Wildfires are an essential component of many natural ecosystems. However, climate change is creating conditions that cause fires to burn longer and hotter, threatening the environment and public health. 

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Wildfires have shaped native landscapes for thousands of years. Fire is woven into the ecological history of native grasslands, oak prairies, longleaf pine forests, and ecosystems all over the world. Before settler colonialism, Indigenous people in North America used fire as a tool to care for the land, promoting new growth and restoring soil fertility. Although the beneficial roles of fire have been obscured by the erasure of Indigenous land stewardship practices, fire has always had an important place in our environment. 

While wildfires have been burning naturally for millennia, their scale, frequency, and intensity have grown to dangerous new levels in recent years. Fire regimes are shifting, and the increasingly destructive nature of fires is now outpacing the sustainable growth they once helped promote. Fire seasons are becoming longer and more destructive, and a growing body of evidence points to climate change as the driving force behind this shift. How are fire and climate related, and what do these connections mean for people living in a more fire-prone world?

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How Climate Drives Wildfire 

Fire requires three ingredients to ignite: fuel, oxygen, and heat. Climate change increases the likelihood of all three. Intense periods of drought, rising temperatures, and dry soils brought about by changing weather patterns produce an abundance of readily ignitable fuels (the organic material consumed by wildfires including grasses, shrubs, and trees). These conditions create an ideal environment for fire to thrive, turning some ecosystems into tinderboxes.

“With climate change, fuels and the forests that we really care about are ending up drier for a longer part of the summer,” said Dr. Susan Prichard, a forest ecologist at the University of Washington who specialises in wildfire ecology. “Increased winds [oxygen] and lightning activity [heat/ignition source] are playing a huge role too.” 

In an interview with Earth.org, she helped draw connections between changing climates and changing fire regimes. 

One of climate change’s many consequences is an increase in severe weather events, like heatwaves and powerful storms. In some areas, this translates to long periods of drought punctuated by intense bursts of precipitation – like the record-setting snowfall observed in northern California this year. 

The idea that fuels are drying out at a dangerous rate may seem at odds with the fact that some areas are seeing an uptick in heavy precipitation. How could wetter winters contribute to more active fire seasons? 

“We could have a really good snow year like we did in the West,” explained Dr. Prichard. “But if we have record-setting warm temperatures in the early spring, like we did, snow melts so quickly. Then those fuels dry out and are ready to burn pretty early in the season.”

In some environments, heavy precipitation events can boost plant growth – particularly in grass-dominated ecosystems – and lead to a stockpile of fuels. Researchers at NASA recently discovered that wet winters may result in a larger number of small wildfires the following fire season. 

Changes in the frequency and intensity of fires also contributes to a destructive climate feedback loop. As large swaths of forest are consumed by fire, the carbon that was sequestered in trees and soil is released back into the atmosphere, perpetuating a destructive cycle. 

Photo by Adra Pallon, finalist of the 2023 Earth.Org Photography Competition.

Smoke on the Horizon: What Comes Next?

Like rising seas and record breaking temperatures, today’s fires are proof that the consequences of climate change are not problems for a distant future – they are happening now. People who have not typically had to worry about fires are now experiencing the devastating impacts first-hand, like the millions of New Yorkers who recently stepped outside to find their city shrouded in orange smoke. Under current conditions, this eerie scene may become more commonplace. 

The National Interagency Fire Center’s predicative report anticipates above normal fire activity for several parts of the US this year, including the Pacific Northwest, the Great Lakes Region, and New England. The World Meteorological Organization (WMO) also predicts increased fire activity for parts of the Arctic, central Europe, Indonesia, and the Brazilian Amazon. One report from the United Nations Environment Programme (UNEP) warns that extreme wildfires are not only here to stay – they will likely get worse. Even with a hypothetical reduction in greenhouse gas emissions, their research shows that wildfires would still increase 50% by the year 2100. 

How Wildfires Impact Human Health

The impacts of severe wildfires are not limited to communities at the edges of forests or historically fire-prone areas. As wildfires move across the landscape, they pump carbon monoxide, nitrogen oxides, and a variety of carcinogenic compounds into the air. These compounds can travel long distances, riding the wind into highly populated areas hundreds of miles away. 

Exposure to wildfire smoke may worsen preexisting respiratory conditions like asthma, exacerbate cardiovascular problems, and even cause birth complications. Wildfires weigh heavily on mental health, stirring up fear, anxiety, and stress for those forced to evacuate (or alternatively, those who cannot). Some groups are at greater risk of experiencing negative health effects than others, making wildfires and their associated health impacts an issue of environmental justice. One study found that between 2017 and 2021, Americans on average were exposed to 350% more wildfire smoke than previous years. For communities with more people of colour and non-English speakers, this number was closer to 450%. 

