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How far does plastic float when it gets tossed in the ocean?

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“It moved so rapidly,” says Emily Duncan, a post doc researcher at the Centre for Ecology and Conservation at the University of Exeter, and lead author of a study on this research published in PLOS ONE. “It shows that plastics are really a global issue. It doesn’t adhere to any geographic, political boundaries.”

The study was led by researchers at University of Exeter and the Zoological Society of London as part of the National Geographic Society’s Sea to Source project, which is researching ways to prevent plastic from entering the ocean from river systems, beginning with the Ganges in India. The Ganges is one of the world’s most polluted rivers, and a huge source of ocean plastic, including the single-use plastic beverage bottles that make up a large volume of ocean litter. (In the 2019 International Coastal Cleanup, volunteers recovered more than 1.8 million plastic beverage bottles from beaches and waterways across the world, and in at least the past 10 years of those cleanups, plastic bottles have been in the top five most collected items.)

[Photo: courtesy University of Exeter]

Duncan’s previous research focused on how plastic pollution affects sea turtles. For years, researchers have used satellite tags to track sea turtles, and if you can track a sea turtle and find out where it goes, Duncan thought, why can’t you track a plastic bottle? The team put lightweight GPS and satellite tags, inside a protective casing, which then went inside the plastic bottles. The casing replicated the buoyancy of a bottle that would still be about half full. (With technology always getting smaller and lighter, Duncan hopes in the future to track even lighter debris, like food wrappers.)

Researchers released 25 500 milliliter bottles in the Ganges and the Bay of Bengal, which opens into the Indian Ocean, and tracked the bottles using open-source tracking software. Many of the bottles released in the river moved in stages, getting stuck on their way downstream. Some got entangled in fishing gear, some were removed by people who picked them up, and some were trapped on beaches. The longest distance tracked was a bottle dropped in the Bay of Bengal that moved 1,768 miles in 94 days, traveling along the west coast of India. Of the bottles dropped in the Ganges, the farthest journey was more than 500 miles.

[Photo: Heather Koldewey/courtesy University of Exeter]

Environmentalists already know that rivers are a major source of ocean plastic, so it seems obvious that the bottles would end up in the ocean. But this study reveals just how fast this pollution moves. “It shows us [plastic] has the ability, once in the aquatic environments, to move very rapidly, so we really need to stop this from the source which is the land,” Duncan says. It could also help inform the global models of plastic pollution by factoring in information on how much the wind or ocean current affects plastic bottles.

Seeing where plastic pollution goes is a first step in better understanding

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Ancient marine predator had a built-in float

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Ancient marine predator had a built-in float
An illustration of Brevicaudosaurus. Credit: Tyler Stone BA ’19, art and cinema; see his website tylerstoneart.wordpress.com

About 240 million years ago, when reptiles ruled the ocean, a small lizard-like predator floated near the bottom of the edges in shallow water, picking off prey with fang-like teeth. A short and flat tail, used for balance, helps identify it as a new species, according to research published in the Journal of Vertebrate Paleontology.


Paleontologists at the Chinese Academy of Scientists and Canadian Museum of Nature have analysed two skeletons from a thin layer of limestone in two quarries in southwest China. They identified the skeletons as nothosaurs, Triassic marine reptiles with a small head, fangs, flipper-like limbs, a long neck, and normally an even longer tail, probably used for propulsion. However, in the new species, the tail is short and flat.

“Our analysis of two well-preserved skeletons reveals a reptile with a broad, pachyostotic body (denser boned) and a very short, flattened tail. A long tail can be used to flick through the water, generating thrust, but the new species we’ve identified was probably better suited to hanging out near the bottom in shallow sea, using its short, flattened tail for balance, like an underwater float, allowing it to preserve energy while searching for prey,” says Dr. Qing-Hua Shang from the Chinese Academy of Sciences, in Beijing.

The scientists have named the new species Brevicaudosaurus jiyangshanensis, from the Latin ‘brevi’ for ‘short,’ ‘caudo’ for ‘tail,’ and the Greek ‘sauros’ for ‘lizard.’ The most complete skeleton of the two was found in Jiyangshan quarry, giving the specimen its species name. It’s just under 60cm long.

