Scientists provide first detailed estimates of how much sediment is supplied to coral islands from the reef system

The island of Dhigelabadhoo in the Maldives is the main field site of the ARISE program
Credit: University of Plymouth

Scientists have produced the first detailed estimates of how much sediment is transported onto the shores of coral reef islands, and how that might enable them to withstand the future threats posed by climate change.

Coral reef islands are low-lying accumulations of sand and gravel-sized sediment deposited on coral reef surfaces.

The sediments are derived from the broken down remains of corals and other organisms that grow on the surrounding reef. Therefore, the rate of supply of sediment from reefs is a critical control on island formation and future change.

The international team of researchers used data available for 28 reef islands in the Indian and Pacific Oceans, widely acknowledged to be among the world’s most vulnerable environments to rising seas.

By identifying the amount of sediment present within reef islands, and comparing this against the known age of the islands, they were able to determine the average amount of sediment delivered to the islands from surrounding coral reefs over their histories.

Walleye struggle with changes to timing of spring thaw

Within a few days of ice-off, when a lakes’ frozen lid has melted away, walleye begin laying eggs and fertilizing them. When lakes thaw earlier than usual, the young walleye that hatch in Midwestern waters may have a more difficult time surviving.
Image Credit: Copilot AI

Walleye are one of the most sought-after species in freshwater sportfishing, a delicacy on Midwestern menus and a critically important part of the culture of many Indigenous communities. They are also struggling to survive in the warming waters of the Midwestern United States and Canada.

According to a new study published in the journal Limnology and Oceanography Letters, part of the problem is that walleye are creatures of habit, and the seasons — especially winter — are changing so fast that this iconic species of freshwater fish can’t keep up.

The timing of walleye spawning — when the fish mate and lay their eggs — has historically been tied to the thawing of frozen lakes each spring, says the study’s lead author, Martha Barta, a research technician at the University of Wisconsin–Madison. Now, due to our changing climate, walleye have been “unable to keep up with increasingly early and more variable ice-off dates,” Barta says.

Within a few days of ice-off, when a lakes’ frozen lid has melted away, walleye begin laying eggs and fertilizing them. In a normal year, that timing sets baby fish up for success once they hatch. But, Barta says, “climate change is interrupting the historical pairing of ice-off and walleye spawning, and that threatens the persistence of walleye populations across the Upper Midwest.”

You may be breathing in more tiny nanoparticles from your gas stove than from car exhaust

Brandon Boor, a Purdue associate professor of civil engineering, studies how everyday activities like cooking on a gas stove can affect indoor air quality.
Photo Credit: Kelsey Lefever / Purdue University

Cooking on your gas stove can emit more nano-sized particles into the air than vehicles that run on gas or diesel, possibly increasing your risk of developing asthma or other respiratory illnesses, a new Purdue University study has found.

“Combustion remains a source of air pollution across the world, both indoors and outdoors. We found that cooking on your gas stove produces large amounts of small nanoparticles that get into your respiratory system and deposit efficiently,” said Brandon Boor, an associate professor in Purdue’s Lyles School of Civil Engineering, who led this research.

Based on these findings, the researchers would encourage turning on a kitchen exhaust fan while cooking on a gas stove. 

The study, published in the journal PNAS Nexus, focused on tiny airborne nanoparticles that are only 1-3 nanometers in diameter, which is just the right size for reaching certain parts of the respiratory system and spreading to other organs. 

Recent studies have found that children who live in homes with gas stoves are more likely to develop asthma. But not much is known about how particles smaller than 3 nanometers, called nanocluster aerosol, grow and spread indoors because they’re very difficult to measure.

“These super tiny nanoparticles are so small that you’re not able to see them. They’re not like dust particles that you would see floating in the air,” Boor said. “After observing such high concentrations of nanocluster aerosol during gas cooking, we can’t ignore these nano-sized particles anymore.”

Glacier melting destroys important climate data archive

Corbassière glacier at Grand Combin in the canton of Valais
Photo Credit: Peter Meyer-Herzog

As part of the Ice Memory initiative, PSI researchers, with colleagues from the University of Fribourg and Ca’ Foscari University of Venice as well as the Institute of Polar Sciences of the Italian National Research Council (CNR), analyzed ice cores drilled in 2018 and 2020 from the Corbassière glacier at Grand Combin in the canton of Valais. A comparison of the two sets of ice cores published in Nature Geoscience shows: Global warming has made at least this glacier unusable as a climate archive.