“There are these compound impacts of wildfire that are really concerning … certain groups like low-income communities and people of colour already experience disproportionate health concerns like asthma,” said Dr. Prichard. “Wildfires can make this even worse.” 

Like so many issues related to climate change, restoring healthy fire regimes is a matter of reducing emissions in the atmosphere. While it would be an enormous feat, it is still possible to avoid some of the worst impacts of climate change, including devastating fire seasons year after year. By shifting towards clean energy and severing the climate-wildfire feedback loop, we can minimise further warming and potentially undo some of the conditions that allow destructive wildfires to thrive. Supporting policies that promote responsible forest management and push back against unsustainable practices like deforestation may help protect ecosystems threatened by fire. 

Despite our best personal intentions, a more fiery future is almost certain. By understanding connections between climate, wildfire, and human health, we can work to educate others and provide better access to care for those at risk of health impacts – especially those at a disproportionate risk.

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The post Fanning the Flames: How Climate Change Fuels More Destructive Fire Seasons appeared first on Earth.Org.

Residents along the Ohio-Pennsylvania border are still grappling with fear and frustration in the wake of a fiery train derailment in East Palestine, Ohio. The train, operated by Norfolk Southern, derailed on February 3, 2023, and spewed large quantities of toxic chemicals into the town and surrounding environment. While no injuries were reported from the 38-car pile-up, the derailment filled residents’ homes with foul-smelling fumes and exposed many to carcinogenic compounds. Local waterways have suffered enormous losses of aquatic life, and some living in the area have reported symptoms of chemical exposure. As details of the Ohio train derailment continue to surface, many worry about the long-term effects this event will have on human and environmental health.   

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The Ohio Train Derailment: An Environmental Disaster 

The initial train derailment and subsequent release of vinyl chloride from unstable railcars dealt a massive blow to local wildlife. Sulfur Run and Leslie Run, two streams that flow through East Palestine and eventually connect to the Ohio River, suffered the worst of these impacts. As contaminated water made its way downstream from the derailment site, it wiped out thousands of fish, amphibians, mollusks, and aquatic insects. After two weeks these streams are still littered with dead fish, and a sickly-sweet chemical odour still lingers over the water.

In an exclusive interview with Earth.org, Taylor (who asked to not use her last name), an ecologist and local resident, recalled the devastation she observed in Leslie Run a few days after the derailment. 

“This was like nothing I’ve seen before,” she said. “To stand in a stream like this, completely surrounded by animals that were dead or dying, was one of the most heartbreaking things I have ever experienced.” 

The Ohio Department of Natural Resources estimates that at least 3,500 fish were killed, though some argue that this estimate is low. To better understand how the derailment has impacted wildlife, some ecologically minded volunteers are working to identify dead aquatic species in local waterways. In addition to aquatic wildlife, others in East Palestine have reported cases of dying pets following the chemical release. 

Thousands of fish, amphibians, and other aquatic animals were poisoned after the derailment dumped toxic chemicals into local waterways. Photo by Logan Rance.

In addition to the derailment’s immediate impacts, there is emerging concern that harmful compounds could remain in the environment for long periods of time. Photos and videos collected by community members appear to show brightly coloured chemicals being released into the water when the stream bed is disturbed, indicating that some of the spilled material has settled into the sediment. This poses a huge risk to benthic organisms and may predict the accumulation of toxic compounds in the food web. 

An oil slick bubbles to the surface of Leslie Run after a rock is thrown into the water. Photo by Logan Rance.

In the Ohio Environmental Protection Agency’s (EPA) preliminary assessment of surface water in East Palestine, concentrations of petroleum products were so high they exceeded the capacity of the testing equipment. The same report also found elevated levels of tetraphene and chrysene, two carcinogenic compounds known to persist in soil and water. While officials have assured residents that their well water is unaffected by impacted surface water, some are concerned that chemicals will make their way through the soil matrix and into the water table that sits 35 feet (10.6 metres) below ground. 

 “Water isn’t static,” says Taylor. “It moves through the landscape, and it carries things through the soil. Our concerns about these toxins making their way into the groundwater are very valid.”

