Condições socioecológicas, composição do Fitoplâncton e qualidade da água da Lagoa de Pituaçu, Salvador, RMS, Bahia, Brasil

Limnological research provides essential data to support the planning and management of water bodies and the development of conservation strategies for aquatic environments. This study aimed to investigate the spatio-temporal variability of physical-chemical, nutrient, and microbiological parameters, as well as the socio-ecological conditions of the Pituaçu Lagoon (2016–2018), located in Salvador, Bahia. Additionally, statistical analysis of data from INEMA's Monitora Projectwas performed, encompassing limnological, nutrient, and microbiological variables in the lagoon, the Pituaçu River, and the Pedras River. The composition of phytoplankton in thePituaçu Lagoon was analyzed both qualitatively and quantitatively. Integrated analyses of total phosphorus levels, ammoniacal nitrogen, BOD₅, trophic state, and multivariate approaches highlighted the influence of eutrophication and pollution linked to sanitation failures on the socio-ecological degradation of the Pituaçu Lagoon, Pituaçu River, and Pedras River. A total of 35 taxa distributed across 7 classes, 10 orders, and 22 families were identified in the phytoplankton of the Pituaçu Lagoon, with notable representation from the classes Chlorophyceae (15 taxa), Bacillariophyceae (8 taxa), and Cyanophyceae (6 taxa). The Cyanobacteria (72%) and Chlorophyta (24%) exhibited the highest relative abundance. It is recommended that further studies be conducted to evaluate the effects of trophic and socio-ecological changes arising from sanitation failures on water usage, risks to human and other organisms’ health, and the richness, diversity, distribution, and abundance of phytoplankton organisms, such as diatoms, in the Pituaçu Lagoon.