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Deer vs. caribou

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The combination of a warming climate and human disruption of traditional habitats has been causing changes in the ranges of many animal species.  Over the past century, white-tailed deer have greatly expanded their range in North America.  Researchers from a group of Canadian institutions have been investigating the expansion of the deer in the boreal forest of Western Canada.  A five-year study used 300 wildlife cameras throughout the region to track the activities of large mammals.

Climate change has created milder winters and habitat alteration from forestry and energy exploration have created new food sources for deer. 

The expansion of deer in the forest has not been a good thing for the woodland caribou. The species was designated as threatened in 2002.  As of 2011, only 34,000 remained in the region.  Deer are ecosystem disruptors, in this case disrupting existing predator-prey dynamics.  Areas with more deer typically have more wolves and wolves are predators of caribou.  Deer can handle high predation rates, but the already threatened caribou cannot.

Understanding the relative roles of climate and human land use is essential in efforts to recover caribou populations.  It is complicated because further north, the climate becomes harsher and human land use decreases.  The debate over the relative effect of climate or habitat change is one of the most pressing issues facing ecologists globally as they pursue efforts for ecosystem restoration.

In any case, winter severity is expected to decline as climate change progresses.  Therefore, deer are expected to keep expanding northward and increasing in abundance, which means increasing risk to caribou.

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Deer are expanding north, and that’s not good for caribou

Photo, posted January 12, 2016, courtesy of Gerry via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Oases and desertification

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Oases are important sources of water for people, plants, and animals in the world’s desert areas.  In fact, oases sustain 10% of the world’s population despite taking up only about 1.5% of land area.  They form when groundwater flows and settles into low-lying areas or when surface meltwater flows down from nearby mountains and pools.

New research from the Chinese Academy of Sciences has found that oases added 85,000 square miles of new area from 1995 to 2020, mostly from artificial expansion projects, but over the same period lost 52,000 square miles from desertification and water scarcity.  The net gain of 33,000 square miles is not considered to be sustainable given that it was mostly due to artificial causes.  The oasis expansion projects were in Asia but losses due to desertification were also mostly in Asia.

Today, oases are found in 37 countries.  Increases in oases mostly come from people intentionally converting desert land into oases using runoff water and groundwater pumping, creating grasslands and croplands. This mostly has taken place in China.

Human over-exploitation of dwindling groundwater can limit the sustainability of oases as can the long-term loss of glaciers.

The study highlighted ways to sustain healthy oases, including suggestions for improving water resource management, promoting sustainable land use and management, and encouraging water conservation and efficient water use.  As the climate continues to change, these efforts will be increasingly important for a significant portion of the world’s population.

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World’s Oases Threatened By Desertification, Even As Humans Expand Them

Photo, posted August 3, 2008, courtesy of Paul Williams via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Major species turnover forecasted for North American cities

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Climate change affects animal species in many ways.  It induces habitat loss, disrupts migration and breeding patterns, threatens marine life, and facilitates an increased spread of disease.  It may also affect where animals can be found in the future. 

According to a new study led by researchers from the University of Toronto Mississauga and Apex Resource Management Solutions in Canada, climate change may dramatically affect the animal species observed in North American cities by the end of the century.

The researchers used species distribution data combined with machine learning to study the impact of human-caused climate change on more than 2,000 animal species historically found in the 60 most populous North American cities. 

According to the research team, changes in biodiversity are brewing for almost every city it studied by the year 2100.  In fact, cities with a rich history of biodiversity are predicted to have the largest declines and fewest gains in species. Cooler and wetter cities like Quebec, Ottawa, Winnipeg, Kansas City, and Omaha are expected to welcome the most new species.  Warmer cities with higher precipitation – like cities in coastal California – are projected to lose the most species. 

More than 95% of bird and insect species are predicted to experience a change in the number of cities they call home.  Canines, most amphibians, and aquatic birds are expected to experience the greatest losses.  Toads, turtles, mice and pelicans are projected to become more common overall. 

The researchers hope their findings will encourage more efforts to protect biodiversity.

