
10 episodes

Science and the Sea podcast The University of Texas Marine Science Institute
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- Science
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4.8 • 13 Ratings
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The goal of Science and the Sea is to convey this understanding of the sea and its myriad life forms to everyone, so that they, too, can fully appreciate this amazing resource.
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Living in Chimneys
Many species of marine life are spread far and wide—across millions of square miles. But others are concentrated in patches no bigger than your backyard garden. And thousands of species can share the space.
Some of these patches surround small structures known as chimneys—columns of rock that form when jets of super-hot water shoot up from below the ocean floor. When the mineral-rich water hits the cold ocean water, the minerals build pillars of rock that can be many feet tall.
Microscopic organisms thrive in these environments. Many species are found around chimneys across the world. But other species are found only in their own little patches.
A recent study, for example, discovered more than 150 species around a single chimney that haven’t been seen anywhere else. It’s on Brothers Seamount, an underwater volcano near New Zealand.
Researchers used state-of-the-art techniques to sequence the genomes of microbes from the chimney. They did the same thing for microbes found in four large patches of chimneys in the Pacific and Atlantic oceans. In all, they logged more than 3500 species of microscopic life. The list included hundreds of species that had never been seen before.
The study also found that many of the organisms depend on each other to survive. Some, for example, can’t get all the nutrients they need on their own. So they depend on other organisms to provide those nutrients—in their own little garden patches on the ocean floor. -
Swirling Fish
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. -
Ocean Gyres
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
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. -
Frothy Eggs
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. -
Shark Graveyard
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.