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Harmful algal blooms and climate change

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An algal bloom is a rapid increase in the density of algae in an aquatic system.  Harmful algal blooms occur when bodies of water get overloaded with nitrogen and phosphorus runoff from agriculture and other human activities. These excess nutrients can facilitate the out-of-control growth of cyanobacteria, also known as blue-green algae. 

Some species of blue-green algae produce a toxin called microcystin.  These toxins pose a serious health hazard to people, animals, and the environment.  Microcystin affects liver function and can cause death in animals, as well as humans in rare instances.  A notable incident occurred in the summer of 2014, when cyanobacteria contamination in Lake Erie left 500,000 residents in Ohio and Michigan without water for 72 hours and sickened more than 100 people. 

According to a study led by researchers from Carnegie Science, as climate change warms the earth, higher-latitude regions will be at a greater risk for microcystin produced by algal blooms.  The study found water temperatures of 68 to 77 degrees Fahrenheit as being at the greatest risk for developing dangerous levels of microcystin. 

In the study, which was published in the journal Nature Water, the research team also demonstrated that the areas most susceptible to high toxin concentrations will continue to move northward. And in some areas, researchers say the relative risk of exceeding water quality guidelines will increase by up to 50% in the coming decades.

The research team hopes its findings raise more awareness about water sustainability, and the need to focus on the quality of the water as much as the quantity of water. 

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Geographic redistribution of microcystin hotspots in response to climate warming

Photo, posted October 27, 2010, courtesy of Nara Souza / Florida Fish and Wildlife Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Abandoned farmland and the environment

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Abandoned farmland has been increasing dramatically in recent decades.  Estimates are that a billion acres – an area half the size of Australia – have been relinquished from cultivation globally.  While more and more of the tropics have been cultivated in recent times, the global amount of land used for agriculture has been in decline since 2001.  In the past 30 years, arable land in the United States has declined by almost a sixth.  The situation in Europe is similar.  Huge amounts of the former Soviet Union now lie abandoned. 

Farmland is abandoned for various reasons.  It may suffer from damaged soil so that crop yields are too low to be worth the effort.  Farm owners may become too old or be physically unable to continue farming.  Many younger people head for jobs in the cities and more attractive opportunities.  Wars, natural and man-made disasters, and political turmoil have all contributed.

Another form of largely ignored lands are so-called degraded forests.  These are forests that were logged in the past but are no longer productive and aren’t protected either.  These places also represent unused land with great potential value.

Ecologists point to the potential of these lands as neglected resources for rewilding efforts, improving biodiversity, and for increasing natural ways to capture carbon.  Left to its own devices, nature will usually reclaim abandoned places.  This generally provides benefits for biodiversity and climate.  But mapping, studying, managing, and protecting the increasingly vast tracts of abandoned land could increase their potential to contribute to climate change mitigation and the restoration of species and their habitats.

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Abandoned Lands: A Hidden Resource for Restoring Biodiversity

Photo, posted January 26, 2023, courtesy of Larry Syverson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Trouble for psychedelic toads

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Back in the 1960s, it was discovered that secretions from toads native to the Sonoran Desert have psychedelic properties.  The information did not have much impact for over 40 years but about ten years ago, the story started having widespread exposure in U.S. media outlets and there was increasing publicity for the fact that the toad’s dried secretions could be smoked to produce a brief but intense high.

There was also a false narrative spreading around that this so-called toad medicine was part of an ancient practice of indigenous tribes in the Sonoran Desert.  The active agent in the toad secretion is a compound called 5-MeO-DMT and it became an increasingly popular item being sold by self-described shamans, new-age healers, and other underground practitioners. 

5-MeO-DMT is mostly banned as a controlled substance in the U.S., but many Mexican ranchers have been amassing the toads to sell to foreigners to take back home.  Despite the fact that 5-MeO-DMT has been successfully synthesized, the mystique surrounding the toads makes potential users want to use the natural version.

Researchers have found that trapping the toads in Mexico has decimated several populations of the amphibians and has sent others into steep decline. The species currently has no protections in Mexico.  These desert toads play key roles as both predators and prey and as their population declines, there are likely to be some serious ecological problems.  There is already anecdotal evidence that in many places in the desert, crop-eating insect populations have surged in recent years.