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North American cities may see a major species turnover by the end of the century

Photo, posted September 29, 2013, courtesy of Jonathan Kriz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An ice-free Arctic

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According to a new study by Colorado University, Boulder, the Arctic could see summer days with practically no sea ice as soon as sometime in the next few years.  Earlier predictions for when the first ice-free day in the Arctic could occur were sometime well into the 2030s.

By mid-century, the Arctic is likely to see an entire month without floating sea ice.  This would likely be in September, when ice coverage is at its minimum.  By the end of the century, the ice-free season could last for many months during the year.

Technically, an ice-free Arctic does not mean zero ice in the water.  The working definition is less than 386,000 square miles of ice, which represents less than 20% of what the minimum ice coverage was in the 1980s. In recent years, the coverage has been about 1.25 million square miles.

Sea ice coverage is a big deal because many Arctic animals rely on sea ice for survival, including seals and polar bears.  With warmer ocean water, invasive fish species could move into the Arctic Ocean, upsetting local ecosystems.  Sea ice loss also is a risk for coastal communities because the ice buffers the impact of ocean waves on the coastal land.  As the ice retreats, ocean waves would get bigger, eroding the coasts.

At this point, an ice-free Arctic is basically inevitable, but its annual duration will depend on society’s efforts to reduce carbon emissions.  Lengthy periods of minimal sea ice would transform the Arctic into a completely different environment with global effects that are mostly highly undesirable.  However, Arctic sea ice is resilient and could return fairly quickly if the atmosphere cools down.

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The Arctic could become ‘ice-free’ within a decade

Photo, posted July 9, 2022, courtesy of Reiner Ehlers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Golf courses gone wild

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Golf courses are a significant burden on the environment.  The US has 16,000 golf courses which use 1.5 billion gallons of water a day and are treated with 100,000 tons of nitrogen, phosphorus, and potassium each year.  In recent years, the golf industry has taken steps to lighten its environmental toll by using less water, introducing pollinator-friendly plants, and decreasing pesticide and fertilizer use.  The US has more golf courses than any other country, accounting for 42% of all courses worldwide.

There is really an oversupply of golf courses and, as a result, more golf courses have closed than have opened since 2006.  Most closed golf courses end up in the hands of commercial or residential developers, but some of them are allowed to return to nature.

For this to happen, there has to be a willing seller and, more importantly, a conservation-minded buyer who can afford both to purchase the land and to restore it to a natural state.  There have been 28 former golf courses transformed into public green spaces between 2010 and the end of 2022.  But that number seems to be growing.

In 2023, the former Cedar View Golf Course on the eastern shore of Cayuga Lake in upstate New York was bought by the Finger Lakes Land Trust.  In California, places like Santa Barbara, Marin County, and even Palm Springs have all undertaken the transformation of former golf courses into public parklands.

Rewilding a golf course is undoubtedly a disappointment to local golfers, but it can bring big benefits to animals, plants, and people. 

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After Shutting Down, These Golf Courses Went Wild

Photo, posted October 19, 2016, courtesy of Cabo Girao via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Bio-based products on the rise

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There is a growing global movement working towards replacing conventional synthetic products – ones that are toxic to make or use, difficult to recycle, and have large carbon footprints – with products made from plants, trees, or fungi that can be safely returned to the earth at the end of their useful life.  This so-called bioeconomy is in its infant stages, but there is increasing interest in turning successful research into manufactured products.

One example is nylon.  Nylon was created in the 1930s by DuPont.  It has been used and continues to be used in a wide range of products.  The problem with it is that it is made from petroleum, it doesn’t biodegrade, and producing it generates nitrous oxide, which is a problematic greenhouse gas.

A San Diego-based company called Genomatica has developed a plant-based nylon using biosynthesis, a process in which a genetically engineered microorganism ferments plant sugars to create a chemical intermediate that can be turned into the nylon-6 polymer, and then into textiles. 

The impetus for developing bio-based products includes the growing public disgust at the mounting environmental toll of plastic, not the least of which is that people and animals are increasingly ingesting it.  Coupled with this, there is a rapidly-growing torrent of funding, especially in the US and Europe, aimed at accelerating the transition away from products that are non-biodegradable, toxic, and that produce carbon emissions.   Last September saw the launch of the National Biotechnology and Biomanufacturing Initiative which will support research and development on such topics as the use of sustainable biomass and waste resources to make non-toxic, bio-based fuels, chemicals, and fertilizers.

