Brazil, Uruguay Lakes Could Warn of Ecosystem Collapse, Researchers Find

A sprawling chain of over 100 shallow lakes along the Atlantic coast of southern Brazil and Uruguay may hold the key to predicting environmental disasters. An international study, published in the journal One Ecosystem, provides the first systematic assessment of these Southern American Coastal Shallow Subtropical Lakes, suggesting they can act as a natural observatory for early signs of ecosystem collapse.

These lakes, stretching over 1,000 kilometers, form one of the Earth's largest continuous networks of coastal shallow lakes. Despite their significance, they have remained relatively understudied compared to freshwater systems in North America and Europe. Scientists believe these interconnected ecosystems offer a unique natural laboratory to observe how freshwater systems function in a subtropical environment and how they respond to complex environmental changes.

The region faces multiple stressors, including climate variability, rapid urbanization, agricultural runoff, untreated wastewater, and the increasing presence of contaminants like pharmaceuticals and microplastics. Frequent extreme rainfall and flooding events further stress these already vulnerable habitats. By monitoring these lakes, researchers hope to detect the initial impacts of climate change, pollution, and ecosystem degradation before irreversible damage occurs, filling a significant gap in global freshwater research.

“

Most of what we know about freshwater ecosystems comes from studies in the Northern Hemisphere, and studying these lakes can help fill a big gap in our knowledge.