invasive species

Can All Plant Species Survive? | Earth Wise

June 9, 2023 By EarthWise Leave a Comment

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

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Earth Wise is a production of WAMC Northeast Public Radio

Life In The Garbage Patch | Earth Wise

May 23, 2023 By EarthWise Leave a Comment

A team of scientists has found thriving communities of coastal creatures living thousands of miles from their original homes and now ensconced on plastic debris in the Great Pacific Garbage Patch.

A new study published in the journal Nature Ecology & Evolution reports that dozens of species of coastal invertebrate organisms – including tiny crabs and anemones – have been able to survive and reproduce on plastic garbage that has been floating in the ocean for years.

The Great Pacific Garbage Patch is an area in the ocean between California and Hawaii, larger than Texas, where plastic debris has been collected by the North Pacific Subtropical Gyre, one of five huge, spinning circular currents in the world’s oceans. The patch is estimated to contain about 1.8 trillion pieces of plastic weighing an estimated 90,000 tons. The Ocean Cleanup Initiative is dedicated to removing this immense accumulation of plastic, but it is an immense job.

Researchers discovered this new ecosystem after analyzing plastic samples collected by The Ocean Cleanup organization during its expeditions in the Pacific. They were surprised to find 37 different invertebrate species that normally live in coastal water and only a dozen species that live in open waters. These species have made their way from North America and have thrived. So, the garbage patch has created a novel community that didn’t previously exist.

Debris from the Great Pacific Garbage patch constitutes the majority of debris arriving on Hawaiian beaches and reefs. Hawaii’s fragile marine ecosystems have long been protected from invasive species because of the very long distances from North America or Asia. With the coastal species now inhabiting the garbage patch, there is increased danger of colonization by them in Hawaii’s ecosystems.

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Coastal species persist on high seas on floating plastic debris

Photo, posted September 30, 2020, courtesy of Kees Torn via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Caterpillars And Light Pollution | Earth Wise

May 3, 2023 By EarthWise Leave a Comment

Most of us are familiar with air pollution, water pollution, soil pollution, and even noise pollution. But it turns out that light can be a pollutant as well, and it’s a consequence of industrial civilization. In fact, nighttime light pollution now covers approximately 23% of the globe and over 80% of inhabited regions.

Light pollution affects more than just our view of the stars. For example, light pollution can alter our circadian rhythm, disrupting our sleep cycle. In nature, light pollution can kill baby turtles by causing them to head inland instead of into the ocean, can cause birds to migrate during the wrong season, and can deter nighttime pollinators like bats. And those are just a few of the examples.

According to new research from scientists at Cornell University, moderate levels of artificial light at night – like a porch light – attract caterpillar predators and reduce the chance that caterpillars grow up to become moths.

In the study, which was recently published in the journal Proceedings of the Royal Society B: Biological Sciences, the researchers placed 552 lifelike caterpillar replicas made of soft clay in a forest to measure predation rates compared to a control group. They found that predation rates on clay caterpillars and the abundance of arthropod predators were significantly higher on the artificial light at night treatment plots. In fact, of the 552 clay caterpillars deployed and glued to leaves to look authentic, 521 models were recovered and 249 of them- or 47.8% – showed predatory marks from arthropods during the summer-long nighttime study.

In addition to light pollution, caterpillars also face major threats from habitat loss, pollution, invasive species, and climate change.

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Artificial light at night aids caterpillar predators

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Earth Wise is a production of WAMC Northeast Public Radio

Agriculture Turning Wild Plants Into Weeds | Earth Wise

February 7, 2023 By EarthWise Leave a Comment

We often hear about the importance of native plants in the environment and how invasive species can wreak havoc with ecosystems. But it turns out that human activities can change the characteristics of native species and create unexpected new problems.

Common waterhemp is plant native to North America that typically grows near lakes and streams. It never used to be any kind of problem, but in recent times it has become nearly impossible to eradicate from farms as a result of genetic adaptations triggered by modern agriculture.

A study led by researchers at the University of British Columbia looked at waterhemp samples from modern farms and neighboring wetlands and compared them with historical samples dating back as far as 1820 stored in various museums.

In recent times, mutations in genes related to drought tolerance, rapid growth, and resistance to herbicides have resulted in waterhemp that has become a pervasive weed on farms. These genetic shifts, scarcely ever seen in historical samples, have made the plant thrive among human agricultural activities and enable it to outcompete crops.