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From Lab to Market: Bio-Based Products Are Gaining Momentum

Photo, posted May 27, 2010, courtesy of André C via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Flower power in agriculture

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Agriculture is the world’s largest industry.  When managed sustainably, agricultural operations can provide many environmental benefits, such as protecting watersheds and habitats, and improving soil health and water quality.  Sustainable agriculture also embraces biodiversity by minimizing its impact on wild ecosystems and incorporating numerous plant and animal varieties into farm ecosystems.

A new study of farms in India has demonstrated the power of incorporating flowers into farming practices.  According to the research by ecologists from the University of Reading in the U.K. and the M.S. Swaminathan Research Foundation in India, planting flowers beside food crops attracts bees, boosts pollination, and improves both the yield and quality of crops.

 The study, which was recently published in the Journal of Applied Ecology, is the first of its kind in India.  The researchers focused on moringa – which is a nutrient-packed superfood native to South India, and bees – the plants’ essential pollinators. 

Working alongside farmers, the researchers planted marigold and red gram crops alongside moringa trees across 12 moringa orchards.  They found that flower-visiting insect numbers and diversity were 50% and 33% higher, respectively, in orchards with floral interventions compared to those without them.  Floral interventions also led to larger moringa pods and a 30% increase in harvestable fruits.

India has many crops of high economic and nutritional value.  The study highlights how farmers can significantly improve crop pollination services and boost yields, while also managing their lands in a more sustainable manner.

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Flower power on Indian farms helps bees, boosts livelihoods

Floral interventions on farms boost pollinators and crop yields

Photo, posted June 24, 2008, courtesy of Jim via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Deeper corals bleaching

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When ocean waters get too warm, corals – which are actually tiny animals – eject the colorful algae that inhabit their tissues.  The symbiotic relationship between coral polyps and algae is essential to coral survival   When the algae is ejected, previously colorful coral turns white, and the coral can ultimately die.  If waters cool off, the algae can reestablish themselves and the coral can regain its color and health.

The world’s oceans have been warming at an unprecedented rate, making coral bleaching and die-off a global phenomenon.  It is estimated that half of the planet’s reefs have already disappeared.  Some places are worse off than others.  For example, almost 95% of coral reefs in Southeast Asia are threatened.  Florida’s reefs are especially threatened, particularly since there have been unprecedented marine heatwaves off its coast.

It has long been assumed that deeper reefs, where water is cooler, would remain safe from the effects of warming, but a few years ago researchers recorded coral bleaching some 300 feet underwater along the Egmont Atoll in the western Indian Ocean.  At one point, bleaching affected 80% of corals in some areas.  This discovery came as a huge surprise to oceanographers.  It was probably associated with an El Niño-like phenomenon in the waters and those reefs have mostly recovered in the intervening years.

Fairly recently, researchers have found pristine coral reefs deep down in the waters off the Galapagos Islands, where shallow reefs have largely disappeared.  There are likely to be similar reefs in the ocean depths around the world, but scientists are expressing concern that even coral reefs lying deep beneath the ocean surface may not ultimately be protected from the warming seas.

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As Oceans Warm, Coral Bleaching Seen at Greater Depths

Photo, posted June 5, 2023, courtesy of Ryan Hagerty / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking down PFAS toxins

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PFAS – per- and polyfluoralkyl substances – are a group of organic compounds that have been extensively used to provide water-, oil-, and dirt-resistance to a wide range of products ranging from non-stick pans, clothing, and packaging to paint, car polish, and fire-suppressant foam.  Exposure to specific PFAS compounds is associated with multiple adverse health effects, including altered immune and thyroid function, liver disease, kidney disease, poor reproductive and developmental outcomes, and cancer.  PFAS compounds do not break down in the environment and therefore, over time, become concentrated in plants, animals, and people.

Government agencies such as the EPA in this country and the EU have set strict limits for allowable levels of PFAS in drinking water.  Testing water for the trace amounts of PFAS that constitute the limits is time-consuming and expensive and requires complex equipment and experienced personnel.

