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Marine Life Moving The Wrong Way | Earth Wise

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As the oceans have warmed in recent decades, various marine species ranging from whales to corals have begun to shift poleward in search of cooler waters.  But a new study, reported in the journal Nature Climate Change, found that many sedentary marine species – including snails, worms, and mussels – are actually being transported in the wrong direction.

What is happening is that bottom-dwelling species – also known as benthic species – in the northwest Atlantic Ocean are spawning earlier in the year because of the warmer water temperatures.  But earlier in the year is when ocean currents travel southward.  As a result, the larvae of these animals are being carried into warmer waters rather than cooler ones, threatening their survival and shrinking their ranges.  These larvae grow into adults in these warmer regions and are basically trapped there.  This creates a feedback loop where the situation for the species gets worse and worse.  Species like common sand dollars and the economically important blue mussel have had a 30 to 50% contraction of their ranges.

The result is that a number of bottom-dwelling species that previously were quite abundant have entirely disappeared from the outer shelf.

The researchers at Rutgers University likened this “wrong-way migration” of bottom-dwelling marine life to so-called elevator-to-extinction events that have been taking place in mountainous regions.  This is where species such as birds and butterflies move to higher and higher elevations to escape rising temperatures until there is nowhere else for them to go.

The essential fact that this research reveals is that species don’t necessarily move to places where the climate is congenial for them.  They may unfortunately end up migrating to even worse conditions.

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As Oceans Warm, Some Species Are Moving in the Wrong Direction

Photo, posted June 10, 2016, courtesy of James_Seattle via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

An Environmental Victory In Cameroon | Earth Wise

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The Ebo Forest in Cameroon is one of the last intact forests in central Africa and is a biodiversity hotspot, home to hundreds of rare plants and animal species, including tool-using Nigeria-Cameroon chimpanzees, western gorillas, forest elephants, red colobus monkeys, and giant goliath frogs.  The 600 square miles of mountain slopes and river valleys are covered by thick tree canopies that shelter a fascinating array of species.

This past July, Cameroon Prime Minister Joseph Dion Ngute signed a decree that turned half of the Ebo Forest into a so-called forest management unit, meaning that the government could begin to sell logging concessions.

However, on August 11, Ngute, at the direction of President Paul Biya, withdrew the decree, suspending any logging plans.  President Biya also ordered a delay to reclassify an additional 160,000 acres of the Ebo, which might have opened up even more forest for logging.

Apart from its rich biodiversity, the Ebo Forest is culturally and societally important for the Banen Indigenous people, who consider it to be their sacred ancestral home.  The Banen were ousted from the forest in the 1960s but took up settlements just a few miles from its borders.  They still rely on the forest for food and medicines.  Meanwhile, the proximity of the forest to big cities makes it an easy target for bushmeat poachers.

Both conservation groups and indigenous leaders welcomed the withdrawal of the decree but remain concerned about the future of the Ebo Forest.  Conservation groups hope that the international community will seize the opportunity to work with the government of Cameroon to make the Ebo Forest a permanent showcase for long-term conservation in harmony with very challenged communities.

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Cameroon Cancels Plan to Log Half of the Ebo Forest, a Key Biodiversity Hotspot in Central Africa

Photo, posted September 17, 2005, courtesy of Salva le Foreste via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Native Bees In A Honeybee World | Earth Wise

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There is a great deal of attention on the plight of bees and other pollinators.  Much of that focuses on the problems plaguing the large, domesticated honeybee colonies that are trucked from region to region to pollinate everything from almonds to fruit trees.  Managed bee colonies have recently been losing more than 40% of their population over the course of a year.  But overall, honeybees are still relatively safe. They are a globally distributed, domesticated species and are not remotely threatened with extinction.

But another group of bees – native bees – faces a different range of threats, most linked to habitat loss.   Worldwide, roughly 20,000 native bee species have evolved over millions of years to thrive in countless habitats, where they have specialized in pollinating specific flowers and plants – in some cases just a single plant.