Reliable information about the past climate and air pollution can no longer be obtained from the Corbassière glacier in the Grand Combin massif, because alpine glacier melting is progressing more rapidly than previously assumed. This sobering conclusion was reached by researchers led by Margit Schwikowski, head of the Laboratory for Environmental Chemistry at PSI, and Carla Huber, PhD student and first author of the study, when they compared the signatures of particulate matter locked in the annual layers of the ice. Glaciers are invaluable for climate research. The climatic conditions and atmospheric compositions of past ages are preserved in their ice. Therefore, they can serve, in much the same way as tree rings and ocean sediments, as a so-called climate archive for research.

Normally, the amount of particle-bound trace substances in ice fluctuates with the seasons. SubstPeter Meyer-Herzogances such as ammonium, nitrate, and sulfate come from the air and are deposited on the glacier through snowfall: The concentrations are high in summer and low in winter, because lower amounts of polluted air can rise from the valley when the air is cold. The 2018 ice core, which was drilled from depths of up to 14 meters during a preliminary study and contains deposits dating back to 2011, shows these fluctuations as expected. But the core from 2020, from a depth of up to 18 metres – drilled under the leadership of PSI researcher Theo Jenk – shows those fluctuations only for the upper three or four annual layers. Deeper in the ice – that is, farther in the past – the curve indicating the concentration of trace substances becomes noticeably flatter, and the total amount is lower. Schwikowski’s team reports on this in the current issue of the journal Nature Geoscience.

Vital Seagrasses in Gulf of Mexico Are Retreating Amid Rapid Sea Level Rise

Marine Science professor Ken Dunton (left) and doctoral student Kyle Capistrant-Fossa (right) in the Gulf of Mexico.
Photo Credit: Courtesy of University of Texas at Austin

The Gulf of Mexico is experiencing sea level rise two to three times as fast as the global average due to a combination of warmer waters and wind circulation patterns. Now, a newly released long-term study from marine scientists at The University of Texas at Austin has found rising sea levels can be linked to a loss of valuable seagrass habitats in Texas.

The paper appears in Communications Earth & Environment.

Seagrasses are recognized globally as a foundation species that play a key role in supporting fisheries and mitigating climate change, efficiently storing substantial amounts of carbon. Meadows occur in shallow waters, and the species are dependent on light for photosynthesis and growth. The researchers are the first to find that sea level rise is yet another human impact that is responsible for the worldwide decline in seagrasses.

Ken Dunton, a professor in UT’s Marine Science Institute, and Kyle Capistrant-Fossa, a doctoral student, made the discovery while examining a 30-year database of observations that Dunton had collected at his study site in the Laguna Madre next to Padre Island. Capistrant-Fossa found that the slow loss of vegetation at the site during the past decade was also coincident with an unprecedented rise in sea level. They also found that seagrasses were disappearing from their historical deeper water ranges throughout the Upper Laguna Madre. But they noted that these losses could be compensated by plant expansion into areas that were once too shallow.

Significant glacial retreat in West Antarctica began in 1940s

Thwaites Glacier from above.
Photo Credit: Ted Scambos.

A new study, involving researchers from British Antarctic Survey, has found that significant thinning and retreat of the vast Thwaites Glacier began in the 1940s.

Accelerating ice loss has been observed since the 1970s, but its unclear when this significant melting initiated – until now. These results coincide with previous work that found the Pine Island Glacier also began its retreat at this time. Climate models indicate that anthropogenic warming has increasingly driven West Antarctic ice loss since that time, and has prevented these glaciers from recovering.

James Smith, a marine geologist at British Antarctic Survey said:

“Our previous work in 2016 provided the first direct evidence that neighbouring Pine Island Glacier started to retreat in the 1940s. However, that was just one glacier draining into the huge Amundsen Sea Embayment. Now that we know Thwaites glacier also started to retreat around the same time is really significant. It demonstrates that glaciers in this area were responding synchronously to an external climatic driver.”

“A significant implication of our findings is that once an ice sheet retreat is set in motion it can continue for decades, even if what started it gets no worse. It is possible that the changes we see today on Thwaites and Pine Island glaciers – and potentially across the entire Amundsen Sea Embayment – were essentially set in motion in the 1940s.”