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Residents Raise Health Concerns Despite Reassurance

On February 6, a black cloud of hydrogen gas, phosgene, and other toxic combustion products towered over East Palestine as Norfolk Southern burned off vinyl chloride from five unstable railcars. While early conversations about the train derailment often focused on this highly carcinogenic material, this was just one of many hazardous compounds listed on the train’s manifest. The manifest also included ethylene glycol, petroleum products, butyl acrylate, and isobutylene – all associated with neurological symptoms and irritation. “While the dystopian plume has dissipated, Ohio and Pennsylvania residents are still reporting symptoms of chemical exposure for miles outside of East Palestine.

Leetonia resident Sierra Lynn shared with Earth.Org how the event has impacted her breathing over 10 miles (16 kilometres) away: “I have asthma, and when I went outside the night of the release, I felt it immediately. You could smell chlorine in the air. I was instantly coughing.” 

Later in the week, she reported having to use her inhaler over twenty times in one day. Some residents have shared pictures of their children covered in rashes, and others have reported migraines, sore throats, burning eyes, and dizziness.

According to the EPA, air monitoring has not revealed alarming levels of pollution, and drinking water near the impacted areas has been deemed safe for consumption. However, many residents are not taking chances. Early on Sunday, February 19, northern Kentucky and the city of Cincinnati temporarily closed drinking water intakes from the Ohio River, which has showed elevated levels of hazardous chemicals in the last week. With most of East Palestine’s nearly 5,000 residents living on well water sourced a mile from the derailment, bottled water donation centres are now a common sight in the area. 

While uncertainties remain, some feel that their health concerns may finally be addressed. On the morning of Tuesday, Feb 21st, the Ohio Department of Health opened a community clinic to treat those experiencing symptoms of chemical exposure. Some are even hopeful that Norfolk Southern will be held accountable for its actions. Later that afternoon, the EPA ordered the multibillion dollar corporation to clean up and remediate all impacted areas, as well as to offer more support to those impacted by the derailment.

On February 21, the Ohio Department of Health opened a community clinic to assist residents impacted by the derailment. Photo by Logan Rance.

Profit Over People

One of the greatest sources of frustration for concerned residents is the lack of transparency from Norfolk Southern. Representatives declined to attend East Palestine’s most recent public information session, citing concerns for their employee’s safety. Their assistance to those impacted by the Ohio train derailment was initially limited to families living in the one-mile evacuation zone, sparking anger among impacted families living beyond this seemingly arbitrary boundary.

Many watching this event unfold are also unsettled by reports of intimidation to suppress media coverage. During her interview, Taylor revealed that she was threatened with arrest by Norfolk Southern contractors while photographing dead fish in Leslie Run. 

“These contractors caught me walking along the road and saw my camera. They thought I was a journalist. They said if I was media, I would be arrested by the national guard stationed up the road,” she shared. “I had to convince them I wasn’t a journalist.” 

One reporter, a Black man, was arrested at a press conference after being told he was covering the event too loudly. The charges filed against him have since been dropped. Other anecdotes of photographers being followed by unmarked vehicles have made their way through the community, leaving some to wonder if Norfolk Southern is actively working to discourage coverage. “It feels like there are things going on here that they just don’t want the world to see,” said Taylor. 

The full scope of the derailment’s impacts to humans and wildlife may not be known for years to come. Photo by Logan Rance.

As cleanup efforts are underway, people in East Palestine and neighbouring towns are trying to regain some sense of normalcy. Norfolk Southern trains have resumed their usual routes, and the chemical odour that permeated the town has mostly faded. Multiple class action lawsuits have been launched against the corporation, and the derailment has drawn increased attention to the industry’s dangerous practice of precision railroading – a strategy to maximise profit by running longer, heavier trains as frequently as possible. While this event could catalyse positive change in the railroading industry, an enormous amount of damage has been done to people and the environment­­ – the extent of which may not be understood for years.  

“I don’t think we’ll understand the full scope of what’s happened here for a long time,” said Taylor. “I worry some of these chemicals are here to stay.”

Featured image by Jordan Miller News.

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The post Ohio Train Derailment: An Ecological and Human Health Disaster? appeared first on Earth.Org.

Glaciers sustain life. They replenish ecosystems and provide fresh water to humans and wildlife alike. Their slow migrations leave impressive signatures on the planet, sculpting mountains and valleys as they grind across the landscape. These icy giants even offer a glimpse into our planet’s past. By studying the chemical makeup of glacial ice, scientists can better understand Earth’s earlier climates. Glaciers play an irreplaceable role in the natural world. While they have naturally cycled through periods of advance and retreat for hundreds of thousands of years, an ever-growing body of evidence shows that glacial melting is happening at an unprecedented rate due to anthropogenic climate change. As glaciers shrink in size and number, what are we at risk of losing, and what are the consequences?