Scientists have estimated that, globally, 1 in 6 bee species is regionally extinct. In the United States there are about 4,000 native bee species, most of which are solitary bees that nest in the ground or cavities, with many that require just one or a few plant species for sustenance. At least 23 percent of U.S. native bees have declined, with bees in areas with heavy commodity-crop production particularly hard hit due to habitat loss and pesticide use. Other threats to native bees include climate-driven sea-level rise and increased temperatures, loss of host plants, and competition and disease from non-native honeybees. 50% of Midwestern native bee species disappeared from their historic ranges in the last 100 years.   Four of our bumblebee species declined 96% in the last 20 years, and three species are believed to already be extinct. 

Native bees are in big trouble.

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Backyard Battle: Helping Native Bees Thrive in a Honeybee World

Photo, posted December 2, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sharks On The Decline | Earth Wise

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During the past 70 years, global shark populations have been on the decline.   Many species have become threatened or endangered.  Conservation efforts have been underway in many places, but shark populations continue to be at risk because of over-fishing and habitat loss.

A comprehensive study by marine biologists at Texas A&M University deployed more than 15,000 baited remote underwater video stations on 371 coral reefs in 58 countries.   The study included 59 different shark species in the Atlantic, Pacific and Indian Oceans.  The researchers were surprised to find that no sharks at all were detected in almost 20% of the locations surveyed and were almost completely absent from coral reefs in several nations. 

Scientists believe that demand for shark products, such as fins and meat, and bycatch (that is, sharks captured in nets by fisherman trapping other kinds of fish) are strong contributors to the widespread declines in shark numbers around the world.

The study shows that if corrective steps are not taken in regions where marine management is still ineffective, continued depletion of shark populations is highly likely. 

Sharks have important roles in marine ecosystems.  When their habitats deteriorate and their populations decrease, ecosystem stability and health is degraded because sharks help regulate prey populations.

Some countries, notably the Bahamas, are combating the problem by providing sanctuaries for sharks where fishing and harvesting is prohibited.  Such places support some of the healthiest shark populations in the world.  However, the decline of coral reefs is just another challenge facing shark populations around the world.

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Study Shows Alarming Decline In Shark Numbers Around The World

Photo, posted January 9, 2017, courtesy of Kris-Mikael Krister via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Moving Up And Away | Earth Wise

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A new study by the Wildlife Conservation Society, the US Forest Service, and UC Berkeley has shown that mountain-dwelling species trying to escape warming temperatures may also be finding refuge from human pressure.

The study shows that nearly 60% of the world’s mountainous areas are under intense human pressure.  Most of that pressure occurs at lower elevations and mountain bases, where more people live, grow food, and build roads.  The researchers used climate models to predict how various species would move as the climate changes.   Based upon these predictions, they found that species tend to move to higher elevations, where temperatures are lower.  But those elevations also have more intact land for species because there is less human activity.

Mountains are home to over 85% of the world’s amphibians, birds, and mammals and these species are at risk from human activities such as agriculture, livestock grazing, and development.  These things reduce their habitats, but meanwhile the warming climate pushes them upslope as they struggle to find tolerable temperatures.

The researchers point to their study as new guidance for conservation efforts.  They warn that many conservation efforts don’t take into account the effects of human pressure.   Factoring in human pressure reveals the true extent of mountainous areas for species that are restricted to intact landscapes.  These are often the species that are of greatest concern to conservationists.  This true shape refers to how much land area is potentially available as habitat for a species as it moves up in elevation.  

The results offer a glimmer of hope for mountain-based species under climate change as they move away from the most intense human activity.

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Climate change may push some species to higher elevations — and out of harm’s way

Photo, posted November 22, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Too Many Bison | Earth Wise

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The population of large herbivores in Yellowstone National Park has undergone many dramatic changes over the course of time.  The numbers of both the iconic Rocky Mountain elk and bison have gone up and down as a result of human interactions.

Bison, of course, once were a dominant species from east of the Appalachians to west of the Rocky Mountains, with most of an estimated 30 million living on the Great Plains.  As the west was settled, bison populations plummeted and by the late 1800s, they were nearly extinct.

When Yellowstone was established, there were exactly 22 bison in the park.  By 1925, there were more than 750 in the park and culling of the herd in the park’s Lamar Valley was practiced for the next four decades.

