytoplankton community composed of Asterionella sp, Aulacoseira sp, Chaetoceros sp, Chaetoceros danicus, Euastrum sp, Gomphonema sp, Melosira sp, Navicula sp, Stigeoclonium, Cyclotella sp, Tabellaria sp, and Oscillatoria sp.. No phytoplankton bioindicators suggesting adverse environmental conditions were found.