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Snow, Pressure, and Time: How Glaciers Are Born

Glaciers are huge rivers of ice that move slowly over land, driven by their own enormous weight. Similar to metamorphic rock, they are created by time and pressure. As new layers of snow accumulate each year, older layers compress until they crystallise into high-density glacial ice. This process usually takes at least a century. As more and more snow accumulates and transforms, glaciers may continue to grow for thousands of years. 

Glaciers come in various shapes and sizes. Alpine glaciers, like Alaska’s famous Exit Glacier, form in mountainous regions. These flow gradually from high rock basins into valleys, leaving a moraine of rocks, sediment, and debris in their wake. Less confined by their surrounding landscape, ice sheets spread out broadly in all directions from a domed centre. Ice sheets grow to take on truly continental proportions: Earth’s two ice sheets, the Antarctic Ice Sheet and the Greenland Ice Sheet, cover a combined total of 15.7 million square miles (40.6 million square kilometres). 

A Force for Good 

In an exclusive interview with Earth.Org, glaciology PhD candidate Allison Chartrand (Ohio State University) weighed in on the importance of glaciers. 

“[Glaciers] hold the largest freshwater reserves on the planet as a whole,” she explained. “Mountain glaciers in particular are important water resources, and they have important cultural significance for indigenous people.” 

Only 2.5% of Earth’s water supply is freshwater, and over two-thirds of this small share takes the form of glacial ice. While this water may seem inaccessible compared to what flows freely in lakes and rivers, glacial melting is a vital resource for nearly 2 billion people worldwide. 

Glaciers also provide for non-human organisms. Each summer, glacial melt fertilises downstream ecosystems and feeds local biodiversity. Nutrients released from the bellies of glaciers make their way to the ocean and fuel blooms of phytoplankton, a cornerstone of marine food webs. This cold water also helps regulate the temperature of alpine stream habitats, ensuring the survival of sensitive aquatic species.

Glaciers are not only important because of what they add to the environment. Thanks to the ice-albedo effect, they also help keep solar radiation out. Albedo is the measure of how much energy a surface can reflect. Due to the high albedo of snow and ice, Earth’s glaciers (particularly ice sheets) reflect a tremendous amount of solar radiation that would otherwise be absorbed by the land beneath. Sea ice, the saltwater cousin of glaciers, also plays a part in this important process by reflecting energy that would otherwise be absorbed by a darker, lower-albedo ocean. With the power to regulate how much solar energy our planet absorbs, glaciers and sea ice are critical components of Earth’s thermostat. 

Going, Going, Gone  

While people and plankton alike reap the benefits of seasonal glacial melting, there is a limit to how much melting is too much. This limit lies in a glacier’s mass balance, the difference between its accumulation in the winter and ablation (or shrinkage) in the summer. Under more ideal climate conditions, the mass lost after a period of melting is regained in the winter as new layers of snow transform into glacial ice. Unfortunately, these conditions do not reflect reality: recent mass balance studies show that Earth’s glaciers are melting at an unsustainable rate. 

Between 2000 and 2019, glacial mass worldwide dropped roughly 267 giga tonnes per year. Researchers estimate that this melting has contributed to roughly 21% of observed sea level rise, an effect of climate change that threatens to displace millions by the end of the century. The rate at which glaciers are disappearing has risen 57% since the 1990s, and under current warming trends, two-thirds of Earth’s glaciers may vanish by 2100. 

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“A high percentage of the world’s population lives on the coast,” says Chartrand. “If sea level rises, these people are going to be displaced, and all the infrastructure we’ve built is going to be destroyed. That’s why we should care.”

Freshwater input from melting glaciers even threatens to disrupt the Atlantic Meridional Overturning Circulation (AMOC), a system of ocean currents that plays an enormous role in Earth’s climate and weather patterns. As the surface area of high-albedo glaciers and sea ice shrinks, more solar radiation is absorbed by the Earth, accelerating the cycle of warming and melting in a destructive feedback loop. 

Alaska’s Exit Glacier, a major attraction in Kenai Fjords National Park, serves as a visual indicator of glacial recession due to climate change. 

Alaska’s Exit Glacier, a major attraction in Kenai Fjords National Park, serves as a visual indicator of glacial recession due to climate change. Image by Logan Rance

With clear evidence that global warming is drastically impacting the cryosphere, concerned scientists are asking an important question: What happens next?

