Tag Archives: coastal erosion

Nano-treatment could help save mangroves from deadly disease

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Seems to be my week for coastal erosion. First, there was my August 23, 2024 posting “Electricity (electrodeposition) could help fight coastal (beach) erosion” and today, August 30, 2024, I’m featuring news I got about a month ago (late July 2024) regarding a special formula to help save mangroves on the Florida coast and other coasts where they are found.

A July 26, 2024 news item on ScienceDaily features news from the University of Central Florida, Note: Links have been removed,

Mangroves and palm trees are hallmarks of the Sunshine State not just for their beauty but for their immense importance to Florida’s coastlines.

Mangroves are crucial because they naturally protect coastal shores from storm damage and serve as vital wildlife habitats around the world.

Scientists at the University of Central Florida are working to preserve mangroves in Florida and across the world from an increasingly prevalent disease-causing variety of fungi that lies dormant but becomes active when the tree is exposed to stressors such as temperature fluctuation, pests or other diseases.

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A July 26, 2024 University of Central Florida (UCF) news release by Eddy Duryea (also on EurekAlert), which originated the news item, describes the disease (which hasn’t yet been formally named) and gives some details about the proposed treatment, Note: Links have been removed,

The disease does not yet have an official name, but it is being referred to by scientists as “Mangrove CNP.” It is caused by a group of fungal pathogens, including Curvularia, Neopestalotiopsis, and Pestalotiopsis, that causes yellowing and spots, and gradually weaken the mangrove until it ultimately dies.

Melissa Deinys, a UCF undergraduate researcher, and Jorge Pereira, a UCF graduate research assistant, are working to help turn the tide by developing and testing a promising nutritional cocktail comprised of nanoparticles to strengthen mangroves and counter the pathogens. The work is through UCF professor Swadeshmukul Santra’s Materials Innovation for Sustainable Agriculture (MISA) center at UCF, which is a U.S. Department of Agriculture-National Institute of Food and Agricultural recognized Center of Excellence.

Mangrove CNP in Florida was first identified as causing mangrove die-offs by Deinys in 2019 in Miami through her work with Fairchild Tropical Botanic Garden. Later, the Marine Resources Council, a non-profit organization dedicated to the protection and restoration of Florida’s Indian River Lagoon, verified and cited her efforts.

Deinys and collaborators with the MRC and Fairchild Tropical Botanic Garden have determined that about 80% of the mangroves they had sampled have tested positive for at least one of the fungal pathogen species. She says they have sampled over 130 mangroves between the Indian River Lagoon and Miami mangrove populations.

The researchers are treating the mangroves by soaking them in a nutrient solution called “Mag Sun” (MgSuN), which is comprised of magnesium and sulfur nanoparticles. The mixture is a refinement of a previous graduate student’s formula that destroyed bacteria on tomatoes, Pereira says.

“The reason why we choose magnesium is because it is more environmentally friendly, and plants need a lot of magnesium,” he says. “I combined our magnesium formulation with a sodium polysulfide. Sulfur is one of those elements that is ubiquitous in the environment, and the idea is that you can combine both to actually enhance the anti-microbial capacity for both bacteria and fungi and you also supply key nutrients to the plants so that they can grow greener and leafier.”

During lab tests, the researchers say they observed growth inhibition of up to 95% when treated with MgSuN at varying concentrations compared to the untreated control.

The formula acts as a sort of antibiotic and multivitamin, and it has shown great potential in bolstering the health of infected mangroves at nurseries across Florida, Pereira says.

“We’ve done some experiments, and we have tested both in vitro and in plants,” he says. “We’re working with the nurseries, and we’ve seen it does kill the pathogens with no detrimental effects to the mangroves while kickstarting their health. They look great after treatment.”

Deinys is continuing her work with the Fairchild Tropical Botanic Garden, MRC and nurseries across Florida while staying the course on her path to graduation and furthering her research at UCF.

She began studying the fungal pathogens in 2018 in Miami prior to being enrolled at UCF and has seen the mangroves become increasingly affected by the pathogens’ opportunistic nature.

“Back at the botanical gardens where I started, I would see the plants have these pathogens but not to a detrimental effect where we now see these organisms collapsing,” she says. “A mangrove nursery [The Marine Resources Council] had reached out to us, and they told us they had an insect infestation and then the whole population got wiped out by the pathogen. We’re also getting reports from places like Tampa that say areas that have more runoff are having more pathogen-related deterioration compared to 10 years ago.”

The fungi have been well-documented for some time, but volatile temperature changes, frequent storms and other increasing stressors open the door to the fungi taking a hold of the mangroves, Deinys says.

“They’re called opportunistic, and they’re called that for a reason,” she says. “They see a change in the plant and that’s when they start to take effect.”

How the pathogens are acquired is something that remains unclear, Deinys says. Researchers hypothesize it may be introduced through water, wind or insects, but further studies are needed to determine how it is acquired since it poses threat to mangrove health.

“You have to study all possibilities to determine what is the vector,” Deinys says. “We’ve seen papers and literature in other countries that have shown these pathogens for a long time. It’s been difficult because there is a disconnect in mangrove communities because we’re worlds apart and with different languages.”