Researchers at MIT have now introduced a technique for making a portable, inexpensive test that can easily and selectively detect PFAS in water samples.  The test makes use of a special polymer containing fluorinated dye molecules that cause the polymer to fluoresce red.  If PFAS are present in the sample, they enter the polymer and displace the dye molecules and switches off the red fluorescence. 

The new technique is suitable for on-site detection in highly contaminated regions.  Detecting smaller concentrations can be achieved with sufficient precision after pre-concentrating the samples using the process of solid-phase extraction.

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Tracking down Environmental Toxins

Photo, posted October 16, 2021, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The end of a supergiant iceberg

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In 2017, a supergiant iceberg known as A-68 calved from the Larsen C ice shelf in Antarctica. In 2020, it drifted close to South Georgia, a British island in the South Atlantic Ocean, and then began to break up.  This iceberg was enormous – nearly the size of Delaware.  When it started to break up, it released huge quantities of fresh, cold meltwater in a relatively small region.

Scientists from the British Antarctic Survey and the University of Sheffield have studied how the melting iceberg has affected the temperature and the salinity of the ocean surface in the area.  They found that the water near the surface was 8 degrees Fahrenheit colder than normal and the water only had about two-thirds of its normal saltiness.

The effects from the melted iceberg eventually extended well beyond South Georgia as the colder, less-salty water was carried by ocean currents to form a long plume that stretched more than 600 miles across the South Atlantic.  It also took several months to disappear.

The calving of this massive iceberg provided a unique opportunity for scientists to study the impact of iceberg melting on surface ocean conditions.  A-68 was one of the largest and most studied of all icebergs.  The study has shown that each individual melting giant iceberg can have widespread and long-lasting impacts on ocean conditions, which has consequences for the plant and animal life that lives there.

Climate change is likely to lead to more giant iceberg calving in the future.  It is important to monitor these events to assess their future impacts on ocean circulation, biology, and even seafloor geology.

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Supergiant iceberg makes surrounding ocean surface colder and less salty

Photo, posted October 24, 2018, courtesy of Jefferson Beck / NASA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Megafires and ecosystems

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Wildfires are a natural phenomenon.  They have occurred long before there were people around.  Ecosystems adapt to fires and some species can benefit from them or even depend upon them.  But in recent times, fires have been intensifying and increasing in frequency and they are beginning to outstrip nature’s ability to bounce back from them.

So-called megafires – ones that dwarf typical wildfires in size – have an immediate ecological toll.  They kill individual plants and animals that might have survived smaller fires. 

Over millennia, many species of plants and animals have evolved to adapt to periodic fires.  They are especially sensitive to smoke and take protective action in a timely fashion. Others take advantage of food sources that arise when trees burn.

But even species that capitalize on burned-out areas of forests require oases of healthy woodland for at least part of their activities.  When fires are too widespread, such oases are too few and far between.

Animals that survive fires must find food, water, and shelter in the aftermath.  And all air-breathing animals are going to be impacted by smoke exposure because the chemicals in smoke are toxic to them as well as to people.

In places like Canada’s Northwest Territories, repeated fires have transformed some forests, eliminating dominant tree species and replacing them with others whose light seeds were carried on the wind.

Scientists have estimated that increased global fire activity could push more than 1,000 threatened plant and animal species closer to extinction.  Changing fire patterns are transforming landscapes and utterly remaking ecosystems.

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How Megafires Are Remaking the World

Photo, posted December 19, 2022, courtesy of Brian Pippin/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Spooky Reality | Earth Wise

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According to the National Retail Federation, American consumers will spend a whopping $12.2 billion on Halloween this year, exceeding last year’s record of $10.6 billion.  A record number of people – 73% of Americans – will also participate in Halloween-related activities this year, up from 69% in 2022.  But it’s not just our wallets that take a beating. 

Halloween generates a frightening amount of waste.  Picture all those flimsy and often single-use costumes, polyester cobwebs, plastic-wrapped candy, mass-produced decorations, and so forth. Scary stuff!  Here are some simple tricks to make the holiday more sustainable this year. 