Genetic analysis of the plants showed that herbicide-resistant mutations that were mostly absent from historical samples stand out as factors that allow waterhemp to prosper in agricultural settings. There are some plants in natural habitats that have herbicide-resistant mutations, but in many cases, these mutations are actually harmful to the plants in the wild.

Understanding how plant adaptations occur on relatively short timescales is increasingly important as farming and climate change continue to drive rapid plant evolution.

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How intensive agriculture turned a wild plant into a pervasive weed

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Earth Wise is a production of WAMC Northeast Public Radio

An Agreement To Protect Biodiversity | Earth Wise

January 18, 2023 By EarthWise Leave a Comment

The UN Biodiversity Conference in Montreal in December concluded with a historic deal aimed at stemming the rising tide of extinctions. Nearly 200 countries signed on to the agreement to protect 30% of the Earth’s land and sea by the end of this decade.

Part of the agreement also pledges that countries will reduce fertilizer runoff from farms by 50%, reduce the use of harmful pesticides by 50%, and stem the flow of invasive species.

Of course, all of these promises are only words unless they are backed up by actions and actions cost money. The agreement promises to direct $200 billion a year towards biodiversity by the end of this decade. Wealthy countries were urged to provide $100 billion a year to fund the actions of poorer countries, but they resisted the pressure. Eventually, they did agree to send $30 billion a year to developing countries by 2030.

It is a significant step forward to establish clear targets for stopping biodiversity loss. However, the ultimate success of the pact will depend on the willingness of countries to cooperate and compromise.

According to UN estimates, about a million species across the globe face extinction as a result of rising temperatures, air and water pollution, invasive species, and habitat loss due to development. At present, only 16% of land and 8% of the oceans are within protected areas.

The UN Environment Program stated that “for far too long humanity has paved over, fragmented, over-extracted, and destroyed the natural world on which we all depend. Now is our chance to shore up and strengthen the web of life, so it can carry the full weight of generations to come.”

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In Historic Deal, Countries Agree to Protect 30 Percent of Earth to Halt Biodiversity Loss

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Earth Wise is a production of WAMC Northeast Public Radio

Moving Endangered Species | Earth Wise

December 5, 2022 By EarthWise Leave a Comment

People have intentionally or accidentally introduced numerous invasive species to habitats around the world. At the same time, the planet’s wildlife is in a steep decline. A recent study estimated that the populations of over 5,000 vertebrate species have declined by an average of nearly 70% since 1970. A United Nations report warns that human activity has threatened as many as a million species with extinction.

With all of this as a background, there is climate change that is altering the habitats of the world’s species – warming lakes and oceans, turning forests into grasslands, tundra into woodland, and melting glaciers. In response to these changes, living things are rearranging themselves, migrating to more hospitable locations. But many species are just not capable of finding more suitable habitats on their own.

Conservationists are now increasingly considering the use of assisted migration. In some cases, when a species’ critical habitat has been irreversibly altered or destroyed, agencies are establishing experimental populations outside of the species’ historical range. Such actions are often deemed extreme but may be increasingly necessary.

However, clear-cut cases are relatively rare. More likely, it is a more difficult judgement call as to whether assisted migration is a good idea or is possibly a threat to the ecosystem of the species’ new location. The relative dearth of assisted migration experiments is less likely a result of legal barriers than it is a lack of scientific and societal consensus on the practice. Scientists are now trying to develop risk-analysis frameworks that various agencies can use in considering potential assisted migration experiments.

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Last Resort: Moving Endangered Species in Order to Save Them

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Coping With Climate Change | Earth Wise

October 11, 2022 By EarthWise Leave a Comment

Extreme weather events including prolonged drought and heavy rainfall are becoming more common and more severe as global temperatures rise. As the climate continues to change in the coming decades, how will animals respond?

Researchers from the University of Southern Denmark have examined how different mammals react to climate change. They analyzed data on population fluctuations from 157 mammal species around the world. They compared these fluctuations with weather and climate data from the same time period. The research team had 10 or more years of data for each species studied.

The researchers found that mammals that live for a long time and/or produce less offspring – like llamas, elephants, bears, and bison – are more climate resilient than small mammals with short lives — like mice, possums, lemmings, and rare marsupials.

