If you’re one of the ocean’s major predators, you go where the food is—even if it might make you a little dizzy. Scientists recently found that tunas, sharks, and other big fish were more common inside eddies in parts of the Pacific Ocean than in the surrounding water. And not surprisingly, that’s where the food was.The scientists looked at records of waters inside the North Pacific Gyre. That’s a region from a little north of the equator to the central Pacific, and from the Americas to Japan. It’s the largest ecosystem in the world.Across much of that region, there’s not much life in the upper layers. But there’s a lot more in the eddies—spinning currents that can be dozens of miles wide. They effect conditions not only at the surface, but far below as well. They can pull nutrient-rich waters from below, enhancing the number of fish that the big guys prey on.The recent study looked at more than 20 years of records from a giant fishery around the Hawaiian islands—catches of both top-level predators and some of the species they feed on. They also looked at satellite observations of ocean currents over that same period. Comparing the two revealed that fishing lines inside eddies caught a lot more of 14 species of big fish—tunas, sharks, billfishes, and others—than lines outside the eddies.So tracking eddies at the ocean surface may help pinpoint the best places to find big fish—and to manage this diminishing resource.

Much of the water in the world’s oceans is herded like cattle being driven to market—not by cowboys on horseback, but by strong currents. Known as gyres, they help control global temperatures and the nutrients available in different parts of the oceans. They also round up floating debris, forming giant garbage patches.Gyres are formed by the winds, Earth’s rotation, and the land. Winds drag the ocean water, forming currents. The currents are deflected by Earth’s rotation. They’re pushed clockwise in the northern hemisphere, and counterclockwise in the southern hemisphere.The surface currents drag the water below them, so the effects of the wind run deep. That sets up a “ring” of currents that circulate around the oceans. Finally, the land acts as a barrier, holding the currents in place.There are five major gyres—two in the Pacific Ocean, two in the Atlantic, and one in the Indian. The water inside the gyres tends to be fairly calm. That prevents deep water from rising to the surface. Since the deeper water contains more nutrients, surface waters inside the gyres have less life than in the currents.The gyres carry debris that was washed into the oceans from land. The debris forms large plastic “garbage dumps.” Bigger bits of plastic wear down into smaller bits that are gobbled up by fish, birds, and some of the ocean’s tiniest creatures. That’s a health hazard for the creatures, and for the people who eat them—rounded up by the “cowboys” of the open ocean.

Green doughnuts are typically something you want to avoid. But some giant green doughnuts on Australia’s Great Barrier Reef may actually be good for us. They may store carbon on the ocean floor. That keeps it out of the atmosphere, where it would add to climate change.The “doughnuts” are created by a type of green algae, known as Halimeda. Each one forms a flat or crinkled disk that can range from less than an inch to several feet across. Combined, they form circular beds that can cover many acres—beds that look like green doughnuts.The largest beds are found on the Great Barrier Reef. They’re on the outside of the reef, where a lot of nutrient-rich water flows up from the ocean. In fact, they may cover as much area as the reef’s famous corals.The beds are important for a couple of reasons. For one thing, like the coral reefs, they provide habitat for a lot of other life. And for another, they lock up carbon that might otherwise be in the atmosphere.That’s because Halimeda has a hard skeleton. The skeletons contain calcium carbonate, a carbon-rich compound. When the algae die, the skeletons form fossil beds that hold the carbon. Over thousands of years, that builds up huge beds—keeping a lot of carbon out of the air.A recent research cruise drilled as deep as 20 feet into the beds on the Great Barrier Reef. Those results will tell us more about these “green doughnuts”—and their possible contribution to the health of Earth’s environment.

