"Environmental groups on Monday petitioned the U.S. government seeking endangered species protection for the American horseshoe crab, a "living fossil" under threat from commercial harvests for bait and biomedical use as well as from habitat loss and climate change."

"Octopuses are capable of sophisticated tasks, from solving puzzles to decorating their dens to remembering people's faces. So when a company in Spain announced that it wanted to commercially farm octopuses to harvest them for seafood, the plan sparked an uproar."

"The return of sea otters and their voracious appetites has helped rescue a section of California marshland, a new study shows. Sea otters eat constantly and one of their favorite snacks is the striped shore crab. These crabs dig burrows and also nibble away roots of the marsh grass pickleweed that holds dirt in place."

"The megalodon went extinct 3.6 million years ago, and is thought to be the largest shark that ever swam the Earth. But there's debate over what it looked like."

"The Warm Springs Dam isn’t coming down anytime soon. Conservationists want to use it to help save salmon."

"The nation’s rivers and streams remain stubbornly polluted with nutrients that contaminate drinking water and fuel a gigantic dead zone for aquatic life in the Gulf of Mexico, according to a recently released Environmental Protection Agency assessment."

"Scientists have mapped the largest coral reef deep in the ocean, stretching hundreds of miles off the U.S. Atlantic coast. While researchers have known since the 1960s that some coral were present off the Atlantic, the reef’s size remained a mystery until new underwater mapping technology made it possible to construct 3D images of the ocean floor."

"The Supreme Court is set to hear arguments on Wednesday that, on paper, are about a group of commercial fishermen who oppose a government fee that they consider unreasonable. But the lawyers who have helped to propel their case to the nation’s highest court have a far more powerful backer: the petrochemicals billionaire Charles Koch."

"There’s still a long way to go, but oyster recovery efforts in Maryland’s portion of Chesapeake Bay and its tributaries continue to show promising results, state officials for the agency charged with monitoring the mollusk ecosystem said."

"The Supreme Court will hear arguments on Wednesday over whether to overturn a key precedent on the power of executive agencies."