2026-07-062026-07-062026-06-19RAMOS, Anailma da Silva. Distribuição espacial e temporal do fitoplâncton no estuário Emboraí Velho, Augusto Corrêa (Pará, Brasil). Orientador: Rauquírio Marinho da Costa; Coorientador: João Victor de Moraes Souza Pinheiro. 2026. 36 f. Trabalho de Curso (Licenciatura em Ciências Naturais) – Faculdade de Ciências Naturais. Instituto de Estudos Costeiros, Campus Universitário de Bragança, Universidade Federal do Pará, Bragança-PA, 2026. Disponível em: https://bdm.ufpa.br/handle/prefix/9703. Acesso em: .https://bdm.ufpa.br/handle/prefix/9703This study aimed to determine the spatial and temporal dynamics of biomass and planktonic floristic composition, as well as the interrelationships of this community with the hydrological variables of the Emboraí Velho estuary. Sampling was carried out simultaneously in 25 hour nycthemeral cycles during spring tides at two fixed stations (E1 and E2) in April (rainy season) and December (dry season) of 2019. Temperature, salinity, and turbidity data were obtained using CTDs. pH, dissolved oxygen (DO), and dissolved nutrients (nitrite, nitrate, total nitrogen, orthophosphate, total phosphorus, and silicate) were obtained from water samples collected with Niskin oceanographic bottles. Phytoplankton was collected using conical plankton nets (64 μm mesh). Samples intended for quantitative analysis were obtained from Niskin bottles. A broad seasonal pattern of precipitation was observed, with well defined rainy and dry periods, as evidenced by the historical average of the previous 20 years. Temperature, salinity, pH, dissolved oxygen, nitrate, orthophosphate, total nitrogen, and silicate exhibited seasonal distribution patterns, ranging from subtle variations, as observed for temperature, to more abrupt changes, as recorded for salinity. Chlorophyll-a, which indicates phytoplankton biomass, didn't show any significant changes in its spatial or seasonal distribution. A total of 158 phytoplankton taxa were identified, with the phylum Bacillariophyta accounting for 91%. Total density ranged from 213,981 ± 141,005 × 10⁻³ cells L⁻¹ at station E2 in April (rainy season) to 2,265,417 ± 1,097,851 × 10⁻³ cells L⁻¹ at station E2 in December (dry season). The most prominent species, Cymatosira belgica, ranged from 177,054 ± 81,785 × 10⁻³ cells L⁻¹ at station E1 in April (rainy season) to 2,053,375 ± 1,027,941 × 10⁻³ cells L⁻¹ at station E2 in December (dry season). The first two ACC axes explained 27.9% of the data variation. Of the 13 variables tested, only three were significant. The integrated analysis of abiotic and biotic variables demonstrated how hydrological factors—especially rainfall—regulate system variations, including salinity and dissolved nutrients (nitrite, total nitrogen, and orthophosphate), directly influencing the metabolism, development, and ecology of phytoplankton.Acesso AbertoEstuáriosNutrientesBiomassaProdutividadeEstuariesNutrientsBiomassProductivityCNPQ::CIENCIAS EXATAS E DA TERRA::OCEANOGRAFIATrabalho de Curso - Graduação - MonografiaAttribution-NonCommercial-NoDerivs 3.0 Brazil