You might want to save those leftover egg whites at breakfast. Researchers at Princeton University found a way to use them to filter salt and tiny bits of plastic from sea water. It’s a method that could be cheap and reliable, and could be used on a large scale. The team was trying to mix up a new recipe for aerogel—a material that’s mostly air or other gas. It’s extremely light weight, but it’s versatile. It’s used for insulation, water filtration, and even to catch bits of comet dust.But the researchers wanted a version that was much more efficient at filtering water. So they mixed carbon with various breakfast ingredients—different bread recipes, eggs, and others. After a lot of trial and error, they settled on egg whites. They made a good aerogel even if the eggs had been cooked or whipped like a merengue.The result was lighter than other aerogels—a cubic yard would weigh about six and a half pounds; by comparison, the same volume of sea water weighs more than 1700 pounds. And the egg whites filtered more than 98 percent of the salt from sea water, and missed only one in 20,000 bits of plastic.At first, the team used the same eggs you buy in the grocery store. Later, it worked with similar proteins found in other products. The researchers say their aerogel would be more efficient and less expensive than current filtration systems—straining sea water with a material developed from a common breakfast food.

If sharks had dentists, one might want to set up shop at Muirfield Seamount, near a set of islands in the Indian Ocean. A recent expedition there pulled up a haul of more than 750 shark teeth—the largest ever seen at a single site. Most of the teeth came from modern-day species. But a few belonged to the ancestors of megalodon, which died out millions of years ago.Scientists from Australia were conducting a research cruise in Cocos (Keeling) Islands Marine Park, around a collection of a couple of dozen islands. The Australian park is about 1700 miles off the country’s western coast.The main purpose of the cruise was to evaluate life in the poorly studied waters. At the end of the cruise, researchers trawled the ocean floor, about three and a half miles deep. Their nets pulled up many species of life—including some that probably had never been seen before.The haul also included the shark teeth. They ranged from about a third of an inch to four inches long. Most of them belonged to modern species—mako and relatives of the great white. But the biggest came from the ancestor of megalodon—the largest shark that ever lived. That means those teeth had been on the ocean floor for millions of years.The scientists aren’t sure why this is such a popular spot for the teeth. Perhaps the contours of the ocean floor funneled the teeth to that spot. Or maybe it has been a gathering area for sharks—making it a graveyard for these ocean giants.

Young killer whales off the coast of Washington and British Columbia like to nip at each other. That leaves white scars on their backs and sides—but they’re not permanent. That allows biologists to use the scars to learn about the life histories of these endangered animals.They’re looking at southern resident killer whales—the smallest of the four types of resident killer whales. There are only 73 known members. They live in family groups, with the offspring staying with their mothers all their lives.A recent study analyzed 38 years of photographs of the southern residents. Scientists identified individual whales from the patterns of scratches, known as rakes. Over the years, early rakes fade away, while new ones appear. That allowed the scientists to track changes, revealing patterns in interactions between the whales.Perhaps not surprisingly, rakes are more common on younger whales, and on males rather than females.The researchers suggest that most of the scars are the result of play between siblings. But there could be a more serious purpose, as the whales try to move up in the family pecking order.Researchers also found that the number of rakes went up when the whales’ main food supply, Chinook salmon, was most abundant. That could be because more whales congregate then. Or it could be because the extra food gives the whales more pep for horseplay—make that whale play—so the youngsters have plenty of energy to nip at their friends and family.

Marion Island is cold, windy, and remote—about half way between Antarctica and the southern tip of Africa. That makes it a great spot for studying the Southern Ocean—from the weather to the seas to the abundant life. In fact, a dozen or more hardy souls spend 13-month stretches doing just that.Marion Island is owned by South Africa. It’s the peak of a volcano, which last erupted in 2004. It measures about 10 miles wide by 15 miles long.The island is packed with life, including three species of seals. There are also lots of birds. In addition, killer whales are common in the waters around the island. And about 30 species of seabirds nest there, while others hang out for parts of the year—millions of birds in all. The list includes four species of penguin, five species of albatross—all of them threatened or endangered—and 14 species of petrel.South Africa established a weather station on Marion in 1948, and has kept it going ever since. Over the decades, the research base has expanded to study the ocean and its life.A ship visits once a year—usually in April—bringing a new crew of scientists, engineers, and support staff. It also drops off work teams to repair and upgrade the base and stage supplies for the coming year. The ship then carries marine scientists out to sea for a few weeks of research before returning to the island to pick up the departing crew—beginning another year of work on this remote outpost in the Southern Ocean.