The elimination of predators like grey wolves and cougars in the early 1900s caused both elk and bison populations to mushroom and both underwent culling.  When culling was ended in 1968, there were 4,000 elk and 100 bison.  Within 20 years, those numbers were 20,000 and 1,000.   Reintroducing wolves and cougars reduced the elk population to about 5,000, but bison numbers have continued to grow, now reaching about 4,000.

While the long-term recovery of the Yellowstone bison herd is a major conservation success story, the fact is that bison are powerful ecosystem engineers.  Large numbers of them disrupt species distribution across scrub steppe and grasslands because of what they eat, trample, and rub their horns and bodies on.  They have a tremendous capacity to limit the structure and composition of ecosystems.

Park administrators have complicated management decisions to make to take into account the often wide range of ecological effects that abundant large herbivores can have on ecosystems.

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Bison in northern Yellowstone proving to be too much of a good thing

Photo, posted August 10, 2016, courtesy of Brian Gratwicke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Metal From Plants | Earth Wise

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Large amounts of metal in soil are generally bad for plants.  But there are about 700 species of plants that thrive in metal-rich soils.  These plants don’t just tolerate minerals from soil in their bodies but actually seem to hoard them to ridiculous levels.

In areas where soils are naturally rich in nickel, typically in the tropics and Mediterranean basin, plants have either died off or have adapted to become nickel loving.  Slicing open a tree with this adaptation produces a neon blue-green sap that is actually one-quarter nickel, which is far more concentrated than the ore that typically feeds commercial nickel smelters.

A group of researchers from the University of Melbourne and other institutions is investigating whether this phenomenon is not just interesting but might also be of real commercial value.  They established a plot of land in a rural village in Borneo and have been harvesting growth from nickel-hyper accumulating plants.  Every six to twelve months, a farmer shaves off one foot of growth from these plants and either burns or squeezes the metal out.  After a short purification, they end up with about 500 pounds of nickel citrate, potentially worth thousands of dollars on international markets.

Phytomining – extracting minerals from hyper-accumulating plants – cannot fully replace traditional mining techniques.  But the technology could enable areas with toxic soils to be made productive and might allow mining companies to use plants to clean up their former mines and waste while actually collecting some revenue.

There are other plants that suck up cobalt, zinc, and similarly crucial metals.  With growing demand for metals, perhaps it is time to harvest them on the farm.

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Down on the Farm That Harvests Metal From Plants

Photo courtesy of the University of Queensland.

Earth Wise is a production of WAMC Northeast Public Radio.

Coastal Plants And Climate Change | Earth Wise

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Rising sea levels and the increased frequency and intensity of extreme weather events are leaving observable effects on beaches, cliffs, and coastal infrastructures all around the world.  But a new study suggests that the impact of climate change on coastal plant communities needs more attention. 

According to research recently published in the journal Annals of Botany, coastal plants are a critical element of global sea defense.  But coastal plants are increasingly under threat from flooding, erosion, and other human-induced effects of climate change.  Habitats like salt marshes, mangrove forests, sand dunes, and kelp beds make important contributions  to coastal protection.

The research was led by scientists from the University of Plymouth, in conjunction with researchers at Utrecht University and Manchester Metropolitan University.

The study follows a recent assessment by the Intergovernmental Panel on Climate Change, which found that anthropogenic climate change poses a severe threat to estuaries and coastal ecosystems.  

Conservative estimates of the capital investments needed to combat rising seas and intensifying storms run into the hundreds of billions of dollars in the coming decades.  However, coastal vegetation could offer a dynamic, natural, and relatively low-cost defense strategy at a fraction of the cost when compared with the cost of so-called hard defenses like concrete walls and barriers. 

According to the research team, identifying the key species and habitats for coastal defense and how coasts can be protected and promoted is critical.  More long-term monitoring is also needed in order to better understand and predict where and how storms and other effects of climate change will impact coastal ecosystems. 

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The gathering storm: optimizing management of coastal ecosystems in the face of a climate-driven threat

Losing coastal plant communities to climate change will weaken sea defences

Photo, posted September 14, 2018, courtesy of Dennis Jarvis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Native Species Or Invasive Species? | Earth Wise

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For decades, conservation biology has characterized the movement of species into new habitats as potential invasions of alien species that pose serious dangers to local ecosystems and resident species.  Wild species are classified as either native or alien.  But this way of looking at the natural world is becoming increasingly controversial.

