Hello. It’s River Davis in Toyko here with you this Tuesday.
Imagine there’s a virtually carbon-neutral version of gasoline. You could keep running your old gas guzzler for years more, top it up at a regular filling station and still enjoy a climate-friendlier drive.
Even as an electric future is assured for most mainstream transport, several of the world’s leading auto giants and Big Oil are working on plans to extend the lives of combustion engine vehicles and aircraft.
Toyota and Audi are among the carmakers exploring the potential of e-fuels, or synthetic fuels, while Porsche and energy giant Exxon Mobil plan to start some production as soon as next year. Japan, meanwhile, is working to establish large-scale manufacturing technologies by the end of the decade and to deliver synthetic fuels in commercial volumes by 2040.
Toyota’s President Akio Toyoda is among the most vocal advocates for the fuels. As chairman of the Japan Automobile Manufacturers Association, he frequently argues the nation’s goal of a carbon-neutral transport sector by 2050 can’t be achieved simply by banning sales of new gasoline-powered cars.
E-fuels could be deployed to curb emissions from existing ICE vehicles, which will continue to be in circulation for decades, he says. That’s a logic that could hold true in other markets like the U.K., Germany and Canada, which are among the dozen or so countries that have set deadlines to phase out sales of new combustion engine models.
A diesel engine in Stuttgart, Germany.
Photographer: Krisztian Bocsi/Bloomberg
Harder-to-electrify segments of the transport sector like planes, ships and large commercial vehicles also could be served by the synthetic products. A February flight from Amsterdam to Madrid operated by Air France-KLM’s Dutch arm was the first to use so-called sustainably derived synthetic aviation fuel, according to the airline.
E-fuel is made when electricity is used to split water into hydrogen and oxygen. That hydrogen is then combined with carbon dioxide and converted into a liquid product that’s similar to petrol or diesel and yet essentially emissions free. One key drawback is the process is hugely expensive. E-fuels today cost about $5.28 per liter, according to a study by German energy agency Dena. That’s about five times the cost of a liter of gas in the U.S.
Companies including Siemens Energy, Mazda and Robert Bosch are among those backing further development of synthetic fuels and seeking support from governments and regulators. Most current work is centered on pilot projects or prototypes, according to industry group eFuel Alliance.
Investments are being made to bring costs down, and developers will benefit from refinements in technology for green hydrogen — produced using a similar process — and advances by the carbon-capture industry. Japan is aiming to make synthetic fuels as cheap as, or cheaper than, gasoline by mid-century.
Cutting the price of a climate-friendly gasoline is one challenge. Securing long-term demand in a world that’s turning away from fossil fuel-powered transport may prove harder.
The Chinese invented playing cards in AD 1000. Some interesting facts
Did you know that the traditional deck of playing cards are a strikingly coherent form of a calendar? There are 52 weeks in the year and there are 52 playing cards in a deck.
There are 13 weeks in each season and there are 13 cards in each suit.
There are 4 seasons in a year and 4 suits in the deck.
There are 12 months in a year so there are 12 court cards namely 4 Jacks, 4 Queens and 4 Kings.
The red cards represent day, while the black cards represent the night.
In this sum we allow Jacks to equal 10 , Queens to equal 11 and Kings to equal 13.
Now, add up all the cards namely one, two, three, four, five, six, seven, eight, nine, ten, Jack, Queen, King and the total comes to 91. Now multiply the 4 suits and the 91 x 4 = 364, then add the Jocker and you will arrive at 365, that being the number of days in a year, or is that a mere coincidence or a greater intelligence?
The Spades indicate plowing or working.
The Hearts indicate love thy crops.
The Clubs indicate flourishing and growth.
The Diamonds indicate reaping the wealth.
Is there a deeper philosophy than just merely playing cards? The mathematical perfection is mind blowing.
... On average, I found Amazon’s prices were slightly lower than Harris Teeter’s, though the difference was small enough that I’m going to call it a tie.
Amazon’s no-checkout technology helps in several ways here. Obviously, buying groceries is more convenient if you don’t have to wait in a checkout line. Equally obvious, Amazon can pass along the money it saves by not having checkout clerks.
