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People have traveled far across the oceans in search of greener pastures. Polynesians journeyed thousands of miles, hopping from island to island as they expanded eastward. And one period of expansion might have been triggered by big changes in the Pacific Ocean. That period began about a thousand years ago. People were well entrenched in Western Polynesia—islands such as Tonga and Samoa. But they quickly turned up in Eastern Polynesia—Tahiti and surrounding islands—journeys of up to 1500 miles or longer across open ocean. A recent study looked at climate conditions across Polynesia at the time. Researchers gathered deep sediments from several locations. They used sophisticated lab techniques to analyze the fat in leaves preserved in the soil. That revealed how rainy the climate was at the time the plants were growing. The scientists combined that with other climate information, and ran it all through models of the climate at the time. They found that the rain began to dry up in Western Polynesia. But it got heavier in Eastern Polynesia. That probably was the result of a change in the South Pacific Convergence Zone—a wide region that produces heavy rains during the summer. Changes in ocean temperatures pushed the zone eastward. The change also would have made the winds more favorable for moving eastward. So the people of Western Polynesia could have headed out—looking for greener pastures far across the Pacific. The post Pacific Migration appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

For anyone who’s ever had a cold, the flu, or any other illness caused by a virus, getting rid of viruses might sound like a good idea. But many viruses play important roles in the environment. That includes marine viruses. They recycle nutrients, and can help control other microscopic organisms. So it’s good to keep them around. But in the northwestern Mediterranean Sea, viruses are disappearing in a hurry. The drop corresponds to changes in the sea caused by Earth’s warming climate. Marine scientists have been keeping tabs on Blanes Bay since the early two-thousands. It’s on the coast of Spain, about 40 miles from Barcelona. An observatory there monitors the temperature, salinity, and clarity of the water. And it samples the water once a month. Lab work reveals the amounts of nutrients and other compounds in the water, along with the populations of bacteria and viruses. Scientists recently used several techniques to analyze the observations from 2005 to 2022. The work showed that the virus population remained steady until about 2011. But since then the population has gone down dramatically. At the same time, the water has gotten warmer. That suggests the viruses are being thinned out by climate change. Reducing the virus population could impact the amount of nutrients in the water, making the region less productive. That could hurt the fishing industry. So the lack of viruses could actually harm the people along the Mediterranean coast. The post Vanishing Viruses appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

The oceans near the poles are cold—really cold. Because of the salt content, water temperatures can remain below freezing for most or all of the year. And that can be bad for life. Ice crystals can develop in the blood and other fluids, destroying cells. Yet many species of fish thrive in these frigid environments. In part, that’s because they produce proteins that work like antifreeze. Inspired by those fish, researchers have developed a synthetic version of the proteins. The “mimics,” as they’re called, could prevent medications that have to be kept cold from freezing. They also could be used to prevent the formation of ice crystals in many other products. Earlier studies nailed down the details of the fish proteins. Whenever a crystal begins to form, the proteins wrap it up. They change the structure of the crystal, keep it from getting any bigger, and lower the freezing temperature. That combo prevents the cold from damaging cells. Researchers isolated the key features of the proteins, then found a way to replicate them in the lab. They tested their brew in living cells. It protected the cells from freezing, and it wasn’t toxic. It also wasn’t a problem for the bacteria in the human digestive system. The researchers say their antifreeze can be manufactured easily and inexpensively. So it could make it easier to store and ship some medications, and extend the shelf-life of ice cream and other frozen foods—a gift from some cold, cold fish. The post Fish Antifreeze appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

