Science and the Sea Podcast

The sei whale is one of the largest creatures on Earth. Adults can be more than 60 feet long and weigh as much as a fully loaded semi—the third-largest of all whales. And they’re found across the world, in all but the warmest and coldest waters. Yet they’re poorly known, by the public and scientists alike. The sei whale—spelled S-E-I—gets its name from a Norwegian name for pollock, a cod-like fish. The name was bestowed because the fish and whales showed up at the same time of year. Sei whales have rows of structures made from the same material as teeth and hair, known as baleen. The baleen filters plankton and tiny fish and squid from the water—about two tons per day. Much about sei whales remains mysterious. In part, that’s because they live mainly in the deep ocean, away from shore. We know they’re usually alone or in small groups, and they can race at more than 30 miles an hour for short distances. But much of their life cycle is poorly understood. Whalers killed a quarter of a million sei before the practice was banned. Recent population estimates range from perhaps 50,000 whales to as many as 80,000. The whales face many threats. They can be hit by ships or entangled in fishing nets. And the warming climate can kill or displace their prey, forcing the whales to change their foraging and breeding grounds. Biologists are trying to find out more about this reclusive giant to better understand how it’s adapting to the environment. The post Sei Whales appeared first on Marine Science Institute. The University of Texas at Austin..

An old hag churns the waters near two islands off the western coast of Scotland. The churning creates the third-largest whirlpool in the oceans—the Gulf of Corryvreckan, or Brecan’s cauldron. Scottish folklore says the Old Hag was the goddess of winter. She stirs the water while washing her plaids. When scientists discovered that a pillar of rock on the ocean floor helps do the churning, they called it “the Old Hag.” The maelstrom fires up as tidal currents flow between the islands of Jura and Scarba. The strait is narrow and deep, so it acts like a funnel. The currents get faster—sometimes reaching As the flow exits the strait, it encounters a large, deep hole, followed by the pillar. Water flows up the side of the pillar, forming whirlpools and other features. When the flow is especially strong, waves can reach heights of 30 feet, and the cauldron’s roar can be heard 10 miles away. The waters are considered some of the most dangerous in Britain. Legend says that King Brechan of Norway tried to prove his bravery to a princess by anchoring in the maelstrom. But when his anchors gave way, he drowned. And in 1947, author George Orwell narrowly avoided the same fate. He was traveling across the cauldron with his son, niece, and nephew when his boat’s motor was damaged. They rowed to a rocky outcrop, where the boat capsized and sank. Orwell and party were rescued by a fishing boat—escaping the watery clutches of the Old Hag. The post The Old Hag appeared first on Marine Science Institute. The University of Texas at Austin..

Scientists are tuning in to seagrasses. That may tell them how much carbon the grass is storing—an important detail in understanding our changing climate. Seagrass beds are among the most efficient carbon-storage depots on Earth. But it’s hard to know how much total carbon they’re socking away, and how the amount changes over time. Researchers have to dig up patches of grass and sediment and analyze them in the lab. But scientists at the University of Texas at Austin are working on a new technique. Seagrasses take up carbon dioxide from the water and produce sugars with the energy of sunlight. They store the carbon in their tissues. But so much oxygen builds up that the grasses begin to blow bubbles. As the bubbles are released, they make noise. And as the seagrass soaks up more carbon dioxide, it makes more bubbles. The researchers are developing a system that uses underwater microphones to record the sound. The sensors could cover wide areas and operate around the clock, all year long. The scientists conducted a two-year test in Corpus Christi Bay. They listened to the natural sounds, plus artificial pulses of sound produced by the equipment. Together, that allowed the researchers to probe the oxygen in the seagrass and the water. The test showed clear changes in the soundscape as the amount of bubbles changed over daily and yearly cycles. It also told them how much seagrass was present and how healthy it was—“tuning in” to the sound of seagrass. The post Bubbly Seagrass appeared first on Marine Science Institute. The University of Texas at Austin..

The oceans are gobbling up Alaska’s northern coastline in a hurry—a result of our planet’s warming climate. That could force some towns to move farther inland, away from the hungry ocean. The Arctic is undergoing especially rapid change. Both air and ocean temperatures have increased three times faster than the global average. That’s drastically reduced the amount of ice covering the Arctic Ocean during much of the year. With more open water, waves can grow bigger and stronger, so they hit land with greater force. At the same time, the warmer conditions are thawing more of the frozen land, making it easier for waves to eat away all the shoreline. In some parts of Alaska, the land has been retreating by more than 60 feet per year. A recent study looked at the region around Point Hope, a small village on the northwestern coast. Part of it had to relocate in the 1970s as the shoreline was eaten away. Today, it’s threatened again. The airport runway is sometimes under water, and several cultural sites are endangered. Researchers used computer models to look at what might happen over the next 50 years. They simulated changing ocean, air, and land temperatures, as well as changes in the amount of sea ice and other factors. They found that the coastline could retreat by about 150 to 300 feet by 2075. The loss could be more intense if more of the tundra thaws out—making it easier for the ocean to gobble up the Alaskan coastline. The post Eating the Coastline appeared first on Marine Science Institute. The University of Texas at Austin..