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These Toads Have Psychedelic Powers, but They’d Prefer to Keep It Quiet

Photo, posted December 12, 2017, courtesy of K.S. Black via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rainforests and thunderstorms

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Tropical forests are dying at an alarming rate, and not just from deforestation. Even intact forests are losing trees, threatening biodiversity, carbon storage, and the global climate. While drought and rising temperatures are often blamed, new research points to a surprising culprit: thunderstorms.

These intense, short-lived convective storms, common in the tropics, are increasing due to climate change. With strong winds and lightning, they can snap trees, strip canopies, and kill even the most robust tree specimens.

In a perspective paper recently published in the journal Ecology Letters, a research team led by the Cary Institute of Ecosystem Studies argues that thunderstorms, often overlooked in carbon storage research, may be the leading cause of tree death in tropical forests. The research team estimates that storms have caused 30 to 60% of tree mortality in the past, a number that is likely rising as storm activity increases 5 to 25% each decade.

Including storm data in forest carbon studies changes the picture significantly. Earlier models showed that carbon levels dropped sharply when temperatures rose beyond a certain point. But when storm impacts were added, that pattern disappeared, suggesting that storms – not just heat – may be a key factor in carbon loss.

Understanding which species are most vulnerable is critical for reforestation and conservation efforts. Mature trees store the most carbon, so if they’re lost to storms, future forests may fall short of their carbon storage potential.

As storm activity increases each decade, the stakes grow higher.  Accounting for storms could reshape how we protect, restore, and plan for the future of our forests. 

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Are the Amazon’s biggest trees dying? Forest coroners investigate

Photo, posted July 2, 2017, courtesy of Anna & Michal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

How much nanoplastic is in the oceans?

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It is unfortunately well-known that microplastics are pretty much everywhere on Earth.  They are also increasingly found in living things like birds and dolphins as well as in human brains and placentas.  The oceans are polluted with plastic, and for the first time, there is now an estimate for the volume of nanoplastics – which are even smaller than microplastics and invisible to the human eye – found in the North Atlantic.

According to a study published in the journal Nature by the microplastics and nanoplastics research group at the Helmholtz Center for Environmental Research in Germany, there are at least 30 million tons of nanoplastics in the North Atlantic, which is more than the weight of all wild land mammals on Earth.

The same researchers have analyzed plastic in lakes, urban air, and even the air in very remote places, but the new study reveals a missing part of the plastics story.

Nanoplastics are microscopic fragments smaller than one micron, about the size of small bacteria.  There has been ongoing concern about nanoplastics in ocean water, but there wasn’t the technology available to really investigate it.  While nanoplastics were expected to be found in the ocean, the sheer amount of it was surprising.

The average concentration of nanoplastics near coastlines is about 25 milligrams per cubic meter of water, about the weight of a single large bird feather.   Nanoplastics are tiny enough that they can easily infiltrate the bodies of living creatures.  For fish and other ocean animals, that means constant exposure that builds up over time.

It is highly unlikely that plastic pollution is going to stop any time soon, but there is a United Nations meeting on the subject in August in Geneva.

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Tons of Invisible Plastic Pieces Lurk in Ocean Water

Photo, posted June 24, 2020, courtesy of G.P. Schmal / NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Raccoons in Europe

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Tens of thousands of raccoons live in Kassel, a city of 200,000 people in central Germany known for its art scene.  Overall, there are an estimated 1.5 million raccoons in Germany.  The omnivorous mammals are native to North America, but they were brought to Germany in the 1930s for fur farming.  Fur farming ultimately ceased but escaping animals and intentional releases ultimately led to a large wild population of raccoons in the years afterward.

Raccoons have gradually made their way across Europe with animals spotted in France, Denmark, Poland, Italy, Austria, and elsewhere.

The people of Kassel have embraced raccoons.  In fact, the place is often called the raccoon city.  Several sports teams are named after the animals.  Many people feed them, and they are pretty much everywhere.  On the other hand, residents have to lock up their trash receptacles and they have to check under their cars before driving places.