More subtly, removing checkout counters allows the stores to be smaller—not only because you don’t need the physical space for the checkout lanes, but also because you don’t need a large volume of business to recoup the fixed cost of running the checkout lanes. So instead of having a single big store, Amazon could profitably build several small stores to serve the same area. That would mean more customers living within easy walking distance of an Amazon Fresh store—customers who might get in the habit of stopping by Amazon Fresh stores every day or two for fruit, milk, and other perishables.
MASS TESTING IN ACTION — “In Los Angeles, price for admission at nation’s second-largest school district is a negative covid test — every single week,” by WaPo’s great Erica Werner , reporting from her new home state: “As hundreds of thousands of kids return to class in the nation’s second-largest school district, they’re participating in what amounts to a massive public health experiment unfolding in real time: Every single student, teacher and administrator in the Los Angeles public schools must get tested for the coronavirus every single week — indefinitely. Even the fully vaccinated are required to get tested. Those who test positive stay home for at least 10 days. And those who decline to get tested can’t come at all. … [I]t amounts to by far the most aggressive anti-coronavirus campaign undertaken or announced by a major school district in the United States.”
This
Physicist Discovered an Escape From Hawking’s Black Hole Paradox
The five-decade-old paradox — long
thought key to linking quantum theory with Einstein’s theory of gravity
— is falling to a new generation of thinkers. Netta Engelhardt is leading the
way.
READ LATER
Netta Engelhardt puzzles over the fates of black holes in her
office at the Massachusetts Institute of Technology.
In
1974, Stephen Hawking calculated that
black holes’ secrets die with them. Random quantum jitter on the spherical outer boundary, or “event
horizon,” of a black hole will cause the hole to radiate particles and slowly
shrink to nothing. Any record of the star whose violent contraction formed
the black hole — and whatever else got swallowed up after — then seemed to be
permanently lost.
Hawking’s calculation posed a paradox — the infamous “black hole information paradox”
— that has motivated research in fundamental physics ever since. On the one
hand, quantum mechanics, the
rulebook for particles, says that information about particles’ past
states gets carried forward as they evolve — a bedrock principle called “unitarity.” But black holes take their
cues from general relativity, the
theory that space and time form a bendy fabric and gravity is the fabric’s
curves. Hawking had tried to
apply quantum mechanics to particles near a black hole’s periphery, and saw
unitarity break down.
So do evaporating black
holes really destroy information, meaning unitarity is not a true principle of
nature? Or does information escape as a black hole evaporates? Solving the
information paradox quickly came to be seen as a route to discovering the true, quantum theory of gravity,
which general relativity approximates well everywhere except black holes.
In the past two years, a
network of quantum gravity theorists, mostly millennials, has made enormous
progress on Hawking’s paradox. One of the leading researchers is Netta Engelhardt, a
32-year-old theoretical physicist at the Massachusetts Institute of Technology.
She and her colleagues have completed a new calculation that corrects Hawking’s
1974 formula; theirs indicates that information does, in fact, escape
black holes via their radiation. She and Aron Wall identified an invisible surface
that lies inside a black hole’s event horizon, called the “quantum extremal surface.” In 2019,
Engelhardt and others showed that this surface seems to encode the amount of
information that has radiated away from the black hole, evolving over the
hole’s lifetime exactly as expected if information escapes.
Engelhardt received a
2021 New Horizons in Physics Prize “for calculating the quantum information
content of a black hole and its radiation.” Ahmed Almheiri of
the Institute for Advanced Study, a frequent collaborator, noted her “deeply
rooted intuition for the intricate workings of gravity,” particularly in the
discovery of quantum extremal surfaces.
Engelhardt set her sights on quantum gravity when she was 9 years old.
She moved to Boston from Israel that
year with her family, and, not knowing any English, read every book in Hebrew
she could find in her house. The last was Hawking’s A
Brief History of Time. “What that book did for me was trigger a desire to understand
the fundamental building blocks of the universe,” she said. “From then on, I
was sort of finding my own way, watching different popular science videos and
asking questions of anybody who might have the answers, and narrowing down what
I wanted to work on.” She ultimately found her way to Hawking’s paradox.
When Quanta
Magazine caught
up with Engelhardt in a recent video call, she emphasized that the full
solution to the paradox — and the quantum theory of gravity — is a work in
progress. We discussed that progress, which centrally involves the concept of entropy, and the search for
a “reverse algorithm” that would allow someone to reconstruct a black
hole’s past. The conversation has been condensed and edited for clarity.
