Potencial para bioindicação e bioprospecção de microalgas e cianobactérias na Lagoa dos Índios, Macapá, Amapá

Abstract

Introduction: An important tool that allows the evaluation of water quality is the use of bioindicators, phytoplankton is seen as a biological marker, as they react expressively to natural or anthropogenic environmental change. Objectives: The objective of this study was to carry out a survey of the microalgae and cyanobacteria of Lagoa dos Índios in the years of 2008, 2012 and 2016/17 and to compare the species found, evaluating if there were changes that could indicate some type of environmental impact. Methodology: Samples were collected using a 20 μm phytoplankton network, carrying out a qualitative analysis, conditioned the samples in glass vials with a volume of 200 ml, fixed and preserved with 4% formalin solution immediately after collection. The hydrogen ionic potential (pH), conductivity (μS / cm), temperature (ºC) and dissolved oxygen (mg / L) of the water were measured. Results and discussion: Have been identified 347 genera and species were identified, distributed in 14 taxonomic groups, the most representative group being Conjugatophyceae. The analysis of variance showed significance for water temperature and dissolved oxygen between the years 2008 and 2016/17. The composition of wealth was higher in the rainy season, for the years 2008 and 2012, while for the year 2016/17, was higher in the dry season. The canonical correspondence analysis (CCA) showed that the relationship between physical and chemical variables was significant with the composition of the phytoplankton community of Lagoa dos Índios. Conclusions: The high wealth found evidence the biological importance of this ecosystem and how the population uses its water for different purposes, it is necessary constant monitoring, because cyanobacteria that can produce toxins have been identified. Microalgae and cyanobacteria can be used as bioindicators because they have been statistically associated with measured physical and chemical factors and species can be isolated for laboratory cultivation resulting in several bioprospecting studies