Dr. Ruth Gates worked tirelessly to conserve coral reefs, promoting a controversial idea called assisted evolution.

In the Caribbean, sargassum deposits have grown to unprecedented sizes, obscuring the sand and turning nearshore waters into seething sargassum soup.

Some authorities are trying to create fish habitats by cleaning old structures and dumping them at sea. But do these artificial reefs really work?

Fish intelligence? Yes, many studies have documented the ability of fish to learn from their environment. Fish exposed to a more complicated environment have an edge in learning.

Australia's iconic Great Barrier Reef is facing a threat from a massive outbreak of crown-of-thorns starfish.

Larger pieces of floating debris, like that caused by the Japanese tsunami, may carry hitchhikers in the form of organisms native to their place of origin.

Confront nature's mysteries, scientists find mutant sea stars surviving in warming waters and that sexual competition forces ducks to grow longer penises.

From microbial biochemistry to recycling dead fish to manure-to-energy converters, here’s this week’s most surprising sustainability news.

Orcas may look cute, but don’t be fooled. They display some of the most sophisticated hunting techniques of any animals on Earth.