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Insects On The Menu | Earth Wise

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According to the World Food Programme, a record 349 million people across 79 countries are facing acute food insecurity.  This constitutes a staggering rise of 200 million people compared to pre-pandemic levels.  Nearly one million people globally are fighting to survive in famine-like conditions, which is ten times more people than just five years ago.  

As a result, many experts contend that alternative or so-called novel food sources – such as lab-grown meats, seaweed aquaculture, and insects – will be necessary to help fight global hunger and global food insecurity. 

Insects already form a significant part of diets in many cultures around the world.  Insects are great sources of nutrients, including protein, vitamins, and minerals.  But insects have yet to be embraced in any substantial way in western cultures… but that may be changing. 

In fact, the European Union has now certified four types of bugs as food fit for human consumption.  The larvae of lesser mealworms and house crickets recently became the third and fourth insects approved for sale as food in the EU, joining yellow mealworms and grasshoppers. Eight more applications are awaiting approval.

Insects are already a delicacy in many high-end restaurants around the world, and a normal and healthy part of diets in countries like Mexico and Thailand.  Embracing insects as a food of the future will not only help in the fight against global hunger, but will also help to reduce greenhouse gas emissions and to slow species extinction. 

In Western food markets, the so-called “yuck factor” remains the biggest hurdle to cross.  But as the world population grows, the need for sustainable solutions in the food industry grows with it. 

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Insects on the menu as EU approves two for human consumption

World Hunger Surged in 2020, U.N. Says

A global food crisis

Photo, posted April, 2014, courtesy of Shankar S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fertilizing The Ocean | Earth Wise

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There are a variety of schemes for removing carbon dioxide from the atmosphere.  Some require advanced and generally not-very-well developed technology.  Others, such as planting vast numbers of trees, are nature-based but are daunting with respect to the scale to which they need to take place in order to be truly effective.

Researchers at the Pacific Northwest National Laboratory in Richland, Washington have been examining the scientific evidence for seeding the oceans with iron-rich engineered fertilizer in order to feed phytoplankton.  Phytoplankton are microscopic plants that are a key part of the ocean ecosystem.

Phytoplankton take up carbon dioxide as they grow.  In nature, nutrients from the land end up in the ocean through rivers and from blowing dust.  These nutrients fertilize the plankton.  The idea is to augment these existing processes to increase the growth of phytoplankton.  As they eventually die, they sink deep into the ocean, taking the excess carbon with them.


The researchers argue that engineered nanoparticles could provide highly controlled nutrition that is specifically tuned for different ocean environments.  Surface coatings could help the particles attach to plankton.  Some could be engineered with light-absorbing properties, allowing plankton to consume and use more carbon dioxide.

Analysis of over 100 published studies showed that numerous non-toxic, abundant, and easy-to-create metal-oxygen materials could safely enhance plankton growth.  According to the researchers, the proposed fertilization would simply speed up a natural process that already sequesters carbon in a form that could remove it from the atmosphere for thousands of years.  They argue that given the current trends in the climate, time is of the essence for taking action.

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Fertilizing the Ocean to Store Carbon Dioxide

Photo, posted August 2, 2007, courtesy of Kevin McCarthy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Oxygen Loss In Lakes | Earth Wise

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Researchers from Cornell University and Rensselaer Polytechnic Institute have found that the continual warming in the world over the past 25 years has been reducing the amount of oxygen in many lakes.

Data from more than 400 lakes – mostly in the United States – shows that lakes with dissolved oxygen losses strongly outnumber those with gains.  Overall, the researchers found that the amount of low oxygen water is increasing by 0.9% to 1.7% per decade on average  and the volume of lake water lacking oxygen has increased by more than 50% from 25 years ago.

In the summer, lake surfaces may be about 70 degrees while the lake bottom may be about 40 degrees.  The colder water is denser than the warmer water which causes resistance to the layers mixing.  It is akin to having oil and vinegar in a cruet.  This is known as stratification.   The result is that oxygen from the atmosphere is prevented from replenishing dissolved oxygen in deep waters.  This is a normal seasonal phenomenon.

