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The Search For Lingering Ash | Earth Wise

January 12, 2021 By EarthWise Leave a Comment

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

October 23, 2020 By EarthWise Leave a Comment

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

Earth Wise is a production of WAMC Northeast Public Radio.

Helping Out Corals With Cool Water | Earth Wise

October 22, 2020 By EarthWise Leave a Comment

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

June 26, 2020 By EarthWise Leave a Comment

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.

Earth Wise is a production of WAMC Northeast Public Radio.

Working Forest Buffers | Earth Wise

April 15, 2020 By EarthWise Leave a Comment

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

Photo, posted March 19, 2010, courtesy of the USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Foods of the Future? | Earth Wise

March 27, 2020 By EarthWise Leave a Comment

In a world where many go hungry in the context of rapidly changing environments, many experts contend that alternative food sources will be necessary to solve global food security problems. So-called novel food sources are central to this conversation, defined as foods with no history of consumption in a region – or perhaps anywhere.

Three popular examples are lab-grown meat, insect farming, and seaweed aquaculture. Each of these offer opportunities as well as challenges.

Lab-grown meat can refer to actual animal tissues raised in vats as well as the increasingly common cultured plant products made to resemble meat. Lab-grown meat faces push back from the livestock industry that contends it should not be labeled as any kind of meat. While results to date are positive, barriers still remain including concerns over product taste, healthiness, and cost. And while less land- and water-intensive than conventional livestock, cultured meat production is still energy intensive.

Insects do form a significant part of diets across the globe but have yet to be embraced in any substantial way in western cultures. Nutritionally, numerous species of insects are rich in key proteins, micronutrients, and minerals. But the “yuck factor” is a big barrier to cross.

Seaweed is a long-established part of many East Asian diets and has many potential dietary uses. Several selectively bred varieties of seaweed supply a range of valuable nutrients. Growing seaweed does not tax freshwater and terrestrial resources. But intensively cultivated seaweeds would have potential negative effects on local marine ecosystems.

There is no single solution to complex issues like food security. Novel foods may very well form part of the solution to a growing food crisis.

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Insects, seaweed and lab-grown meat could be the foods of the future

Photo, posted March 12, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Road Salt Pollution

January 8, 2020 By EarthWise 1 Comment

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.

Lake George Health Report

December 26, 2019 By EarthWise Leave a Comment

The Offshore Chemistry Program, run by the Darrin Fresh Water Institute at RPI, has been monitoring the deep waters of Lake George in New York for 40 years. Lake George, nicknamed the Queen of American Lakes, is famed for the transparency of its water and a new report on the health of the lake reveals that it is doing rather well.

According to the report, although concentrations of chemicals and pollutants like salt and nutrients have increased in the deep waters of Lake George, they are still too low to harm the ecosystem at those depths.

The Offshore Chemistry Program studies the lake as part of a collaboration between RPI, IBM Research, and the FUND for Lake George that is called the Jefferson Project. This long-term commitment provides a wealth of information over time matched by few lake studies in the world.

The recent results show that levels of salt, the nutrient orthophosphate, and chlorophyll have increased substantially over time, but none are yet at a level that will cause harm.

Orthophosphate occurs naturally, but most likely the higher levels are due to improperly functioning septic systems, failing wastewater treatment systems, and stormwater runoff. The orthophosphate most likely triggered the increase in chlorophyll, which probably is associated with increased density of chlorophyll in individual algal cells, rather than an increase in total algal mass in the lake.

Overall, the results demonstrate the continuing resilience of Lake George to a growing array of stressors. In nearly 40 years of human activities, the lake has changed in a number of ways, but the changes have so far been relatively small. With such careful monitoring, we can hope to keep them that way.

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Four Decades of Data Sounds Early Warning on Lake George

Photo, posted September 24, 2009, courtesy of GPA Photo Archive via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Giant Seaweed Bloom

August 19, 2019 By EarthWise Leave a Comment

Scientists using data from NASA satellites have discovered and documented the largest bloom of seaweed in the world, stretching all the way from West Africa to the Gulf of Mexico. The gigantic macroalgae bloom has been dubbed the Great Atlantic Sargassum Belt.

