Tag Archives: Mussel

In Poznan, Poland, eight clams get to decide if people in the city get water or not

Clean drinking water, like democracy, is one of those things you tend to take for granted until it runs out or becomes polluted. But just like democracy, securing it takes a lot of work and constant oversight.

In Poznań, a city in the western stretches of Poland, this work takes place in a round building with round windows in the middle of the Warta River. This building, the Dębiec Water Treatment Plant, harbors one of the most interesting and wacky takes on the issue of water quality management.

Here, artificial and biological monitoring systems ensure that the water pumped throughout the city’s pipes is safe to drink. The artificial systems take precise measurements of chemical contamination in the water, which is definitely handy. However, as Aquanet.pl explains, it is the plant’s biological systems (or ‘bioindicators’) that allow for a more reliable estimation of the water’s overall toxicity, as they account for a broad range of factors “simultaneously”.

Image credits Julia Pełka / GRUBA KAŚKA via Reddit.

These biological systems are comprised of eight mussels with sensors hot-glued to their shells. They work together with a network of computers and have been given control over the city’s water supply. If the waters are clean, these mussels stay open and happy. But when water quality drops too low, they close off and shut the water supply of millions of people with them.

Enter the mussel

According to a presentation from AquaNES, a project of the European Union that aims to integrate nature-based elements into water management systems, Poznań’s main source of water is the Warta River. The only issue here is that the Warta passes through some of the country’s densest population centers, and some of its oldest industrial areas (where heavy industry has been present since the later parts of the 19th century). This creates an avenue through which pollution can wind up into the city’s drinking water. One particular point of worry is heavy metals such as chromium seeping through the ground and into the river.

Which naturally raises a question — how can Poznań ensure that the drinking water running through its pipes isn’t dangerously contaminated?

“Using an organism as an indicator (bioindicator) cannot be accidental. It requires extensive field research that aims to accurately characterize natural occurrence conditions,” writes Aquanet.

“The best indicator organisms are those that have specific life requirements, i.e. they have a narrow ecological (occurrence) scale. This means that a number of different factors will limit their vital functions or even eliminate them from the environment.”

In essence, these “indicator organisms” allow engineers at the plant to know if the water is safe for human use or consumption, even if they don’t produce hard data on its quality. Organisms such as mussels are good indicators of water quality because they have a low tolerance for pollutants, and they show an obvious response to improper water quality: they clamp shut.

Shellfish service

Mussels require clean, well-oxygenated water with low levels of physical or chemical impurities to thrive. They’re less and less common in Polish lakes (and in virtually all coastal waters across the globe) because of pollution, which shows just how sensitive they are to changes in water quality. In Poland’s case, a former communist country, most of the damage is caused by pollutants seeping up from contaminated aquifers (groundwater) into lakes or rivers.

This sensitivity to pollutants made them ideal for monitoring Poznań’s water supply. When waters are nice and clean, mussels open up completely in order to feed — which they do by filtering water and eating any organic matter they find. When water quality drops, they very quickly close their shells, inlet siphon (their ‘mouth’), and slow down their metabolism.

The use of mussels as part of an automated water supply system was tested at the Department of Water Protection at the University of A. Mickiewicz in Poznań and found to be a very reliable indicator of water quality.

Whenever a mussel clamps down, it closes a circuit via a spring that was simply hot-glued to its shell, which alerts a computer that it may be time to turn off the water supply. The computer’s job is to monitor parameters obtained through artificial sensors and produce an alarm if anything seems amiss. This step is meant to account for any possible change in the individual behavior or mussels, of which there are 8; one presumes they may sometimes grow tired and close off for a nap.

If four of the mussels close at the same time, however, the system shuts down automatically. It’s engineering at its best.

Mussels are typically viewed as a nuisance that clogs and damages water supply systems. But the clam-powered system has been running at the Dębiec Water Treatment Plant since September 1994 and might change that view.

Gruba Kaśka (Fat Kathy)

This is one of those stories that you hear and just can’t believe its real. I first ran into it as a meme on Reddit and was convinced it’s just a funny story someone made up for laughs until I started digging around a bit.