The MgSuN nutrient solution is a treatment, but not a cure, Deinys says. There still are ample stressors that should be managed and mitigated, such as human-caused habitat destruction, in addition to treating the pathogens.

“I think there’s a big restoration effort to repopulate mangroves,” she says. “But first we need to look at the health of these mangroves and the health of the ecosystem before we determine what more we should do. We’re working with mangrove nurseries to see if we can together develop solutions.”

Maintaining and restoring mangroves is an essential component of ecological stewardship, and it’s a passion that Deinys hopes to continue throughout her career.

“I started this project my freshman year,” she says. “I didn’t want to leave what I was doing, and I came here with a mission. I met with Dr. Santra, our PI, and he wanted to help. He gave me a lot of freedom, and I’m really grateful.”

Deinys says that her research at UCF has been incredibly gratifying.

“There is a sense of community here that I found,” she says. “I joined the lab, and it felt like I found my family and that’s one of the best things to have come out of this experience. This has been one of my life’s passions, and I hope I’ll always stay with this project even after.”

Santra is encouraged by the research conducted by Pereira and Deinys, and he is hopeful it continues to bolster mangrove ecosystems.

“The UCF MISA center is dedicated to solving global problems that threaten agricultural sustainability,” he says. “We are excited to have another crop protection tool in our toolbox for protecting mangroves. I see the future of MagSun as a broad-spectrum fungicide, where GRAS (Generally Recognized As Safe) materials are empowered through nanotechnology.”

Further studies are needed to pinpoint which stressors are affecting the mangroves the most so that scientists can better preserve them, Pereira says.

“It’s very important to understand the stressors, and we need to really address if it’s a change in temperature, if it’s runoff or if it’s an additional pathogen,” he says. “In the meantime, we need to do something to prevent this damage from occurring.”

Researchers’ Credentials

Deinys graduated from BioTECH @ Richmond Heights High School, a conservation biology magnet school, where she began her research journey at Fairchild Tropical Botanic Garden and specialized in botany. In Fall 2022, Deinys joined UCF and became a member of the Santra Lab the following spring. She is an undergraduate research assistant working towards her bachelor’s degree in biotechnology.

Pereira graduated from Universidad Nacional Autónoma de Honduras with a degree in industrial chemistry. He joined Santra’s lab in 2020 and is currently a graduate research assistant and working toward his doctoral degree in chemistry.

Santra holds a doctorate in chemistry from the Indian Institute of Technology Kanpur. After graduating, he worked at the University of Florida (UF) as a postdoctoral researcher and later as a research assistant professor at the UF Department of Neurological Surgery and Particle Engineering Research Center. In 2005, Santra joined UCF as an assistant professor at the NanoScience Technology Center, the Department of Chemistry and the Burnett School of Biomedical Sciences. He is the director of the UCF Materials Innovation for Sustainable Agriculture center, a USDA-NIFA-recognized Center of Excellence.

They don’t seem to have published a paper about their work but there is this video,

Electricity (electrodeposition) could help fight coastal (beach) erosion

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I live in a coastal region and a few months ago our local municipal voted down an initiative that included some mitigation for beach erosion. So, this research caught my eye.

Caption: An artistic impression of how electricity could be used to strengthen coastlines. Credit: Northwestern University

An August 22, 2024 news item on phys.org announces an unexpected approach to dealing with coastal erosion,

New research from Northwestern University has systematically proven that a mild zap of electricity can strengthen a marine coastline for generations—greatly reducing the threat of erosion in the face of climate change and rising sea levels.

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An August 22, 2024 Northwestern University news release (received via email and also found on EurekAlert) by Amanda Morris, which originated the news item, delves further into the topic, Note: Links have been removed,

In the new study, researchers took inspiration from clams, mussels and other shell-dwelling sea life, which use dissolved minerals in seawater to build their shells.

Similarly, the researchers leveraged the same naturally occurring, dissolved minerals to form a natural cement between sea-soaked grains of sand. But, instead of using metabolic energy like mollusks do, the researchers used electrical energy to spur the chemical reaction.

In laboratory experiments, a mild electrical current instantaneously changed the structure of marine sand, transforming it into a rock-like, immoveable solid. The researchers are hopeful this strategy could offer a lasting, inexpensive and sustainable solution for strengthening global coastlines.

The study will be published on Thursday (Aug. 22 [2024]) in the journal Communications Earth and the Environment, a journal published by Nature Portfolio.

“Over 40% of the world’s population lives in coastal areas,” said Northwestern’s Alessandro Rotta Loria, who led the study. “Because of climate change and sea-level rise, erosion is an enormous threat to these communities. Through the disintegration of infrastructure and loss of land, erosion causes billions of dollars in damage per year worldwide. Current approaches to mitigate erosion involve building protection structures or injecting external binders into the subsurface.

“My aim was to develop an approach capable of changing the status quo in coastal protection — one that didn’t require the construction of protection structures and could cement marine substrates without using actual cement. By applying a mild electric stimulation to marine soils, we systematically and mechanistically proved that it is possible to cement them by turning naturally dissolved minerals in seawater into solid mineral binders — a natural cement.”