However, with winter ending sooner than it used to, seasonal stratification is starting earlier and ending later. As warming continues, it is likely that there will be an increasing number of oxygen-depleted lakes in the future.

Oxygen deprivation in water can lead to hypoxia (low oxygen) and even anoxia (no oxygen), which have negative consequences for fish and other species.  Reducing oxygen in lake water can lead to buildup of methane.   Nutrients from agricultural runoff, released from unsettled lake sediment, increase the likelihood of harmful algal blooms.

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Warming climate prompts harmful oxygen loss in lakes

Photo, posted June 23, 2010, courtesy of Alexander Acker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fuel From Coffee Grounds | Earth Wise

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The world drinks a lot of coffee.  Americans alone consume 400 million cups a day.  Each cup of coffee results in about half an ounce of coffee grounds.  Adding that up, this country produces over 6,000 tons of coffee grounds each day.  While coffee grounds are not particularly harmful, that is an awful lot of waste that mostly ends up in landfills or is incinerated.

Researchers at Aston University in the UK have developed a method of producing high-quality biodiesel fuel from coffee grounds.  Their study was published in the journal Renewable and Sustainable Energy Reviews.

The technique consists of growing a particular species of microalgae (Chlorella vulgaris) directly on spent coffee grounds.  The coffee grounds provide both the nutrients for the microalgae and a structure upon which it can grow.   Exposing the algae to light for 20 hours a day and dark for just four hours a day produced the best quality biodiesel.

Microalgae is well-known as a feedstock for biodiesel production.  Previously, it has been grown on materials like polyurethane foam or nylon which don’t provide any nutrients.   Using the coffee grounds as the substrate for growth means that no external nutrients are needed.

The resultant enhanced biodiesel produces minimal emissions and good engine performance and meets both US and European specifications.  This feedstock for producing biodiesel is ideal since it doesn’t require any competition with food crops and instead makes use of a widely available waste product.  The hope is that it may reduce the cutting down of palm trees to extract oil for biofuel.  In southeast Asia, this has been a major source of deforestation and increased greenhouse gas emissions.

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Aston University researchers ‘feed’ leftover coffee grounds to microalgae to produce low emission biodiesel

Photo, posted October 13, 2007, courtesy of David Joyce via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Onshore Algae Farms | Earth Wise

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According to some estimates, food production will need to increase by 50% by 2050 in order to feed a projected global population of 10 billion people.  How can this be achieved?  

One solution, according to researchers at Cornell University, could be to grow nutritious and protein-dense microalgae in seawater-fed onshore aquaculture systems.

According to the research, which was recently published in the journal Oceanography, growing algae onshore could close a projected gap in society’s future nutritional demands while also improving environmental sustainability.  

Climate change, environmental degradation, limited arable land, and lack of freshwater will all constrain the amount of food that can be grown in the coming decades.  Wild fish stocks are already heavily exploited, and there are limits to how much finfish, shellfish, and seaweed aquaculture can be produced in the coastal ocean. 

As a result, the researchers argue for expanding algae production in onshore aquaculture facilities.  The research team’s models found that the best locations for onshore algae farming facilities are along the coasts of the Global South, including desert environments. 

Algae can grow as much as ten times faster than traditional crops.  Algae can also be produced in a manner that is more efficient than agriculture in its use of nutrients.  In addition to its high protein content, algae also provides nutrients lacking in vegetarian diets, such as essential amino acids, minerals, and omega-3 fatty acids.

Algae could become the breadbasket of the Global South.

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Onshore algae farms could feed the world sustainably

Photo, posted June 17, 2011, courtesy of NOAA Great Lakes Environmental Research Laboratory via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaning Up Urban Rivers With Nature’s Tools | Earth Wise

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Fifty years after the passage of the Clean Water Act, urban waterways across the United States are continuing their comeback and are showing increasing signs of life.  A strategy that is being adopted in many places is to use natural restoration techniques focused on bolstering plants and wildlife to improve water quality.

