Researchers map 100+ lakes in Brazil, Uruguay that could warn of ecosystem collapse

Published 8 August 2026 · science

Published in the journal One Ecosystem, the research provides the first systematic assessment of the Southern American Coastal Shallow Subtropical Lakes A hidden giant of

Published in the journal One Ecosystem, the research provides the first systematic assessment of the Southern American Coastal Shallow Subtropical Lakes A hidden giant of the freshwater Why these lakes are important These lakes are also exposed to multiple stressors at the same time, giving scientists a rare opportunity to study how freshwater ecosystems respond to complex environmental changes Nature’s early-warning system The science that underlies early detection Scientists may examine the water samples to tell which species are present without having to catch or see the animals Constructing an international monitoring network What if lakes could warn us about an environmental disaster? These freshwater systems may be giving off subtle biological signals long before the fish start dying off, the algae bloom on the water, or the pollution becomes hazardous. Well, the difficulty has always been how to read them. But, a new international study suggests that a vast chain of shallow lakes stretching more than 1,000 kilometers along the Atlantic coast of southern Brazil and Uruguay could become one of the world's most valuable natural observatories for detecting those warning signs. Watching these connected lakes over time, scientists believe they can see the first signs of climate change, pollution and ecosystem collapse—long before any damage is irreversible.

Published in the journal One Ecosystem, the research provides the first systematic assessment of the Southern American Coastal Shallow Subtropical Lakes, emphasizing their importance for South America and for global freshwater research.Despite being one of the largest continuous networks of coastal shallow lakes on Earth, the lake network has been relatively understudied compared to iconic freshwater ecosystems in North America and Europe.As per the report published by Phys Org, together, these lakes offer a unique natural laboratory, enabling scientists to see how freshwater ecosystems function in a sub-tropical environment. They are among the most diverse and interconnected ecosystems on Earth, and are affected by natural climate cycles and human activities that make them ideal for long-term ecological research. “Most of what we know about freshwater ecosystems comes from studies in the Northern Hemisphere,” the researchers say, “and studying these lakes can help fill a big gap in our knowledge.”The region is already suffering from many of the environmental pressures which are expected to be widespread in the future. These freshwater habitats are increasingly subject to the pressures of climate variability associated with the El Niño–Southern Oscillation, rapid urbanisation, agricultural runoff, untreated wastewater and the increasing occurrence of contaminants such as pharmaceuticals and microplastics.