Since 2016, the EU has classified racoons as an invasive species because of the threat they pose to native wildlife.  There are no equivalent species like them in Europe.  So, they are a threat to ground-nesting birds, bats in caves, amphibians, and more.  They are able to eat almost anything. 

What to do about raccoons in Europe is unclear.  Despite their popularity in Germany, 200,000 raccoons were culled last year.  But raccoon supporters argue that minks, which are native to Europe, and especially cats, are responsible for much of the pressure on species racoons are accused of consuming.  Meanwhile, Kassel citizens continue to enjoy their raccoons.

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Rampaging raccoons: how the American mammals took over a German city – and are heading across Europe

Photo, posted December 20, 2016, courtesy of Big Cypress National Preserve via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Can birds outfly climate change?

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As global temperatures continue to rise and ecosystems shift, animals are left with limited options. They must either adjust to the changing conditions in their habitats or relocate to cooler environments. For many species, neither choice is easy – or sometimes even possible.

Ecologists had long assumed birds were among the most adaptable species in a warming world simply because they can fly to higher altitudes or towards global poles. But a new study by researchers from Yale University found that even birds are struggling to stay ahead of rising global temperatures.

The study, which was recently published in the journal Nature Ecology and Evolution, analyzed 20 years of data from 406 bird species across North America. They found that while most birds did shift their ranges northward – by about 40 to 50 miles on average during the summer – the changes weren’t enough to keep up with the rapid pace of climate change.

Birds still experienced significant warming in their new areas when compared with temperatures in their original home range.  In fact, warming was about 1.35 degrees Celsius more in summer, and a striking 3.7 degrees more in winter. And some species, especially those with limited flight ranges or specific habitat needs, like the cactus wren, didn’t move at all.

Highly mobile birds like the blue-winged warbler did better, avoiding nearly two degrees of warming by traveling more than 100 miles north. But even they couldn’t completely dodge the heat.

The findings raise serious concerns about whether less mobile species can survive in a warming world, and underscores the urgent need to better understand and manage those most vulnerable to climate-driven extinction.

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Even birds can’t outfly climate change

Photo, posted March 1, 2023, courtesy of Henry via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Parks for bugs

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Urban areas can have a variety of green spaces:  gardens, parks, and roadside and median plantings.  It turns out that these spaces can serve as pollinator refuges.

A study by researchers at the University of British Columbia found that reducing lawn mowing and creating pollinator meadows – essentially parks for bugs – significantly boosts pollinator diversity and creates healthier and more resilient ecosystems.

The 3-year study surveyed pollinators in 18 urban parks across the city of Vancouver.  It compared parks where meadows were planted and mowing was restricted with parks that were kept as standard turfgrass lawns.

Parks with meadows saw an immediate increase in pollinator species – from 21 to 47 more wild bee and hoverfly species – compared to parks without meadows.  These increases continued over the entire three-year study period.

The researchers identified more than 100 species of wild bees and hoverflies and 35 of them were only found in parks with meadows.

People think of urban landscapes as poor environments for biodiversity, but this study demonstrated that even relatively small changes can have significant impacts.  Even a patchwork of small habitats can allow species to move freely and settle into multiple areas quickly.

The researchers had advice for urban residents as well.  They suggest that people reduce mowing, plant native flowering shrubs and trees, create diverse habitats that incorporate a variety of plants that bloom at different times, avoid pesticide use, and leave natural nesting sites for pollinators.

Preserving pollinators is an important task and having a few parks for bugs can really help.

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How ‘parks for bugs’ boost pollinators in Vancouver

Photo, posted September 19, 2011, courtesy of Eric Bridiers / U.S. Mission Geneva via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Bees and urban wildflowers

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Post-industrial cities often have large numbers of vacant lots, left behind as people have moved out of the area.  Local residents are often tempted to plant wildflowers to make these deserted spaces more attractive. 

Wildflowers are an important food source for bees.  Pollinators like bees play a vital role in food production and attracting them with food sources is a good idea.  However, a study by researchers at the University of Cambridge in the UK found that there are dangers associated with planting wildflowers in some urban settings.

