Ocean

Ocean ‘garbage patch’ is filled with fishing gear from just a few places

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The bulk of large plastic bits in the North Pacific garbage patch have been lost or discarded by fishing vessels.

Samples of plastic caught in the Great Pacific garbage patch.
A crate with Japanese text on it was among the plastic debris collected by researchers studying the North Pacific garbage patch.Credit: The Ocean Cleanup

Fishing gear from just five regions could account for most of the floating plastic debris in the ‘North Pacific garbage patch’, a vast swathe of the North Pacific Ocean that holds tens of thousands of tonnes of plastic.

A study published on 1 September in Scientific Reports1 found that as much as 86% of the large pieces of floating plastic in the garbage patch are items that were abandoned, lost or discarded by fishing vessels. The finding is counterintuitive, given that most marine plastic makes its way into the ocean through rivers.

These findings “change our understanding of the sources of plastic in the North Pacific garbage patch”, says Matthias Egger, an ocean plastic researcher at the Ocean Cleanup, a non-profit organization based in Rotterdam, the Netherlands, that develops techniques to remove plastic from the oceans. The information could help to shape future policy to reduce plastic pollution in the ocean, he says.

A sea of plastic

The contaminated area was discovered in 1997 when a ship’s crew, sailing from Hawaii to California, noticed plastic littering a remote stretch of the open ocean. The plastic accumulates where ocean currents converge, forming a ‘garbage patch’ that some researchers estimate includes 1.8 trillion pieces of plastic. This debris is sometimes mistaken for food by turtles and other animals, and can trap wildlife.

PLASTIC HAVEN ON THE HIGH SEAS: map locating the North Pacific garbage patch inn the Pacific Ocean
Source: Ref. 2

In 2018, a survey2 found that fishing nets made up nearly half of the debris. The nets clearly came from fishing vessels, but the research team couldn’t determine the source of the rest of the plastic in the area. So, in 2019, the Ocean Cleanup collected more than 6,000 floating items totalling around 547 kilograms from the patch, and analysed the debris for letters and logos to pin down its origins.

The researchers determined production dates for dozens of items, including a buoy dating back to 1966. They were also able to track down the regions of origin of 232 objects. One-third of the identified debris came from Japan — possibly in part because of the tsunami that hit the country in 2011 — with the rest split between Taiwan, the United States, South Korea and the Chinese mainland, Hong Kong and Macau.

A CATCH OF PLASTIC: piechart showing origin of large plastic debris in North Pacific garbage patch
Source: Ref. 1

Notably absent from the debris was plastic from nations with lots of plastic pollution in their rivers. This was surprising, says Egger, because rivers are thought to be the source of most ocean plastic. Instead, most of the garbage-patch plastic seemed to have been dumped into the ocean directly by passing ships.

This suggests that “plastic emitted from land tends to accumulate along coastal areas, while plastic lost at sea has a high chance of accumulating in ocean garbage patches”, Egger says. The combination of the new results and the finding that fishing nets make up a large proportion of the debris indicates that fishing — spearheaded by the five countries and territories identified in the study — is the main source of plastic in the North Pacific garbage patch.

Fishing for rubbish

“What this paper and other investigations have shown is that there is really one sector — fishing — responsible for this plastic,” says Lisa Erdle, director of science at the 5 Gyres Institute, an ocean-research organization in Los Angeles, California. Knowing how plastic ends up in various environments can help to inform policy choices and clean-up tactics, such as putting trackers on nets, she says.

This information could also be used to shape the United Nations Treaty on Plastic Pollution, which has been under negotiation since March 2022, says Egger. But more directly, “the findings highlight the vital role of the fishing and aquaculture industries in making ocean garbage patches a relic of the past”, he says.

Can technology help save our oceans?

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https://www.weforum.org/agenda/2022/01/prevent-mass-extinction-ocean-ai-robots-3d-printers?utm_source=linkedin&utm_medium=social_video&utm_term=25278_robotic_fish_human_heart_cells&utm_content=social_video_2022&utm_campaign=

Hidden ‘Dead Zones’ in The Ocean Have Quadrupled Since The ’50s, And That’s Really Bad

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The ocean is suffocating.

It’s no secret that the world’s oceans are struggling with plastic pollution and rising temperatures, but hidden below the surface is a very serious problem – the ocean is running out of oxygen, and fast, according to the most comprehensive study of the ocean’s ‘dead zones’ to date.