The brown seaweed floats in surface water and in recent years has become a problem to shorelines lining the tropical Atlantic, Caribbean Sea, Gulf of Mexico, and east coast of Florida. The stuff carpets popular beach destinations and crowded coastal waters. In 2018, more than 20 million tons of it floated on the ocean surface.

Scientists have been studying the Sargassum algae using satellites since 2006, but the major blooms have only started appearing since 2011. They have occurred every year between 2011 and 2018 except for 2013. Before 2011, most of the free-floating Sargassum in the ocean was primarily found in patches around the Gulf of Mexico and the Sargasso Sea located on the western edge of the central Atlantic Ocean.

Sargassum provides habitat for turtles, crabs, fish and birds, and produces oxygen via photosynthesis. However, too much of it can crowd out many marine species.

According to researchers, the ocean’s chemistry must have changed in order for the bloom to get so out of hand. The factors involved include a large seed population left over from a previous bloom, nutrient input from West Africa, and nutrient input from the Amazon River. The increase in nutrients may be a result of deforestation and fertilizer use.

Climate-change effects on precipitation and ocean currents ultimately do play a role in this, but increased ocean temperatures do not. Unfortunately, these giant seaweed blooms are probably here to stay.

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NASA Satellites Find Biggest Seaweed Bloom in the World

Photo courtesy of NASA.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Nutrients

August 15, 2019 By EarthWise Leave a Comment

Ending hunger isn’t a question of producing enough food. Globally, enough food is produced to feed all 7.7 billion people on the planet. But despite this, approximately 1 in 9 people go hungry. Conflict, natural disasters, and extreme poverty are some of the main drivers of global hunger.

Climate change is another. The more frequent and intense extreme weather events increase food insecurity and malnutrition by destroying land, livestock, crops, and food supplies. Climate change makes growing crops harder every year, especially for those who lack the tools and technology to adapt.

But the challenge of reducing hunger and malnutrition is to not only produce foods that provide enough calories, but to also produce foods that make enough necessary nutrients widely available. According to new research, climate change is projected to significantly reduce the availability of critical nutrients such as protein, iron, and zinc over the next 30 years. The total impact of climate change could reduce global per capita nutrient availability of protein, iron, and zinc by 19.5%, 14.4%, and 14.6%, respectively.

While higher levels of carbon dioxide can boost growth in plants, wheat, rice, corn, barley, potatoes, soybeans, and vegetables are all projected to suffer nutrient losses of about 3% on average by 2050 due to the elevated CO2 levels.

The study, which was co-authored by an international group of researchers and published in the peer-reviewed journal, Lancet Planetary Health, represents the most comprehensive synthesis of the impacts of climate change on the availability of nutrients in the global food supply to date.

Climate change is complicating the quest to end global hunger and malnutrition.

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Rising CO2, climate change projected to reduce availability of nutrients worldwide

Photo, posted April 30, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Intense Rainfall And Crops

July 2, 2019 By EarthWise Leave a Comment

The warming of the planet does not necessarily imply local weather will be warmer or drier than average. While heatwaves and droughts are increasingly common events in many places, so are intense rain events.

A new study led by scientists at the University of Illinois has found that intense rainfall is as damaging to the U.S. agricultural sector as heatwaves and excessive droughts.

The study examined more than three decades of crop insurance, climate, soil, and corn yield data. Researchers found that since 1981, corn yields in the U.S. Midwest were reduced by as much as 34% during years with excessive rainfall. Years with drought and heatwaves experienced yield losses of up to 37%.

Intense rain events can physically damage crops, delay planting and harvesting, restrict root growth, and cause oxygen deficiency and nutrient loss. The study estimated that between 1989 and 2016, excessive rainfall caused $10 billion in agricultural losses. However, excessive rainfall can have either negative or positive impact on crop yield and the effects can vary regionally.

Parts of the Midwest have already experienced a 42% increase in the heaviest precipitation events since 1958. Climate change models predict that much of this region will experience even more frequent and intense precipitation events in the coming decade.

According to the study, excessive rainfall is the major cause of crop damage currently in the U.S. for corn, and also has broad impacts for other staple crops such as soybeans and wheat. The authors suggest that as rainfall becomes more extreme, reforms will be needed in the U.S. crop insurance industry in order to better meet planting challenges faced by farmers.

