About three-quarters of all the antibiotics in use today were developed from a type of bacteria that lives in the soil. But nasty bacteria are becoming more resistant to those treatments. So scientists are scouring the world for sources of new antibiotics—including the ocean floor. And they recently found a couple of good candidates at the bottom of the Arctic Ocean, off the coast of Norway.

Biologists gathered many organisms during a research cruise in 2020. And they collected bacteria from four of those organisms, including a type of sponge and a scallop. The bacteria are similar to the soil-based varieties that have yielded all the antibiotics. But under the extreme pressure, cold, and darkness in the deep sea, they’ve developed many chemical compounds that aren’t seen in their land-based cousins.

The researchers isolated some of those compounds. And they tested them against a strain of E. coli bacteria—a form that causes severe diarrhea in young children, especially in the developing world.

Two of the compounds did a good job of stopping the E. coli. And one of them did it without killing the dangerous bacteria. That’s important because the E. coli isn’t as likely to become resistant to the compounds that don’t kill it.

There’s still a lot of work to be done to develop the helpful compound into a treatment for people. But the research demonstrates that we might find many new treatments for human diseases in the world’s oceans.

A team of astronomers recently reported the possible discovery of a compound in the atmosphere of another planet that could be produced by life. If the compound really is there, then the planet might smell familiar—like a day at the beach.

Many factors go into creating the “smellscape” of the sea. Locally, things like pollution, red tides, and decaying seaweed can make the beach smell less than pleasant. Globally, though, the two major odors come from evaporated sea spray, and from a compound of sulfur and carbon known as DMS—dimethylsulfide—the compound that might have been seen on the other planet.

Microscopic organisms in the water produce a related chemical compound. When they die, they release it into the water. Bacteria and enzymes convert it to DMS. A lot of it then enters the atmosphere—about one ton per second.

In the air, it’s destroyed within 48 hours, releasing particles of sulfur. Water vapor gloms onto the sulfur, creating clouds. The clouds reflect sunlight, helping control global temperatures. In fact, some scientists have looked at DMS as a way to combat global warming. They suggest pumping nutrient-rich water from the deep ocean up to the surface. That would feed outbursts of the organisms that start the DMS chain—creating more planet-cooling clouds.

In any event, perhaps astronomers on some distant world might find life on Earth by detecting DMS in our atmosphere—the living “breath of the sea.”

The weedfish is cryptic. That doesn’t mean that it speaks in riddles or leaves notes that no one can decipher. Instead, it’s easily hidden—it blends into its environment. Divers say it’s so well disguised that even if you find one, it’s impossible to find it again if you look away for even just a second.

There are several species of weedfish. Most of them live around New Zealand or southern Australia. They’re mainly found in shallow waters, living in dense beds of kelp—the “seaweed” that’s anchored to the bottom.

The weedfish is small—no more than about seven inches long. It has a slender body that’s crested by a tall, forward-angled fin that looks a bit like a mohawk. It feeds on small fish and crustaceans, usually at depths of no more than a hundred feet.

Each species of weedfish blends in with the type of kelp bed it inhabits. The golden crested weedfish, for example, has a canary-yellow body with a streak below its eye like a dark teardrop. Other species have their own colors and patterns to match the background.

Like many other fish, the weedfish is facing some tough times. Lobsters, fish, and other types of marine life have been overharvested. That’s allowed sea urchins to flourish. And they gorge on kelp, sometimes wiping out entire beds. Without the kelp, there’s no place for the weedfish to hide. So there’s nothing cryptic about it—the population of weedfish could plunge in the decades ahead.

Many volcanoes are among the most majestic sights on the planet: Tall and wide, they belch molten rock or plumes of ash that can tower miles high. But there’s another class of volcano that’s much less impressive. These guys are short and squatty. And they burp out bubbles and blobs of mud, water, and gas. What they lack in majesty, though, they make up for in numbers: more than a thousand have been discovered on land, and many others have been found at the bottom of the ocean.

