Every marbled crayfish is a female clone. The population is exploding in Europe, but the species seems to have originated in the American Southeast.

Killer whales able to copy words such as “hello” and “bye bye” as well as sounds from other orcas, study shows

Millions of tons of plastic waste end up in the ocean every year. And the trash stays there: Whether it's grocery bags or water bottles or kids' toys, plastic is practically indestructible. Now marine scientists have discovered that it's killing coral reefs. A new study based on four years of diving on 159 reefs in the Pacific shows that reefs in four countries — Australia, Thailand, Indonesia and Myanmar — are heavily contaminated with plastic. It clings to the coral, especially branching coral. And where it clings, it sickens or kills.

Some 49.9 percent of Sekisei coral reef -- Japan's largest -- had bleached by the end of 2017, the Environment Ministry has revealed. The figure is substantially less than the bleaching ratio of 91.4 percent on the reef between Okinawa Prefecture's Ishigaki and Iriomote islands at the end of 2016. However, "the water temperature remains high and the bleaching ratio is still high. We can't be optimistic," said an Environment Ministry official. "Coral in the area hasn't shown signs of real recovery, and remains in critical condition."

For decades, marine scientists have been warning of the demise of coral reefs in a warming world. But now, those warning calls have reached a full-scale alarm, leaving researchers at a loss for exactly how best to save the reefs. A study published Thursday in Science by some of the world’s top coral experts amounts to a last rites for the ecosystems often referred to as “the tropical rainforests of the sea.” Scientists surveyed 100 reefs around the world and found that extreme bleaching events that once occurred every 25 or 30 years now happen about every five or six years.

Australia is calling on the world's top scientific minds to help save the Great Barrier Reef, offering hundreds of thousands of dollars to fund research into protecting the world's largest living structure. The UNESCO World Heritage-listed reef is reeling from significant coral bleaching due to warming sea temperatures linked to climate change.

Dolphins develop the ability to recognize themselves in a mirror at an earlier age than children, which fits with how fast they develop generally.

Psssst, mud crabs, time to hide because blue crabs are coming to eat you! That’s the warning the prey get from the predators’ urine when it spikes with high concentrations of two chemicals, which researchers have identified in a new study. Beyond decoding crab-eat-crab alarm triggers, pinpointing these compounds for the first time opens new doors to understanding how chemicals invisibly regulate marine wildlife.

At the Pacific Ocean's largest green sea turtle rookery, a crisis is unfolding, likely thanks to warming temperatures. Will this become a global problem?

The giant Pacific octopus you saw at the aquarium last month? It might not have actually been a giant Pacific octopus.

Each scallop eye is built something like the gigantic telescopes that peer into deep space, researchers reported on Thursday.

How a triple infanticide in Germany shed light on an elusive cold-water predator. By M. R. O’Connor.

Deep within Turkey's biggest lake, archaeologists made a fascinating discovery. A 3,000-year-old fortress was found during an underwater excavation of Lake Van.

It’s difficult to imagine the voracious great white shark as prey. Could orcas really be overpowering them and removing their livers? By Lauren Smith.

It’s difficult to imagine the voracious great white shark as prey. Could orcas really be overpowering them and removing their livers?

While most photographers are tucked in bed, this sharpshooter dons dive gear and searches for his subjects at the ocean’s surface, in the black of night. By Michael Patrick O’Neill.

Intentional actions by usually solitary octopuses improve a sandy site, allowing group living in 'Octlantis'. But the buzz around the site grew quickly, creating some interesting interpretations.

This Clip of Clownfish Working Together Could Be Straight Out of a Disney Movie.

Three species of sharks and three species of rays will now have extra protection wherever they go, thanks to a conservation agreement signed by 126 countries around the world.

Unprecedented amounts of coral reef bleaching destroyed the coasts of Hawaii, and it will probably keep getting worse.