A nonprofit called the Upstream Alliance has focused on public access, clean water, and coastal resilience in the Delaware, Hudson, and Chesapeake watersheds.  Working with the Center for Aquatic Sciences and with support from the EPA and the National Fish and Wildlife Foundation, the alliance has been repopulating areas of an estuary of the Delaware River near Camden, New Jersey with wild celery grass, which is a plant vital to freshwater ecosystems.

In many places, scientists, nonprofits, academic institutions, and state agencies are focusing on organisms like bivalves (typically oysters and mussels) along with aquatic plants to help nature restore fragile ecosystems, improve water quality, and increase resilience.

Bivalves and aquatic vegetation improve water clarity by grounding suspended particles, which allows more light to penetrate.  These organisms also cycle nutrients both by absorbing them as food and by making them more available to other organisms.

Underwater restoration projects have been underway in New York Harbor for more than a decade, where the Billion Oyster Project has engaged 10,000 volunteers and 6,000 students. 

The hope is that bringing back bivalves and aquatic plants can create a lasting foundation for entire ecosystems.  It is restoring nature’s ability to keep itself clean.

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How Using Nature’s Tools Is Helping to Clean Up Urban Rivers

Photo, posted December 19, 2019, courtesy of Scott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Healthy Soil Is Healthy For People | Earth Wise

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A new study by researchers at the University of Washington looked at the impact of regenerative farming practices on the nutritional content of the food that is grown. 

Regenerative agriculture involves farming practices that not only “do not harm” to the land but actually improve it by regenerating and revitalizing the soil.  The practices focus on topsoil regeneration, increasing biodiversity, improving the water cycle, and enhancing ecosystem services.  Examples are soil-building techniques that minimize plowing, the use of cover crops, and the planting of diverse crops rather than monocultures.

The study included 10 farms across the U.S. that followed soil-friendly practices for at least five years. The results were that the crops from those farms had a healthier nutritional profile than the same crops grown on neighboring, conventional farms.  In particular, there was a boost in certain minerals, vitamins and phytochemicals that are beneficial to human health.  Across the board, regenerative practices resulted in crops with more anti-inflammatory compounds and antioxidants.

The participating farms grew one acre of a test crop – peas, sorghum, corn, or soybeans – for comparison with the same crop grown on a neighboring farm using conventional agriculture.  Analysis showed that the farms practicing regenerative agriculture had healthier soils, as measured by their organic matter – or carbon – content and by other tests. 

Organic farms avoid chemical pesticides, but they operate with a variety of farming processes.  Nonetheless, they have also been found to produce crops with higher levels of beneficial nutrients.  The biology of the soil in which crops are grown is an important factor for human health.  It isn’t just what we eat that matters; it is how we grow it.

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Farms following soil-friendly practices grow healthier food, study suggests

Photo, posted January 10, 2020, courtesy of Les via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Carbon With The Oceans | Earth Wise

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There is increasing concern that reducing carbon emissions alone will not be sufficient to stabilize the climate and that technologies that actively remove carbon dioxide from the air will be needed.  There has been a fair amount of analysis of the efficacy of storing carbon in agricultural soil and in forests, but there has not been comparable studies of the risks, benefits, and trade-offs of ocean-based strategies. 

The oceans currently absorb about a quarter of the world’s carbon dioxide emissions.  There are multiple ways in which oceans could be induced to store much more.  A new report from the National Academies of Sciences, Engineering, and Medicine looks at several ocean carbon dioxide removal strategies in terms of efficacy, potential costs, and potential environmental risks.

One approach involves adding nutrients to the ocean surface to increase photosynthesis by phytoplankton.  The approach has a medium to high chance of being effective and has medium environmental risks.