Invest in quality costumes.  Those mass-produced costumes leave the largest carbon footprint from Halloween.  They are often made from non-recyclable plastic and most end up in landfills by mid-November.   By renting, thrifting, swapping, or making your own costumes, many of the negative impacts of dressing up for the holiday can be avoided.

Find environmentally-friendly decorations and supplies.  For example, carve local pumpkins and either save the seeds and flesh to eat later, compost it, or feed it to animals.  Make your own spooky decorations.  If you do buy decorations, ensure that they are durable and reusable.  And use wicker baskets, old bags, or pillowcases when trick-or-treating.

Finally, purchase organic and fair trade candy if you’re able to do so.  Some of the largest candy manufacturers are major drivers of deforestation and species extinction around the globe due to their demand for sugar, palm oil, and cocoa beans.

Together, we can “green” Halloween.  

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Halloween Data Center

Photo, posted November 13, 2019, courtesy of Christian Collins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Finding Homes For Rhinos | Earth Wise

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Northern White Rhinos are virtually extinct; only two female individuals survive in Kenya.  Southern White Rhinos also nearly vanished early in the 20th century, mostly because of excessive hunting.   A surviving group of fewer than 100 animals was identified in South Africa, and ongoing conservation efforts led to the existing population of southern white rhinos, which now numbers more than 16,000.

Among the most successful conservation efforts took place at a 30-square-mile farm, Platinum Rhino, that was set up in 2009 about 100 miles southwest of Johannesburg.  The owner of the farm did a great job of maintaining genetic diversity of the herd and protecting it from poachers.  Eventually, it was costing $175,000 a month just for security against illegal hunters seeking rhino horns.

Faced with unsustainable expenses, the farm put the herd of 2,000 rhinos up for auction in April with a starting price of $10 million.  No bidders came forward. 

Fortunately, in September, the conservation group African Parks announced that it had reached a deal to take over the herd.  African Parks partners with 12 countries in Africa to manage 77,000 square miles of protected areas.

The plan is to start moving the rhinos into a series of new sites in the wild starting next year.  Moving the 5,000-pound animals to new locations will be complicated and expensive, costing anywhere from $1,500 to move a single rhino by land within South Africa to $50,000 for far afield air transport.  African Parks is now raising funds to relocate the animals.

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Now Available: 2,000 Rhinos, Free to Good Homes With Plenty of Space

Photo, posted September 4, 2023, courtesy of Eric Huybrechts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Cost Of Invasive Species | Earth Wise

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According to a new report published by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services for the United Nations, invasive species introduced to new ecosystems around the world are causing more than $423 billion in estimated losses to the global economy every year.  These economic costs are incurred by harming nature, damaging food systems, and threatening human health.

According to the report, these costs have at least quadrupled every decade since 1970 and the estimates are actually conservative because it’s difficult to account for all of the effects of invasive species.

The report estimates that humans have intentionally or unintentionally introduced more than 37,000 species to places outside their natural ranges.  More than 3,500 of them are considered invasive because they are harmful to their new ecosystems.  Invasive nonnative species were a major factor in 60% of known extinctions of plants and animals.

Some species are relocated deliberately by the wildlife trade and international shipping.  Other plants and animals end up hitching a ride with ordinary travelers as they move about by car, boat, plane, or train. 

Invasions can damage human health.  Mosquitos that transmit diseases like malaria, dengue fever, and the Zika virus have become invasive around the world. The wildfires in Hawaii this summer were fueled by invasive nonnative grasses in a warming climate. 

Nearly every country in the world has agreed to participate in a sweeping agreement to preserve biodiversity and reduce invasive species.  It is an essential global goal.

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Invasive Species Are Costing the Global Economy Billions, Study Finds

Photo, posted June 2, 2022, courtesy of Sam Stukel (USFWS) via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Captive Lion Problem | Earth Wise

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In the 1990s, there was rapid growth in South Africa of the private wildlife industry.  Large numbers of cattle, sheep, and goat ranchers replaced their domestic livestock with wild animals that wealthy hunters would pay lots of money to shoot.  Lions were among the most prized targets for these people.  Over time, hundreds of ranchers became involved in the business of breeding large numbers of the big cats in cages or small enclosures.  Wealthy clients paid $25,000 to $40,000 to shoot a captive-bred lion – cheaper than the cost of a true wild lion hunt and much easier too.  The animals were not afraid of humans and were easy to find.