As the world warms, a mass exodus of tens of thousands of species is transforming the distribution of biodiversity.  Scientists have documented countless species shifting their ranges towards the poles, higher up into the mountains, and deeper into the oceans in response to the changing climate.

Deciduous shrubs have spread into the Arctic tundra.  Tropical fish have arrived in the kelp forests of the eastern Mediterranean. 

A growing number of scientists now say that continuing to base conservation policy on the native-alien dichotomy may actually endanger biodiversity.  The climate-driven range shifts may be the only way for many species to survive.  Furthermore, only a small fraction of new arrivals may actually endanger resident species and ecosystems.

There are real distinctions between climate-displaced species and disruptive alien species introduced through global trade and travel.  Among other things, climate-displaced species tend to shift their ranges alongside other species they have co-evolved with.

There is talk of establishing a Climate Change Redistribution Treaty that would create a transnational system to manage species shifting across geopolitical and biogeographical borders.  The assumptions traditionally made as to which species to protect, which to leave to their own devices,  and which to eradicate are no longer valid and the time has come to base conservation policies on the new reality.

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Native Species or Invasive? The Distinction Blurs as the World Warms

Photo, posted March 21, 2011, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Road Salt Pollution

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Mirror Lake is a popular recreational lake located in the Village of Lake Placid.  It is the most developed lake within the Adirondack Park, which is a publicly protected area that is actually larger than Yellowstone, Yosemite, Glacier, and Grand Canyon National Parks combined.

New research has revealed that road salt runoff into Mirror Lake is preventing natural water turnover which poses a risk to the balance of its ecology.  The study, which was published in Lake and Reservoir Management, found that road salt runoff is preventing spring mixing of the water column.    This creates more anoxic water conditions, meaning there is less oxygen in the water, and limits the ability of the habitat to support the native lake trout. 

Mirror Lake is the first lake in the Adirondack Park to show an interruption in lake turnover due to road salt.  Many lakes in northern climes experience so-called “dimictic turnover”, which is a natural process where wind and less stratified water conditions of spring and fall allow mixing of the water column that redistribute oxygen and nutrients throughout the lake.  High levels of surface-water chloride introduced into the lake from road salt runoff inhibit the mixing of the water column.

The lack of mixing and oxygenation is bad news for fish species such as lake trout, which require cold, oxygenated water to survive.  It may also put the lake at a greater risk of algal blooms.

Mirror Lake is small, surrounded by concentrated development, and receives the direct discharge of stormwater.  So, it is particularly vulnerable to road salt contamination.  Other lakes elsewhere in New York may experience similar conditions.  The researchers are confident that natural turnover conditions could be restored to the lake if road salt application in the watershed is reduced.

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Road salt pollutes lake in one of the largest US protected areas, new study shows

Photo, posted January 5, 2018, courtesy of MTA of the State of NY via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Community Action And Coral Reefs

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Coral reef habitats are some of the densest and most varied ecosystems on earth.  While coral reefs cover just 0.2% of the ocean floor, scientists estimate that nearly one million different species of fish, invertebrates, and algae can be found in or around coral reefs. 

However, climate change is wreaking havoc on the health of coral reefs.  Warming and acidifying oceans are resulting in enormous coral losses.  Overfishing, development, and pollution are also threatening coral reef health.

According to new research, positive community action can help boost fish populations in coral reefs and safeguard future fish numbers.  The paper, which was recently published in the journal Proceedings of the National Academy of Sciences, details the social and ecological outcomes of work being done in Papua New Guinea since 2001. 

These communities have established a traditional system of rotational fishing closures in order to manage their fisheries resources.   They ban fishing on part of their reefs for a few years, and then open these closures when village elders believe fish behavior has changed and fish populations have recovered.  They then close a different part of their reefs, and repeat the process. 

The researchers found that these rotational practices resulted in more than twice as many fish on the closed reefs as compared to open ones, and the closures made fish less scared of people and easier to catch.  But the researchers did caution that this short term boost in fish numbers may not be enough to stop the overall impact of fishing.

