Banca de QUALIFICAÇÃO: ASTRID OLIVEIRA DOS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ASTRID OLIVEIRA DOS SANTOS
DATE: 29/04/2024
TIME: 16:00
LOCAL: Sala virtual Google Meet
TITLE:

SEASONAL VARIATION AND COMPOSITION OF THE PHYTOPLANKTONIC COMMUNITY OF CLEAR AND WHITE WATER RIVERS IN THE LOWER AMAZONAS AND LOWER TAPAJÓS REGION

KEY WORDS:

anthropogenic action; biomonitoring;  phytoplankton; water resources

PAGES: 30
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

The growing demand for water in Brazil has caused significant impacts on aquatic ecosystems, mainly due to urbanization, agriculture and deforestation for mining activities. These activities affect river quality by increasing nutrient and pollutant concentrations. Thus, biomonitoring, a technique using organisms (bioindicators) to assess environmental changes, It is an important tool for diagnosing the ecological status of these aquatic ecosystems. Phytoplankton, considered a bioindicator, can be found in the water column (euphotic zone), they have great ecological importance in aquatic ecosystems, because they perform the function of primary producers, being also effective in understanding how anthropic actions and the uses of basins River basins affect water quality, considered an important monitoring tool. Therefore, the objective of this study is to evaluate the conditions shaping the structure of the phytoplankton community by correlating analyzes of temporal and spatial patterns with limnological variables in three rivers of the Amazon, Brazil. The study is being carried out on the Tapajós River, Arapiuns River and Amazon River. The collection of phytoplankton material and limnological data has already started (2022) and will continue until the end of the current year (2024).The sampling was divided into four expeditions: Expedition I - dry season; Expedition II - flood season; Expedition III - high water season; and Expedition IV - low water season, where in each expedition the three rivers reported are sampled (three points in each river). The collection points were chosen based on their proximity to riverside communities. Abiotic data are obtained in situ using the AKSO Model AK88 multiparameter probe, transparency is obtained using the Secchi disk and turbidity (NTU) with a turbidimeter device. At each point, samples are collected for quantitative analysis from the water surface and subsequently fixed with Lugol (4%). These, later, in a laboratory environment, will continue with the counting of individuals using the Utermöhl method (1958), in an inverted microscope from Zeis, model Primovert. In addition to quantitative analysis, qualitative analysis is performed. For this sampling, a plankton net (20 micron opening) is used. After collection, the material is fixed with formalin (4%) while still in the field, and in the laboratory the identification of the qualitative material is carried out using an Optical Microscope from Zeis Model Scope A1, both microscopes are in the Algae and Plants Laboratory of the Amazon (LAPAM) on the Oriximiná Campus. For the identification of phytoplanktonic organisms, specialized keys are being used for taxonomic identification and the basis of scientific articles. In order to explore the spatio-temporal variations of limnological data, Principal Component Analysis (PCA) will be used and to relate biotic data with limnological data, canonical correspondence analysis (CCA) will be used. Furthermore, a cluster analysis will be performed to understand the dynamics between rivers and over time. Differences in phytoplankton communities are expected to occur, mainly according to water transparency, pH, conductivity and hydrological period. Wealth, Diversity and Equitability data may indicate degrees of environmental change. These changes are related especially to the use of the land surrounding the sampled locations.

COMMITTEE MEMBERS:
Presidente - 2391001 - DAVIA MARCIANA TALGATTI
Interna - 1334145 - GRACIENE DO SOCORRO TAVEIRA FERNANDES
Externo ao Programa - 1544196 - DIEGO MAIA ZACARDI - UFOPA