Wildflowers growing on land previously used for buildings and factories can accumulate lead, arsenic, and other metal contaminants from the soil.  These metals have previously been shown to damage the health of pollinators that ingest the metals in the nectar as they feed.

The Cambridge study was carried out in Cleveland, Ohio, which has nearly 34,000 vacant lots.  Cleveland was previously the site of iron and steel production, oil refining, and car manufacturing.  The researchers tested the nectar from flowering plants growing on disused land throughout the city.  Lead was the contaminant found in the highest concentrations.  They also found that different species of plants accumulate different amounts and different types of metals.

The goal of the study was not to discourage the planting of wildflowers in towns and cities.  It is to highlight the importance of growing the right species of wildflowers as well as to encourage testing soils for metals before planting wildflowers and to clean up pollution.  Wildflowers are important for pollinators, but it is also important that they don’t contribute to the decline of pollinator populations that has already been happening for a number of reasons.

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Growing wildflowers on disused urban land can damage bee health

Photo, posted August 26, 2012, courtesy of RJP via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Relocating native plants

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Climate change is endangering many native plant species.  As the climate warms, many species will need to establish themselves in new places that are more hospitable than their historic ranges.  But many native plants in the U.S. cannot move themselves by natural forces quickly enough to avoid climate-change driven extinction.  For such plants to survive into the future, they will need human help to move into adjacent areas, a process called “managed relocation.”

Such a process has its problems.  There is no guarantee that a plant will thrive in a new area.  On the other hand, relocating plant species historically has often had disastrous consequences.  Consider, for example, the story of kudzu in the American south.

Researchers at the University of Massachusetts Amherst have studied this problem in detail and reported the results in the journal Global Change Biology.

The issue is how to help plants move successfully without their causing harm in their new locations.  The study found that some plant traits can lead to success and some to ecological disaster.  In some cases, the same traits that help plants to establish themselves in a new location make them powerful invasive species.  Traits like having a large size predispose a plant to not only establish itself but spread wildly. 

The study recommends that people managing relocation need to focus on plants whose traits they have determined to be conducive to successful relocation but more unlikely to cause harm in their new environment. 

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If Native Plants Are Going to Survive Climate Change, They Need Our Help to Move—Here’s How to Do It Safely

Photo, posted August 17, 2012, courtesy of Joshua Mayer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The human impact on biodiversity

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Biodiversity is under threat.  More and more plant and animal species are disappearing and humans are to blame.  Humans cause biodiversity loss through habitat destruction, invasive species, pollution, direct exploitation, and climate change, all of which are significantly influenced by human activities.

But until now, drawing broad conclusions about human impacts on biodiversity has been difficult because a clear, global overview of how human activity affects nature across all species did not exist. Most studies have focused on specific places, impacts, or time periods.

To fill these research gaps, a research team from the University of Zurich in Switzerland and the Swiss Federal Institute of Aquatic Science and Technology conducted an unprecedented synthesis study.  The researchers compiled data from around 2,100 studies that compared biodiversity at almost 50,000 sites affected by humans with similar places that hadn’t been affected by humans. 

The synthesis study, which was recently published in the journal Nature, found humans are having a highly detrimental impact on biodiversity worldwide.  In fact, not only is the number of species declining, but the composition of species communities is also changing.  On average, the number of species at impacted sites was almost 20% lower than at unaffected sites.

The study, which is one of the largest ever conducted on this topic, highlights the widespread negative impact of human activities on nature, and emphasizes the need to consider all forms of life when assessing biodiversity loss. 

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The Devastating Human Impact on Biodiversity

Photo, posted November 19, 2014, courtesy of Green Mountain Girls Farm via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Almost a dire wolf

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Researchers around the world are working on what some call the ‘de-extinction’ of iconic animals of the past such as the wooly mammoth, the dodo, and the Tasmanian tiger.  The idea is to decipher the genome from DNA of preserved specimens and, using the tools of modern genetic engineering and cloning technology, alter the DNA of closely related modern species to recreate the extinct species.