Globally, more than 500 million people depend on coral reefs for food, income, and coastal protection.  Balancing community needs with environmental needs can be tricky business.  

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Positive community action can help coral reef health

Photo, posted October 11, 2011, courtesy of Paul Toogood via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Save Endangered Species?

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One often hears the argument that humans need to save the world’s endangered species in order to save ourselves.  Carl Safina, a marine ecologist and award-winning environmental writer, has written a thought-provoking essay that offers the viewpoint that we don’t actually need the wild species of the world but that they need us.

The truth is that human beings have thrived by destroying nature.  We have exploited other species when they were useful to us and simply pushed them aside when they weren’t.  We drove America’s most abundant bird – the passenger pigeon – to extinction.  The most abundant large mammal – the bison – was driven to functional extinction.

In today’s world, people live at high densities in places devoid of wild species and natural beauty.  And while we express concern for elephants, gorillas, sperm whales, tigers, and various other species, how would the lives of most of us be affected at all should they vanish entirely?  The unfortunate truth is that it would make little difference to our lives.

The only species that are really essential to modern living are actually microbes of decay, a few insect pollinators, and the ocean’s photosynthesizing plankton.  Life would go on little changed without most other co-inhabitants of our planet.

Safina argues that our obligation to protect endangered species does not come from our dependence upon them but rather on a moral obligation.  Humans consider ourselves to be the most moral species and, as such, we have moral obligations.  In this case, it is to protect the beauty and wonder of our world, which is not trivial but in fact is the most profound thing on earth.

Safina has much more to say about this and I strongly recommend reading his essay.  You can find the link here.

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The Real Case for Saving Species: We Don’t Need Them, But They Need Us

Photo, posted December 9, 2014, courtesy of Gerry Zambonini via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Monster Tumbleweeds

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Tumbleweeds have long been seen as symbols of America’s old west.  Tumbleweeds are a structural part of the above-ground anatomy of a number of species of plants known as diaspores.  Diaspores are essentially seed dispersal units.  In a few seed plants, they comprise most or all of the plant.  Once they are mature and dry, they detach from the roots and roll around due to the force of the wind.

There is a new species of gigantic tumbleweed – the Salsola ryanii – that is expanding its territory in the American west.  It is the result of a relatively unusual genetic process known as polyploidy, which produces offspring with multiple sets of chromosomes.  Researchers believe that that the new hybrid species of tumbleweed is healthier than earlier versions.  As a result, one geneticist described Salsola ryanii as a nasty species replacing other nasty species of tumbleweed in the US.

These tumbleweeds can grow up to 6 feet tall.  Tumbleweeds in general are invasive plants that cause traffic accidents, damage agricultural operations, and cause millions of dollars in property damage.  Last year, the town of Victorville in the California desert was buried in them, piling up to the second story of some houses.

Salsola ryanii has a relatively small range, but it is expanding rapidly.  The new study determined that it is more vigorous than its predecessors, which are invasive in 48 states.  The plant is an annual but tends to grow on the later side of winter.  It is one of the only things that is still green in late summer.  With summer rains increasing as the climate changes, these monster tumbleweeds are poised to wreak havoc.   The experts are warning that there should be efforts to suppress them before they take over.

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Monster tumbleweed: Invasive new species is here to stay

Photo, posted February 27, 2018, courtesy of Tracie Hall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Birds Are Disappearing

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A new analysis, published in the journal Science, reports that the number of birds in the United States and Canada has fallen by 29% since 1970.  There are 2.9 billion fewer birds in the two countries now than there were 50 years ago.

The analysis is the most comprehensive attempt to date to look at the status of avian populations.  The results were a shock to researchers and conservation organizations.

It is well-known that some bird species have become vulnerable to extinction, but the new study, which surveyed more than 500 species, uncovered steep losses even among such traditionally abundant birds as robins and sparrows.

There appear to be multiple causes for the steep declines.  The largest ones are likely habitat loss and the wider use of pesticides.  Rachel Carson’s 1962 book Silent Spring warned of the dangers of pesticides and took its title from a world that has lost its birds.

