Missing Predator Returns to Signal Ecosystem Recovery

In the United States and Canada, river otters have returned to the Great Lakes region after decades of absence, signalling cleaner waterways and recovering ecosystems.

“Their return isn’t just welcome. It’s a sign the lakes themselves are healing,” said Timothy Mihocik, environmental writer and researcher.

River otters had largely disappeared by the 1970s due to pollution, habitat loss, and over-trapping, but reintroduction efforts since the 1980s, including the release of more than 400 otters across multiple states, have helped restore populations. Alongside this, water quality agreements, wetland restoration, and dam removal have improved habitats across a basin that holds about 20% of the world’s surface freshwater, allowing otters to re-establish stable, expanding populations.