A company called Colossal Biosciences recently announced that it has brought back the dire wolf, a species that has been extinct for 10,000 years.  Dire wolves have white coats and are larger than modern wolves, have more powerful shoulders, a wider head, and larger teeth and jaws.  Colossal is now raising three wolves they have engineered at a 2,000-acre site at an undisclosed location.

 The wolves were created by taking the DNA of modern grey wolves and editing 14 genes substituting ones from ancient dire wolf specimens.  Wolves have about 19,000 genes, so the changes from the grey wolf genome are very minor but enough to produce an animal that looks just like a dire wolf.  But is it a dire wolf?

It really isn’t.  Ancient DNA is always greatly damaged.  Only parts of it survive.  We don’t actually have the complete genome of the dire wolf.  What we have is bits and pieces that, thanks to modern technology, allow us to produce a phenotype of a dire wolf; that is, an animal with the same observable features. 

Whether this accomplishment is a worthwhile and appropriate thing to do is a question that continues to be debated.

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The Return of the Dire Wolf

Photo courtesy of Colossal Laboratories & Biosciences.

Earth Wise is a production of WAMC Northeast Public Radio

The American butterfly census

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There has been a great deal of interest in the plight of monarch butterflies in this country.  Monarchs’ population and migratory habits are closely watched, and many people have been planting milkweed in their gardens to help their caterpillars.  But other butterfly species have received much less attention despite the fact that many butterfly populations are in decline.

A groundbreaking new study has provided comprehensive answers about the status of butterflies in America.  Over the past 20 years, the contiguous US has lost 22 percent of its butterflies.

The study is based on over 12 million individual butteries counted in 77,000 surveys across 35 monitoring programs from 2000 to 2020.  Three hundred forty-two butterfly species in total were analyzed.  Thirty three percent showed statistically significant declines while less than 3% displayed statistically significant increases.  Overall, 13 times as many species decreased as increased.

Why are butterfly populations crashing?  Experts point to a combination of factors:  habitat loss as land in converted for agriculture or development, climate change, and pesticide use.  It is not clear which factor is most important and may well vary by location.  Pesticide use – especially neonicotinoids – has been shown to play a particularly lethal role in studies. 

Insects including butterflies play a huge role in supporting life on earth.  They pollinate plants, feed birds and many other creatures in the food web.  Nature collapses without them.  And butterflies are clearly in trouble.

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See How Butterflies Are Surviving, or Not, Near You

Photo, posted August 9, 2016, courtesy of Rachel Larue/Arlington National Cemetery via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Bad news for birds

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The 2025 U.S. State of the Birds report was released recently.   The report is produced by a coalition of leading science and conservation organizations.  The bottom line is that there have been continued widespread declines in American bird populations across all mainland and marine habitats. 

More than one-third of U.S. bird species are of high or moderate conservation concern.  Among these, 112 are tipping point species that have lost more than 50% of their populations over the last 50 years. 

Protecting bird species is not just about biodiversity and stewardship of nature.  Wild birds have surprisingly large economic impact.  Nearly 100 million Americans are engaged in birding activities which contribute substantially to local and state economies.  The 2022 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation estimated that the total economic output related to bird watching activities was an amazing $279 billion and birding-related activities support 1.4 million jobs.  Bird watching and other encounters with nature are beneficial for human well-being, including reducing stress, anxiety, and depressive symptoms.

The rapid declines in birds are related to habitat loss, environmental degradation, and extreme weather events.  Moreover, if conditions are not healthy for birds, they are unlikely to be healthy for people as well.  Fortunately, many actions that are good for birds are good for us, so conservation efforts going forward are important.

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State of America’s birds: Population declines continue

Photo, posted October 30, 2018, courtesy of Shenandoah National Park via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Microplastics and birds

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Microplastics are tiny plastic particles, less than 5 millimeters in size, that come from the breakdown of larger plastics, synthetic fibers, microbeads, and tire wear.  Microplastics are found in oceans, rivers, soil, and even the air we breathe. These particles can take hundreds of years to degrade, spreading across ecosystems and accumulating in unexpected places, such as deep-sea sediments and Arctic sea ice.

