Brazilian Journal of Enviromnent
Open Access Journal
CiteScore
0.5
Indexada na
SCOPUS
QUALIS
B3
2017-2021
quadriênio
Open Access Journal
0.5
Indexada na
SCOPUS
B3
2017-2021
quadriênio
Tecnologias e Estudos Ambientais | Vol. 13 Issue 1 (2025)
Published in March 08, 2025
Barros’s Lake, in southern Brazil, is the outlet of 11 tributaries (AS) that encompass its catchment (240 km²). In 2020 and 2022 phytoplankton blooms were registered. Monthly water samples from the lake and AS, grouped by land uses (agriculture, grassland, forest, and urban drainage), were collected between 2021 and 2022 to estimate: pH, electrical conductivity (EC), concentration of total solids (ST), dissolved (SD) and particulate (SP) by gravimetry, total phosphorus (PT) and dissolved (Pdiss) by ICP-OES, and total nitrogen (NT) by Kjedahl distillation, to explain the concentration of chlorophyll-a (Chl-a), by spectrophotometry, collected at 7 points in the lake. A difference (p<0.05) by Kruskal-Wallis was observed between the drainage AS in relation to the others for CE, Pdiss, ST, SD and NT, and in relation to the Lake, for CE and Pdiss. PT was above the standard for class 2 freshwater (CONAMA Nº 357/2005) for AS and Lake, being positively related to the SP (R²=0.47). The grassland and forest AS had the lowest concentrations of solids, PT and NT. Principal Component Analysis and Spearmann test evidenced that the only parameter, linear strongly and positively related to Chl-a was SP (ρ>0.72 and p<0.05), indicating suitable environmental scenario the the recruitment of species adapted to turbidity (R²=0.5, p<0.05). The increase of sediments and PT, characteristic of human activities, associated with the morphometry of the Lake, indicate the need for water monitoring, minimization of inputs and preservation of native vegetation for the management of eutrophication.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2025 Luce Helena Kochem, Luciane Oliveira Crossetti, Claudia Alessandra Peixoto de Barros
https://orcid.org/0000-0002-0049-4229