Another approach is large-scale seaweed farming that transports carbon to the deep ocean or into sediments.   It has medium efficacy chances but higher environmental risks.

Protection and restoration of coastal ecosystems including marine wildlife would have the lowest environmental risk but only low to medium efficacy.

Chemically altering ocean water to increase its alkalinity in order to enhance reactions that take up carbon dioxide would be highly effective but a medium environmental risk.

The report describes some other approaches as well.  It recommends a $125 million research program to better understand the technological challenges as well as the potential economic, social, and environmental impacts of increasing the oceans’ absorption of carbon dioxide.

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Oceans Could Be Harnessed to Remove Carbon From Air, Say U.S. Science Leaders

Photo, posted August 21, 2016, courtesy of Quinn Dombrowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfires And Algal Blooms

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Australia is no stranger to wildfires. But the 2019-2020 season proved to be particularly severe: wildfires destroyed 3,100 homes, displaced 65,000 people, and burned more than 72,000 square miles – roughly the same size as Washington State. The season is colloquially referred to as the Black Summer.

According to a new study recently published in the journal Nature, clouds of smoke and ash from these wildfires triggered widespread algal blooms thousands of miles downwind to the east in the Southern Ocean.

The study, which was led by researchers from Duke University, shows that aerosol particles in the smoke and ash fertilized the water as they fell into it.  This provided the nutrients that fueled unprecedented blooms in that region, conclusively linking for the first time a large-scale response in marine life to fertilization by pyrogenic iron aerosols from a wildfire.

This finding raises questions about the role wildfires may play in the growth of phytoplankton, the microscopic marine algae that – through photosynthesis – absorbs large amounts of climate-warming carbon dioxide from Earth’s atmosphere. 

According to the research team, the Australian algal blooms were so extensive that the subsequent increase in photosynthesis may have temporarily offset a substantial portion of the wildfires’ CO2 emissions.  It remains to be seen how much of the absorbed CO2 remains safely stored in the ocean and how much it has been released back into the atmosphere. 

The researchers plan to investigate the fate of the phytoplankton further.  They also plan more research to better predict where and when aerosol deposition will boost phytoplankton growth in the future.  

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Australian wildfires triggered massive algal blooms in Southern Ocean

Photo, posted January 12, 2020, courtesy of BLM-Idaho via Flickr.

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Protecting Bees From Pesticides | Earth Wise

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Studies have shown that the wax and pollen in 98% of beehives in the U.S. are contaminated with an average of six pesticides.  These substances lower bees’ immunity to devastating varroa mites and other pathogens.  By some estimates, pesticides cause beekeepers to lose about a third of their hives every year on average.

Researchers at Cornell University have developed a new technology that effectively protects bees from insecticides.  The insecticide antidote delivery method is now the basis of a new company called Beemunity.

The Cornell researchers developed a uniform pollen-sized microparticle filled with enzymes that detoxify organophosphate insecticides before they are absorbed and can harm bees.  Organophosphate insecticides account for about a third of the insecticides on the market.  The microparticles have a protective casing that allows the enzymes to move past the bees’ crop (basically the stomach), which is acidic and would otherwise break them down.  The safeguarded enzymes then enter the midgut, where digestion occurs and where toxins and nutrients are absorbed.  There the enzymes act to break down and detoxify the organophosphate insecticides.

In experimental tests, bees that were fed the enzyme-filled microparticles had a 100% survival rate after exposure to the insecticide malathion.  Unprotected control bees died within days.

The Cornell work appears to represent a low-cost, scalable solution to the insecticide toxicity issue and may help to protect essential pollinators.

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Pollen-sized technology protects bees from deadly insecticides

Photo, posted January 30, 2020, courtesy of George Tan via Flick.

Earth Wise is a production of WAMC Northeast Public Radio.

