Chinese Water Aliens, Egg Whites & Microplastics, Damn Dams

A?warm welcome to the 167 (!) people who subscribed since last month's newsletter. I hope you enjoy reading this as much as I enjoy curating it.

For those visiting for the first time, welcome to the 10th issue of At Water's Edge. If you haven’t yet subscribed, join?over 2,500 other tech & water lovers by clicking?here.

I never expected this level of support for my interesting finds in the world of water. I welcome suggestions on future content - you will help make this newsletter more valuable to readers and subscribers.

Now on to the good stuff...

1. Aliens have landed - and it looks like they love water.
2. Egg whites may be our next weapon in filtering microplastics from water
3. Undamming dams leads to damn good results

Bonus video of the month: this mesmerizing time lapse of raising bridges on the way from Rotterdam to Amsterdam

First: ‘Definitely aliens’ - drying Chinese lake bed reveals mysterious patterns that some say are from an ancient Martian civilization

A recent heatwave has exposed giant strange patterns on the floor of China’s second-largest freshwater lake - triggering a range of conspiracy theories from?aliens?to ancient tombs.

Months of intense drought have caused 70% of the water to disappear from the 2,800 sq. km Dongting Lake in Hunan, central China, revealing several square-shaped patterns on the lake bed’s red mudflats, Beijing News reported.

Locals are going loco

A local resident, surnamed Hu, took aerial videos of the exposed patterns which he said looked like giant mazes.

“Those square blocks, with some straight patterns inside, look like mazes.”

Another resident, Yang Xinwei, said he didn’t think the patterns were made by human beings as he did not find any evidence of construction.

“It’s astonishing to see those patterns. Each block is as big as standard football fields, inside those square blocks are special bone inscription-like patterns. Some strokes could be as long as 10 meters,” he said.

Which is more scary - aliens or droughts?

The videos of the patterns have been viewed eight million times on Douyin alone, with many enthusiastically joining the speculation about what the patterns could be.

“Definitely alien civilization,” wrote one user.

Another person said: “Don’t touch it. It’s the door to a secret underground chamber.”

Some were more concerned by the lake drying out than speculation about aliens.

“I don’t care what those special signs mean. What I am concerned about is that even Dongting Lake has dried up. Isn’t that a horrifying fact?” wrote one person.

But the official explanation is a bit more bland

An official from the East Dongting Lake Management Committee dismissed the possibility of ancient tombs.

“We guess the signs are traces of former?ai wei?(meaning ‘short fences’ in English),” said the anonymous official, referring to fish traps built by fishermen years ago in shallower areas of the lake.

When the water rises fish are pushed into the enclosures and when it retreats the fish are trapped inside. The traps were dismantled in 2018 during a government campaign against illegal fishing.

“Dongting Lake connects with the Yangtze River. Its water rises or falls as the water from Yangtze River enters or leaves the lake. So it’s much easier for fishermen to catch fish with this kind of trap,” Zhang told the South China Morning Post.

Climate change may bring about more historic finds...

Dongting Lake is not the only body of water to fall victim to the extremely hot and dry weather in southern China this year.

Poyang Lake, the country’s largest freshwater lake, is now only 20% of its normal size at this time of year. A high proportion of the exposed lake has become grassland as a result of the absence of water for so long, according to local residents.

Next: egg whites - a new super material capable of filtering microplastics from seawater

Researchers at Princeton University have found a way to turn your next omelet into a new material that can remove salt and microplastics from seawater.

Egg whites are a complex system of almost pure protein that—when freeze-dried and heated to 900 degrees Celsius in an environment without oxygen—create a structure of interconnected strands of carbon fibers and sheets of graphene.

Scientists are calling this innovation an aerogel, a lightweight and porous material that can be used in many types of applications, including?water filtration,?energy storage, and sound and thermal insulation.

Your next brilliant idea might be lurking in a breakfast sandwich

Craig Arnold, the Princeton professor whose lab innovates to create new materials, was struck by inspiration one day while sitting in a faculty meeting.

"I was sitting there, staring at the bread in my sandwich," said Arnold. "And I thought to myself, this is exactly the kind of structure that we need." So he asked his lab group to make different bread recipes mixed with carbon to see if they could recreate the aerogel structure he was looking for. None of them worked quite right initially, so the team kept eliminating ingredients as they tested, until eventually only egg whites remained.

"We started with a more complex system," Arnold said, "and we just kept reducing, reducing, reducing, until we got down to the core of what it was. It was the proteins in the egg whites that were leading to the structures that we needed."

And it turns out the egg whites are eggscellent filters

In a paper published Aug. 24 in?Materials Today, Arnold and his coauthors showed that the resulting material can remove salt and microplastics from seawater with 98% and 99% efficiency, respectively.

"The egg whites even worked if they were fried on the stove first, or whipped," said Sehmus Ozden, first author on the paper. While regular store-bought?egg whites?were used in initial tests, Ozden said, other similar commercially available proteins produced the same results.

"Eggs are cool because we can all connect to them and they are easy to get, but you want to be careful about competing against the food cycle," said Arnold. Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply.

One next step for the researchers, Ozden noted, is refining the fabrication process so it can be used in?water purification?on a larger scale.