Sea birds face all kinds of threats these days: a warmer climate, decreasing food supplies, attacks by invasive species, and others. One of the most basic is rising sea level, which threatens to cover some of their nesting grounds. To help species survive, conservationists are relocating sea bird chicks to higher ground.An example is the Tristram’s storm petrel. It breeds in the Northwestern Hawaiian Islands. But it was wiped out on the island of Midway by rats, and it’s threatened by plastic pollution on other islands in the chain.And on the island of Tern, it’s threatened by the rising waters. Tern covers just 26 acres. And much of that was built up by the Navy during World War II for use as an airstrip. The runway is rarely used today, but it’s still there. Even so, there’s plenty of room for petrels and other species of birds, sea turtles, and seals.But the island extends only six feet above sea level. And with the ocean rising, petrel nesting grounds could be flooded out in the years ahead. So a conservation group recently moved about 40 chicks to new digs on the island of Oahu, 500 miles away.The group had already moved some chicks to another island a few years ago. And it’s done the same thing with other species, including albatross and another species of petrel. Most of the chicks have survived and returned to their new homes to breed.So relocating a few chicks today could help Tristram’s storm petrel survive for decades to come.

The Chengjiang formation in China is one of the world’s most important fossil sites. It’s not that big—it covers a couple of square miles in Yunnan province, in the southwestern corner of the country. But it’s a UNESCO World Heritage Site, and an International Geological Heritage Site. That’s because the location has yielded some of the earliest fossils of complex life on Earth—more than 500 million years old. That includes what may be the oldest fish yet seen.The fish is known as Myllokunmingia fengjiaoa. The only sample was found in rock layers that are roughly 525 million years old. The fossil was only about an inch long and a quarter of an inch tall. But it was so well preserved that scientists could see lots of details, including inside the fish.The fossil showed a well-defined head—an important feature in the development of life. It also showed fins, gills, and a full digestive system. Those contours revealed that the fish probably was a relative of modern-day lampreys and hagfish, both of which resemble eels.The Chengjiang site probably consisted of a shallow sea with a muddy bottom. When the fish died, it was covered by a layer of mud that kept it from decomposing, preserving its fossil. That environment also preserved other marine creatures—worms, jellyfish, sponges, and more. That suggests that Myllokunmingia was part of a busy ecosystem—one of the oldest collections of complex life on Earth.

Blue crabs live their entire lives in the water. That’s where they eat, breed, and even breathe. So, some marine scientists were a bit astonished when they saw blue crabs popping out of muddy pits on shore to grab fiddler crabs. Blue crabs are found all along the East Coast and the Gulf of Mexico, on the bottoms of shallow bays and estuaries. They have been seen to dart out of the water to grab prey, but only by a few feet. But in September of 2021, researchers in Virginia saw them emerging from small pits in the sand. It was low tide, so some of the pits were up to a couple of hundred feet from the water. In some cases, the crabs “exploded” from the pits to snatch fiddler crabs that were close by. In other cases, they crept out of the pits and snuck up on their prey. They then dragged the fiddler crabs back to the pits for a leisurely meal. And it was clear the blue crabs had been hanging out for a while. The scientists said some of the pits were littered with fiddler crab claws “like the discarded bones of villagers outside a dragon’s lair.” The researchers returned a couple of weeks later with cameras to confirm the goings-on. They recorded the crabs digging their pits, switching to new ones, and even kicking other crabs out of their pits. The scientists found one other report of such behavior, but nothing had been formally recorded. So, this is the first confirmed instance of blue crabs living—and attacking—from outside their usual watery environment.