Wind Farms Slowing Each Other Down | Earth Wise

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Offshore wind is booming in Europe.  The expansion of wind energy in the German Bight and Baltic Sea has been especially dramatic.  At this point, there are about 8 gigawatts of wind turbines in German waters, the equivalent of about 8 nuclear power plants.  But space in this region is limited so that wind farms are sometimes built very close to one another.

A team of researchers from the Helmholtz Center Hereon, a major German research institute, has found that wind speeds downstream from large windfarms are significantly slowed down.  In a study published in the journal Nature Scientific Reports, they found that this braking effect can result in astonishingly large-scale lowering of wind speeds.

On average, the regions of lowered wind can extend 20-30 miles and, under certain weather conditions, can even extend up to 60 miles.  As a result, the output of a neighboring wind farm located within this distance can be reduced by 20 to 25 percent.

These wake effects are weather dependent.  During stable weather conditions, which are typically the case in the spring in German waters, the effects can be especially large.  During stormy times, such as in November and December, the atmosphere is so mixed that the wind farm wake effects are relatively small.

Based on their modeling, it is clear that if wind farms are planned to be located close together, these wake effects need to be taken into account.  The researchers next want to investigate the effects that reduced wind speeds have on life in the sea.  Ocean winds affect salt and oxygen content, temperatures, and nutrients in the water.  It is important to find out how reduced winds might affect marine ecosystems.

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Are wind farms slowing each other down?

Photo, posted November 23, 2011, courtesy of David J Laporte via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Vanishing Kelp Forests | Earth Wise

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Bull kelp is the dominant species in offshore kelp forests north of Santa Cruz, California along the west coast of North America.  Bull kelp has similar physical structures to terrestrial plants; it anchors to the ocean floor with root-like structures called holdfasts, and has stem-like structures called stipes from which leaf-like blades stretch out through the water, absorbing nutrients and sunshine.

These giant seaweeds form lush underwater forests in northern California’s coastal waters and have long provided critical habitat for many species like salmon, crabs, and jellyfish.  But now, for much of the California coast, only a few patches of bull kelp remain.

A team from University of California Santa Cruz has studied satellite images of about 200 miles of coastline.  They found that starting in 2014, the area covered by kelp has dropped by more than 95%. 

The die-off was driven in part by an underwater heat wave that depleted nutrients in the water and made it harder for the kelp to grow.  Making matters much worse, populations of purple sea urchins, which eat kelp, have exploded in the region because of overfishing and other reductions in urchin predators such as sea otters.  The sea urchins eat kelp holdfasts, creating so-called urchin barrens where their destructive grazing has decimated kelp forests.

Bull kelp is a species at high risk of becoming endangered.  In coming decades, more marine heatwaves are expected.  These events as well as stronger El Niños will become more common and frequent with climate change.  Between these thermal events and the sea urchins, it will be difficult for kelp forests to survive.

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Ninety-five percent of bull kelp forests have vanished from 200-mile stretch of California coast

Photo, posted October 28, 2015, courtesy of Florian Graner/Green Fire Productions via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Corn Belt Is Losing Topsoil | Earth Wise

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According to a new study published in the Proceedings of the National Academy of Sciences, more than a third of the farmland in the U.S. Corn Belt has completely lost its carbon-rich topsoil due to erosion.   The affected area is nearly 100 million acres and the amount of carbon loss is nearly 2 million tons.

The study, led by scientists at the University of Massachusetts, Amherst, found that the greatest loss of carbon-rich topsoil was on hilltops and ridgelines.  This indicates that tillage – the repeated plowing of fields – was the primary cause of the erosion because loosened soils move downslope.

The loss of topsoil has reduced corn and soybean yields in the Midwest by 6%, resulting in a loss of nearly $3 billion a year for farmers.  In addition, the loosening of the topsoil increases runoff of sediment and nutrients into nearly waterways, worsening water quality.

Previous studies have shown that no-till farming practices can have a significant impact on reducing erosion.  A study published last November found that if farmers shifted entirely to no-till practices, it would reduce soil erosion from U.S. agricultural fields by more than 70%, as well as significantly reducing nutrient and sediment runoff. 

