Most corals are homebodies. They settle in one spot, link with hundreds or thousands of their friends, and never move. They build the structures we recognize as corals: rock-like spires, branches, domes, and others. But a few corals “walk” along the sea floor. They don’t go very far. And they certainly don’t get there in a hurry. But their mobility…

Earth’s warming climate has really heated up Atlantic hurricanes in recent years. Two recent studies, in fact, found that hurricane wind speeds were boosted by an average of 18 miles per hour. That was enough to kick most of the hurricanes to a higher category—including some that were juiced up to category five, the most powerful of all. As the atm…

A couple of years ago, marine biologists bought some giant “seabugs” from fishers in Vietnam. The creatures had been pulled from the mud at the bottom of the South China Sea. They were up to a foot long, weighed a couple of pounds, and had armor plating. The creature had never been cataloged before—it was a new species. Its face resembled the mask …

There’s a big hole in the Indian Ocean. It’s nothing you can actually see. And the ocean itself isn’t especially deep. Instead, it’s a hole in Earth’s gravitational field—the weakest pull across the entire planet. The “hole” was discovered in 1948. It’s centered about 750 miles off the southwestern coast of India. It covers more than a million squa…

For an oyster, gender is more than a matter of genetics—it’s also about the environment. Water temperature, salinity, pollution, and other factors determine whether an oyster will be male or female. And a recent study added something new to the list: acidity. The oceans are becoming more acidic as they absorb carbon dioxide from the air. Over the p…

The great white shark probably is the most feared of all ocean animals. It gained that scary reputation 50 years ago thanks to a blockbuster movie: Jaws. The movie premiered on June 20th, 1975, and quickly became the all-time box office champion. It scared a lot of people out of the water—and set off a frenzy of shark killings. People killed thousa…

When tropical storm systems barrel across the Atlantic Ocean toward North America, they often take aim at the Lesser Antilles—an arc of small islands that marks the eastern boundary of the Caribbean Sea. In fact, the islands often are the first thing forecasters talk about when a tropical system heads our way. The Lesser Antilles arc from the U.S. …

For some coral, home isn’t where the heart is—it’s where the sounds are. A recent study showed that one type of coral prefers to settle on reefs that sound healthy—even if they’re not. Young corals, known as larvae, float or swim through the water for a while. When they find a good spot, they drop to the bottom and grab hold. They use several cues …

The oceans are losing their memory. That could make it harder to forecast everything from monsoons to blizzards. Ocean “memory” is maintained in the top layer, called the mixed layer. Winds push warm surface water downward, where it mixes with water at greater depths. This layer is typically about 150 feet thick. And overall, it maintains a fairly …

Otto the octopus didn’t appreciate the spotlight shining on his laboratory tank at night. So he turned it off. In fact, he turned off the lights in the whole lab. Octopuses are smart and curious. They use tools and learn from watching other octopuses. They can solve mazes, open the lids of glass jars, and build dens. In the lab, they learn to tell …