Fish

Dozens of frogs, fish, orchids and other species — many unseen for decades — may no longer exist due to humanity’s destructive effects on the planet.

Alabama’s Mobile River basin has the most aquatic biodiversity in the country. But we’re in danger of losing it before we even know what’s there.

The United States must grapple with a legacy of 90,000 dams, many unsafe or unwanted.

U.S. states hope to tap Canada’s network of large dams to meet low-carbon goals, but do better options exist closer to home?

Smalltail shark populations have declined by 90% in Brazil, and new research finds that overfishing has pushed the species perilously close to extinction.

After a half-century of failures, the recovery of the Connecticut River ecosystem hangs in the balance. Will authorities finally act to save it?

Solving this biodiversity mystery could reveal one of the most important sites to conserve these “rhinos of the sea.”

Subsistence, artisanal and small-scale fisheries represent a previously unrecognized threat to many protected shark and ray species.

A collection of our best articles and essays about some the world’s most at-risk groups of species — and what we can learn from them.

More frequent, longer-lasting blooms can harm both wildlife and human health — and even kill. Can we learn to predict and prevent them?