‘Janitors’ of the Sea: Overharvested Sea Cucumbers Play Crucial Role in Protecting Coral

Photo Credit: Cody Clements

Corals are foundational for ocean life. Known as the rainforests of the sea, they create habitats for 25% of all marine organisms, despite only covering less than 1% of the ocean’s area. 

Coral patches the width and height of basketball arenas, used to be common throughout the world’s oceans. But due to numerous human-generated stresses and coral disease, which is known to be associated with ocean sediments, most of the world’s coral is gone.

“It’s like if all the pine trees in Georgia disappeared over a period of 30 to 40 years,” said Mark Hay, Regents’ Chair and the Harry and Anna Teasley Chair in Environmental Biology in the School of Biological Sciences at the Georgia Institute of Technology. “Just imagine how that affects biodiversity and ecosystems of the ocean.”

In first-of-its-kind research, Hay, along with research scientist Cody Clements, discovered a crucial missing element that plays a profound role in keeping coral healthy — an animal of overlooked importance known as a sea cucumber.

Modern hydropower plants also cause massive damage to ecology

Water samples collected by TUM researchers
Photo Credit: Lehrstuhl für Aquatische Systembiologie / TUM

Even modern and supposedly gentler hydropower plants cause considerable damage to river ecosystems. This is shown by a study by Prof. Jürgen Geist from the Chair of Aquatic Systems Biology at the TUM School of Life Sciences published in the Journal of Applied Ecology. Geist and his team investigated the changes in the complex biocoenoses in rivers at five locations in Bavaria before and after the installation of hydropower plants. They looked not only at fish but also at microorganisms, aquatic plants, and algae growth.

Significant differences in living conditions were observed at all locations, emphasizes Geist. This applies to the situation upstream and downstream of the power plants as well as before and after installation. "Contrary to what was hoped for and predicted by the operators, the new types of power plant have not improved the habitat conditions for current-loving species," the biologist states. In particular, retrofitting existing weirs in conjunction with further damming would have negative effects.

"When planning future plants, in addition to the question of the sometimes-considerable damage to fish when passing through hydropower plants, the previously neglected effects on the habitat and the food web must also be taken into account. This is about the ecological continuity and connection of different river sections as an important criterion for healthy river systems," said Geist. The requirements are defined in the EU Water Framework Directive.

New study uncovers the importance of deepwater ecosystems for endangered species

Hawksbills typically forage on coral reefs where their diet is predominantly sponges.
Photo Credit: Jeanne A Mortimer

Using tracking data, a new study has revealed for the first time that hawksbill turtles feed at reef sites much deeper than previously thought.

Critically endangered hawksbill turtles are found in every ocean and are the most tropical of sea turtles. Adult hawksbills have long been considered to have a close association with shallow (less than 15 meters depth) seas where coral reefs thrive.

Young hawksbills drift in currents during their open water phase of their development before they move to seabed habitats. Hawksbills are usually seen foraging in coral reefs where their diet is predominantly sponges.

To study their feeding habits in more detail, researchers at Swansea, Florida and Deakin universities used high-accuracy GPS satellite tags to track 22 adult female hawksbills from their nesting site on Diego Garcia in the Chagos archipelago in the Indian Ocean to their foraging grounds.

Scientists assemble a richer picture of the plight and resilience of the foothill yellow-legged frog

Foothill yellow-legged frogs live in the flowing water of rivers and streams, so are especially vulnerable when these shrink to isolated pools.
Photo Credit: Brome McCreary / USGS

Up to only a few inches in length, with a lemon-hued belly, the foothill yellow-legged frog may seem unassuming. But its range once stretched from central Oregon to Baja California. In 2023, it was listed under the federal Endangered Species Act. Its rapidly decreasing range is due in part to a fungal pathogen called Batrachochytrium dendrobatidis, or Bd, that has devastated amphibians around the world.

A team of researchers, including UC Santa Barbara’s Andrea Adams, has conducted the most comprehensive study to date of disease dynamics in foothill yellow-legged frogs. The team’s data — sourced from both wild frogs and specimens in museum collections — enabled them to track patterns of infection across a large geographic range. In a study published in Royal Society Open Science, the researchers reveal that drought, rising temperatures and the increasing conversion of land for agriculture appear to be the largest factors driving Bd infection in this species.