By 2015, about 200 ranches held at least 8,000 captive-bred lions.  Over 600 were trophy-hunted that year, generating about $16 million in trophy fees, mostly from Americans.

Journalists and conservationists exposed poor conditions on many lion farms and many other abuses.  Over time, the South African government cracked down on the export of lion bones and other body parts for taxidermy, traditional Chinese medicine, and other uses.  The days of captive lion breeding seemed numbered but shutting down the lucrative industry is not easy.

Wild lions in South Africa are not endangered.  In fact, existing sanctuaries and preserves have as many lions as they can sustain.  What to do with thousands of captive lions is a real problem.  Some have suggested mass euthanasia, but that appalling idea has garnered very little support.  The future of these animals still hangs in the balance and so far, there are really no truly desirable solutions in the offing.

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If South Africa Ends Lion Breeding, What to Do With Captive Cats?

Photo, posted August 21, 2011, courtesy of Leszek Leszczynski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryo Conservation | Earth Wise

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Recent studies have shown that there has been a 69% decline in global animal populations since 1970.  There is a biodiversity crisis in the world.  In the face of this situation, there is a growing interest in using cold storage to preserve genetic samples taken from animals threatened with extinction.

Just as egg-freezing is used to preserve human fertility for a later date, the cryogenic freezing of genetic material from animals could be important in reducing species extinctions.  Living cell banks – also known as cryobanks – could preserve genetic materials from animals that include skin cells, embryos, semen, and live tissues.  These materials could be cultured and used for various applications including DNA extraction, assisted reproduction, ensuring genetic diversity in animal populations, and potentially reintroducing species back into their natural habitats.

There is a facility called the Frozen Zoo at the San Diego Wildlife Alliance which has genetic material from 965 different species, including 5% of the vertebrates currently listed as threatened on the IUCN Red List.  Further sampling from zoos and aquariums could increase that representation to almost 17%.

Genetic samples of 50% of the species currently listed as extinct in the wild are already represented in the Frozen Zoo.  Further sampling from the zoological community could increase this number to 91%.  This could provide a critical lifeline for these species that are on the brink of extinction.  As wildlife populations continue to decline around the world, it is more critical than ever to collect and preserve genetic samples from threatened species.

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Cryo conservation – a cool solution to saving species from extinction

Photo, posted September 30, 2018, courtesy of Andy Morffew via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Orcas Versus Boats | Earth Wise

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Over the past three years, orcas (also known as killer whales) have been attacking boats off the coasts of Portugal and Spain.  The subpopulation of orcas in this region has been harassing boats, most often by biting at their rudders.

There have been over 500 reported instances of orcas reacting to boats.  Sometimes they simply approach the vessels, but some of the time they actually attack.  Almost 20% of the attacks have caused enough damage to disable the vessels.  In three cases, including one in May in the Strait of Gibraltar, the animals damaged a boat so badly that it sank.  To date, no one has been injured during these attacks.

Orca researchers have observed several different killer whales during these attacks.  They seem to come from two separate groups: a trio of juveniles occasionally joined by a fourth, as well as a mixed-age group consisting of an adult female, two of her offspring, and two of her sisters.  The attacks typically last less than 30 minutes but can go on for up to 2 hours.

Researchers don’t really know why orcas are going after watercraft.  This behavior has not been observed anywhere else in the world.  One theory is that the orcas have invented a new fad.  That’s actually something that they are known to do.  Much as with people, orca fads are often spearheaded by juveniles.  An alternative theory is that the attacks may be a response to a bad past experience involving a boat.  The fact that nobody has been injured in any of these attacks, even when the boats sank, suggests that only the boats themselves are the target of the attacks and not the people on them.

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Why Has a Group of Orcas Suddenly Started Attacking Boats?

Photo, posted May 24, 2023, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Climate Change And Species Tipping Points | Earth Wise

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In climate science, tipping points are critical thresholds that, once crossed, lead to large and often irreversible changes in the climate system. For example, surpassing a 1.5 degree C rise in global warming has long been considered a tipping point for the planet. 