According to a new study by researchers from the University of Texas at Arlington, microscopic plastic pollutants drifting through the air are lodging in the lungs of birds.  These findings raise  significant concerns about the impact on their respiratory health, but also raise alarms about potential risks to human health.

Birds were chosen for the study because they are found in almost every corner of the world and often share environments with humans. 

In the study, the research team examined 56 different wild birds from 51 distinct species, all sampled from the Tianfu airport in western China.  The researchers found high concentrations of microplastics in bird lungs, with an average of 221 particles per species.  The most common types identified were chlorinated polyethylene, which is used for insulating pipes and wires, and butadiene rubber, which is a synthetic material in tires.

Although there is no established “safe” level of plastic particles in lung tissue, high levels of microplastics have been linked to serious health risks, including heart disease, cancer, respiratory issues, and fertility problems.

The study highlights an urgent need to tackle plastic pollution in the environment because of its far-reaching impact on ecosystems and human health.  

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Birds breathe in dangerous plastics—and so do we

Photo, posted January 28, 2017, courtesy of Pete Richman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tigers in India

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The Anthropocene is the term that describes the current era in Earth’s history when human activities are having a significant impact on the planet.  It is an epoch filled with species extinction and species attrition in both numbers and range.  The population of large carnivores are among the most affected species and recovering these animals that play important roles in ecosystems is a formidable challenge.

Tigers in Asia are a prime example of extirpation – removal of a species from a specific area.  They have been eliminated in more than 90% of their historic Asian range over the past century.  A new study, published in Science has found that tigers in India are making a comeback.

India’s National Tiger Conservation Authority estimates that between 2010 and 2022, India’s tiger population grew from 1,706 to 3,682.  Tigers are thriving not only on protected lands but also near some human communities.

Tigers are gone from poorer areas where poaching was prevalent and from areas affected by the violent conflict associated with India’s Maoist rebellion.  On the other hand, the big cats can be found near some prosperous communities where poaching is rare.  Farmers keep cattle in enclosures to protect them from tigers.  

The success in protecting tigers in India could provide some insights for Europe where wolves are making a comeback, and perhaps even in the American West where the resurgence of wolf populations is triggering a violent backlash.

Large predators can survive in the modern world with creative thinking and willingness to find a balance between protection and coexistence.

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India Doubled its Tiger Population in a Little More Than a Decade

Photo, posted January 8, 2014, courtesy of Roderick Eime via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sharks and rays in a warming world

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Sharks and rays belong to a group of cartilaginous fish called elasmobranchs, which have been swimming in the world’s oceans for 450 million years. The resilient species have survived five mass extinction events, and are older than dinosaurs, trees, and Mount Everest. 

But despite their resilience, many species of sharks and rays today are threatened by human activities, including overfishing, habitat loss, and climate change.  In fact, according to a new study led by researchers from the University of Vienna in Austria, more than one third of the shark and ray species known today are severely under threat. 

The study, which was recently published in the journal Biology, found that higher carbon dioxide levels were having a negative effect on sharks and rays, ranging from impacts on the animals’ senses to changes in the skeleton during embryonic development.  An examination of fossil records found that higher CO2 levels had contributed to the extinction of individual shark and ray species in the past. 

But the study also found that global warming could be creating opportunities for sharks and rays.  Rising sea levels and higher temperatures have historically expanded shallow coastal habitats and warm waters, supporting species biodiversity.

But according to the research team, the rapid environmental changes, combined with the impacts from human activities, outpace the ability of sharks and rays to adapt, making it unlikely that they will benefit from global warming.

Protecting sharks and rays is crucial not only for their survival but also for maintaining entire ocean ecosystems. Without top predators, these ecosystems could collapse, impacting both marine life and the people and industries that depend on it.

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Sharks and rays benefit from global warming – but not from CO2 in the Oceans

Myths About Sharks and Rays

Photo, posted November 27, 2007, courtesy of Laszlo Ilyes via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Microplastics in Antarctica

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Microplastics are small plastic pieces less than five millimeters long and typically far smaller than that.  They come from a variety of sources, often from larger plastic debris that degrades into smaller and smaller pieces.  There are also microbeads, which are tiny pieces of manufactured polyethylene plastic that are added to various health and beauty products.  Tiny bits of plastic easily pass through filtration systems and end up in the ocean and other bodies of water.