Rotta Loria is the Louis Berger Assistant Professor of Civil and Environmental Engineering at Northwestern’s McCormick School of Engineering. Andony Landivar Macias, a former Ph.D. candidate in Rotta Loria’s laboratory, is the paper’s first author. Steven Jacobsen, a mineralogist and professor of Earth and planetary sciences in Northwestern’s Weinberg College of Arts and Sciences, also co-authored the study.

Sea walls, too, erode

From intensifying rainstorms to rising sea levels, climate change has created conditions that are gradually eroding coastlines. According to a 2020 study by the European commission’s Joint Research Centre, nearly 26% of the Earth’s beaches will be washed away by the end of this century.

To mitigate this issue, communities have implemented two main approaches: building protection structures and barriers, such as sea walls, or injecting cement into the ground to strengthen marine substrates, widely consisting of sand. But multiple problems accompany these strategies. Not only are these conventional methods extremely expensive, they also do not last.

“Sea walls, too, suffer from erosion,” Rotta Loria said. “So, over time, the sand beneath these walls erodes, and the walls can eventually collapse. Oftentimes, protection structures are made of big stones, which cost millions of dollars per mile. However, the sand beneath them can essentially liquify because of a number of environmental stressors, and these big rocks are swallowed by the ground beneath them.

“Injecting cement and other binders into the ground has a number of irreversible environmental drawbacks. It also typically requires high pressures and significant interconnected amounts of energy.”

Turning ions into glue

To bypass these issues, Rotta Loria and his team developed a simpler technique, inspired by coral and mollusks. Seawater naturally contains a myriad of ions and dissolved minerals. When a mild electrical current (2 to 3 volts) is applied to the water, it triggers chemical reactions. This converts some of these constituents into solid calcium carbonate — the same mineral mollusks use to build their shells. Likewise, with a slightly higher voltage (4 volts), these constituents can be predominantly converted into magnesium hydroxide and hydromagnesite, a ubiquitous mineral found in various stones.

When these minerals coalesce in the presence of sand, they act like a glue, binding the sand particles together. In the laboratory, the process also worked with all types of sands — from common silica and calcareous sands to iron sands, which are often found near volcanoes.

“After being treated, the sand looks like a rock,” Rotta Loria said. “It is still and solid, instead of granular and incohesive. The minerals themselves are much stronger than concrete, so the resulting sand could become as strong and solid as a sea wall.”

While the minerals form instantaneously after the current is applied, longer electric stimulations garner more substantial results. “We have noticed remarkable outcomes from just a few days of stimulations,” Rotta Loria said. “Then, the treated sand should stay in place, without needing further interventions.”

Ecofriendly and reversible

Rotta Loria predicts the treated sand should keep its durability, protecting coastlines and property for decades.

Rotta Loria also says there is no need to worry negative effects on sea life. The voltages used in the process are too mild to feel. Other researchers have used similar processes to strengthen undersea structures or even restore coral reefs. In those scenarios, no sea critters were harmed.

And, if communities decide they no longer want the solidified sand, Rotta Loria has a solution for that, too, as the process is completely reversible. When the battery’s anode and cathode electrodes are switched, the electricity dissolves the minerals — effectively undoing the process.

“The minerals form because we are locally raising the pH of the seawater around cathodic interfaces,” Rotta Loria said. “If you switch the anode with the cathode, then localized reductions in pH are involved, which dissolve the previously precipitated minerals.”

Competitive cost, countless applications

The process offers an inexpensive alternative to conventional methods. After crunching the numbers, Rotta Loria’s team estimates that his process costs just $3 to $6 per cubic meter of electrically cemented ground. More established, comparable methods, which use binders to adhere and strengthen sand, cost up to $70 for the same unit volume.

Research in Rotta Loria’s lab shows this approach also can heal cracked structures made of reinforced concrete. Much of the existing shoreside infrastructure is made of reinforced concrete, which disintegrates due to complex effects caused by sea-level rise, erosion and extreme weather. And if these structures crack, the new approach bypasses the need to fully rebuild the infrastructure. Instead, one pulse of electricity can heal potentially destructive cracks.

“The applications of this approach are countless,” Rotta Loria said. “We can use it to strengthen the seabed beneath sea walls or stabilize sand dunes and retain unstable soil slopes. We could also use it to strengthen protection structures, marine foundations and so many other things. There are many ways to apply this to protect coastal areas.”

Next, Rotta Loria’s team plans to test the technique outside of the laboratory and on the beach.

The study, “Electrodeposition of calcareous cement from seawater in marine silica sands,” was supported by the Army Research Office (grant number W911NF2210291) and Northwestern’s Center for Engineering Sustainability and Resilience.

Here’s a link to and a citation for the paper,

Electrodeposition of calcareous cement from seawater in marine silica sands by Andony Landivar Macias, Steven D. Jacobsen & Alessandro F. Rotta Loria. Communications Earth & Environment volume 5, Article number: 442 (2024) DOI: https://doi.org/10.1038/s43247-024-01604-3 Published: 22 August 2024

This paper is open access.