Would you say you and
your colleagues have solved the black hole information paradox?
Not yet. We’ve made a
lot of progress toward a resolution. That’s part of what makes the field so
exciting; we’re moving forward — and we’re not doing it so slowly, either — but
there’s still a lot that we have to uncover and understand.
Could you summarize what
you’ve figured out so far?
Certainly. Along the way
there have been a number of very important developments. One I will mention
is a 1993 paper by Don Page. Page said,
suppose that information is conserved. Then the entropy of everything outside
of a black hole starts out at some value, increases, then has to go back down
to the original value once the black hole has evaporated altogether. Whereas
Hawking’s calculation predicts that the entropy increases, and once the black
hole is evaporated completely, it just plateaus at some value and that’s it.
So the question became,
which entropy curve is right. Normally, entropy is the number of possible
indistinguishable configurations of a system. What’s the best way to understand
entropy in this black hole context?
You could think of this
entropy as ignorance of the state of affairs in the black hole interior. The
more possibilities there are for what could be going on in the black hole
interior, the more ignorant you will be about which configuration the system is
in. So this entropy measures ignorance.
Page’s discovery was
that if you assume that the evolution of the universe doesn’t lose information,
then, if you start out with zero ignorance about the universe before a black
hole forms, eventually you’re going to end up with zero ignorance once the
black hole is gone, since all the information that went in has come back out.
That’s in conflict with what Hawking derived, which was that eventually you end
up with ignorance.
You characterize Page’s
insight and all other work on the information paradox prior to 2019 as
“understanding the problem better.” What happened in 2019?
The activity that
started in 2019 is the steps towards actually resolving the problem. The two
papers that kicked this off were work by
myself, Ahmed Almheiri, Don Marolf and Henry Maxfield and,
in parallel, the second paper, which
came out at the same time, by Geoff
Penington. We submitted our papers on the same day and coordinated
because we knew we were both onto the same thing.
The idea was to
calculate the entropy in a different way. This is where Don Page’s calculation
was very important for us.
If we use Hawking’s method and his assumptions, we get a formula for the
entropy which is not consistent with unitarity. Now we want to
understand how we could possibly do a calculation that would give us the curve of the entropy that Page
proposed, which goes up then comes back down.
And for this we relied
on a proposal that Aron Wall and I gave in 2014: the quantum extremal surface
proposal, which essentially states that the so-called quantum-corrected area of a certain surface
inside the black hole is what computes the entropy. We said, maybe
that’s a way to do the quantum gravity calculation that gives us a unitary
result. And I will say: It was kind of a shot in the dark.
When did you realize
that it worked?
This entire time is a
bit of a daze in my mind, it was so exciting; I think I slept maybe two hours a
night for weeks. The calculation came together over a period of three weeks, I
want to say. I was at Princeton at the time. We just had a meeting on campus. I
have a very distinct memory of driving home, and I was thinking to myself, wow,
this could be it.
The crux of the matter
was, there’s more than one quantum extremal surface in the problem. There’s one
quantum extremal surface that gives you the wrong answer — the Hawking answer.
To correctly calculate the entropy, you have to pick the right one, and the
right one is always the one with the smallest quantum-corrected area. And so
what was really exciting — I think the moment we realized this might really
actually work out — is when we found that exactly at the time when the entropy
curve needs to “turn over” [go from increasing to decreasing], there’s a jump.
At that time, the quantum extremal surface with the smallest quantum-corrected
area goes from being the surface that would give you Hawking’s answer to a new
and unexpected one. And that one reproduces the Page curve.
What are these quantum extremal surfaces, exactly?
Let me try to intuit a
little bit what a classical, non-quantum extremal surface feels like. Let me
begin with just a sphere. Imagine that you place a light bulb inside of it, and
you follow the light rays as they move outward through the sphere. As the light
rays get farther and farther away from the light bulb, the area of the spheres
that they pass through will be getting larger and larger. We say that the
cross-sectional area of the light rays is getting larger.
