Using phytoplankton biomonitoring to strengthen environmental governance in Argentina: a case study

Urban streams rank among the most degraded ecosystems worldwide, yet the complex drivers behind their deterioration are often studied in isolation. In this study, we develop an integrated approach that links governance performance with ecological indicators and propose pathways for more effective environmental management of degraded urban streams in South America. We combined year-long limnological monitoring, including nutrient, metal, pesticide, and phytoplankton samples from six lowland streams (n = 72), with an in-depth legal review of water management frameworks in Entre Ríos Province. Our findings reveal significant spatiotemporal variability in water quality, with eutrophication and organic pollution emerging as dominant stressors, alongside persistent inorganic turbidity. We conclude that Entre Ríos has a robust legal framework with several laws related to ecosystem protection and management; however, this legislation remains heavily oriented toward productive water use, implementation is notably deficient, and this results in moderate to high urban stream degradation.