A massive hailstorm blasted northeastern Spain a couple of years ago. It lasted only 10 minutes or so. But it produced the largest hailstones ever recorded in the country—the size of softballs. It might have been kicked up a couple of notches by another type of “weather” event—a marine heatwave.

The storm roared to life on August 30th, 2022. It caused major damage to roofs, cars, and crops. It injured 67 people, and killed a toddler, who was hit in the head by one of the giant hailstones.

A recent study blamed the intensity of the storm on global climate change. Scientists simulated climate conditions under different levels of air and ocean warming.

The storm took place during a marine heatwave in the western Mediterranean Sea. The surface water temperature topped 85 degrees Fahrenheit—five degrees higher than normal. That produced more evaporation, which fed extra moisture into the air. It also heated the air, providing the energy to build storm clouds. As hailstones developed, strong updrafts pushed them back up, so they just kept getting bigger and bigger. Finally, they became heavy enough to plunge to the ground—causing chaos.

The study said the hailstorm itself could have happened without today’s higher temperatures. But it would not have been as intense or as destructive.

Major hailstorms have been getting more common across Spain and the rest of Europe. And the study says that trend should continue—powered by our warming climate.

Many gardeners use clam shells as decorations. But not many garden the clams themselves. Yet clam gardens can yield more clams than untended shorelines, provide more species diversity, and even protect the clams from the acidity in today’s oceans.

Clams were gardened as early as 4,000 years ago by the people of the Pacific Northwest, from Alaska to Washington. In some regions, the gardens lined the entire coastline.

The gardens consisted of short walls built along the shore, forming enclosures, with terraces behind the walls. Water flowed in, and some of it was trapped as the tide rolled out. That provided habitat for littleneck and butter clams.

The gardens were abandoned after European settlers moved in. But research over the past decade shows that the gardens were highly effective. They could produce up to twice as many littleneck clams as uncultivated areas, and four times as many butter clams. The gardens also attracted other life, including seaweed and sea cucumbers, providing a more diverse diet for the gardeners.

Gardens also contained a lot of clam shells, which provide the minerals clams need to make new shells. That’s especially important today, because higher levels of ocean acidity make it harder for clams to produce shells.

The Swinomish people of Washington have recently built new clam gardens. They produce food, provide a training ground, and give scientists a place to study the gardens and their “crops”—butter and littleneck clams.

Life along the American coastline has been getting more perilous. Earth’s warming climate is causing a rise in sea level, an increase in major hurricanes, more marine heatwaves, and many other problems. That costs time, money, and lives. And things are expected to get even worse in the decades ahead.

A new national climate assessment, issued in late 2023, forecasted that sea level will rise an average of almost a foot from 2020 to 2050. That equals the total rise over the past century. As a result, the report says that coastal flooding at high tide should happen 5 to 10 times more often. Erosion will wash away beaches and bring cliffs tumbling down. And some hurricanes will become far more destructive.

The assessment says the combination of the changing climate and human adaptations, such as more seawalls and levees, will make it more difficult for coastal ecosystems to adapt. Such ecosystems function as buffers against tropical storms, help control erosion, and provide habitat for fish and other organisms.

The report says that some actions now may help minimize the impacts of climate change and human adaptations in the future. Restoring coastal habitat is one of the most important. Cities and towns can also beef up their infrastructure—moving roadways and improving stormwater systems, for example. And they can start planning to relocate people and buildings to less-hazardous areas—to meet the growing threat of climate change.

Thresher sharks are some of the “snappiest” fish in the oceans. They have an oversized tail fin that looks like a scythe—and is almost as deadly. A shark “snaps” the fin like someone snapping a towel in a locker room, stunning its prey. And a recent study worked out some of the details on how the shark does it.

Threshers are found around the world. Most stay fairly close to shore, and not very deep. Adults can grow to about 20 feet long.

What really sets them apart is that snapping motion. A shark first winds up a bit like a baseball pitcher. It twists its body in one direction, its tail in the opposite direction. The tail, which is almost as long as the body, is held high. The shark then uncoils, snapping the tail around in a fast, powerful motion. It then takes a minute to relax before grabbing its prey.

Researchers recently studied the spines of 10 thresher sharks that had stranded on shore or been caught by anglers. The sharks ranged from an embryo to an adult 13 feet long.

The scientists did CAT scans on the sharks, revealing the structure of the shark spines and vertebrae. The work showed that the vertebrae in the body are longer and thicker than those close to the tail—a trait that developed as the sharks got older. The interiors of the two types of vertebrae were different as well.

The researchers said the differences may make a thresher more flexible while adding strength to its tail—allowing the sharks to “snap up” their dinner.