But I’m definitely glad I did. The simplicity and creative thought that underpin this system is what I enjoy about it the most. I find it particularly exciting to see engineers cooperating with wildlife in such an important task: to protect public health and the quality of tap water.

Julia Pełka, the director of Gruba Kaska, a documentary film that follows the story of such mussels in Poland’s capital is the one who brought this story out of the plant and into the Internet. Her interest in the topic began when she was little, as Warsaw’s water pumping facility was clearly visible from a bridge she needed to pass over when going to visit her grandparents.

“I read an article about this building called ‘Gruba Kaśka’ which is a water pump and can be accessed through an underground 300-meter tunnel,” Julia Pełka told me. “Inside, 8 clams control the purity of our water.”

“No computer can replace these super-sensitive mussels.”

As an adult, she ran into a story detailing how clams help keep the water supply clean, and thus a documentary film was born. Julia’s documentary follows a clam-based control system similar to the one from Poznan in the city of Warsaw.

“These unassuming creatures take care of the safety of millions of people in Warsaw. I saw a certain metaphor in this, but at the same time a very good subject from a cinematic perspective,” , told me in an email.

She adds that the clams are “paid back after three months of work by releasing them to a place from which they will never be caught again”. While I definitely enjoy the thought of clams earning a comfortable retirement spot, this is done because they eventually become resistant to contamination in the water.

One thing that struck me in my back and forth with Julia (apart from the obvious coolness of the story) is the depth of themes that can be derived from a simple water safety system.

“By making this film I wanted to show man’s dependence on nature. I thought it was brilliant that humans are using mussels to create a warning system against danger. They use the clams’ senses to protect themselves from the dangers of modern civilization.”

“You could say that people use them as protection from themselves.”

Alongside malacologist Piotr Domek, who specializes in finding and selecting appropriate mussels for the Warsaw plant, Julia wanted to offer thanks to the Polish Waterworks, who allowed her to film “inside such a strictly guarded facility”. The documentary premiered late last month as part of the World Showcase Shorts Program 3.

Double buttons.

Prehistoric craftsmen were really into freshwater mussel shells, research reveals

New research is showing that ancient Europeans were really fond of ornaments made from freshwater mussel shells.

Double buttons.

Prehistoric shell ornaments made with freshwater mother-of-pearl.
Image credits Jérôme Thomas / University of Burgundy-Franche-Comté.

An international research team says that freshwater mussel shells were all the rage in Europe between 4200 and 3800 BC. The findings are based on an analysis of proteins extracted from prehistoric shell ornaments found on the continent. Despite being found at extremely far-off locations in Denmark, Romania, and Germany, the artifacts used in this study were all remarkably similar in look, the authors note — and were all made using the mother-of-pearl of freshwater mussels.

Shell we make some jewelry?

“We were surprised to discover that the ornaments were all made from freshwater mussels because it implies that this material was highly regarded by prehistoric craftsmen, wherever they were in Europe and whatever cultural group they belonged to,” says senior author Dr Beatrice Demarchi, from the Department of Archaeology at the University of York and the University of Turin, Italy.

“Our study suggests the existence of a European-wide cross-cultural tradition for the manufacture of these double-buttons.”

The ornaments the team looked at (known as “double-buttons”) were manufactured between 4200 and 3800 BC. They were generally found in coastal regions, which isn’t very surprising, but they were even found in those areas where plenty of other shells would have been available — which is quite surprising.

Double-buttons were likely applied to leather garments such as armbands or belts through pressing, the team notes. This implies that they were more of a stylish accessory rather than a practical one, a way to show off status or wealth through clothing. As such, archeologists rarely considered freshwater mollusks as a potential source of materials for these buttons in prehistory. They were, simply put, too local and easy to acquire to be considered flashy.

However, it seems that our prehistoric ancestors didn’t really agree. Mother-of-pearl is a very strong and resilient material and, the findings suggest, quite sought-after. It also seems to have been an important driver of prehistoric trade.