The researchers aimed to assemble as much data as they could, both in space and time. They surveyed in the creeks and rivers of California and Oregon, where they swabbed wild yellow-legged frogs for the presence of Bd. It also led them into fluorescent-lit museum collections to sample specimens from as far back as the 1890s.

Vanishing Forests and Suffering Children: The Hidden Toll of Deforestation in Cambodia

Deforestation is suspected to have adverse impacts on child health. Investigating this phenomenon in Cambodia, a recent study sheds light on the devastating impact of prenatal exposure to deforestation on child health in Cambodia. The study reveals that children born in areas with recent deforestation suffer from lower birth weights and stunted growth. Moreover, pregnant women exposed to deforestation are more likely to experience anemia. These findings underscore the urgent need for effective targeted policies.

Deforestation, a critical consequence of human activity, has garnered significant attention due to its impact on environmental sustainability, biodiversity and climate change. However, an equally pressing yet less explored aspect is the relationship between deforestation and human health, especially in impoverished regions. Scientists have increasingly recognized the detrimental effects of deforestation on various aspects of human health, particularly among children. Studies reveal that children residing in areas with high deforestation rates are at an elevated risk of malaria, respiratory illnesses, diarrheal diseases, and malnutrition. This is particularly alarming given that these regions are often home to the most economically disadvantaged populations, worsening existing health disparities.

An increase in blood-sucking black flies is expected in Germany

Simulium ornatum is a black fly species of veterinary and human medical relevance.
Photo Credit: Dorian Dörge

Researchers from Goethe University Frankfurt and the Senckenberg Biodiversity and Climate Research Centre have modeled the spatial distributional patterns of black flies in Hesse, North Rhine-Westphalia, Rhineland-Palatinate and Saxony for the first time. In the study published in the renowned journal Science of the Total Environment, the research team shows that black flies in Germany can be categorized into three groups with different distribution patterns and ecological requirements. The researchers point out that medically relevant species in particular could become more prevalent as a result of ongoing climate and land-use change. 

Only six millimeters in length, black flies (Simuliidae) may look harmless like house flies, but their bites can be very unpleasant. Similar to mosquitoes, the females of these insects that are able to fly need a blood meal to produce eggs. Known as “pool feeders", they use their sharp “teeth" to scratch the skin of the host and then ingest the resulting drop of blood. “The anticoagulant and anesthetic substances introduced into the wound by mosquitoes can trigger serious allergic reactions or lead to secondary bacterial infections," states Prof. Dr. Sven Klimpel from the Senckenberg Biodiversity and Climate Research Centre, Goethe University Frankfurt, the LOEWE Centre for Translational Biodiversity Genomics (TBG), and the Fraunhofer IME Giessen. Klimpel continues: "Black flies are also vector-competent, meaning they are able to transmit pathogens that cause infectious diseases through their bites." One of the most well-known diseases transmitted by black flies is onchocerciasis, also known as “river blindness", caused by the nematode Onchocerca volvulus, which is native to Africa. According to the World Health Organization, more than 1.15 million people worldwide have already lost their sight as a result of the disease. 

Research reveals new insights into marine plastic pollution

Photo Credit: Lucien Wanda

A groundbreaking study led by researchers at the University of Stirling has uncovered the crucial role of bacteria living on plastic debris.

The research also identifies rare and understudied bacteria that could assist in plastic biodegradation, offering new insights for tackling plastic pollution.

Plastic pollution is a worldwide problem, with up to two million tons estimated to enter oceans every year, damaging wildlife and ecosystems.

In a pioneering study, experts at the University of Stirling’s Faculty of Natural Sciences and the University of Mons (Belgium) analyzed the proteins in plastic samples taken from Gullane Beach in Scotland.

Unlike previous studies carried out in warmer climates that focus on the genetic potential of biofilms inhabiting plastics, this research led by Dr Sabine Matallana-Surget took a unique approach by analyzing the proteins expressed by active microorganisms.

Their findings have unveiled a remarkable discovery of enzymes actively engaged in degrading plastic. Moreover, the team has pioneered new methodologies for enhanced predictions in marine microbiology research.

Side effects of wide scale forestation could reduce carbon removal benefits by up to a third

Combining forestation with other climate mitigation strategies is vital for more effective long-term climate action
Photo Credit: Andrew Coelho

The side effects of large-scale forestation initiatives could reduce the CO2 removal benefits by up to a third, a pioneering study has found.