Microplastics are a pervasive problem for which nowhere on Earth is truly untouched.  Despite stringent regulations on materials entering Antarctica, scientists have discovered microplastics in the snow near some of the deep field camps there.

A study by the British Antarctic Survey made use of a new and advanced technique that can detect microplastics as small as 11 microns – about the size of a red blood cell.

The research team found microplastics at concentrations ranging from 73 to 3,099 particles per liter of snow. 

Snow samples from three different sites identified polyamide (used in textiles), polyethylene terephthalate (found in bottles and packaging), polyethylene, and synthetic rubber.  The results suggest that at least the polyamide, which accounted for half the microplastics found, came from local sources.

Additional research is needed to fully understand the sources of microplastic pollution in Antarctica and to understand the broader implications of microplastics in that frozen wilderness. Microplastics have already been detected in several penguin, seal, and fish species.

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Microplastics discovered in Antarctica

Photo, posted February 3, 2015, courtesy of Christian Stangl via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Is de-extinction possible?

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Advances in genomics have created the possibility of bringing back extinct species from the past by making use of recovered DNA from preserved specimens.  Companies attempting to “de-extinct” iconic species have received hundreds of millions of dollars from venture capitalists.

These companies are trying to bring back iconic species that include ivory-billed woodpeckers, Tasmanian tigers, dodos, passenger pigeons, and woolly mammoths. 

Efforts to recreate extinct species are controversial.  The arguments in favor include the positive effects on ecosystems when keystone species are restored, and the excitement generated about conservation in general.  The opposing view is that concentrating all this effort on these restorations diverts attention and funding from more urgent conservation work.

A more nuanced viewpoint that has emerged is that actually de-extincting species is not possible.  The genome of these vanished species cannot be reconstructed perfectly.  Specimens are not cryopreserved from when the animal died.  What can be retrieved is at best significant fragments of the genome.  These are combined with DNA from related contemporary animals to produce the new species.   

As a result, what emerges are proxies.  They are animals that are similar to extinct animals – in some cases convincingly so – but they are not the same species that existed in the past.   They may be able to fill the same ecological niches and they may have similar behavior.  But they are not de-extincted specimens of the past species.  Is it worth doing?  Quite possibly but it’s not actually bringing back what is gone.

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Despite Biotech Efforts to Revive Species, Extinction Is Still Forever

Photo courtesy of Grazelands Rewilding.

Earth Wise is a production of WAMC Northeast Public Radio

Wrong trees in the wrong places

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Temperatures in cities are rising around the world and urban heat stress is already a major problem.  Extensive surfaces of man-made materials absorb the sun’s energy, and lead to temperatures well above those in the surrounding countryside.  This is known as the urban heat island effect, and it can lead to greater energy use, higher air pollution levels, and a greater risk of heat-related illnesses, as well as death. 

Some cities have already started implementing mitigation strategies, with tree planting prominent among them.  Planting trees can cool the climate by absorbing carbon dioxide, providing shade, and releasing water vapor, which lowers air and surface temperatures. 

However, while trees can cool cities significantly during the day, new research from the University of Cambridge in the U.K. shows that tree canopies can also trap heat and raise temperatures at night. 

According to the study, which was recently published in the journal Communications Earth & Environment, planting the wrong species or the wrong combination of trees in suboptimal locations or arrangements can limit their benefits.

The researchers found that in temperate climates, trees can cool cities by up to 6°C during the day but can increase nighttime temperatures by 1.5°C.  Cities with open layouts in temperate and tropical climates benefit from a mix of evergreen and deciduous trees, enhancing cooling by 0.5°C more than in cities with only deciduous or evergreen trees. 

The researchers hope their findings will help urban planners choose the best combinations of trees and planting locations to combat urban heat stress.

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Wrong trees in the wrong place can make cities hotter at night, study reveals

Photo, posted October 29, 2017, courtesy of Lars Plougmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)