The future of Earth’s glaciers depends on whether humans can work together to limit warming. The Intergovernmental Panel on Climate Change (IPCC) predicts that a temperature rise of 1.5C beyond pre-industrial levels could trigger a series of climate tipping points. By surpassing this 1.5C threshold, there is a high likelihood of the following consequences by the end of the century:

• Half of Earth’s mountain glaciers vanish. 
• The Greenland Ice Sheet reaches a tipping point of irreversible melting.
• Sea level rises roughly 48 centimetres, reshaping coastlines and displacing millions.

While limiting warming to 1.5C is an optimistic target, business as usual emissions policies will likely crank Earth’s thermostat even higher– closer to 2.7C. As the temperature climbs, the projected consequences intensify. At 3C, over 70% of Earth’s glaciers are projected to vanish. At 4C, research predicts that over one-third of Antarctica’s ice shelves will collapse. 

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Thwarting the Thaw: Can Glaciers Be Saved?

Protecting glaciers requires us to prevent any additional warming we can, no matter how small it may seem. 

“We’ve already passed the threshold for some glaciers being completely gone in our lifetime,” says Chartrand. “But for every bit of warming we can curb, we’ll be able to save more glaciers.”

Optimistic scientists believe that with immediate, large-scale reductions in greenhouse gas emissions and stronger emissions pledges, there is still a small possibility of limiting warming to 1.5C. Doing so would protect a larger portion of glaciers and reduce other climate-related consequences, like severe weather events and sea level rise. However, accomplishing this goal will be no small feat. As many countries continue to invest in fossil fuels and make emissions pledges they refuse to keep, the cards are stacked against glaciers and other imperilled natural resources.

Aialik Glacier in Alaska’s Kenai Peninsula. Image by Logan Rance

While our individual actions may feel insignificant, every effort is important. 

“One of the most effective things we can do, something that gives me hope, is writing to congress and our lawmakers,” says Chartrand. “Writing them, or calling them, and asking ‘Hey, can you support this bill that limits emissions?’” 

She also advocates using our wallets to send a message. “We can refuse to support companies that are not working to limit their emissions, and choose to support the ones that do.”

Harbor seals congregate at the base of Aialik Glacier. Image by Logan Rance.

Despite grim projections, we must not willingly accept a world void of glaciers. With their irreplaceable ecological and cultural significance, they are well worth protecting. It is essential that we collectively work to reverse our emissions and stop future warming. Earth’s glaciers, as well as the life they support, are counting on it.

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The post What Does Glacial Melting Tell Us About Our Changing Planet? appeared first on Earth.Org.

Certain vulnerable species have become living symbols of conservation. Monarch butterflies grab the public eye with their brilliant colours, and beloved megafauna like the polar bear have rallied environmental support for decades. But the spotlight that shines on imperilled wildlife is not shared equally. Many lesser-known organisms are threatened by human activity and equally deserving of support. One such group is the unionids, or freshwater mussels.

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Mussels are the unsung heroes of the freshwater world. These shy bivalves might not impress at first glance. They often go unnoticed, spending their lives hidden from sight at the bottoms of lakes, rivers, and streams. But do not be fooled by their unassuming nature – freshwater mussels are fascinating animals with their own unique charisma. They have wonderfully complex life cycles and play vital roles in maintaining healthy freshwater ecosystems. 

Many species’ common names highlight their diverse colours and shapes. A single river may be home to elktoes, three-horn wartybacks, pink heelsplitters, and wavy-rayed lampmussels. Lucky waders may even stumble across the aptly-named Appalachian monkeyface mussel, a critically endangered species. With over 890 species worldwide, mussels are one of the most diverse groups of animals in the world. Unfortunately, they are also one of the most imperilled.  

Why Do Freshwater Mussels Matter?

Mussels are ecosystem engineers, working around the clock to remove organic material and impurities from the water. It is a job that never stops. Embedded in the sediment, mussels continuously syphon bacteria, algae, and excess nutrients as they feed and breathe. With each mussel filtering around 10 gallons (37.8 litres) per day, it is also a job they do quite well. Large populations have powerful impacts on water quality: one study found that in a 300 mile (approximately 480 kilometre) stretch of the Mississippi River, mussels filter 14 billion gallons (53 billion litres) of water per day. 

In an act of aquatic alchemy, mussels transform what they syphon into food for other organisms. They make essential contributions to nutrient cycling by breaking down compounds and excreting them as material that is more readily bio-assimilated. Where mussels go, others follow. Researchers in the UK found that greater mussel abundance predicted higher diversity among other freshwater organisms.

Freshwater mussels like the white heelsplitter (Lasmigona complanata, left) and mapleleaf mussel (Quadrula quadrula, right) keep water clean and play vital roles in healthy ecosystems. Photo by Logan Rance.