The survey includes 76% of all bird species in the US and Canada, but actually represents almost the entire population of birds.  Grassland species have suffered the biggest declines by far, as a result of modern agriculture and development.  Pesticides, such as neonicotinoids, make it harder for birds to put on weight needed for migration, delaying their travel.

There are a few bright spots:  bald eagles are thriving, and falcon and waterfowl populations are on the upswing.  These are species that have been the subject of conservation measures in recent decades.

Stopping the bird decline will require a great deal of effort to defend habitats, restrict chemicals, and redesign buildings.  Without that effort, birds will continue to disappear.

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Birds Are Vanishing From North America

Photo, posted April 1, 2012, courtesy of Barry Skeates via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Decline Of Earth’s Largest Freshwater Creatures

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While nearly 70% of the globe is covered by water, only 2.5% of it is freshwater.  The rest is saline and ocean-based.  And only 1% of our freshwater is easily accessible, with much of it locked away in snowfields and glaciers.  

Despite freshwater only making up a small fraction of all water on the planet, it’s home to one third of all vertebrate species.  Some have survived hundreds of millions of years, but many of the world’s largest freshwater creatures – including fish, reptiles, amphibians, and mammals – may soon find themselves on the brink of extinction.

According to a study recently published in the journal Global Change Biology, scientists from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries and international colleagues have quantified the global decline of freshwater megafauna for the first time.  In four decades since 1970, the global populations of these freshwater giants have declined 88% – twice as much as the loss of vertebrate populations on land or in the oceans. 

Freshwater megafauna include all freshwater animals that weigh 30 kilograms (about 66 pounds) or more, such as certain dolphins, beavers, crocodiles, turtles and sturgeons.

Overexploitation is one of the main threats to freshwater megafauna.  (These animals are often targeted for their meat, eggs, and skin).  The other main threat is the loss of free-flowing rivers. Many of the world’s large rivers are already highly fragmented, which impacts access to spawning and feeding grounds.  The research team says another 3700 large dams are planned or under construction, including 800 in habitats rich with freshwater megafauna, including the Amazon, Congo, and Ganges river basins.

Current conservation measures are clearly failing our freshwater creatures. 

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88 percent decline of big freshwater animals

Earth’s largest freshwater creatures at risk of extinction

Photo, posted March 25, 2012, courtesy of the U.S. Fish and Wildlife Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Refugee Corals

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As climate change warms the ocean, subtropical environments are becoming more favorable for corals than the equatorial waters where they traditionally thrived.  As a result, drifting coral larvae are settling and growing in new regions.

According to new research in the journal Marine Ecology Progress Series, the number of young corals on tropical reefs has declined by 85% over the past 40 years.  At the same time, the numbers on subtropical reefs has doubled.

Only certain types of coral can reach these new subtropical locations.  That depends on how far the microscopic larvae can swim and drift on currents before they exhaust their limited fat stores.  Thus, the reef ecosystems that develop have new blends of species that have previously never coexisted.  It is not clear how long it will take for the new systems to reach equilibrium.

Coral reefs are complicated systems that depend on the interplay between species to enable their healthy functioning.  Apart from the corals themselves, there are the coraline algae that symbiotically coexist with them.  How all of this will play out in these evolving ecosystems is unknown.

In the meantime, the research has found that these refugee corals are settling at latitudes up to 35 degrees both north and south of the equator.  It is no longer so clear what constitute native species in the reefs.  It remains to be seen whether new reefs in subtropical oceans can support the incredible biodiversity seen in tropical reefs.  But ultimately, these changing ecosystems could potentially bring new resources and opportunities, such as fishing and tourism, to places where they never existed before.

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Coral Reefs Shifting Away from Equatorial Waters

Photo, posted March 22, 2011, courtesy of Simone Lovati via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shifting Ecosystems

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The Great Plains ecosystem has been shifting northward over the past fifty years, driven by climate change, wildfire suppression, energy development, land use changes, and urbanization.  The ecosystem is an area historically rich with grasslands and shrub steppe and is prime habitat for grassland birds.

According to a recent study published in the journal Nature Climate Change, the northernmost ecosystem boundary of the Great Plains has moved more than 365 miles north since 1970, amounting to about 8 miles a year.  The region’s southernmost ecosystem boundary has shifted 160 miles north, or about 4 miles a year.