 

Dead zones are vast patches of water that contain low or zero oxygen, and they’re a serious problem because, as their name suggests, most marine life suffocates and dies if they’re unlucky enough to find themselves in one.

The new study reviewed evidence on low-oxygen zones collected around the world, and found that these deadly swathes of water in the open ocean have quadrupled in number since the 1950s, expanding by millions of square kilometres. And that’s a much bigger problem than most people recognise.

“Oxygen is fundamental to life in the oceans,” said Denise Breitburg, lead author and marine ecologist with the Smithsonian Environmental Research Center. She’s part of the GO2NE (Global Ocean Oxygen Network), which was founded in 2016 to tackle this problem.

“The decline in ocean oxygen ranks among the most serious effects of human activities on Earth’s environment.”

While scientists have long been aware of these dead zones, this is the first review paper to take such a broad, global view of the issue. And the results aren’t pretty.

If the problem in the open ocean isn’t bad enough, closer to shore, things are even worse – dead zones in coastal water bodies such as estuaries and seas have increased more than 10-fold since the ’50s.

 As Earth’s climate continues to warm, the team predicts that the oceans will continue to lose oxygen at a rapid pace.

And, as the paper in the journal Science points out: “Major extinction events in Earth’s history have been associated with warm climates and oxygen-deficient oceans.”

So what’s causing these dead zones?

Climate change is a huge part of the problem, especially for the open ocean. Because warm water holds less oxygen, as surface water temperatures warm up, it makes it harder for oxygen to get down into the depths of the ocean.

Closer to shore, nutrient pollution – such as the runoff from agricultural practises – is also playing a big role.

Nutrients like phosphorous from fertiliser can easily end up in rivers and estuaries, which creates algal blooms that drain oxygen from the water as they die and decompose.

It’s no surprise then that scientists are worried about the algae bloom the size of Mexico in the Arabian Sea.

Unfortunately, as the oceans get warmer, marine life actually needs more oxygen to survive, not less. The result is huge patches of bleached coral and dead marine life.

“Approximately half of the oxygen on Earth comes from the ocean,” said Vladimir Ryabinin, executive secretary of the Intergovernmental Oceanographic Commission that formed the GO2NE.

“However, combined effects of nutrient loading and climate change are greatly increasing the number and size of ‘dead zones’ in the open ocean and coastal waters, where oxygen is too low to support most marine life.”

You can see some of these major dead zones in the map below:

map globallowoxygen(GO2NE working group)

In known dead zones, such as the Gulf of Mexico, oxygen can drop so low that many animals in the water suffocate and die. While a few species survive, overall, biodiveristy plummets in these areas.

Fish are lucky enough to be able to avoid these zones, but that still poses a major problem as this shrinks their habitat and puts them in more danger from predators.

Even if oxygen isn’t so low that it kills animals, it can still stunt growth, hinder reproduction, or trigger disease, according to the researchers.

Oh, and if that’s not bad enough, low oxygen also can trigger the release of dangerous chemicals from the ocean, such as nitrous oxide, a greenhouse gas up to 300 times more powerful than carbon dioxide.

The good news is that the GO2NE is focussed on finding ways to fix the problem, and in their study they propose a three-part plan: tackling climate change and nutrient pollution; protecting the most vulnerable marine life; and better monitoring low-oxygen tracking around the world.

“This is a problem we can solve,” said Breitburg.

“Halting climate change requires a global effort, but even local actions can help with nutrient-driven oxygen decline.”

She uses the example of Chesapeake Bay, which once contained a huge dead zone, but thanks to improved sewage treatment and better farming practices almost has no zero oxygen water left.

“Tackling climate change may seem more daunting,” she added, “but doing it is critical for stemming the decline of oxygen in our oceans, and for nearly every aspect of life on our planet.”

We’re One Step Closer to Pulling Nuclear Fuel Straight Out of the Ocean

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Better than digging it out of the ground.

Pulling uranium out of seawater could be a cost-effective way to source nuclear fuel, scientists have found, and the technique could pave the way for coastal countries to switch to nuclear power.

With the International Atomic Energy Agency currently predicting an increase of up to 68 percent in nuclear power production over the next 15 years, finding a new, more environmentally friendly source of uranium – the most critical ingredient in nuclear power – could give this alternative to fossil fuels a boost.

Researchers from Stanford University in California have found a way to more efficiently extract the uranium dissolved in our oceans, which could one day help nations with plenty of ocean-front land and no uranium collect fuel for nuclear energy.