Beth Hollinden, a malacologist for a North American environmental consulting firm, discussed in an interview how mussels also function as biological indicators. “Mussels are like a canary in the coal mine,” she explained. “If you’ve got a big mussel die off, you can tell pretty much immediately that something is wrong and try to address that problem.” 

Sudden mussel declines may point to issues like agricultural runoff or sedimentation. By monitoring mussel populations, researchers can simultaneously monitor the health of the surrounding ecosystem. Lately, these monitoring efforts reveal that mussels are struggling: in North America alone, populations have declined nearly 70%. 

A Bizarre and Brilliant Reproductive Strategy    

Even in a world of marsupial frogs and mate-eating mantises, mussels’ fascinating (and somewhat diabolical) reproductive methods set them apart. After a female syphons a male’s sperm from the open water, her eggs develop internally into microscopic larvae called glochidia. When it is time to leave mom behind, glochidia hitch a ride to a new location by attaching to the gills of an unsuspecting host fish. Glochidia remain attached for several weeks, tapping into nutrients present in their host’s gill tissue. They eventually drop off to the sediment where they continue growing into adults.

In order to help glochidia make the leap from mom to host, mussels have developed some creative methods for luring fish close. In some species, a female attracts hosts by dangling part of her mantle – the tissue that encloses the internal organs – that resembles a minnow or crayfish. Others bundle glochidia into a string of worm-like mucus packets and release the line into the water. When a prospective host bites a female’s lure, glochidia are released and latch on to the fish’s gills. Freshwater mussels in the genus Epioblasma take an even more shells-on approach: a female uses her exposed body to lure a fish close, then clamps on to its head and blasts it with a cloud of glochidia. When the deed is done, she releases the newly-infested host. 

Up the Creek: Why Mussels are Threatened

While pawning off parental duties to fish is an incredible feat of evolution, this strategy makes mussels particularly vulnerable to environmental change. 

“One of the biggest threats for mussels today is habitat fragmentation in the form of impoundments and dams,” said Hollinden. “This separates fish populations. If fish can’t travel up and down the stream you end up with isolated populations, and mussels can’t disperse.” 

As more dams are constructed to meet growing demands for electricity, mussels and the fish who carry them face a difficult road ahead. Even protected watersheds are at risk: one 2020 study found that 1,200 dams existed in global protected areas, with 509 more planned for future construction. 

A dead mussel sits just downstream from a construction site along Ohio’s Olentangy River. Photo by Logan Rance . 

Dams are not mussels’ only upstream battle. As human activity floods waterways with heavy metals, pharmaceuticals and personal care products (PPCPs), fertilisers, and industrial waste, water quality is plummeting at an unprecedented rate. Despite powerful filtration abilities, mussels have limits to what they can syphon. With fewer environmental buffers like wetlands to sequester pollutants and minimise erosion, they are succumbing to poor water quality and sedimentation. Today, 45% of species worldwide are threatened with extinction or already extinct.  

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A Murky Future

Mussels are not only an essential part of today’s ecosystems – they are also a window into the past. Scientists study the geochemical makeup of their shells to learn about previous environmental conditions, and have even used them to research climate as far back as the Miocene era. Despite their long standing place in healthy freshwater habitats, they now face an uncertain future. 

While mussels may not have the same support as other high-profile species, passionate researchers are working overtime to prevent them from disappearing for good. Some scientists are developing ways to grow mussels in labs and introduce them into restored habitats, with initial studies producing hopeful results. For malacologists like Hollinden, the fight for mussels is personal.

“Being able to contribute in whatever way to the preservation of this group of animals is very fulfilling,” she shared. “By doing things like relocations you can actively make a difference in the life of that animal.” 

Relocations are an important part of protecting mussels from environmental disturbance. Feeling blindly along the bottoms of lakes and rivers, researchers collect mussels from areas at risk of being impacted by development (like in-water bridge construction) and move them to safer locations. Other work like habitat restoration, monitoring, and public outreach are vital to mussel conservation. Groups like Xerces Society for Invertebrate Conservation partner with researchers, tribes, and volunteers to restore mussel habitat and communicate the importance of mussels with the public. 

Despite the best efforts of mussel-loving conservationists, the freshwater mussel faces difficult odds. Each species lost is a huge blow to water quality and biodiversity, leaving a hole in the ecosystem that is impossible to fill. Educating the public about mussels and the services they provide is essential to preserving their place in the world. While these humble filterers bring tremendous value to freshwater habitats, mussels deserve protection simply for being mussels. With their wonderfully weird lifecycles and robust biodiversity, they are among the most unique animals in the world. Mussels are well worth protecting and have earned a place in the spotlight. Time will tell if we can keep that spotlight from going out for good.   