That’s an intuition that
works really well in approximately flat space where we live. But when you
consider very curved space-time like you find inside a black hole, what can
happen is that even though you’re firing your light rays outwards from the
light bulb, and you’re looking at spheres that are progressively farther away
from the bulb, the cross-sectional area is actually shrinking. And this is
because space-time is very violently curved. It’s something that we call
focusing of light rays, and it’s a very fundamental concept in gravity and
general relativity.
The extremal surface
straddles this line between the very violent situation where the area is
decreasing, and a normal situation where the area increases. The area of the
surface is neither increasing nor decreasing, and so intuitively you can think
of an extremal surface as kind of lying right at the cusp of where you’d expect
strong curvature to start kicking in. A quantum extremal surface is the same
idea, but instead of area, now you’re looking at quantum-corrected area. This
is a sum of area and entropy, which is neither increasing nor decreasing.
What does the quantum
extremal surface mean? What’s the difference between things that are inside
versus outside?
Recall that when the
Page curve turns over, we expect that our ignorance of what the black hole
contains starts to decrease, as we have access to more and more of its
radiation. So the radiation emitted by the hole must start to “learn” about the
black hole interior.
It’s the quantum
extremal surface that divides the space-time in two: Everything inside the
surface, the radiation can already decode. Everything outside of it is what
remains hidden in the black hole system, what’s not contained in the
information of the radiation. As the black hole emits more radiation, the
quantum extremal surface moves outwards and encompasses an ever-larger volume
of the black hole interior. By the time that black hole evaporates altogether,
the radiation has to be able to decode everything that way.
Now that we have an
explicit calculation that gives us a unitary answer, that gives us so many
tools to start asking questions that we could never ask before, like where does
this formula come from, what does it mean about what type of theory quantum gravity
is? Also, what is the mechanism in quantum gravity that restores unitarity? It
has something to do with the quantum extremal surface formula.
Most of the
justification for the quantum extremal surface formula comes from studying
black holes in “Anti-de Sitter” (AdS) space — saddle-shaped space with an outer
boundary. Whereas our universe has approximately flat space, and no boundary.
Why should we think that these calculations apply to our universe?
First, we can’t really
get around the fact that our universe contains both quantum mechanics and
gravity. It contains black holes. So our understanding of the universe is going
to be incomplete until we have a description of what happens inside a black
hole. The information problem is such a difficult problem to solve that any
progress — whether it’s in a toy model or not — is making progress towards
understanding phenomena that happen in our universe.
Now at a more technical
level, quantum extremal surfaces can be computed in different kinds of
space-times, including flat space like in our universe. And in fact there
already have been papers written on the behavior of quantum extremal
surfaces within different kinds of space-times and what types of entropy curves
they would give rise to.
We have a very firm interpretation
of the quantum extremal surface in AdS space. We can extrapolate and say that
in flat space there exists some interpretation of the quantum extremal surface
which is analogous, and I think that’s probably true. It has many nice
properties; it looks like it’s the right thing. We get really interesting
behavior and we expect to get unitarity as well, and so, yes, we do expect that
this phenomenon does translate, although the interpretation is going to be
harder.
You said at the
beginning of our conversation that we don’t know the solution to the
information paradox yet. Can you explain what a solution looks like?
A full resolution of the
information paradox would have to tell us exactly how the black hole
information comes out. If I’m an observer that’s sitting outside of a black
hole and I have extremely sophisticated technology and all the time in the
world — a quantum computer taking incredibly sophisticated measurements, all
the radiation of that black hole — what does it take for me to actually decode
the radiation to reconstruct, for instance, the star that collapsed and formed
the black hole? What process do I need to put my quantum computer through? We
need to answer that question.
So you want to find the
reverse algorithm that unscrambles the information in the radiation. What’s the
connection between that algorithm and quantum gravity?
This algorithm that
decodes the Hawking radiation is coming from the process in which quantum
gravity encodes the radiation as it evaporates at the black hole horizon. The
emergence of the black hole interior from quantum gravity and the dynamics of
the black hole interior, the experience of an object that falls into the black
hole — all of that is encoded in this reverse algorithm that quantum gravity
has to spit out. All of those are tied up in the question of “how does the
information get encoded in the Hawking radiation?”
You’ve lately been
writing papers about something called a python’s lunch. What’s that?
It’s one thing to ask how
can you decode the Hawking
radiation; you also might ask, how complex is the task of
decoding the Hawking radiation. And, as it turns out, extremely complex. So maybe the difference
between Hawking’s calculation and the quantum extremal surface calculation that
gives unitarity is that Hawking’s calculation is just dropping the
high-complexity operations.