Charles Darwin wrote about much more than evolution. Among other things, after his ’round-the-world trip in the 1830s, he wrote a book about coral reefs—an attempt to explain the origins of different types of reefs. A century and a half after the book was published, people got the idea that Darwin described reefs as “oases in marine deserts.” He didn’t—and they’re not. A recent study showed that, while reefs are some of the most vibrant ecosystems on the planet, the waters around most of them are busy as well. Researchers studied satellite observations of reefs and their surrounding waters from around the world. They also studied direct measurements of many of those environments. They looked at two key markers. One was chlorophyll—a pigment that tiny organisms use to produce energy. It colors the water green, so green water means a lot of life. The other marker was a set of compounds that serve as nutrients. They found that about 80 percent of all the reef systems were surrounded by plentiful conditions—waters that were teeming with both chlorophyll and nutrients. Currents, tides, and fish and other organisms carry those life-giving ingredients onto the reefs. That makes the reefs oases in a land of plenty. But the easy way that these materials infiltrate the reefs also means that reefs can be more easily influenced by pollution, global warming, and the results of other human activity—damaging these vibrant ecosystems. The post Marine Oases appeared first on Marine Science Institute. The University of Texas at Austin..

“Medicane” sounds like a mash-up of medicine and a candy cane—maybe something to get your kiddos to take their medicine. The term is a mash-up, but there’s nothing sweet about it. The word is short for “Mediterranean hurricane”—a compact storm twirling across the Mediterranean Sea. Unlike hurricanes in the Atlantic or Pacific oceans, those in the Mediterranean are most likely to fire up in the fall and early winter. A cold low-pressure system moves in from the Atlantic or the Arctic. As the cold air crosses the warmer sea water, the temperature difference builds big thunderstorms. Air swirls around the storms, forming a spinning system that looks like a tropical storm or hurricane. Because the Mediterranean is fairly small, so are the medicanes. They’re seldom more than about 150 miles in diameter. And they seldom last more than about three days. With less time and space to develop, they can’t grow as powerful as their bigger cousins in the Atlantic and Pacific. Only one has reached the equivalent of a category-two hurricane. Even so, medicanes are deadly. They can dump huge amounts of rain, causing major flooding. The strongest medicane pelted parts of Greece with more than two feet of rain, killing four people. And the deadliest one, known as Daniel, hit in September of 2023. It killed 16 people in Greece, then crossed the Mediterranean to Libya. Flooding there killed an estimated 6,000—the deadly power of a medicane. The post Medicanes appeared first on Marine Science Institute. The University of Texas at Austin..

A forest fire both destroys and creates. It destroys the plants and animals that live there. But it creates the conditions for a new ecosystem to develop through a process called ecological succession. Scientists recently reported that a similar process plays out in one of the deepest spots in the oceans. Big blobs of sediments settle on the bottom. That can destroy the organisms that inhabit the region. But the sediments bring nutrients and stir things up in a way that starts a new cycle of life. The scientists studied sediments from the bottom of the Japan Trench. It’s a long gash in the Pacific Ocean where two of the plates that make up Earth’s crust intersect. The scientists X-rayed the top layers of sediments in samples taken from depths of almost five miles. And they found that a cycle of life played out over and over again. The cycle begins with a big “pulse” of sediments. It flows down the slopes of the trench, then settles on the bottom. The sediments bring nutrients and churn things up on the sea floor. As the flow ends, organisms burrow into the soft mud. The burrows can be several inches long, and can form straight tunnels, corkscrews, or other shapes. As these organisms use up the fresh supplies, microbes that prefer low-oxygen environments move in. They attract microbe-eating organisms—some of which dig their own burrows. Every time a new load of sediments arrives, the cycle starts over—destruction and creation in the ocean depths. The post Deep Life appeared first on Marine Science Institute. The University of Texas at Austin..

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. The post Deep Antibiotics appeared first on Marine Science Institute. The University of Texas at Austin..

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 post Smelly Seas appeared first on Marine Science Institute. The University of Texas at Austin..

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. The post Weedfish appeared first on Marine Science Institute. The University of Texas at Austin..

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. The post Mud Volcanoes appeared first on Marine Science Institute. The University of Texas at Austin..

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 post Fish Tools appeared first on Marine Science Institute. The University of Texas at Austin..

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. The post Deep Oxygen appeared first on Marine Science Institute. The University of Texas at Austin..

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 post Mountain Sharks appeared first on Marine Science Institute. The University of Texas at Austin..

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. The post Sunda Trench appeared first on Marine Science Institute. The University of Texas at Austin..

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. The post Carbon Farms appeared first on Marine Science Institute. The University of Texas at Austin..

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. The post Crumbling City appeared first on Marine Science Institute. The University of Texas at Austin..