No-till farming is the practice of planting crops without tilling the soil.  Instead, seeds are planted through the remains of previous crops by planters or drills that cut seed furrows, place the seeds, and close the furrow.  Currently less than 15% of farmland in the upper Mississippi River watershed is farmed with no-till practices. 

Even partial changes in tilling practices could produce positive results for topsoil retention and for waterways.

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One-Third of Farmland in the U.S. Corn Belt Has Lost Its Topsoil

Photo, posted September 15, 2010, courtesy of the United Soybean Board / Soybean Checkoff via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Residential Gardens And Pollinators | Earth Wise

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A new study led by the University of Bristol in the UK measured for the first time how much nectar is produced in urban areas to gauge the role of residential gardens in providing nutrients for pollinators.  They discovered that home gardens accounted for the vast majority of the crucial nutrients for pollinators; in fact, some 85% on average.

The study found that gardens generated a daily average of about a teaspoon of the unique sugar-rich liquid found in flowers which pollinators drink for energy.  A teaspoon sounds like very little, but it is enough to feed thousands of bees.

The research examined nectar production in four major UK towns and cities and measured nectar production in nearly 200 species of plants.  The results were that the nectar supply in urban landscapes is more diverse than in farmland and nature reserves.   In addition, gardens are critical because they produce the most nectar per unit area of land and actually cover the largest area of land in the cities studied.  In those cities, nearly a third of the land comprised domestic gardens, which is six times the area of parks and 40 times the area of small green allotments.

The upshot of the research is that home gardeners have a huge role to play in pollinator conservation.  Without domestic gardens, there would be far less food for pollinators that include bees, wasps, butterflies, moths, flies, and beetles.  Thus, it is important for home gardeners to keep planting nectar-rich flowers, mow lawns less often to let dandelions, clovers, and daisies flourish, avoid harmful pesticides, and avoid covering gardens in paving, decking, or artificial turf.

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Pioneering research reveals gardens are secret powerhouse for pollinators

Photo, posted June 23, 2018, courtesy of Wolfferl via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cell-Based Meat And Seafood | Earth Wise

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We have heard about laboratory meat for a number of years, generally in terms of something that may happen at some point in the indeterminate future. But at least for a couple of California companies, that future is now.

These high-tech companies are producing products – real meat and seafood – that are originally cultured from animal cells but are made without the actual animal.

San Francisco-based Eat Just makes chicken nuggets that have recently gained regulatory approval in Singapore and are now available to order at a downtown restaurant.  San Diego’s BlueNalu creates cell-based seafood fillets including yellowtail, mahi-mahi, red snapper, and tuna.

The companies use stem cells obtained from actual animals and cultivate them in steel tanks with the same nutrients that living animals consume.  The original cell donor is not sacrificed.  The harvested cells multiply and are eventually shaped to form meat or fish that cooks, looks, and tastes just like its natural counterpart.

The “mouth feel” of conventional meat or fish can be mimicked by recreating the same proportions of muscle, fat, and connective tissue in the cell-based product.  Eat Just says their product cooks, looks, and tastes like chicken because it is chicken.  BlueNalu says their product has all the same characteristics as fish because it is fish.

These products have major environmental, safety, and ethical advantages.  The big question is whether people will eat them.  Is there an “ick factor” to overcome?  Ultimately, the key thing is how they taste.  If they pass muster on that score and cell-based meats and seafood are scaled up and accepted, we can have the nutritional and sensory advantages of meat proteins without the environmental, ethical and safety disadvantages.

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Can We Enjoy Meat and Seafood and Save the Planet?

Photo, posted February 1, 2012, courtesy of Andrea Parrish-Geyer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Search For Lingering Ash | Earth Wise

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Ash trees are some of the most important plants along riverbanks and in wetlands.  There are three ash species in North America:  the white, green, and black ash.  Unfortunately, all three species are critically endangered because of the emerald ash borer.