It may sound surprising, but many mountains are hiding from us—some of which may be more than a mile high. Scientists are finding more of them all the time, though—at the bottom of the sea. A research cruise in 2023, for example, found four of them in the Southern Ocean.

The scientists were studying the Antarctic Circumpolar Current, which circles around Antarctica. It’s the strongest ocean current in the world. It prevents most of the warm water from the other oceans from reaching Antarctica. But some warm water sneaks through. That makes the Antarctic ice melt faster, speeding up the rise in global sea level.

Researchers were looking for these “leaks,” and studying how the warm water was flowing around Antarctica. As part of their work, they used sonar to scan a 7700-square-mile patch of the ocean floor. They also used an orbiting satellite to look for small “bumps” on the surface that indicate the presence of mountains.

They found a chain of eight mountains, called seamounts. They’re extinct volcanoes that formed within the past 20 million years. Some of them were already known, but four had never been seen before. The tallest is almost a mile high.

The mountain range is in the middle of the Antarctic Circumpolar Current. As the current flows over and between the mountains, it forms turbulent patches that break off as eddies. Those whorls can disrupt the current, allowing warmer water to punch through—helping thaw out the frozen south.

When you build a house, it affects the surrounding ecosystem. The same thing applies to houses built by fiddler crabs in salt marshes. Their burrows can help or hinder the surrounding plants, affect the flow of water, and perhaps cause the marsh to send more greenhouse gases into the air. Thanks to all of that, fiddlers are sometimes described as “ecoengineers.”

Fiddler crabs are only about an inch across. They’re found in salt marshes all along the coast. They dig burrows that can be long and deep. The burrows protect the crabs from predators and the environment. They also give the crabs a place to mate. In fact, the quality of a burrow plays a role in a female’s pick of a partner.

The burrows pass below the marsh grasses. They can form networks that allow water and nutrients to flow through the marsh. They can “aerate” the soil, increasing the growth of the grass—something that can boost the discharge of greenhouse gases from microbes in the soil. But if the burrows are too extensive, they can damage root systems, slowing growth.

A recent study simulated these effects with computers. The work showed that a lot of their impact may depend on the details of the burrows themselves—their depth and shape, the number of entrances, and more. Burrows that are deeper and have more “doors” may increase the exchange of water between aquifers and the surface, for example—changing the ecosystems around these small but abundant houses.

In 1875, Navy lieutenant commander Charles Dwight Sigsbee and his ship, the George S. Blake, began a journey into the history books. They started measuring the depth of the Gulf of Mexico with a mechanism that Sigsbee created. When the job was finished three years later, the ship had measured the entire Gulf—the first ocean basin to have an accurate map of all its contours.

Sailors had been measuring depths for centuries. They threw a rope with a heavy weight on the end into the water. Distances were marked on the rope every few feet. Counting the marks revealed the ocean depth.

The technique became known as depth sounding. Crew members would “sound off” the depth as the rope played out. But it wasn’t especially accurate—especially for deep water. But it improved in the mid-19th century. Sir William Thomson of England developed a machine to do the job, using piano wire on a motorized spool.

Sigsbee refined that design. He made the machine larger and more stable, and replaced the piano wire with steel. That improved accuracy. His device became known as the Sigsbee sounding machine. And it was the standard for measuring depths for 50 years.

Scientists named many of the features mapped by the Blake after its commander. So maps of the Gulf of Mexico show the Sigsbee Escarpment, Sigsbee Abyssal Plain, and Sigsbee Deep—the deepest spot in the Gulf—first recorded by Sigsbee’s machine a century and a half ago.

Olive trees are sprouting all across the Balearic Islands—a chain off the Mediterranean coast of Spain. The largest island, Mallorca, has more than 800,000 cultivated trees. They yield a good portion of the world’s supply of extra virgin olive oil.

More trees—of both wild and cultivated varieties—have been showing up on the surrounding islands. They’ve been planted not by farmers, but by sea gulls. The gulls eat olives—especially those from Mallorca—then fly miles over the Mediterranean to their home islands. Once there, they spit up the olive pits, which can sprout and grow trees.

Biologists recently studied yellow-legged gulls, which are common across the Balearic Islands. The scientists brought some of the birds into the lab, and attached GPS trackers to others. They also examined the populations of olive trees in the islands.

The researchers found that the birds ate both wild and cultivated olives. But they preferred the ones raised on farms. On average, they flew about three miles farther to get them—about eight miles per trip, although some gulls flew more than 60 miles.

The gulls upchucked most of the olive pits on the rocky outcrops where they nest. But many of the pits were dropped where they could produce trees. On one island, an area that had been mostly grass and shrubs was being transformed into an olive grove, with both wild and domestic varieties—thanks to the wings and appetites of yellow-legged gulls.