The world's most affordable water purifier?

If this challenge can be solved, the material has significant benefits because it is inexpensive to produce, energy-efficient to use and highly effective. "Activated carbon is one of the cheapest materials used for water purification. We compared our results with activated carbon, and it's much better," said Ozden. Compared with?reverse osmosis, which requires significant energy input and excess water for operation, this filtration process requires only gravity to operate and wastes no water.

While Arnold sees water purity as a "major grand challenge," he is also exploring other uses related to energy storage and insulation.

And finally: the unexpected benefits of demolishing dams

In October 2021, ecologists busted up the top of a dam near Davenport, California. For at least 110 years, the long-obsolete dam had kept threatened steelhead from reaching important spawning habitat just upstream.

For the next three days, workers and scientists from Sempervirens Fund, the land trust that owns the 8,500-acre preserve around Mill Creek, moved granite and gravel, aiming to restore the creek to its natural state. Members of the Amah Mutsun Tribal Band, stewardship partners working on their traditional lands, held ceremonies praying for salmon — an invaluable cultural resource — to return.

“We were thinking it was going to take five, six years for them to come home,” said Valentin Lopez, chairman of the tribal band. Ian Rowbotham, stewardship manager at Sempervirens Fund, thought the same: In order to spawn, steelhead and salmon require gravel beds, which form where material flushed by rain, melt or springwater collects throughout the streambed. Years of drought suggested that ecologists and fish alike had a long wait ahead.

But if you destroy it, they will come

Then, in September 2022, Rowbotham’s team spotted juvenile steelhead above the former dam site. To their surprise, they also found 15 juvenile coho salmon downstream. It was the first time coho, an endangered species, had ever been recorded in Mill Creek.

For Rowbotham and Lopez, the presence of both fish is a testament to the years of work they’ve put in to restore the watershed and re-establish traditional practices. To some degree, luck was also a factor: Record rain fell just weeks after the dam came down. The experience adds to a growing body of research documenting the speedy recovery of fish and other species after dams are removed — work that will only grow in importance as?more?and?bigger?dam removals are planned nationwide.

“We were thinking it was going to take five, six years for them to come home.”

As dam removal nationwide accelerates, experts are learning just how quickly rivers and fish respond.

Lisa Hollingsworth-Segedy isn’t surprised when fish come back soon after a dam is breached. A Pennsylvania-based river restoration director for the nonprofit American Rivers, she’s overseen the teardowns of more than 100 dams. “I have seen fish attempting to jump through the part of the dam that we’re actually removing,” she said.

People build dams to produce power and provide drinking water, irrigation and flood protection, often with little regard for the damage they cause to ecosystems that rely on fish migrating upstream and sediment flowing down.

Dams large and small have contributed to the extinction of 29% of the salmon populations in California and the Pacific Northwest, and the threat or endangerment of many that remain, according to American Rivers. Of the more than 90,000 dams in the U.S., most are aging, which in recent years has caused a number of?catastrophic failures?— and some frightening?near misses.

Since 1912, nearly 2,000 dams have been removed in the U.S., and that number is accelerating; 76% of those have come down since 1999, when a federal agency for the first time ordered a dam removed because the maintenance costs outweighed its benefits.

It was a tipping point that set the stage for many more removals and spurred a new era of research. As evidence quickly accumulated showing just how rapidly rivers and wildlife respond, habitat restoration became a second key factor prompting communities, agencies and landowners to rethink their dams.

Rivers are more than flowing water; they're ecosystem power players

Many ecologists consider?the 2011-14 removal of two dams on Washington’s Elwha River?— the largest removal so far in the U.S. — to be a threshold moment. The rapid physical and ecological changes documented there added scale to what researchers had learned from smaller dams. Among other things, removing those dams reversed decades of coastal erosion near the river’s mouth as sediment movement was restored.

“That was a huge ‘aha’ moment for us to understand that rivers do more work than just what we humans think they do,” Hollingsworth-Segedy said.

“It provided a lot of hope that we can undertake larger, more complex projects and have the river respond positively,” said Jeff Duda, a U.S. Geological Survey ecologist and a leading expert on dam removal.

Duda’s research and that of his colleagues has led to a number of conclusions over the last two decades: Physical changes, caused by sediment redistribution and water movement, happen very quickly, stabilizing within years rather than decades. Ecological changes manifest at different time scales, but upstream fish migration is one of the first to occur, often within weeks or months.

Those fish contribute to further shifts: Within a year of the first Elwha dam removal, ecologists found?nutrients from adult salmon in dippers upstream of the dam site?— nutrients that they’ve recently shown have?boosted the birds’ survival.

Longer-term recovery, from reforestation of old reservoir beds to the multigenerational returns of salmon and other fish, is only beginning to be studied. “A lot of the dam removals have happened so recently that we haven’t had a chance for those outcomes to fully develop,” Duda said.

In the Elwha, most migratory fish have only been documented for one generation. “We’re just waiting and measuring, but a lot of the early returns are in, and they’re positive.”

--------------------------------------------------------

That's a wrap for this month's At Water's Edge

Hate it? Love it? Have a cool story for the next issue?

Connect with me?here on LinkedIn,?Twitter, or my?personal website?and send me a note.

-Adam