The study used bird distribution data as an indicator of shifting ecosystem boundaries.  The researchers analyzed 46 years of data for 400 bird species across a 250-mile-wide strip stretching from Texas to North Dakota.  They tracked how the birds’ distributions changed as a measure of how these ecosystems were shifting.

While climate change has been a major driver of these ecosystem shifts since the 1970s, several other factors such as wildfire trends, land use changes, and invasion of tree species into grassland habitat have also played a role.  Like most things in ecological systems, the changes are likely to have multiple causes.  One cannot really separate causes like tree invasions, warming climate, and wildfires, as they are all interrelated.

Using bird distribution patterns for tracking ecosystem shifts could be a useful tool for scientists and land managers in the coming decades to give them an early warning of how habitats are changing in response to rising global temperatures and therefore allow them to take action to protect vulnerable species.

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Great Plains’ Ecosystems Have Shifted 365 Miles Northward Since 1970

Photo, posted March 24, 2017, courtesy of Rick Bohn / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Keeping Lights On For Turtles

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Gillnets are one of the most common types of fishing gear and are used extensively in most places where people fish for food.  They operate by suspending a wall of netting in the water column.

Unfortunately, they are not selective in the species they catch.  Sea turtles are one of the most common bycatch species that become entangled in these nets.  When turtles are caught in gillnets, they can drown and die.  Marine mammals, seabirds, and sharks are also frequently caught in gillnets.

Recently, researchers have been experimenting with illuminating the nets with LED lights to see if increasing net visibility reduces sea turtle bycatch.

Studies in Mexico show green sea turtle bycatch is reduced between 40-60% with no changes in target catch.  Studies in Peru show green sea turtle bycatch is reduced between 65-80% with no changes in target catch.  Studies in Indonesia show green olive ridley, and hawksbill sea turtle bycatch is reduced by 60% with increases in target catch and catch value.

Recent research shows that net illumination also reduces bycatch of other protected species such as seabirds, sharks and rays, as well as dolphins and porpoises.

The use of illuminated gillnets could prove beneficial to both sea turtles and fisherman by reducing the bycatch that can damage fishing gear. 

Studies are now underway off the coast of North Carolina, where state gillnet fisheries are carefully managed to reduce turtle bycatch.  Initial studies show that net illumination does not change target catch rates and may even decrease the bycatch of unwanted fish species.  When it comes to protecting sea turtles, it looks like a good idea to keep the lights on.

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Illuminated Nets Could Provide A Brighter Future For Sea Turtles

Photo, posted June 2, 2016, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Banning The Shark Fin Trade

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Shark fins are considered a delicacy in many parts of the world, especially in China.  Shark fin soup, for example, is often served at engagement parties and weddings.  But the use of shark fins has come under increasing scrutiny in recent years, especially since an estimated one-third of fins are harvested from species deemed at risk.  

Many of the fins used in shark fin soup come from a practice known as “finning,” which is an inhumane and wasteful practice where the fins are hacked from live sharks and then the sharks are thrown back into the water and left to die.  According to U.N. estimates, 73 million sharks are killed every year for their fins.

The possession, sale, and distribution of shark fins is banned in 12 U.S. states, as well as in all European Union member states.

In 1994, Canada banned the practice of finning in its own waters, but allowed the import of fins to continue.  Canada has been one of the largest markets for shark fins outside Asia, importing nearly 300,000 pounds of shark fins last year.  But in late June, Canada passed a bill that bans both the import and export of shark fins harvested by shark finning.  They are the first G7 and the first G20 country to do so. 

But shark fins taken from sharks sustainably harvested for their meat will continue to be allowed in Canada.  While demand for shark fins is decreasing globally, demand for shark meat is rising.

Since sharks still face a myriad of environmental pressures, including illegal fishing and high bycatch rates, there are concerns that this Canadian ban oversimplifies the threats facing global shark populations. 

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Canada becomes the first G20 country to ban shark fin trade

Photo, posted January 4, 2013, courtesy of Andrew Currie via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

One Million Extinctions

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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

Photo, posted January 1, 2014, courtesy of Eric Kilby 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...)