Featured image by Logan Rance

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The post The Threats of Human Activity to Freshwater Mussels appeared first on Earth.Org.

Despite how the ocean has influenced the natural world throughout history, human-triggered global warming is now changing ocean chemistry through a process called ocean acidification. Described by some researchers as “the other CO2 problem”, this phenomenon refers to the reduction in the pH of seawater over time – a change that comes with negative impacts on life above and below the waves. How does ocean acidification affect marine life and humans and what can we do to mitigate its impact?

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With its powerful tides and vast expanses that stretch into the horizon, the ocean captivates us. It is the cradle of early life – over billions of years our oceans have witnessed the evolution of simple cellular organisms to the wonderfully complex communities we see today. Whether we are standing with our feet in the surf or landlocked thousands of miles from the coast, we are surrounded by the ocean’s influence. By distributing heat, sequestering carbon, and storing solar radiation, it drives weather and climate across the globe. 

What is Ocean Acidification?

Ocean acidification refers to a decrease in the pH of seawater due to increased levels of carbon dioxide (CO2) in the atmosphere. Our oceans are carbon sinks – think of them as sponges that soak up excess carbon from the atmosphere.

By natural processes, CO2 absorbed by the ocean reacts with seawater to create carbonic acid, a weak acid that breaks apart into ions of different charges (imagine ions as Lego pieces that make up a larger structure– in this case,  carbonic acid). These include hydrogen ions and bicarbonate ions. The latter disassociates further to produce additional ions of hydrogen and carbonate. Animals like corals, shellfish, oysters, and urchins  –collectively referred to as calcifiers – use carbonate to build their shells and skeletons.

How does this process change when more CO2 is added to the mix? Since the industrial revolution, the amount of CO2 in the atmosphere has risen nearly 50%, jumping up to nearly 420 parts per million. Our seas currently soak up more than a quarter of the CO2 emitted from human activity. More CO2 in the ocean means more carbonic acid is produced, resulting in extra hydrogen and bicarbonate ions in seawater. pH is determined by the number of free hydrogen ions in a solution; the more they are, the lower the pH (and the more acidic the water). Additional CO2 in the water also leads to a decrease in the bioavailability of carbonate, making it harder for calcifiers to build their shells. 

How Does Ocean Acidification Affect Marine Life?

The National Oceanic and Atmospheric Administration determined that the pH of the ocean’s surface water has dropped by 0.1 pH units in the last 200 years. This may sound insignificant. However, it is important to note that pH increases and decreases on a logarithmic scale; a drop of 0.1 represents a 30% increase in acidity. The impacts of this change, combined with other factors like rising temperatures and pollution, are felt by species across trophic levels. Multiple studies show that the net growth (or calcification) of different corals has decreased significantly, leading to a loss of habitat and biodiversity. 

One study found that half of all coral coverage has been lost since the 1950s due to a variety of factors including ocean acidification. At the microscopic level ocean acidification is altering populations of certain species of phytoplankton, a crucial part of ocean food webs. Lower pH has a strong negative impact on mollusks, with shell dissolution observed in oysters, shellfish, urchins, and sea butterflies. Acidic conditions may interfere with regeneration and wound recovery in certain corals used for restoration, hampering ecosystem recovery efforts (Hall et al., 2015). In addition to direct impacts on marine life, acidification ramps up the damaging effects of local stressors like pollution and agricultural runoff, weakening the resilience of important coastal ecosystems.

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Impacts of Ocean Acidification on Humans

One of the ocean’s most amazing attributes is the interconnectedness of its ecosystems and processes. Ocean communities are mosaics of life where a change in one species can be felt through a community. The impacts of acidification act similarly. They ripple out with the potential to alter entire ecosystems, and these ripples do not stop at the surface. With livelihoods and resources under threat, humans are already experiencing the effects of ocean acidification. 

Coral reefs provide important buffer zones to coastal communities, absorbing the blow from storm surges and extreme weather events. With fewer, weaker coral reefs protecting our coasts, we can expect upticks in coastal flooding resulting in loss of property and even loss of life. The shellfish industry, valued at over one billion dollars in the US, faces an uphill battle under acidifying conditions. With economically important species like oysters and lobsters in decline, some coastal cities built on the seafood industry are on the brink of economic collapse. 