It’s important to
understand the complexity geometrically. And in 2019 there was a paper by some of my colleagues that
proposed that whenever you have more than one quantum extremal surface, the one
that would be wrong for the entropy can be used to calculate the complexity of
decoding the black hole radiation. The two quantum extremal surfaces can be
thought of as sort of constrictions in the space-time geometry, and those of us
who have read Le Petit Prince see an elephant
inside a python, and so it has become known as a python’s lunch.
We proposed that multiple quantum extremal
surfaces are the exclusive source of high complexity. And these two papers that
you’re referring to are essentially an argument for this “strong python’s
lunch” proposal. That is very insightful for us because it identifies the part
of the geometry that Hawking’s calculation knows about and part of the geometry
that Hawking’s calculation doesn’t know about. It’s working towards putting his
and our calculations in the same language so that we know why one is right, and
the other is wrong.
Where would you say we
currently stand in our effort to understand the quantum nature of gravity?
I like to think of this
as a puzzle, where we have all the edge pieces and we’re missing the center. We
have many different insights about quantum gravity. There are many ways in
which people are trying to understand it. Some by constraining it: What are
things that it can’t do? Some by trying to construct aspects of it: things that
it must do. My personal preferred approach is more to do with the information
paradox, because it’s so pivotal; it’s such an acute problem. It’s clearly
telling us: Here’s where you messed up. And to me that says, here’s a place
where we can begin to fix our pillars, one of which must be wrong, of our
understanding of quantum gravity.
...U.S. activities there saved a million or more lives, a significant net positive.
Consider: Infant mortality dropped by half during the U.S. operation. Life expectancy improved by six years. Electricity consumption, a key quality of life indicator, increased by a factor of 10. Years in school increased by at least three years for men and four for women. University graduates rose from under 31,000 to almost 200,000. (Those and other indicators are available at the Brookings Afghanistan index.)
Those gains would count for less if they had come at a major strategic cost—as was the case in Iraq, where the deposition of Saddam Hussein cleared a path for Iran’s domination of the region. But none of the people I spoke to for this article cited any comparable strategic cost in Afghanistan. No American adversary was strengthened; to the contrary, ambitions of rivals like Iran, Pakistan, China, and Russia were blocked. No allies were alienated; to the contrary, four dozen countries had joined the campaign by 2014, and 36 countries, from Albania to Ukraine, were still contributing forces as of February, according to NATO. If anything, the operation strengthened NATO and America’s alliances. “It was remarkable how much the NATO coalition held throughout this thing,” O’Hanlon said.
Ian Bremmer here, and the unceremonious end to the longest military adventure, longest war in American history. Plenty of blame to go around for how this war started, was pursued, the money that was spent, the human lives that were cost, and certainly many, many books will be written about that. But for today, we have to look at the close, at the staggering incompetence of execution, to bring this war to a close, to withdraw American troops from Afghanistan. A policy that I agree with, the actual strategy, that you have to either expand the presence or you have to pull out because the Taliban were gaining and were likely to take over with the status quo ante. But the execution has been an extraordinary failure. This is by far the most consequential foreign policy crisis that we have witnessed, I would say, since the Iranian hostage crisis and then the failed rescue. So, it's quite something. We've seen bigger domestic policy crises in the United States, heck, on January 6th. But from a foreign policy crisis, this is an extraordinarily big deal.
What went wrong? I would say there are four different types of failure of execution on Biden's watch here. Number one, the military and intelligence failure. The US intelligence agencies, at the time that Biden first made the announcement that they were going to withdraw all troops by August, September 11th, said that the Afghan defense forces would be able to hold off the Taliban for two to three years. After the Taliban offensive kicked in over the course of the last few days, the intelligence assessment dropped to two to three days. I have never seen that kind of intelligence failure in my career. Two facts here are truly breathtaking. Number one, the United States spent 20 years and nearly $90 billion training an Afghan force that refused to fight. And number two, after two decades of personally training Afghans on the ground, the United States still did not understand, in any way, the morale and the capabilities of the forces that they had trained.