One of the most recently discovered marine examples is the Borealis Mud Volcano. It’s a quarter of a mile deep in the Barents Sea, an extension of the North Atlantic Ocean, between Finland and Greenland. It’s a little more than 20 feet wide and about eight feet high. It’s in a large field of craters and small cones. Like Borealis itself, many of the cones put out plumes of methane gas.

Geologists discovered Borealis during a 2023 research cruise. They studied it in more detail a year later. They suggest that it formed about 18,000 years ago, at the end of the last ice age.

During the ice age, what is now the ocean floor was covered by a giant slab of ice. As the ice melted and retreated, the pressure went down and the temperature went up. That allowed a big pocket of methane ice to begin vaporizing. The pressure blew a hole in the sediments above it. Today, the Borealis Mud Volcano continues to belch out methane, mud, and water from below the Barents Sea.

Using an anvil to smash prey sounds like something Wile E. Coyote would try—unsuccessfully, of course. But some other creatures are a lot more successful at it: fish. More than two dozen species of fish have been seen using “anvils” to smash open their prey. All of them were types of wrasse, a colorful fish found around the world.

Tool use has been observed in birds, mammals, and other animals on land. In marine environments, it’s been seen in octopuses and crabs. And for several decades, the list has included wrasses.

The fish grabs a potential dinner—a crab, urchin, or other morsel with a shell. It then swims to a rock, a coral, or some other hard surface—objects that scientists describe as “anvils.” The fish then smashes the prey against the anvil until the shell cracks open.

A recent study added three species of wrasse to the list of anvil users, and confirmed the use by two other species. All five species were found in the western Atlantic Ocean, from the Caribbean Sea down to the southern coast of Brazil. The smashups were recorded by divers—either on video or in writing—then uploaded to a web site.

On average, the fish had to smash the prey more than half a dozen times, in a bout lasting more than a minute. If one anvil didn’t work, they’d move to another. Of the 16 prey-bashing episodes recorded, only one ended in failure. So perhaps the wrasse could teach Wile E. a thing or two about using an anvil to get the goods.

The world has a huge appetite for the batteries that power electric vehicles. Many of the elements needed to make batteries are spread across the ocean floor—especially in the Pacific. They form nodules the size of potatoes that contain a lot of manganese, nickel, and other key metals. But some of the nodules may already be acting as batteries—generating an electric current that produces oxygen.

Most oxygen in the oceans comes from tiny organisms near the surface that use photosynthesis—a process that requires sunlight. But researchers recently found a possible new source of oxygen on the ocean floor, between Mexico and Hawaii.

They nestled small chambers into the sediment and filled them with seawater. Then, they monitored the amount of oxygen in the water over a period of two days. They expected to see the level drop as organisms in the sediments used the oxygen. Instead, the level went up. There’s no sunlight that deep, so the oxygen could not have come from photosynthesis.

It may come from the nodules. In seawater, a nodule generates a small electric current on its surface. It’s not enough to split the water molecules into hydrogen and oxygen. But if several nodules are touching, the combined current might do the job.

The scientists said this source of oxygen could be important for life in that region. So mining operations could disrupt things—not an appetizing prospect for the ecosystem at the bottom of the Pacific Ocean.

If you want to avoid sharks, then steer clear of the mountains. No, we’re not talking about the next “Sharknado” movie. It’s underwater mountains—called “seamounts”—that you want to avoid. A recent study found there were 40 times more sharks around a couple of shallow seamounts than in the surrounding open ocean.

Researchers spent about 20 months perusing three seamounts near Ascension Island—a lonely spot in the South Atlantic Ocean. The peaks of two of the seamounts rose to within a few hundred feet of the surface, while the third was deeper.

Scientists studied life in the region with underwater video cameras, surface counts, and sonar scans. And they placed tracking devices on several sharks and tunas.

They found that all forms of life were more abundant around the two shallower seamounts, from the tiniest organisms all the way up to top-level predators. But the higher up the food web, the greater the abundance compared to the open ocean.

