As sea temperatures rise, mammals and birds may lose their edge over the cold-blooded species they eat, as well as the sharks that hunt them.

In addition to detecting unseen organisms in the ocean, studies of environmental DNA can shed light on the genetic structure of marine populations.

Eight environmental groups took the legal measure in an effort to protect North Atlantic right whales and other marine organisms.

The dolphins and their trainers will search for the endangered porpoises and enclose them in a protected pen.

Data collected by elephant seals in Antarctic waters provide a closer look at the processes driving ocean circulation.

Louis Herman, who made seminal discoveries on dolphin cognition, has passed away at age 86.

The University of St. Andrews behavioral ecologist studies the social structures and behaviors of whales and dolphins, recording and analyzing their acoustic communications.

Watch underwater footage of a dolphin sleeping in the wild.

Results could explain why the marine mammals have been stranding on the West coast in record numbers.

Fossilized remains from a river dolphin relative provide some details about when the mammals left the oceans.

Fetal specimens collected by commercial whalers offer insights into how whales may have evolved their specialized hearing organs.

US dogs face a deadly threat from algae-spawned toxins lurking in lakes, but there may be an antidote.

A hidden toxin stalks marine mammals off the coast of California and kills dogs and cats farther inland.