Structure and temporal variation of the phytoplankton of a macrotidal beach from the Amazon coastal zone



Document title: Structure and temporal variation of the phytoplankton of a macrotidal beach from the Amazon coastal zone
Journal: Anais da Academia Brasileira de Ciencias
Database: PERIÓDICA
System number: 000400426
ISSN: 0001-3765
Authors: 1
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1
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Institutions: 1Universidade Federal do Para, Instituto de Estudos Costeiros, Braganca, Para. Brasil
Year:
Season: Sep
Volumen: 88
Number: 3
Pages: 1325-1340
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Analítico, descriptivo
English abstract The present study aimed to analyze the structure and the temporal variation of the phytoplankton of Ajuruteua beach (Bragança, Pará) and to investigate the influence of environmental variables on the dynamics of this community to provide a basis about the trophic state of this environment. Biological, hydrological and hydrodynamic samplings were performed during a nyctemeral cycle in the months of November/08, March/09, June/09 and September/09. We identified 110 taxa, which were distributed among the diatoms (87.3%), dinoflagellates (11.8%) and cyanobacteria (0.9%), with the predominance of neritic species, followed by the tychoplankton species. Chlorophyll-a concentrations were the highest during the rainy period (24.5 mg m-3), whereas total phytoplankton density was higher in the dry period (1,255 x 103 cell L-1). However, phytoflagellates density was significantly higher during the rainy period. Cluster Analysis revealed the formation of four groups, which were influenced by the monthly differences in the environmental variables. The Principal Component Analysis indicated salinity and chlorophyll-a as the main variables that explained the components. Spearman correlation analysis supported the influence of these variables on the local phytoplankton community. Overall, the results obtained suggest that rainfall and strong local hydrodynamics play an important role in the dynamic of the phytoplankton of Ajuruteua beach, by influencing both environmental and biological variables
Disciplines: Biología
Keyword: Biología acuática,
Fitoplancton,
Dinámica de poblaciones,
Biomasa,
Variación estacional,
Playas macromareales
Keyword: Biology,
Aquatic biology,
Phytoplankton,
Population dynamics,
Biomass,
Seasonal variation,
Macrotidal beaches
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