The research, led by scientists at the University of Sheffield and published today (Thursday 22 February 2024) in the journal Science, provides a new insight into the broader impacts of forestation on the Earth's climate, indicating that its positive impact is potentially smaller than previously thought. 

Carbon removal strategies, such as forestation, alongside greenhouse gas emissions reduction efforts, have been recognized by the IPCC as essential measures to mitigate the risk of dangerous future climate change. 

By simulating global forest expansion with advanced computer modelling techniques, academics from the University of Sheffield, in collaboration with the Universities of Leeds and Cambridge, and NCAR and WWF, found that while forestation increases absorption of carbon dioxide from the atmosphere, other complex Earth System responses could together partially offset these benefits by up to a third.

Dr James Weber, from the University of Sheffield’s School of Biosciences and lead author of the study, said: “The public are bombarded with messages about climate change, and the suggestion that you can plant trees to offset your carbon emissions is widespread. Many businesses now offer to plant a tree with a purchase, and some countries plan to expand, conserve, and restore forests. 

Air Pollution Hides Increases in Rainfall

Humans have an impact on rainfall through both air pollution and greenhouse gas emissions.
Photo Credit: Patrick Hendry

We know that greenhouse gas emissions like carbon dioxide should increase rainfall. The emissions heat the atmosphere, causing a one-two punch: warmer oceans make it easier for water to evaporate, and warmer air can hold more water vapor, meaning more moisture is available to fall as rain. But for much of the 20th century, that increase in precipitation didn’t clearly show up in the data.

A new study led by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) finds that the expected increase in rain has been largely offset by the drying effect of aerosols – emissions like sulfur dioxide that are produced by burning fossil fuels, and commonly thought of as air pollution or smog. The research is published today in the journal Nature Communications.

“This is the first time that we can really understand what’s causing extreme rainfall to change within the continental U.S.,” said Mark Risser, a research scientist at Berkeley Lab and one of the lead authors for the study. He noted that until the 1970s, the expected increases to extreme rainfall were offset by aerosols. But the Clean Air Act caused a drastic reduction in air pollution in the United States. “The aerosol masking was turned off quite suddenly. That means rainfall might ramp up much more quickly than we would have otherwise predicted.”

RIT researchers highlight the changing connectivity of the Amazon rainforest to global climate

The Amazon rainforest is one of the largest ecosystems in the world, and its climate is changing due to warming and deforestation. Researchers from Rochester Institute of Technology studied the region’s connectivity to the global climate crisis.
Photo Credit: Arın Turkay

The Amazon rainforest is one of the largest ecosystems in the world, and its climate is changing due to warming and deforestation. Researchers from Rochester Institute of Technology studied the region’s connectivity to the global climate crisis.

The Amazon rainforest is a unique region where climatologists have studied the effects of warming and deforestation for decades. With the global climate crisis becoming more evident, a new study is linking the Amazon to climate change around the rest of the world.

Scholars at Rochester Institute of Technology have looked at the issue from a mathematical perspective and have reinforced the idea that the Amazon’s climate is very much connected to the global climate system and that the connectivity is reconfiguring.

Mathematical modeling Ph.D. student Adam Giammarese ’21 BS/MS (applied mathematics) and Assistant Professor Nishant Malik recently had their findings published as a featured article in Chaos: An Interdisciplinary Journal of Nonlinear Science. Giammarese began the work as part of RIT’s Research Experience for Undergraduates (REU) program, along with co-author Jacob Brown.

The team used both old and new approaches to climate network analysis for their research, analyzing decades of temperature data.

Graphene research: numerous products, no acute dangers

The "Graphene Flagship" initiative has investigated the effects of graphene (blue) and related materials on health and the environment. Colored scanning electron microscopy
Image Credit: Empa

The largest EU research initiative ever launched has come to a successful end: The Graphene Flagship was officially concluded at the end of last year. Empa researchers were also involved, such as molecular biologist Peter Wick, who was part of the Health and Environment work package from the very beginning – and has just summarized the findings in this area with international colleagues in a comprehensive review article in the specialist journal ACS Nano.

Think big. Despite its research topic, this could well be the motto of the Graphene Flagship, which was launched in 2013: With an overall budget of one billion Euros, it was Europe's largest research initiative to date, alongside the Human Brain Flagship, which was launched at the same time. The same applies to the review article on the effects of graphene and related materials on health and the environment, which Empa researchers Peter Wick and Tina Bürki just published together with 30 international colleagues in the scientific journal ACS Nano; on 57 pages, they summarize the findings on the health and ecological risks of graphene materials, the reference list includes almost 500 original publications.

