PPG-SEA and NEEA/SHS, São Carlos School of Engineering, University of São Paulo, São Carlos, SP, Brazil.
Nucleus of Ecotoxicology and Applied Ecology, Department of Hydraulic and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador Sancarlense Avenue, 400, São Carlos, São Paulo, 13560-970, Brazil.
Environ Sci Pollut Res Int. 2022 Dec;29(59):89426-89437. doi: 10.1007/s11356-022-22070-4. Epub 2022 Jul 19.
Land use changes threaten the maintenance of water quality and challenge the management of tropical reservoirs. In particular, eutrophication alters several ecosystem functions and services, compromising multiple uses of water. For example, in the Lajeado Reservoir (Araraquara, São Paulo, Brazil), aquatic macrophytes rapidly spread and occupied more than 90% of the system's surface area (from 2016 to 2019). In such a scenario, this research aimed to evaluate the eutrophication causes and impacts to provide technical and scientific support to public agencies and propose remediation alternatives. First, a diagnosis of the study area was performed, using available data on land use, water quality, and climate (between 2010 and 2018). Second, water and sediment samples were collected for physical, chemical, and ecotoxicological analyses. The Ecological Risk Assessment consisted of a triad of Lines of Evidence, including physical-chemical, chemical, and ecotoxicological results. The expansion of agricultural activities (e.g., sugarcane cultivation) and diffuse pollution were highlighted among possible causes, and water quality was affected by increases in the concentration of nutrients (e.g., nitrogen and phosphorus), metals (e.g., iron), and emerging contaminants (e.g., pesticides and caffeine). As a result, the Lajeado Reservoir presented a high ecological risk, and alternatives for macrophyte removal are needed. This research involved several stakeholders (i.e., community, government agencies, and universities) who participated more effectively in environmental monitoring and recovery.
土地利用变化威胁着水质的维持，并对热带水库的管理提出了挑战。特别是富营养化改变了几个生态系统功能和服务，损害了水资源的多种用途。例如，在拉热多水库（巴西圣保罗阿拉拉夸拉），水生大型植物迅速蔓延，占据了系统表面积的 90%以上（2016 年至 2019 年）。在这种情况下，本研究旨在评估富营养化的原因和影响，为公共机构提供技术和科学支持，并提出补救替代方案。首先，对研究区域进行了诊断，使用了土地利用、水质和气候方面的现有数据（2010 年至 2018 年）。其次，采集了水和沉积物样本，进行物理、化学和生态毒理学分析。生态风险评估由三部分证据组成，包括物理化学、化学和生态毒理学结果。农业活动（如甘蔗种植）的扩张和分散污染被列为可能的原因之一，水质受到营养物质（如氮和磷）、金属（如铁）和新兴污染物（如农药和咖啡因）浓度增加的影响。因此，拉热多水库的生态风险很高，需要去除大型植物。这项研究涉及了几个利益相关者（即社区、政府机构和大学），他们更有效地参与了环境监测和恢复。