The emerald ash borer is an exotic beetle from Asia that first showed up in the U.S. in southeastern Michigan in the summer of 2002.  The adult beetles do little damage but the larvae feed on the inner bark of ash trees and disrupt the tree’s ability to transport water and nutrients.  The beetles are now found in 35 states and 5 Canadian provinces and have killed hundreds of millions of ash trees.

The greatest hope for preserving ash tree species relates to lingering ash, which are those rare trees that have managed to survive the onslaught of the emerald ash borer. The idea is that those trees have some natural genetic resistance to the borer.  Getting seeds and cuttings from lingering ash and propagating them at nurseries may be the only way to get ash trees back into the natural landscape.

Lingering ash are extremely rare and therefore very hard to find.  As a result, researchers are reaching out to the public to help with the search and report the presence of these surviving trees in woodlands.

Researchers want to find large, mature trees left among those that were killed by the invasive insect and therefore display great resilience.  In Kentucky, university and Division of Forestry researchers are making use of software tools to engage the assistance of the public. An app called TreeSnap allows people to provide data on trees that they find in their community, on their property, or out in the wild.

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Researchers Ask Public for Help Finding Lingering Ash Trees

Help Our Nation’s Trees!

Photo, posted May 31, 2014, courtesy of Katja Schulz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saharan Dust And The Amazon | Earth Wise

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We talk about globalization primarily in the context of how human activities connect up distant parts of the world.  But there are natural processes that are global in scope as well.  One of these is the transportation of mineral-rich dust from the Sahara Desert in North Africa to the Amazon Basin in South America.

Every year, this dust is lifted into the atmosphere by winds and carried on a 5,000-mile journey across the North Atlantic.  It turns out that this dust plays a critical role in the Amazon basin ecosystem.  The Amazon Basin in turn plays a major role in global climate.  Its trees and plants remove huge quantities of carbon dioxide from the atmosphere and stores the carbon in vegetation.

The transcontinental journey of dust is important because of what is in the dust.  The dust picked up from ancient lake beds in Chad comes from rock minerals formed by dead microorganisms and is loaded with phosphorus.  Phosphorus is an essential nutrient for plant growth and is in short supply in Amazonian soils.  Local nutrients like phosphorus in the Amazon mostly come from fallen, decomposing leaves and organic matter but tend to be washed away by rainfall into streams and rivers. 

Studies have shown that the phosphorus that reaches Amazon soils from Saharan dust is essential to replace the amounts lost to rain and flooding.

Recent research has found that the quantities of dust transported to South America are inversely linked to rainfall in North Africa and is likely to be affected by climate change.  Changes in dust transport could affect plant growth in the Amazon and the amount of CO2 removed from the atmosphere.  The forces that affect the climate are truly global in nature.

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Study quantifies Saharan dust reaching Amazon

Photo, posted April 19, 2011, courtesy of CIAT via Flickr. Photo credit: ©2011CIAT/NeilPalmer.

Earth Wise is a production of WAMC Northeast Public Radio.

Helping Out Corals With Cool Water | Earth Wise

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Coral bleaching is happening five times more frequently than it did forty years ago.  Its increasing occurrence is a result of global warming which leads to marine heat waves – periods of higher ocean water temperatures.  Heat stress on living coral animals causes them to expel the algae that live symbiotically within the coral structure.  As the algae is expelled, the coral fades in color looking like it is bleached.  Without its algae partner, the coral eventually dies.

Given the increasing occurrence of marine heat waves, scientists are seeking novel ways to decrease heat stress in corals.  A new study by the Bermuda Institute of Ocean Science is investigating the use of artificial upwelling – the application of cooler, deep water – as a way to mitigate thermal stress on corals.

Upwelling is a natural process in the ocean in which winds push surface water away from a region – for example, a coastline – which then allows the uplift of deeper, colder waters to the surface.  Because such deeper waters are typically rich in nutrients, upwelling is important for supporting many of the world’s important commercial fisheries.  For this reason, artificial upwelling has sometimes been used to increase fish stocks in certain locations.