Acidification amplifies already significant declines in marine life due to overfishing and will have serious consequences for millions around the world who get their protein from eating fish. If acidification continues as projected under current conditions, the consequences will become more and more apparent to those whose livelihoods centre around the ocean.

Promising Research

It is easy to slip down a rabbit hole of gloom and doom when learning about the inevitable consequences of ocean acidification. However, there are bright spots we can look to when good news feels scarce. Dr. Emily Hall, a senior researcher and ocean acidification expert at Mote Marine Laboratory & Aquarium in Florida, discussed some of her lab’s positive findings in an interview.

“Looking at different genotypes of corals is a big focus that we’ve had for the past few years,” she said. “It’s been really interesting to see that even within a single species, different genotypes within that species show different responses.” 

Research conducted by Dr. Hall and other collaborators found that specific genotypes of endangered staghorn coral (Acropora cervicornis) have the adaptive capacity to withstand conditions associated with climate change, including lower pH (Muller et al., 2021). While it may be difficult to predict how some organisms fare after combining other factors like warming events, she’s hopeful that adaptive evolution and high genetic diversity will help species survive. 

Dr. Hall also discussed the importance of ecosystem restoration in combating the harmful effects of ocean acidification. Her laboratory is working to understand how seagrass and mangrove ecosystems take up excess carbon dioxide, creating pockets of refugia that buffer against global change. Despite the challenge of studying a changing climate, she remains hopeful: “Our lab and our restoration scientists are looking on the positive side, looking at ways to boost these ecosystems and get them to grow more.” 

Scientists at the University of Washington are also finding positive results surrounding the potential of aquatic plants to suck up extra CO2 in seawater. Scientists teamed up with farmers and biofuel experts to examine how kelp and seaweed can remove excess carbon, protect marine life from the erosive effects of acidification, and create a more sustainable shellfish industry. This work shows promise for future mitigation efforts and will likely play an important role in protecting our oceans from anthropogenic change.  

Solutions to Ocean Acidification? 

Beyond the ocean’s monetary value and ecosystem services, it has intrinsic value that should not be forgotten. As we watch the damaging impacts of climate change unfold, we should ask ourselves: Do humans have the right to cause potentially irreversible change for the purpose of maintaining a lifestyle reliant on fossil fuels and consumption? Do we want to imagine a future where we no longer share a world with sea butterflies or vibrant coral reefs? 

While reducing fossil fuel consumption is an essential part of preventing these losses, the unfortunate reality is that change is more complex than simply riding a bike to work. Many cities and towns are not walkable, low-carbon lifestyles are often not feasible, and legislators are slow to enact meaningful change that will lead to independence from fossil fuels. 

According to Dr. Hall, this should not dissuade us from trying. “Any little bit you can do personally to reduce CO2 really does make a difference.” She explained that seemingly small actions like carpooling, reusing bottles, and empowering others can rub off and inspire more people to make better choices for the environment. Even those living in landlocked states can make choices that are better for the ocean. Learning about our local environments, keeping our backyards clean, and planting local vegetation are simple ways we can protect our waterways. The benefits of healthy ecosystems on land add up and ultimately find their way to the ocean. “We need everybody on board to make sweeping global change, and that starts locally,” she concluded.

Learning about ocean acidification and why it matters is an important part of fighting this global problem. Many are unaware of this issue and would be motivated to care simply by having a better understanding of the impacts. For those wanting to learn more, networks and organisations like NOAA’s Sea Grant and Woods Hole’s Oceanographic Institution provide excellent resources that break down the science of ocean acidification. 

Under business as usual projections, CO2 emissions will intensify and vulnerable species will feel increasing stress from an acidifying ocean. Without a collaborative effort to decrease emissions and swift legislative action on a global scale, reducing these impacts will be an uphill battle. While consequences are already being felt in and out of the water, there is still time for humanity to change course and reduce the impacts still to come. Our oceans, the life they hold, and the people who need them depend on it.   

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Sources

Hall, E. R., DeGroot, B. C., & Fine, M. (2015). Lesion recovery of two scleractinian corals under low pH conditions: Implications for restoration efforts. Mar. Pollut. Bull., 100(1), 321–326. doi: 10.1016/j.marpolbul.2015.08.030

Muller, E. M., Dungan, A. M., Million, W. C., Eaton, K. R., Petrik, C., Bartels, E., Kenkel, C. D. (2021). Heritable variation and lack of tradeoffs suggest adaptive capacity in Acropora cervicornis despite negative synergism under climate change scenarios. Proc. R. Soc. B., 288(1960), 20210923. doi: 10.1098/rspb.2021.0923

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