A new study finds a surprising number of fish, birds and mammals in the oceans 100 and 1,000 years ago. Can this information help regulators slow the decline of important marine animals?

Three giant new reserves, extend 50 miles out from shore, will protect coral reefs, fish, clams, and other life forms. But how effective are marine protected areas?

When too much fertilizer reaches the Gulf of Mexico through the Mississippi River, a vast area gets robbed of oxygen. What can be done to reduce the dead zone that appears each summer?

Some people find sea gulls annoying, but they have their uses.

Gills are the equivalent of a mammal’s lungs, says Jeffrey Malison, director of the aquaculture program at University of Wisconsin-Madison. “Their primary purpose is to exchange gases, take oxygen in and release carbon dioxide out of the fish.”
Both lungs and gills have a bed of very small blood vessels with thin walls that the gases [...]

New tracking systems watch long-distance migrants move across the ocean. Follow whales, turtles and albatrosses across the watery planet.

Genetically male fish in the Columbia River look and act like females.