ABSTRACT
The Delta do Parnaíba Environmental Protection Area (EPA) represents one of the largest deltaic systems in the Americas. This study investigated the spatiotemporal variability of phytoplankton communities and their correlation with environmental factors and assessed their trophic status and water quality across three mesotidal estuaries (Parnaíba-PRE, Comum-CRE, and Bom Gosto-BGRE) over a year-long sampling period. Multivariate analyses explored the interplay between environmental parameters, phytoplankton communities, and trophic indices. Salinity has emerged as a key determinant in these estuaries. Trophic components influence nutrient dynamics, with Redfield ratios indicating colimitation by orthophosphate () and silicate (). This study identified 355 taxa within the phytoplankton community, with Chlorophyta predominating in the PRE and diatoms dominating in estuaries with relatively high salinities (BGRE and CRE). Environmental drivers vary across estuaries, with temperature, dissolved oxygen (DO), total nitrogen (TN), chlorophyll-a (Chll-a), and the trophic index (TRIX) influencing the phytoplankton community in the PRE, while salinity, , total phosphorus (TP), and TN affect the CRE, and salinity and Chll-a influence the BGRE. The Delta do Parnaíba EPA exhibits eutrophic to hypertrophic conditions, emphasising the need for comprehensive environmental monitoring, nutrient management, and conservation efforts to safeguard biodiversity, water quality, and ecosystem health.
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No potential conflict of interest was reported by the author(s).
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Notes on contributors
Marco Valério Jansen Cutrim
Marco V. J. Cutrim is a full professor in the Postgraduate Program in Science and Technology at the Federal University of Maranhão, Brazil. He obtained his Ph.D. in Biological Sciences from the University of Sao Paulo, Brazil. His research focuses on the phycology and aquatic ecology of marine and estuarine systems.
Quedyane Silva da Cruz
Quedyane Silva da Cruz is a Ph.D. student at Federal University of Pernambuco, Brazil. Her studies focus on phytoplankton community structure and dynamics.
Denise dos Santos Costa
Denise dos Santos Costa obtained her master’s degree in Oceanography from the Federal University of Maranhão. Her studies focused on the phytoplankton community structure, composition, and ecology of marine and estuarine systems.
Amanda Lorena Lima Oliveira
Amanda L. L. Oliveira obtained her master’s degree in Oceanography from the Federal University of Maranhão. Her studies focused on phytoplankton community structure and composition.
Ana Karoline Duarte dos Santos Sá
Ana Karoline D. S. Sá obtained her Ph.D. in Oceanography from the Federal University of Pernambuco, Brazil. Her studies focused on phytoplankton dynamics and aquatic ecology.
Lisana Furtado Cavalcanti-Lima
Lisana F. Cavalcanti obtained her Ph.D. in Oceanography from the Federal University of Pernambuco, Brazil. Her studies focused on the phytoplankton community structure and water quality of coastal environments.
Andrea Christina Gomes de Azevedo-Cutrim
Andrea C.G. Azevedo-Cutrim is an adjunct professor in the Department of Biology at the University of Maranhão State, Brazil. She obtained her Ph.D. in Oceanography from the Federal University of Pernambuco. Currently, she works with biological oceanography and phycology.
Taiza Pimentel Santos
Taíza Pimentel Santos is a Ph.D. student at Federal University of Pernambuco, Brazil. Her research focuses on plankton dynamics and taxonomy.