Some of the tagged sharks and tunas hung around a single seamount. A few others made appearances at both. And one intrepid shark journeyed up to 85 miles out to sea.

The researchers aren’t sure why there’s such a concentration of sharks and other life at the seamounts. Currents may push more prey up the sides of the mountains, attracting larger fish. Or perhaps the currents just make it harder for prey to escape. Whatever the reason, the sharks just loved hanging around these underwater mountains.

The deepest part of the Indian Ocean is one of the least explored spots on Earth. It’s also one of the most dangerous. Major earthquakes have rocked it, causing major destruction—including what may be the deadliest natural disaster of the 21st century.

The Sunda Trench—also known as the Java Trench—is a gash in the ocean floor. It curves around the islands of Sumatra and Java, on the eastern edge of the Indian Ocean, between Australia and India. It’s about 2,000 miles long, and up to four and a half miles deep.

Only one expedition has studied the trench in detail. In 2019, both people and robotic vehicles descended to its floor. They found an abundance of life, including several new species. One highlight was a possible sea squirt—a critter that looked like a wrinkled balloon tied to a long string.

The Sunda Trench was created by the motions of the plates that make up Earth’s crust. Plates to the west are plunging below the plates to the east. The zone where they intersect forms a V-shaped hollow.

It’s an active zone—the motions of the plates trigger powerful earthquakes. A quake in 2004 caused a tsunami that killed a quarter of a million people around the Indian Ocean. In this century, only an earthquake in Haiti might have been deadlier. The event led to the creation of a tsunami warning system for the region—keeping a lookout for danger from the Sunda Trench.

Seaweed farms offer many benefits. They provide food for people, habitat for fish and other organisms, and protection against erosion during storms. They can help prevent “red tides,” and could become a source of biofuel.

Seaweed stores carbon in the sediments on the ocean floor. That helps reduce the amount of carbon dioxide in the atmosphere, which is the major cause of our warming climate.

Wild seaweed forests already stash away huge amounts of carbon. Farms cover a much smaller area, so their benefit is smaller. But seaweed farming is a “growing” business—the yield has been increasing by more than seven percent per year. Almost all of the farming takes place in Asia. The United States is a minor player, but farms have been developed in New England, the Pacific Northwest, and Alaska.

Researchers studied the sediments below 20 seaweed farms in various parts of the world. The oldest, in Tokyo Bay, has been around for 320 years. The largest, in China, covers 58 square miles.

The scientists found that the amount of carbon in the sediments below the farms was twice that found in the surrounding sediments. And they found that as a farm ages, it becomes more efficient at “planting” the carbon.

Estimates say that seaweed farms could cover many times their present area by 2050. And the researchers said that if the farms are efficiently managed, they could become important weapons in the fight against our warming climate.

Alexandria, Egypt, has stood for almost 2400 years. Today, though, parts of it are crumbling—one building at a time. As Earth’s climate changes, the Mediterranean Sea is rising, the coast is eroding, and saltwater is seeping into groundwater supplies. That weakens buildings, causing them to collapse. And according to a recent study, without action to protect the coastline, the problem will get worse in the years ahead.

Alexandria is the largest city on the Mediterranean, and one of the busiest ports. But its maritime location is causing trouble. Researchers looked at records of building collapses over the past quarter century. They also compared the coastline to that of previous decades, studied the soil, and made other observations.

They found that 280 buildings have collapsed in the past 20 years. Over that span, the rate of collapse jumped from fewer than one per year to almost 40. Almost all of the destroyed buildings were within a mile of the coast.

The jump was largely the result of climate change. Higher sea level and stronger storms have eroded the coastline by an average of 12 feet per year, with one district averaging 120 feet. And seawater is filtering into aquifers below the city. That corrodes foundations, causing buildings to crumble.

The scientists recommended creating dunes and greenbelts along the coast to keep the Mediterranean at bay—and keep Alexandria from crumbling into the sea.