In the form of the isotope U-235, uranium is currently the radioactive element of choice when it comes to using nuclear energy to produce electricity.

Right now, about 450 nuclear power plants spread across 30 countries chew through more than 60,000 tonnes of the stuff each year.

As an element, uranium is about as common as tin, being found in most rocks in a few parts per million. Getting your hands on enough to boil water for power, however, requires finding patches of it concentrated in Earth’s crust – at least if you want it to be cost-effective.

For countries without vast deposits of uranium, going nuclear relies on importing the fuel from countries with significant reserves, such as Australia, Kazakhstan, Canada, and Russia.

Pulling it out of rocks can have a big impact on the environment, both as a result of digging a great big hole, and through the process of extracting the fuel from the surrounding waste material.

Because of that, finding another source for uranium that risks less damage to the environment would also make the power source more environmentally friendly.

And it turns out, the ocean contains an enormous amount of uranium that doesn’t require digging – but the bad news is you need a lot of buckets of water to get even a small amount of the stuff.

“Concentrations are tiny, on the order of a single grain of salt dissolved in a litre of water,” said team researcher Yi Cui from Stanford University. “But the oceans are so vast that if we can extract these trace amounts cost effectively, the supply would be endless.”

“Endless” might be a small exaggeration, but the 4.5 billion tonnes of uranium dissolved in our planet’s waters would see us through for at least a few millennia of energy, with any we remove being replenished as uranium in the surrounding rocks dissolves.

We have a lot of water to sift through – about 1.37 billion cubic kilometres, in fact, (that’s more than 332 million cubic miles), with only about 3 particles of uranium per billion particles of seawater.

But uranium happens to form a positively charged ion in seawater as it reacts with oxygen to form the compound uranyl, providing a potentially easy way to selectively pull it out of solution.

One procedure uses a compound called amidoxime to pick up particles of uranyl while avoiding other positively charged particles.

By coating fibres in amidoxine, it’s possible to sweep a brush through a current of seawater and pull it up once it has a layer of the uranium compound – then it’s a matter of washing the brushes in a chemical bath to remove the uranyl, and sending it off for refining.

Being possible is one thing – being able to compete in a market where existing approaches are cheaper is another.

But in their new study, the Stanford researchers found several ways to improve the process, bringing it a step closer to becoming an economically viable industry.

Adding amoxidone to a pair of carbon electrodes, the scientists created a binding layer which could be hit with alternating pulses of low voltage electricity, allowing at least nine times the amount of uranyl to accumulate before saturation.

Using actual ocean water, the team was also able to collect three times as much uranyl in an 11-hour period, showing an improvement not just in the amount which could be collected in one sweep, but in the rate of collection.

Lastly, they showed this adjustment to the process tripled the lifespan of the amidoxine coating, reducing costs even further.

While it’s an improvement on the existing technology, a lot more needs to be done before mining ocean water for uranium can compete with digging it out of the ground. The next step would be to reduce the voltage required to be fed into the process.

Of course, there is still the question of whether nuclear is the way to go at all; while it’s a carbon-free alternative to fossil fuels, anxiety over the risk of nuclear accidents, access to raw nuclear material, and the need to safely and responsibly dispose of spent fuel remains high.

“For much of this century, some fraction of our electricity will need to come from sources that we can turn on and off,” says researcher Stephen Chu.

“I believe nuclear power should be part of that mix, and assuring access to uranium is part of the solution to carbon-free energy.”

One thing is for certain – nuclear energy isn’t going away any time soon, so finding cheaper, less risky ways to supply the fuel can only be a good thing.

Scientists Discover An Ocean 400 Miles Beneath Our Feet That Could Fill Our Oceans 3 Times Over!

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After decades of theorizing and searching, scientists are reporting that they’ve finally found a massive reservoir of water in the Earth’s mantle — a reservoir so vast that could fill the Earth’s oceans three times over. This discovery suggests that Earth’s surface water actually came from within, as part of a “whole-Earth water cycle,” rather than the prevailing theory of icy comets striking Earth billions of years ago. As always, the more we understand about how the Earth formed, and how its multitude of interior layers continue to function, the more accurately we can predict the future. Weather, sea levels, climate change — these are all closely linked to the tectonic activity that endlessly churns away beneath our feet.