Cats sometimes drop food at their owner’s front door—lizards, mice, or other small prey. A recent study found that killer whales sometimes offer food to people as well. But the reason for that sharing is unclear. Orcas are social animals. They hunt together, they play, and they share their food. And they’re often found around people. They swim along with boats and divers, and they’ve even hunted with human fishers. In a recent study, scientists compiled reports of orcas sharing food with people on boats, in the water, or on shore. They found 34 examples, including some from their own experience. Many of the events were photographed or caught on video. To qualify for the study, a whale had to approach the people, not the other way around. It had to get close before releasing the food. And it couldn’t take the food back right away—it had to wait for a response from the people. The sharing orcas included males and females, of all ages. Sometimes a single whale made the offer, but sometimes it was two or more. They offered fish, birds, mammals, and other treats. They sometimes waited minutes for a response. And if the human didn’t snatch the food, or gave it back, the whale sometimes offered it again. The researchers said there could be several reasons for the sharing. It could be a way to communicate or to learn more about the people. It could simply be a way of playing. Or it could be a way to lure the people in—a not-so-friendly way of sharing. The post Sharing Orcas appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

Most of the tropical storms that roar across the Atlantic basin are born over Africa—especially the really big ones. They begin as low-pressure systems over the Sahara Desert, and are pushed into the Atlantic Ocean by a powerful jet stream. La Niña may boost that process. A recent study found that it may help create stronger systems over Africa, potentially leading to stronger tropical storms. La Niña is part of a back-and-forth cycle in the eastern Pacific Ocean, from warmer to cooler waters. La Niña is the cooler phase. And it can impact climate across the globe. The study found a link between La Niña and African easterly waves—the systems that form over Africa and head out to sea. During La Niña years, the waves are stronger, wetter, and more turbulent, so they produce more thunderstorms. That brings heavier rains to parts of Africa, the Caribbean, and the Americas, even if the systems don’t become tropical storms. La Niña changes the way air circulates across the entire planet. Over Africa, it appears to strengthen two jet streams, and it pushes one of them northward. It also has an effect on the African monsoon season. Those changes rev up the easterly waves—and the intensity of hurricanes. African easterly waves give birth to about 60 percent of all tropical cyclones in the Atlantic, Caribbean, and Gulf—and more than 80 percent of the major ones. So understanding the link between La Niña and the waves could improve hurricane-season forecasts. The post Stronger Waves appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

The frigid waters of the Arctic and Antarctic hide some giants: sea spiders the size of serving trays, sharks as long as minibuses, half-ton squid twice that length—almost all of them the largest examples of their type anywhere on the planet. This phenomenon is known as polar gigantism. Biologists are still trying to explain it. In fact, they’re even trying to confirm that it’s a real thing; giants have been found in the deep ocean, and they may also inhabit other parts of the ocean, but we just haven’t seen them yet. There’s no doubt that giants inhabit the Arctic and Southern Oceans—the coldest waters of all. The list includes sponges, sea spiders, shellfish, tube worms, and others. Some of these creatures are many times the size and weight of most of their counterparts elsewhere. The colossal squid, for example, is not only the largest squid, but the largest invertebrate of any kind. Several explanations have been proposed for polar gigantism. The leading idea is the oxygen-temperature hypothesis. It says there’s more oxygen in colder waters, so there’s plenty to support larger organisms. And in the cold, the animals grow more slowly but they may live longer, allowing them to reach giant proportions. As an example, the Greenland shark, which can reach lengths of 24 feet, can live for centuries.           Not every type of polar marine animal is a giant—some are especially small. So scientists are still pondering what makes some of them the giants of the deep. The post Polar Giants appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

If you happen to have a spare fiber in your undersea fiber-optic cable, marine scientists might like to have a chat. They’re using the cables to listen to the sounds of the oceans—from the rumble of underwater earthquakes to the low moans of blue whales. Scientists typically listen in with special undersea microphones. But they’re expensive, and their range is limited. Fiber-optic cables stretch across hundreds of thousands of miles of ocean floor, so they offer greater coverage at lower cost. The technique is known as D-A-S—distributed acoustic sensing. A laser fires regular pulses through the cable. Any disturbance introduces a “strain” on the cable. That causes some of the light to reflect back to the source. Analysis of this reflection tells scientists when and where it happened. It can also tell them the cause of the change. Early experiments tested the technique as a way to listen for earthquakes and landslides. More recently, biologists have been checking out D-A-S as well. They’ve done tests with dedicated cables, and with existing cables that are used for telecommunications. Scientists can piggyback on those cables—using fibers that aren’t otherwise in service. The cables have detected the vocalizations of blue whales and other large whale species. The technique could help biologists count the number of whales, monitor their movements, and look at how they’re impacted by shipping—a new type of communication for undersea fibers. The post Piggybacking appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