For example, large, long-lived mammals can invest their energy into one offspring, or simply wait for better times if conditions become challenging. On the other hand, small, short-lived mammals like rodents have more extreme population changes in the short term. In the event of a prolonged drought, large portions of their food base may rapidly disappear, and they are left to starve because they have limited fat reserves.

However, the research team notes that the ability of a species to withstand climate change must not be the only factor when assessing a species’ vulnerability. In fact, in many cases, habitat destruction, poaching, pollution, and invasive species pose a larger threat to animal species than climate change.

While the study only examined 157 species, the findings enable researchers to also predict how animals they know less about will react to climate change.

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Which animals can best withstand climate change?

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Earth Wise is a production of WAMC Northeast Public Radio

Tourism And Invasive Species | Earth Wise

March 7, 2022 By EarthWise Leave a Comment

Tourism has experienced exponential growth during the past 70 years. In 1950, there were 25 million international tourist arrivals. By 1990, it had ballooned to 435 million. Between 1990 and 2018, the numbers more than tripled reaching more than 1.4 billion. And by 2030, the number of international tourist arrivals is expected to reach 1.8 billion.

Tourism is vital to the success of many economies around the world. Tourism can boost revenue, provide jobs, develop infrastructure, protect wildlife, and help preserve heritage sites and cultures. But there can also be many downsides to tourism, one of which is that it can contribute to the introduction and spread of invasive species. Non-native organisms can cause all sorts of social, environmental, and economic damage.

Tourists help spread invasive organisms far and wide. These organisms hitch rides in their luggage and on their shoes and clothing. A 2011 study in New Zealand found that for every gram of soil on the shoes of in-bound international passengers, there were 2.5 plant seeds, 41 roundworms, 0.004 insects and mites, and many microorganisms.

A new study by researchers from the University of Melbourne in Australia and AgResearch New Zealand examined to what degree tourism plays a role in the spread of invasive species. According to the study, which was recently published in the journal NeoBiota, the research team found that the number of nights spent in hotels significantly correlated to the incursion of invasive species during that period.

Creating effective mechanisms to prevent the introduction of invasive species in the first place is the best way to prevent this problem.

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Unwelcome guests: International tourism and travel can be a pathway for introducing invasive species

Number of tourist arrivals

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Earth Wise is a production of WAMC Northeast Public Radio.

Invasive Species On Ships In Antarctica | Earth Wise

February 23, 2022 By EarthWise Leave a Comment

The Southern Ocean around Antarctica is the most isolated marine environment on Earth. Antarctica’s native species have been isolated for the last 15-30 million years. As a result, wildlife there has not evolved the ability to tolerate the presence of many groups of species.

New research by the University of Cambridge and the British Antarctic Survey has traced the global movements of all the ships entering Antarctic water and has found that Antarctica is connected to all regions of the globe via ship activity to an extent much greater than previously thought. Fishing, tourism, research, and supply ships are exposing Antarctica to invasive, non-native species that threaten the existing ecosystems.

In all, the research identified over 1,500 ports with links to Antarctica. From all these places, non-native species including mussels, barnacles, crabs, and algae attach themselves to ships’ hulls. The process is known as biofouling.

The greatest concern is the movement of species from pole to pole. These species are already cold-adapted. They may come on tourist or research vessels that spend the northern hemisphere summer in the Arctic before traveling south for the Antarctic summer season.

Mussels have no competitors in Antarctica should they be accidentally introduced. Shallow water crabs would introduce a new form of predation that Antarctic animals have never encountered before.

Current biosecurity measures to protect Antarctica, such as cleaning ships’ hulls, focus on a small group of so-called gateway ports. The new findings indicate that these measures need to be expanded to protect Antarctic waters from non-native species.

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Invasive species ‘hitchhiking’ on ships threaten Antarctica’s unique ecosystems

Photo, posted April 12, 2016, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost Of Invasive Species | Earth Wise

May 7, 2021 By EarthWise Leave a Comment

A new study published in Nature has tried for the first time to put a price tag on the impact of invasive species. Researchers have been studying the effects of invasive species for decades, but it is a problem that has not really captured the attention of the public and policy makers.

According to the research by scientists at the French National Museum of Natural History, from 1970 to 2017, invasive species have cost the global economy at least $1.28 trillion dollars in damages and efforts to control them.