“The ornaments are associated with the Late Mesolithic, Late Neolithic and Copper Age cultures,” says Dr André Colonese, from the Department of Archaeology at the University of York, a co-author of the paper.

“Some of these groups were still living as hunter gatherers, but in the south they were farmers switching to a more settled lifestyle. The fact that these ornaments look consistently similar and are made from the same material suggests there may have been some kind of interaction between these distinct groups of people at this time.

The findings show that these peoples either traded for the buttons, shared knowledge of how to manufacture them, or inherited the craft from the groups that came before them. Whatever the case may be, people living at this time “clearly had a sophisticated understanding of the natural environment and which resources to use,” Colonese adds.

Mollusc shells only contain a small quantity of proteins compared to other bio-mineralized tissues (such as bone). This makes them notoriously difficult to analyze, the team goes on to explain. To address this issue, they are not working on “palaeoshellomics,” a set of techniques that should allow them to extract proteins from mollusk fossils.

“This is the first time researchers have been able to retrieve ancient protein sequences from prehistoric shell ornaments in order to identify the type of mollusc they are made from,” says Dr Demarchi added.

“This research is an important step towards understanding how molluscs and other invertebrates evolved. We hope that using these techniques we will eventually be able to track an evolutionary process which began at least 550 million years ago.”

The paper “‘Palaeoshellomics’ reveals the use of freshwater mother-of-pearl in prehistory” has been published in the journal eLife.

Mussel-glue-and-protein balm could spell the end of scars forever

The unassuming mussel could deliver us from scars forever, a new paper from the Pohang University of Science and Technology in South Korea.

Scarred cat.

Image credits George Li.

A sticky substance secreted by the common mussel (family Mytilidae) could spell the end of scarring. A glue based on this substance has been shown to help heal rats’ skins seamlessly, without any scars. If shown effective in human trials, this glue could prevent scarring after accidental injuries or surgery.

Old injuries

Our skin scars because when injured, the wave-like arrangement of collagen fibers that give it strength, like rebar in concrete, break apart. If the injury is severe enough these fibers don’t go back together in an orderly fashion during the healing process — instead, they bunch up together, growing thick bundles of parallel collagen fibers that give scars their distinctive lumpy appearance.

This bunching up can be mitigated through the use of decorin, a protein naturally found in the skin which governs how collagen fibers arrange themselves. Still, decorin has a very complex structure and is really hard to synthesize, so most clinics and hospitals don’t have it available.

But fret not, for Hyung Joon Cha and his colleagues at Pohang University of Science and Technology, South Korea have a solution. They developed a simplified version of decorin which retains its collagen-ordering properties by putting together a section of the protein, a collagen-binding agent, and a glue-like substance secreted by mussels.

This substance is sticky enough to help keep wounds closed and help them heal, while at the same time making sure they don’t scar. The team applied the glue on lab rats with deep 8-millimetre-wide wounds, then covered them with clear plastic film. A control group of rats with similar wounds were dressed in the plastic film without the substance being applied first.

In 11 days, 99% of the wounds in the glue group were closed, compared with only 78% in the control group. By day 28, the treated rats were fully recovered and had no visible scarring, while their counterparts healed with thick, purple scar tissue.

New skin

Human skin.

Image credits Montavius Howard.

Microscope inspection of the tissue confirmed that the collagen fibers in the treated wounds returned to their original weave arrangement. Even better, the new skin grew back hair follicles, blood vessels, and glands — all bits and pieces of skin that don’t regrow in scars.

The team notes that their gel promotes normal collagen fiber development because negative charges on the decorin fragments hold these fibers apart. This gives them wiggle room to weave between each other instead of sticking together.

Still, while the results are encouraging, there’s much work to be done before they can be applied to human use. For starters, rat and human skin might respond differently to the protein. Then there’s the fact that rats tend to have loose skin and heal more quickly while humans have tight skin, making scarring more likely.

The team’s next step is to test their glue on pigs, as their skin resembles ours more closely.

The paper “Natural healing-inspired collagen-targeting surgical protein glue for accelerated scarless skin regeneration” has been published in the journal Biomaterials.