1933 was a bad year for the Eastern Shore of Virginia. Slime mold wiped out the eelgrass beds in the shallow coastal waters. A big hurricane made things even worse. Without the seagrass habitat, fish and crab populations were decimated, and bay scallops vanished. And neither seagrass nor scallops were seen again for almost seven decades. Today, though, both are recovering. Healthy eelgrass covers 10,000 acres. And there are enough scallops that people are talking about opening a recreational harvesting season. The comeback began when a scientist at the College of William & Mary discovered a small patch of eelgrass, in 1997. He then began a program to restore the grass along the Eastern Shore, which is separated from the mainland by Chesapeake Bay. As the beds expanded, researchers began looking at restoring bay scallops. The scallops are about three inches across. They use small tentacles on the edges of their shells to sense their surroundings, and gills to filter food from the water. Scientists harvested scallops from North Carolina and elsewhere. They cultivated new generations in the lab, then slowly released them into the wild. And the population has taken off. A 2025 survey found by far the highest number of scallops since the project began. And researchers estimated the population could double over the following year and a half. That could make it possible for people to harvest a few of the tasty morsels in the coming years. The post Restoring Scallops appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

After the 1944 D-Day invasion of Europe, Germany launched a months-long attack on London and Belgium. Its V-1 “buzz bombs” killed thousands. Today, though, the remnants of some of these terror weapons are providing homes for marine life. An estimated 1.6 million tons of unexploded munitions litter German waters. The weapons were dumped at the end of the two world wars. As their metal casings rust away, their toxic explosives wash into the water. And that should be bad for marine life. But a recent study found abundant life at a previously unknown dump site: fish, tube worms, anemones, crabs, and sea stars. The site is at the edge of the Baltic Sea. It’s about 60 to 70 feet deep, and it’s between two well-known dump sites. Researchers mapped the area with underwater cameras. They found a dozen unexploded weapons, which they identified as V-1 warheads. They also found life—a lot more than expected. Some organisms were living on the metal casings. Others were in the nearby sediments, although few were on the actual explosives. The scientists saw a low diversity of life—there were fewer species than found on natural surfaces in the region. But the density of life was greater than on the surrounding seabed. Most of the rock was dredged from the bottom of the region for construction projects in the 19th and 20th centuries. So the warheads provide some of the few hard surfaces around—dangerous homes off the German coast. The post Dangerous Living appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>

Some of the clouds that waft across the Southern Ocean may have an icky source: penguin poop. Ammonia in the poo mixes with other chemicals in the air. That creates the “seeds” that form water droplets, which clump together to make clouds. Water doesn’t form droplets on its own. It has to have something to glom on to—a grain of dust, a bit of pollen, or some other solid particle. Some of the particles are known as aerosols. They form when different chemicals link up in the air. And the clouds they create are brighter than other clouds, so they reflect more sunlight—helping control Earth’s temperature. And that’s what appears to be happening with the poop. Researchers discovered the connection during the summer of 2023. They were studying the atmosphere from an island off the northernmost tip of Antarctica. That part of the continent has two large colonies of Adelie penguins—about 45,000 breeding pairs in all. When the winds blew across the island from the open ocean, the air contained almost no ammonia. But when the wind blew in from the continent, the amount of ammonia in the air increased by a factor of a thousand—picked up from the penguin poo. When the penguins moved to their winter grounds, the amount of ammonia dropped, but still remained high—carried from the leftover poo. The ammonia mixed with sulfur produced by microscopic organisms in the ocean to produce aerosols—the “seeds” for clouds over the Southern Ocean. The post Poopy Clouds appeared first on Marine Science Institute. The University of Texas at Austin.. ]]>