The team screened over 19,000 published papers, ultimately analyzing nearly 2,000 that detailed costs of various invasions at particular times. Annual costs roughly doubled every six years, reaching a yearly bill of $162 billion in 2017.

The five costliest invasive species are Aedes mosquitos, rats, cats, termites, and fire ants, collectively accounting for a quarter of the global damage.

Asian tiger mosquitos and yellow fever mosquitos alone accounted for $149 billion in damage to public health as they spread from country to country. Rats hitchhike on human boats and drive native species to extinction on islands around the world. Cats inflict damage primarily by their impact on native biodiversity. By some estimates, they kill a billion birds each year in the US alone. Termites, as they spread across the globe, wreak havoc on all sorts of infrastructure. Fire ants can feed on a variety of seedlings, from citrus to soybeans, reduce the size of grazing lands for livestock and bite and sting farm animals and humans.

The study shows invasive species are a massive problem that is getting worse.

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Invasive Species Cost Billions of Dollars in Damages Annually, Researchers Find

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Assisting Evolution | Earth Wise

March 11, 2021 By EarthWise Leave a Comment

As plants and animals around the world grapple with climate change, invasive species, disease, and other threats, conservationists grapple with the issue of what it means to protect what is natural and how far to go to prevent extinctions.

Australia is where many of these issues have risen to the forefront. Imported mammals – particularly cats and foxes – have decimated many of Australia’s indigenous marsupials. Much of the focus for decades has been on killing off the invaders and cordoning off protected animals. In recent years, however, there have been efforts to expose prey animals to limited numbers of predators to develop prey populations that are better equipped to survive among predators. Getting rid of all the predators is not realistic. Saving species may require helping them to adapt.

On the Great Barrier Reef, where half its coral populations have perished because of rising water temperatures, scientists are breeding corals that are more heat tolerant. They are even considering the use of gene editing technology to “assist evolution” in developing corals that can survive in a changing world.

At SUNY College of Environmental Science and Forestry in Syracuse, New York, researchers have produced a genetically modified American chestnut tree that is resistant to chestnut blight, the fungal pathogen that killed off nearly every chestnut tree in North America in the early 20^th century.

The idea of conservation is to protect what is natural in our world. However, at a time when there are unprecedented threats to so many species, the distinction between what is natural and what is artificial may no longer provide a sound guide to what should be done to protect life on earth.

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Assisting Evolution: How Far Should We Go to Help Species Adapt?

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Earth Wise is a production of WAMC Northeast Public Radio.

Alien Species On The Rise | Earth Wise

November 3, 2020 By EarthWise Leave a Comment

Alien species are species that are introduced, accidentally or intentionally, outside of their natural geographic range as a result of human activities. More than 35,000 alien species have been recorded through 2005, which is the most recent year for which researchers have comprehensive global data.

Some of the alien species go on to become invasive alien species, which can have damaging impacts on both ecosystems and economies. In fact, alien species are one of the main drivers of plant and animal extinctions around the globe.

According to a new study by an international research team involving University College London, the number of alien species, particularly insects, arthropods and birds, is expected to increase globally by 36% by 2050 when compared to 2005 levels. The research was recently published in the journal Global Change Biology.

Using a mathematical model developed for the study, the researchers identified high levels of variations between regions. For example, the largest increase in alien species by the middle of the century is expected in Europe, where numbers are predicted to jump by 64%. The temperate regions of Asia, North America, and South America are also predicted to be hotspots of alien species. The lowest relative increase in alien species is expected in Australia.

The researchers do not expect a reversal or slowdown in the spread of alien species. In fact, with global transportation and trade forecasted to increase in the coming decades, they anticipate many new species will infiltrate non-native habitats by hitching rides as stowaways.

According to the research team, it would take a concerted global effort with stricter regulations and more rigorous enforcement to slow the flow of new species.

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Alien species to increase by 36% worldwide by 2050

Photo, posted October 3, 2016, courtesy of the Asian Carp Regional Coordinating Committee via Flickr. Photo credit: Ryan Hagerty/USFWS.

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Family Forests And Climate Change | Earth Wise

July 13, 2020 By EarthWise Leave a Comment

Climate experts consider sequestration and storage of carbon in trees to be among the most affordable and scalable natural climate solutions. If implemented globally, trees could provide a third of the near-term climate change mitigation needed to meet the terms of the Paris Agreement.