Number two. A failure of coordination. And I've talked a fair amount about this, but it bears repeating. The United States fought alongside our allies for two decades, asked them to fight with us after 9/11, and they gladly and broadly agreed, and spent lives, fighting bravely, and lost lives fighting bravely on the ground. But when it came time to leave, President Biden did so alone, both looking at the decision making process, the actual announcement, and consideration of ongoing policies, like for example whether or not and how you're going to accept refugees and provide humanitarian support. Even things like the role of the ambassador on the ground, the US ambassador, acting ambassador over the weekend flees, leaves the country. The British ambassador, still there, actually working to get his people, his citizens out. How could we not be coordinating with our allies on something this simple? An extraordinary failure of coordination and American allies are pissed about it, and they're making that known. They were making that known privately over the past few months. They're now making that known very publicly.
Number three. A failure of planning. It's one thing to get the intelligence wrong and get the coordination wrong, but it didn't have to be such a disaster if there had been planning in alternative scenarios. Things don't always go the way you hope they're going to, and certainly the US military and intelligence historically has tried to put efforts in that regard. This is a stunning failure on the basis of that. Based on everything we know, we absolutely had a complete failure of planning here. The fact that the United States did this on our timeline and had to airlift in the troops from the mainland to assist in the evacuation, sending in more, 6,000, than the United States had withdrawn in the first place, the planning to provide the safety for the thousands upon thousands of Afghans who had helped the American forces has been abysmal, and many will be left behind. Many will surely die. All of that could have been done, should have been done, in the months leading up to the final withdrawal. It's extraordinary that it didn't happen.
And then finally, the communications failure. You've seen the videos by now that in selling withdrawal, President Biden, back on July 8th, assured Americans that it was highly unlikely for the Taliban to be overrunning everything and owning the whole country. He insisted that, "There's going to be no circumstance," I'm quoting here, "Where you see people being lifted off the roof of the US Embassy like in Saigon in 1975." These predictions unraveled in real time, and you still had Biden and the secretary of state and others in the White House making public statements that this was a success, which is a breathtaking thing to posit. The fact that President Biden chose to stay in Camp David, a working vacation, during this crisis and had a photograph of the conversation he's having with his national security advisors, none of whom are actually there in person with him, they're on a Zoom call, I mean at the time that I am filming this, we still haven't heard live from Biden with a speech to the American people as to how they got this so wrong. And that's pretty extraordinary too.
Now, I will say that as it stands right now, I don't believe that this crisis for the American people, or for Biden, rises to the level of Saigon in '75, and there are a few reasons for that. One is because the average American, not the politically engaged American that's on Twitter and throwing fusillades on foreign policy, but the average American doesn't really care about Afghanistan and really wants out, and for all of the human rights atrocities that we are going to witness in the coming weeks and months and years on the ground, it doesn't really move the needle for what is fundamentally a popular policy. Having said that, we are not through this, and this can get much worse. It is certainly possible that you will end up with firefights between American forces and Taliban on the ground. It's certainly possible Americans will be killed, beheaded, possible that you would see a kidnapping crisis, a hostage crisis on the ground. If anything like that transpires, then this is an Iran hostage crisis, again, and this could destroy the Biden presidency.
I think right now as it stands, domestically it plays out more like Obama's failed red line on Syria, where he says "Assad must go," and Assad goes nowhere. But internationally, it has more significance. American allies, who had hoped that America was indeed back the way that Biden said it was, feel like this is America alone, this is America unilateralist, this is an America that can't be trusted. And while the Chinese and the Russians, I do not believe that this puts the Baltics at risk or Taiwan at risk, I do believe that ideologically their ability and willingness to lean into the narrative of the US lacks legitimacy internationally is going to cause more damage with other countries around the world, will lead to more hedging behavior, does create more of a GZERO world, not the one that we really would rather be living in.
That's my view, and I'm sure I'll be in touch, but wanted to get this out to you. Be well, and let's hope for the best over the course of this week on the ground in Afghanistan.
Along the edge of Bastia’s colorful, seafood restaurant-lined port, a wetsuit-clad diver plunges beneath the surface with a large black cage full of oysters in hand and carefully attaches it to an underwater hook on the boardwalk. Resurfacing a few seconds later, the French diver takes another cage to fit alongside the dozens of others already in place.