The new work placed coral colonies in aquaria in Bermuda and tested the effects of varying amounts and temperatures of deep cold-water pulses upon corals subjected to thermal stress.  The results showed that even short intrusions of cooler deep water (less than two hours per day) can mitigate thermal stress in corals.  The next steps are to find suitable parameters for artificial upwelling that maximize the benefits while minimizing potential harmful side effects on the corals and the ecosystems they support.

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Can pumping up cold water from deep within the ocean halt coral bleaching?

Photo, posted February 24, 2008, courtesy of Roderick Eime via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Making Use Of Invasive Seaweed | Earth Wise

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In recent years, millions of tons of brown Sargassum seaweed have formed gigantic blooms stretching all the way across the Atlantic Ocean from West Africa to the Gulf of Mexico.  The seaweed has become a problem for shorelines in the Caribbean, the Gulf of Mexico, and the east coast of Florida.  The massive increase in seaweed populations is related to changes in ocean chemistry resulting from nutrients from fertilizer use entering the water as well as from changes to the climate affecting ocean currents and temperatures.  The seaweed is harming the tourism industry as well as fisheries and ocean ecosystems.

Cleaning up the seaweed that washes ashore is labor-intensive and therefore expensive.  A research team led by two British universities has developed a cheap and simple way to pre-process seaweed to facilitate making it into bulk chemicals and biofuels.  With the new process, cleaning up the seaweed can be both economically and environmentally viable.

Previous techniques for processing seaweed generally required removing it from the saltwater, washing it in fresh water, and drying it – all of which add significant costs.  The new technique makes use of catalysts to release sugars from untreated seaweed that feed a yeast to produce a palm oil substitute.  At the same time, the process creates heat and pressure, turning the residual materials into a bio-oil that can be processed further into fuels, and a high-quality, low-cost fertilizer.

Apart from getting economic value out of the seaweed that is collected, any plastic collected alongside the seaweed can be converted to useful materials as well. 

It appears that the seaweed scourge is here to stay, so finding an economically viable way to deal with it is a welcome development.

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Solve invasive seaweed problem by turning it into biofuels and fertilisers

Photo, posted August 10, 2015, courtesy of Flickr.

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Working Forest Buffers | Earth Wise

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More than 100,000 miles of U.S. rivers and streams are polluted by nitrogen and phosphorus, mostly from agricultural runoff.  In the past, forests grew naturally alongside these waterways and helped stabilize stream banks and decrease flooding while trapping and filtering pollutants.  But most of these forests have been cut down to make way for towns, cities, livestock, and crops.

Farmers are reluctant to retire valuable farmland with non-productive buffer planting.  But in Pennsylvania, there is an innovative program that encourages farmers to plant cash crops in waterway buffer zones that can help stabilize stream banks and clean up the waterways.  These plantings are called working buffers.

Strips of streamside land are replanted with native floodplain trees and shrubs.  These are known as riparian forest buffers.  Pennsylvania has instituted a grant program under which farmers and landowners plant these buffers and turn a profit.

Many of these buffers have three zones.  A conventional forest buffer that can be just 15 feet wide is composed of native woodland and stabilizes the bank with tree roots and enhances wildlife habitat.  A second zone, some 20 feet wide, is planted with trees and shrubs that can tolerate periodic flooding.  Apart from slowing floodwater and taking up nutrients, this zone can provide profits by planting trees like black walnut, hazelnut, persimmon, and elderberry.  Only hand harvesting is allowed.  A third zone, adjacent to conventional crop, can contain blueberries, raspberries, and decorative woody florals.

How many farmers can be enticed to create these riparian buffers remains to be seen, but they do represent a way to help farmers to reduce pollution and turn a profit along the way.

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A Movement Grows to Help Farmers Reduce Pollution and Turn a Profit

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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...)