This new study, authored by a range of geophysicists and scientists from across the US, leverages data from the USArray — an array of hundreds of seismographs located throughout the US that are constantly listening to movements in the Earth’s mantle and core. After listening for a few years, and carrying out lots of complex calculations, the researchers believe that they’ve found a huge reserve of water that’s located in thetransition zone between the upper and lower mantle — a region that occupies between 400 and 660 kilometers (250-410 miles) below our feet. [DOI: 10.1126/science.1253358 – “Dehydration melting at the top of the lower mantle”]

Earth-crust-cutaway-english.svg_-640x439

As you can imagine, things are a little complex that far down. We’re not talking about some kind of water reserve that can be reached in the same way as an oil well. The deepest a human borehole has ever gone is just 12km — about half way through the Earth’s crust — and we had to stop because geothermal energy was melting the drill bit. 660 kilometers is a long, long way down, and weird stuff happens down there.

Basically, the new theory is that the Earth’s mantle is full of a mineral called ringwoodite. We know from experiments here on the surface that, under extreme pressure, ringwoodite can trap water. Measurements made by the USArray indicate that as convection pushes ringwoodite deeper into the mantle, the increase in pressure forces the trapped water out (a process known as dehydration melting). That seems to be the extent of the study’s findings. Now they need to try and link together deep-Earth geology with what actually happens on the surface. The Earth is an immensely complex machine that generally moves at a very, very slow pace. It takes years of measurements to get anything even approaching useful data.

Scientists Have Discovered An Ocean 400 Miles Under Our Feet .

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earth onion

After decades of theorizing and searching, scientists are reporting that they’ve finally found a massive reservoir of water in the Earth’s mantle — a reservoir so vast that could fill the Earth’s oceans three times over. This discovery suggests that Earth’s surface water actually came from within, as part of a “whole-Earth water cycle,” rather than the prevailing theory of icy comets striking Earth billions of years ago. As always, the more we understand about how the Earth formed, and how its multitude of interior layers continue to function, the more accurately we can predict the future. Weather, sea levels, climate change — these are all closely linked to the tectonic activity that endlessly churns away beneath our feet.

This new study, authored by a range of geophysicists and scientists from across the US, leverages data from the USArray — an array of hundreds of seismographs located throughout the US that are constantly listening to movements in the Earth’s mantle and core. After listening for a few years, and carrying out lots of complex calculations, the researchers believe that they’ve found a huge reserve of water that’s located in thetransition zone between the upper and lower mantle — a region that occupies between 400 and 660 kilometers (250-410 miles) below our feet. [DOI: 10.1126/science.1253358 – “Dehydration melting at the top of the lower mantle”]

image: http://higherperspective.com/wp-content/uploads/2015/01/crust.png

crust

As you can imagine, things are a little complex that far down. We’re not talking about some kind of water reserve that can be reached in the same way as an oil well. The deepest a human borehole has ever gone is just 12km — about half way through the Earth’s crust — and we had to stop because geothermal energy was melting the drill bit. 660 kilometers is a long, long way down, and weird stuff happens down there.

Basically, the new theory is that the Earth’s mantle is full of a mineral called ringwoodite. We know from experiments here on the surface that, under extreme pressure, ringwoodite can trap water. Measurements made by the USArray indicate that as convection pushes ringwoodite deeper into the mantle, the increase in pressure forces the trapped water out (a process known as dehydration melting). That seems to be the extent of the study’s findings. Now they need to try and link together deep-Earth geology with what actually happens on the surface. The Earth is an immensely complex machine that generally moves at a very, very slow pace. It takes years of measurements to get anything even approaching useful data. [Read: Is earthquake prediction finally a reality?]

image: http://higherperspective.com/wp-content/uploads/2015/01/resvoir.jpg

resvoir

Earth’s underground ringwoodite ocean .

With all that said, there could be massive repercussions if this study’s findings are accurate. Even if the ringwoodite only contains around 2.6% water, the volume of the transition zone means this underground reservoir could contain enough water to re-fill our oceans three times over. I’m not saying that this gives us the perfect excuse to continue our abuse of Earth’s fresh water reserves, but it’s definitely something to mull over. This would also seem to discount the prevailing theory that our surface water arrived on Earth via a bunch of icy comets.

Finally, here’s a fun thought that should remind us that Earth’s perfect composition and climate is, if you look very closely, rather miraculous. One of the researchers, talking to New Scientist, said that if the water wasn’t stored underground, “it would be on the surface of the Earth, and mountaintops would be the only land poking out.” Maybe if the formation of Earth had be a little different, or if we were marginally closer to the Sun, or if a random asteroid didn’t land here billions of years ago… you probably wouldn’t be sitting here surfing the web.