According to a new study led by researchers from University College London, climate change will abruptly push species over tipping points as their geographic ranges reach unforeseen temperatures. 

In the study, which was recently published in the journal Nature Ecology and Evolution, the research team analyzed data from more than 35,000 species of animals and seagrasses from every continent and ocean basin, alongside climate projections up to 2100.  The researchers found a consistent trend:  for many animals, the thermal exposure threshold will be crossed for much of their geographic range within the same decade. 

The thermal exposure threshold is defined as the first five consecutive years where temperatures consistently exceed the most extreme monthly temperature experienced by a species across its geographic range over recent history. 

The researchers also found that the extent of global warming will make a big difference for animals.  If the planet warms by just 1.5°C, 15% of species studied will be at risk of experiencing unfamiliarly hot temperatures across at least 30% of their current  geographic range in a single decade.  But this figure will double to 30% of species at 2.5°C of warming.

Since their data provides an early warning system, the researchers hope that their findings will help species conservation efforts. 

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Climate change to push species over abrupt tipping points

Photo, posted May 27, 2017, courtesy of Sarah Lemarié via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Can All Plant Species Survive? | Earth Wise 

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Many animal populations around the world are struggling and people are mostly to blame.  Species are declining because of all sorts of things including changes in land and sea use, pollution, invasive species, and climate change.

Like many animal species, plants are also struggling to adapt to a human-dominated world.  Plants provide the planet with food, oxygen, and energy, and are used to produce fibers, building materials, and medicines.  Even though plants are easier and cheaper to protect, they are often overlooked in conservation efforts. 

According to a paper recently published in the journal Trends in Plant Science, preventing all future land plant extinctions across the globe is possible with the right approaches.  The author of the paper, Richard Corlett of the Xishuangbanna Tropical Botanical Garden in China, writes that “if zero extinction is potentially achievable for plants, a less ambitious target would be inexcusable.” 

According to the paper, one big barrier in plant conservation is the lack of trained specialists, especially in tropical areas where there is a backlog of unidentified species.  It’s likely that many “dark extinctions,” which is when species slip away without us knowing they existed, have already occurred.

Another roadblock in preventing plant extinctions is information access, which can be solved by building an online “metaherbarium.”  This collaborative database would link digitized records from herbarium specimens with photographs, status assessments, and recovery plans.

Finally, the creation of “microreserves” – which are tiny pieces of protected land designed to get around space constraints – would further contribute to effective conservation of targeted plant species. 

Zero plant extinctions should be the goal.   

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‘Zero plant extinction’ is possible, says plant ecologist

Photo, posted May 16, 2008, courtesy of Andrew Otto via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic Eating Fungus | Earth Wise

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More than five billion tons of plastic have accumulated on land and sea including the most remote regions of the planet as well as in the bodies of animals and humans.  There is a compelling need to recycle as much plastic as possible but doing so is a major challenge. Plastic comes in many varieties and breaking it down for reuse requires different methods for each.

Polypropylene is one of the biggest challenges for recycling.  It is a very common plastic used for all sorts of products including food containers, coat hangers, plastic wrap, toys, and much more. It accounts for roughly 28% of the world’s plastic waste, but only 1% of it is recycled.

Polypropylene is seldom recycled because it generally has a short life as a packaging material, and it often becomes contaminated by other materials and plastics.  Thus, it generally ends up in landfills.

Researchers at the University of Sydney in Australia have discovered that two common strains of fungi were able to successfully biodegrade polypropylene.  The fungi species – with unavoidable Latin names of Aspergillus terreus and Engyodontium album – are typically found in soil and plants.

The researchers found that the fungi were able to break down polypropylene after it had been pre-treated with either UV light or heat, by 21% over 30 days, and by 25-27% over 90 days.  This seems rather slow but compared with the nearly endless life of polypropylene in landfills, it is a major improvement.

The hope is that methods like this could ultimately reduce the amount of plastic polluting the environment by encouraging plastic to biodegrade naturally under the appropriate conditions.

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Fungi makes meal of hard to recycle plastic

Photo, posted March 5, 2010, courtesy of Kevin Krejci via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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