Ancient marine predator had a built-in float
Brevicaudosaurus jiyangshanensis, gen. et sp. nov., skeletons in dorsal view. A, IVPP V 18625, holotype; B, IVPP V 26010, referred specimen. Credit: QING-HUA SHANG, XIAO-CHUN WU and CHUN, Journal of Vertebrate Paleontology

The skeleton gives further clues to its lifestyle. The forelimbs are more strongly developed than the hind limbs, suggesting they played a role in helping the reptile to swim. However, the bones in the front feet are short compared to other species, limiting the power with which it could pull through the water. Most of its bones, including the vertebrae and ribs, are thick and dense, further contributing to the stocky, stout appearance of the reptile, and limiting its ability to swim quickly but increasing stability underwater.

However, thick, high-mass bones act as ballast. What the reptile lost in speed, it gained in stability. Dense bones, known as pachyostosis, may have made it neutrally buoyant in shallow water. Together with the flat tail, this would have helped the predator to float motionless underwater, requiring little energy to stay horizontal. Neutral buoyancy should also have enabled it to walk on the seabed searching for slow-moving prey.

Highly dense ribs may also suggest the reptile had large lungs. As suggested by the lack of firm support of the body weight, nothosaurs were oceanic nut they needed to come to the water surface for oxygen. They have nostrils

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Newly discovered Triassic lizard could float underwater to pick off prey

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Some 240 million years ago, the Triassic predator Brevicaudosaurus jiyangshanensis skulked, nearly motionless, in the sea — and researchers found clues in its skeleton that could explain its unusual hunting methods.

Scientists at the Chinese Academy of Scientists in Beijing and Canadian Museum of Nature in Ottawa studied two skeletons discovered in a thin layer of limestone in two quarries in southwest China. The most complete skeleton, measuring just under 60 centimeters long, was found in a quarry in Jiangshan.

Experts identified the 240 million-year-old remains as a previously unknown species of nothosaurs: small-headed marine reptiles with fangs, flipper-like limbs and a long neck. Usually, nothosaurs had a longer tail, which experts think was used for propulsion — but the newly discovered reptile had a short and flat tail.

The reptile’s forelimbs were more developed than its hind limbs, and could have played a role in helping the animal to swim, the researchers noted. With its thick and dense bones — including vertebrae and ribs — it was likely stocky and stout in appearance.

What’s more, Brevicaudosaurus jiyangshanensis was not necessarily a speedy swimmer, experts believe, based on the evidence. However, its dense bones may have afforded it an advantage: stability. Its thick, high-mass bones could have made it neutrally buoyant in shallow water, and with the help of its flat tail, the predator could float motionless underwater while using little energy.

Stealth hunter

The creature, researchers also believe, could have used its neutral buoyancy to stalk the seabed in search of its next meal.

“Our analysis of two well-preserved skeletons reveals a reptile with a broad, pachyostotic body (denser boned) and a very short, flattened tail,” said study co-author Qing-Hua Shang, a paleontologist at the Chinese Academy of Sciences, in a statement. “A long tail can be used to flick through the water, generating thrust, but the new species we’ve identified was probably better suited to hanging out near the bottom in shallow sea, using its short, flattened tail for balance, like an underwater float, allowing it to preserve energy while searching for prey,” Shang added.

'Massive' coral reef taller than the Empire State Building discovered in Australia

The reptile was well suited for underwater hunting: neutral buoyancy should also have enabled it to walk on the seabed searching for slow-moving prey. Meanwhile, the skeleton’s high density ribs also suggest the reptile had large lungs, increasing the time the species could spend without surfacing.

Paleontologists found another feature that would help Brevicaudosaurus in its underwater exploits: The creature also had thick, long stapes — bar-shaped bones in the middle ear, used for sound transmission — which could have helped the reptile hear under the surface.

“Perhaps this small, slow-swimming marine reptile had to be vigilant for large predators as it floated in the shallows, as well as being a predator itself,” said co-author Xiao-Chun Wu, a paleobiologist at the Canadian Museum of Nature, in a statement.

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