Invasive weed could be turned into a viable economic crop

Prof Rahman and Dr Karim collecting paddy melons for urease enzyme extraction.
Photo Credit: Courtesy of University of South Australia

One of the most invasive Australian weeds is being touted as a potential economic crop, with benefits for the construction, mining and forestry industries, and potentially many First Nations communities.

The prickly paddy melon weed, which costs the agricultural industry around $100 million a year in lost grain yields, cattle deaths, and control measures, could turn into an unlikely money spinner as a source of urease enzymes to create bio cement and prevent soil erosion.

In a world-first study, researchers at the University of South Australia (UniSA) screened 50 native plants and weeds to find a cheaper and more environmentally friendly source for bulk producing of urease enzymes to strengthen soil.

Among the weeds tested, paddy melon ticked all the boxes and was almost as effective as soybean enzymes, which are more expensive and used primarily for food.

UniSA geotechnical engineer Professor Mizanur Rahman and his students collected the paddy melon weed from roadsides in Port Pirie in South Australia. After crushing the seeds and extracting enzymes in a liquid form, they freeze-dried them to create a powdered, high-concentration cementation agent.

Methane Mystery

Maggie Capooci stands at the St. Jones Reserve where the team conducted its research.
Photo Credits: Evan Krape and Andrew Hill

Tidal salt marshes are fairly common across the Mid-Atlantic. These coastal ecosystems provide habitat for plants, birds and fish. Existing at the intersection of land and sea, tidal salt marshes act as armor against hurricanes and shoreline erosion.

Tidal salt marshes are also a powerful tool to combat climate change, said Rodrigo Vargas, an ecosystem ecology and environmental change professor in the Department of Plant and Soil Sciences at the University of Delaware. These ecosystems absorb the greenhouse gas carbon dioxide from the atmosphere, and their soils act as a carbon vault. 

“These ecosystems are threatened across the world. They are disappearing because of different problems, such as land use change and sea level rise,” Vargas said. “But they store a lot of carbon. So, there is a big concern about what will happen to salt marshes now under climate change and what is going to happen with the carbon stored in these ecosystems.” 

If tidal salt marshes shrink or disappear because of climate change or how human activities have transformed natural landscapes, could all the carbon they have stored go back into the atmosphere and further contribute to the warming of the Earth? Vargas said this is an important question that scientists are working on.

Tidal salt marsh soils are great at storing carbon because they're often flooded and have salty water. These conditions lower oxygen levels and make it difficult for most microorganisms to consume the carbon in the soil. However, some microorganisms called methyl-methanogens can eat some of the carbon in the soil and produce methane under these conditions. That’s a far more powerful greenhouse gas with the ability to heat up the Earth more intensely than carbon dioxide. In some marshes, the amount of methane produced and emitted can offset the amount of carbon captured by the ecosystem in the growing season. 

The ties that bind

The soils in many iconic Australian landscapes, like the outback and deserts, are colored red by an abundant mineral known as goethite. This mineral tends to lock away trace metals over time, according to research from Washington University in St. Louis
Photo Credit: Nathan March

Trace metals are nutrient elements, like zinc, that animals and plants need in small amounts to function properly. Animals generally get trace metals in their diets or through environmental exposures, while plants take their trace minerals up from soil. If we get too little, we may experience a deficiency, but the opposite can also be true: too much of a trace metal can be toxic.

Scientists believe that up to 50% of the trace metals in soils and urban environments may be bound to the surfaces of mineral grains — rendering the trace metals essentially unavailable for consumption or exposure. Researchers at Washington University in St. Louis wondered what holds them in place.

“When minerals bind trace metals, we often assume that they act like a sponge,” said Jeffrey G. Catalano, a professor of earth, environmental and planetary sciences and the director of environmental studies in Arts & Sciences. “But sometimes, they bind trace metals and won’t let them go. That is great when they are contaminants, but bad when they are serving as micronutrients.”

In a study published in the journal Environmental Science & Technology, Catalano and Greg Ledingham, a PhD candidate in his laboratory, discovered that a common mineral called goethite — an iron-rich mineral that is abundant in soils that cover the Earth — tends to incorporate trace metals into its structure over time, binding the metals in such a way that it locks them out of circulation.