Eficiência da utilização da comunidade do fitoplâncton e parâmetros ambientais na avaliação da qualidade de água em setores ambientalmente críticos do Lago Titicaca, Perú.

Abstract

Degradation of water quality and deterioration of ecosystems represent two problems of great concern in the world's lakes. Lake Titicaca, in South America, is also concerned. One of the main causes of the environmental deterioration of Lake Titicaca is the poor management of urban wastewater, which is causing serious eutrophication problems in specific areas such as Puno Bay in Peru and Cohana Bay in Bolivia. Therefore, this research aimed to evaluate water quality through physical, chemical, and microbiological parameters (bacteria and phytoplankton) to assess its conservation status and spatial and temporal variability. To achieve the objectives, first, the scientific literature was reviewed using bibliometric and network analysis techniques. As part of the research, water quality was assessed in critical sectors of Lake Titicaca, based on an index calibrated using physical, chemical, and water microbiological parameters, through principal component analysis. Likewise, the ecological status of the lake was assessed based on the phytoplankton community and the physical and chemical parameters of the water. The results of the bibliometric analysis indicated that the area under study is subject to strong scientific monitoring at a global level, with emphasis in recent years on topics such as water quality, eutrophication, phytoplankton and cyanobacteria. From the study of water quality in Lake Titicaca, it was determined that all evaluated bays of the lake had moderate to poor water quality. Similarly, the Q index, ecological state index based on Reynolds phytoplankton functional groups, identified the main seasonal variations in the ecological condition of the Lake Titicaca, which was mostly moderate to bad. Phytoplankton biomass ranged between <0.0001 to 0.3 mg L-1. During the study period, 85 phytoplankton species were identified, divided into 22 functional groups. The seasonal succession of the main functional groups followed this sequence, in order of biomass (major to minor) was: LM, F, Lo, J, and T; highlighting that the first four groups are indicators of eutrophication processes. Lake Titicaca presented tolerable and bad ecological status during the evaluated period. In this context, stakeholders have the responsibility to implement management strategies to achieve an adequate ecological condition of Lake Titicaca.