Small family-owned forests make up 38% of U.S. forests, a total area 1.5 times the size of Texas and more than any other ownership type. Most small landowners want to do right by their land, but they rarely have access to the expertise or resources needed to optimize their forests for carbon sequestration.

This spring, the Nature Conservancy, the American Forest Foundation, and the Vermont Land Trust announced two new programs, funded in part by a $10 million grant by Amazon, that will provide funds to small landowners to grow larger, healthier forests.

Few forests are managed for carbon sequestration. Practices like fast logging rotations, so-called high-grading that strips out the largest, most valuable trees, and rampant invasive species all compromise the ability of a forest to lock away carbon. It turns out that most small landowners would like to do better, but they don’t have the expertise or the financial resources to implement sustainable management.

Existing carbon markets are not geared towards small forest owners. Their payments are tiny and the required contract terms are onerous. The Family Forest Carbon Program commits landowners for only 10 to 20 years. Typical landowners won’t get a windfall. A 100-acre landholding would stand to earn around $24,500 over 20 years.

If these programs can sign up 20% of U.S. forest landowners, it could offset the emissions from 6 million cars.

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How Small Family Forests Can Help Meet the Climate Challenge

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What Is An Endangered Species? | Earth Wise

March 3, 2020 By EarthWise Leave a Comment

Biodiversity is declining rapidly throughout the world and people are mostly the reason. Species are disappearing because of changes in land and sea use, the direct exploitation of organisms, climate change, pollution, and invasive alien species resulting from globalization. The challenges of conserving the world’s species are many and difficult. Among these challenges are determining which species are endangered and how and when to protect them.

What constitutes an endangered species is not necessarily obvious.

Extinction risk increases as a species is driven to extinction from portions of its natural range. Most mammal species have already been driven to extinction from half or more of their historic ranges because of human activities.

According to a recent survey of ordinary Americans, three-quarters of participants said that a species deserves special protections if it had been driven to extinction from any more than 30% of its historic range. This compares with the language of the U.S. Endangered Species Act that defines an endangered species as one that is “in danger of extinction throughout all or a significant portion of its range.”

Experts and decision-makers are more accepting of risks and losses because they believe greater protection would be impossibly expensive. Decision-makers tend to be influenced by special interest groups with a vested interest in not instituting protections.

Before human activities began elevating extinction risk, a typical vertebrate species would have experienced an extinction risk of 1% over a 10,000-year period. Current policies consider a 5% risk over 100 years to be acceptable. Policies consider whether we can afford to protect species. Given the dangers of declining biodiversity, we should ask whether we can afford not to.

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What Is An Endangered Species?

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Earth Wise is a production of WAMC Northeast Public Radio.

Exotic Pets Can Become Problems

August 26, 2019 By EarthWise Leave a Comment

Each year, millions of exotic animals are sold as pets around the world. The term “exotic” lacks a set definition but is generally used to refer to an animal that’s wild or more unusual than standard pets, like cats and dogs.

The exotic pet trade is a multi-billion dollar industry, involving tens of millions of individual animals from thousands of species, including reptiles, amphibians, fish, birds, and mammals.

Some of the exotic pet trade is legal, but a lot of it isn’t. Many animals are illegally captured from the wild to meet the global demand for exotic pets.

People often purchase exotic animals without completely understanding the consequences. Some exotic pets, for example, can live nearly twice as long as the average dog. Caring for exotic pets can be both expensive and risky, since they are largely undomesticated (and therefore can have unpredictable behavior).

As a result, it’s not uncommon for owners to release exotic pets intentionally. When this happens, the consequences can be catastrophic. Sometimes the animal dies from starvation or predation, but in other instances, the animal proliferates and becomes an invasive species.

Invasive species are the second largest driver of biodiversity loss worldwide, and they cost the U.S. $120 billion a year.

According to an academic review recently published in the journal Frontiers in Ecology and the Environment, the exotic pet trade is one of the primary causes of the spread of invasive species and has fueled the establishment of hundreds of them. Tegus, Burmese pythons, and red lionfish are examples of pets-turned-pests.

The best way to combat this trend is through education, detection, and rapid response.

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Why you should never release exotic pets into the wild

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One Million Extinctions

June 14, 2019 By EarthWise Leave a Comment

A group of 145 expert authors from 50 countries has produced a report based upon a review of 15,000 scientific and government sources that is the first comprehensive look at the state of the planet’s biodiversity in 15 years. The conclusions are alarming.