“The oysters are ready,” he gasps, slowly clambering back on board the small boat laden with ropes, diving gear and empty cages. “Now we just have to let them do their magic.”
In a reversal of norms, instead of extracting this delicacy to serve up at the nearby waterfront eateries, the team from Corsica University’s marine research institute Stella Mare is depositing the oysters into the sea — and instead of cleansing the palates of hungry diners, these industrious mollusks are being used to clean up the water.
Oysters naturally filters water in order to absorb nutrients and grow their shells. Credit: Peter Yeung
The project, which launched in the Corsican city Bastia last September and is now in the second of three phases, will see a total of around 150,000 juvenile Ostrea edulis, commonly known as the European flat oyster, deployed to help depollute the port.
“We wanted to see what would happen if we introduced oysters, what pollution would be cleaned from the water and what would remain in the oysters’ shells,” says Sylvia Agostini, lead of the project for Stella Mare. “Normally, you can’t treat PCBs [an industrial chemical known as polychlorinated biphenyls]. But it’s proven to be a revolutionary method.”
Agostini’s team initially tested the impact of both oysters and sea anemones on pollution levels in the 260,000 cubic meter port. But while the latter struggled to survive and few were left after a year, around 80 percent of the oysters survived — those that didn’t largely suffered due to boat traffic rather than pollution — and water quality has already improved. Monthly checks and quarterly in-depth analyses of water samples for contaminants will be carried out in Bastia’s port for three years. Leftover oyster shells will then be upcycled as construction materials such as roof tiles.
Crushed by negative news?
Sign up for the Reasons to be Cheerful newsletter.
The species naturally filters water in order to absorb nutrients and grow their shells. But scientists have discovered that a byproduct of this oyster growth process is that harmful pollutants such as phosphorus, pesticides, pharmaceuticals and nitrogen from fertilizers, which are difficult to remove from water and can persist for decades if left alone, are also extracted from the sea.
Overfishing, disease, pollution, poor water quality and dredging have dramatically altered oceans over the past century, pushing some species to the brink of extinction. But proponents believe Stella Mare’s method could be a low-cost, relatively simple solution to improve the health of our oceans.
The Corsican city of Bastia. Credit: Peter Yeung
Oyster habitats are crucial for marine ecosystems, and biodiversity levels are known to increase dramatically around reefs, which also act as barriers against storms and sea tides, mitigating erosion and flooding, according to Boze Hancock, senior marine habitat restoration scientist at The Nature Conservancy, a global environmental organization.
“The decline of global oyster reefs has been enormous,” says Hancock. “Oyster habitats clean the water for seagrass, influence wave dynamics and improve shoreline protection. Restoring them has the potential to do a lot of good things.”
However, Hancock warns that oyster reefs can’t, as some have suggested, replace traditional waste water processing facilities. “These habitats are part of the solution, not all of it,” he explains. “You can’t put in enough oysters to process what a waste water plant would. We need to try to stop these pollutants from going into the water in the first place.”
“Each place is slightly different, in relation to the quantity and variety of pollutants, and we need to adapt to that,” says Agostini. Credit: Peter Yeung
For the team at Stella Mare, while improvements in water quality have been made, there is also no guarantee that the model will be instantly replicable in other parts of the world — or even parts of Corsica.
“Each place is slightly different, in relation to the quantity and variety of pollutants, and we need to adapt to that,” says Agostini, who will be carrying out testing at several sites across Corsica. “Will some pollutants be toxic for the oysters? The water salinity, temperature and pH can vary too.”
Nonetheless, there is optimism that the project, which is being funded by the European Union, will stimulate other successful efforts across the continent. “The objective is to be able to use this method to purify polluted sites in a natural way,” she adds. “If it works, why not export that savoir-faire elsewhere?”
Other similar restoration efforts support the belief that it could be widely replicated. One project in the U.K. found 95 different species growing on reefs after oysters had been introduced, including European eels, which are classified by the IUCN as critically endangered. The Billion Oyster Project in New York Harbor, meanwhile, aims to distribute one billion live oysters by 2035 — enough to filter the entire harbor every three days.
“It could help protect and restore critical coastal habitats like saltmarsh, mangroves, coral reefs and seagrass, as well as the communities that live in these areas,” says Hancock, who is also a professor at the URI Graduate School of Oceanography. “The potential is huge.”
