Rivers and Lakes Hold Key to Climate Resilience

The tiny caddisfly larvae building pebble homes on riverbeds might be more important to our climate future than anyone imagined.

A major international review led by Professor Gemma Harvey at Queen Mary University of London reveals how freshwater creatures act as "ecosystem engineers," physically reshaping their environments in ways that help rivers, lakes, and wetlands cope with climate pressures. These organisms, ranging from beavers constructing dams to insects building underwater structures, alter water flow, modify riverbeds, and create habitats that make entire ecosystems more resilient.

The research, published in WIREs Water, shows these natural architects have been hiding in plain sight while getting far less scientific attention than their land-based counterparts. Most studies focus on dramatic flooding events rather than the slow burn of rising temperatures and drought, even though these threats are intensifying under climate change.

The geographical gaps are striking too. While American and European rivers have been well studied, regions facing the most severe climate shifts remain largely unexplored. Scientists have also overlooked smaller creatures like insects and crustaceans in favor of charismatic species like beavers, despite these tiny engineers wielding enormous influence over their ecosystems.

This builds on Professor Harvey's groundbreaking 2025 study that first quantified how animals act as "architects of the Earth" at a planetary scale. Together, the research shifts how we understand nature: organisms aren't just living in ecosystems but actively shaping how those systems respond to environmental change.

Professor Harvey emphasizes the stakes: "Freshwater ecosystems are often overlooked in climate research, despite being central to biodiversity, water security and human well-being." These waterways support countless species and provide drinking water for billions of people worldwide.

The Ripple Effect

Understanding these natural engineers could transform how we protect and restore freshwater systems. When ecosystem engineers thrive, they create structures that slow water during floods, retain moisture during droughts, and provide cool refuges as temperatures climb. These benefits cascade through entire food webs and extend to surrounding landscapes.

The researchers argue that filling these knowledge gaps is essential for effective conservation. Future studies need to examine how multiple engineers work together, expand into understudied regions, and better integrate warming and drought pressures into freshwater science.

As climate change intensifies, these findings offer a hopeful path forward: working with nature's own engineers rather than against them. The creatures already reshaping our rivers and lakes could become powerful allies in building climate-resilient ecosystems for generations to come.