Thanks to human pressures, one million species may be pushed to extinction in the next few years, something with serious consequences for human beings as well as the rest of life on earth.

Based upon scientific studies as well as indigenous and local knowledge, the evidence is overwhelming that human activities are the primary cause of nature’s decline. The report ranked the major drivers of species decline as land conversion, including deforestation; overfishing; bush meat hunting and poaching; climate change; pollution; and invasive alien species.

The tremendous variety of living species on our plant which number at least 8.7 million and perhaps many more – biodiversity – constitutes a life-supporting safety net that provides our food, clean water, air, energy, and more.

In parts of the ocean, little life remains but green slime. Some remote tropical forests are nearly silent because insects have vanished. Many grasslands are becoming deserts. Human activity has severely altered more than 75% of Earth’s land areas and has impacted 66% of the oceans. The world’s oceans increasingly are characterized by plastics, dead zones, overfishing, and acidification.

The main message of the 1,500-page report is that transformative change is urgently needed. In order to safeguard a healthy planet, society needs to shift from a sole focus on chasing economic growth. This won’t be easy, but we must come to the understanding that nature is the foundation for development before it is too late.

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One million species at risk of extinction, UN report warns

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Protecting Vulnerable Shorelines

May 21, 2019 By EarthWise Leave a Comment

Global climate change is having noticeable effects on the environment. For example, glaciers are shrinking. Plant and animal ranges are shifting and populations decreasing. And droughts, floods, and wildfires are becoming more frequent and more intense. According to the Intergovernmental Panel on Climate Change, the evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time.

Our coastal shorelines, which are already stressed by human activity, pollution, storms, and invasive species, are one of many areas expected to be further threatened by climate change. Sea level rise and more intense and frequent storms are expected to erode and inundate coastal ecosystems and eliminate wetlands. Ocean acidification is also projected to disrupt marine environments.

But according to scientists at the Massachusetts Institute of Technology, seagrasses could play a key role in protecting these vulnerable shorelines from this onslaught. The MIT research team demonstrated how the ubiquitous marine plants dissipate wave energy and help protect against erosion, which could help mitigate damage from rising seas.

Using mathematical modelling and experiments, the MIT researchers were able to quantify for the first time how large and dense a continuous meadow of seagrass must be in order to provide adequate damping of waves in a given setting. They also found that seagrasses offer significant environmental benefits, including preventing beach erosion, protecting seawalls and coastal structures, improving water quality, and sequestering carbon.

Submerged aquatic vegetation, including seagrasses, provides an ecosystem service exceeding $4 trillion annually. Hopefully these findings can help provide useful guidance for seagrass restoration efforts.

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Seagrass’ strong potential for curbing erosion

The Effects of Climate Change

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Shipping And Invasive Species

May 7, 2019 By EarthWise Leave a Comment

The increasing numbers of invasive species around the world are a major driver of biodiversity change and cause billions of dollars in economic damages annually. Climate change is a major factor in the spread of invasive species, but a new study by McGill University suggests that global shipping growth will far outweigh climate change in the spread of non-indigenous pests to new environments in the coming decades.

One of the most significant ways in which the disparate regions of the world are interconnected is via transportation networks. The global shipping network is the primary means by which materials and goods are moved worldwide, accounting for over 80% of world trade. And for this reason, the global shipping network is responsible for much of the introduction of non-indigenous species across the planet.

Living organisms are often transported through ballast water, which is taken up to stabilize cargo vessels. Other species are transported by biofouling, whereby they attach to the hulls of ships. Taken together, these two pathways account for anywhere between 60 and 90% of marine bioinvasions. (Terrestrial invaders are generally moved as a byproduct of shipping, for example by infesting wood packaging material).

The McGill study looked at trends in global shipping and how socioeconomic factors are driving change. For example, China’s share of global container throughput has gone from 1.4% in 1990 to 20.1% in 2013. So, the distribution and patterns of shipping have been changing dramatically and with it the spread of non-indigenous species.

Awareness of this issue is increasing. For example, there have been policy initiatives such as the International Ballast Water Management Convention that is an effort to control bio-invasions through measures such as ballast exchange. We need to take measures to limit the unintentional spread of species.

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