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Intense Rainfall Is As Damaging to Crops As Heatwaves and Drought, and Climate Change Is Making It Worse

Photo, posted October 2, 2013, courtesy of the United Soybean Board via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Forecasting A Massive Dead Zone

June 18, 2019 By EarthWise Leave a Comment

The Gulf of Mexico dead zone occurs every summer, and is considered one of the largest dead zones in the world. This cyclical event occurs where the Mississippi River empties into the Gulf of Mexico, just off the coast of Louisiana and Texas.

This annual dead zone is primarily caused by excess nutrient pollution from human activities, such as urbanization and agriculture, occurring throughout the Mississippi River watershed. Washed off the land by spring rains, these excess nutrients stimulate an overgrowth of algae once they reach the Gulf of Mexico. The algae in the Gulf eventually die, and then sink and decompose in the water. The resulting area of the ocean ends up with a condition known as hypoxia, which is an insufficient amount of oxygen to support most marine life. In hypoxic or dead zones, animals that can’t swim away will often suffocate and die.

Scientists from the National Oceanic and Atmospheric Administration estimate that this year the dead zone in the Gulf of Mexico will be approximately 8,000 square miles, which is roughly the size of Massachusetts. The research team uses U.S. Geological Survey river flow and nutrient data to make its forecast.

According to NOAA, the abnormally high amount of spring rainfall is a major factor contributing to this year’s dead zone. Last month, nitrate loads entering the Mississippi River watershed were 18% above the long-term average, and phosphorus loads were about 49% above the long-term average.

While the 2019 forecast is slightly less than the record size of more than 8,700 square miles set in 2017, it’s still much larger than the five year average size of 5,700.

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Very large dead zone forecast for the Gulf of Mexico

Massive 8,000-mile ‘dead zone’ could be one of the gulf’s largest

Photo, posted May 22, 2009, courtesy of Michael McCarthy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

High-Tide Flooding And Pollution

April 30, 2019 By EarthWise Leave a Comment

Global sea levels are steadily rising. They are up 8 inches in the past century and now increasing at an average of 1.3 inches per decade. As a result, the incidence of high-tide “sunny day” flooding is on the rise, especially along the U.S. East Coast.

Norfolk Virginia experienced fewer than 2 days of high-tide flooding a year in the 1960s; it had 14 in 2017. Up and down the East Coast, flood days have increased by factors of 5 and more.

This has led to a form of pollution that hasn’t gathered much attention in the past: when these floodwaters recede, they can carry debris, toxic pollutants and excess nutrients into rivers, bays, and oceans.

In the aftermath of high-tide flooding in Norfolk, Chesapeake Bay was littered with tipped-over garbage cans, tossed-away hamburgers, oil, dirty diapers, pet waste and all manner of other things. Water that comes up on the landscape takes everything back into the river or ocean with it.

Analysis of tidal flooding along the Lafayette River in Norfolk indicated that just one morning of tidal flooding poured nearly the entire EPA annual allocation of nitrogen runoff for the river – nearly 2,000 pounds – into Chesapeake Bay. The effects of excess nitrogen in the water are well-known and responsible for the toxic algal blooms that endanger aquatic life as well as human health.

According to the National Oceanic and Atmospheric Administration, high-tide flooding frequency along the southeastern coast of the U.S. rose 160% since 2000. With the expected continuing rises in sea level, NOAA projects that as many as 85 days of high-tide flooding will occur along the coast by the year 2050. It’s a big problem.

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As High-Tide Flooding Worsens, More Pollution Is Washing to the Sea

Photo, posted September 20, 2018, courtesy of SC National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rigs To Reefs

March 29, 2019 By EarthWise Leave a Comment

There are about 6,000 offshore oil platforms in the world’s oceans. They have an immense presence physically, financially and environmentally. As these massive structures extract hydrocarbons from deep beneath the sea, they also undergo a remarkable transformation under the water. The enormous substructures that support the platforms become vertical reefs, home to millions of individual plants and animals.

Over time, many oil platforms are decommissioned, and their owners are faced with the choice of either removing them entirely or transitioning them into permanent reefs. Traditional practice was to restore the site to its original condition, but more recently the idea of “reefing” old platforms has gained popularity. As of 2016, more than 11% of decommissioned platforms in the U.S. portion of the Gulf of Mexico have become permanent reefs.

Decommissioning and completely removing a platform is a daunting and pricey proposition. The most recent estimate for removing all platforms off the coast of California alone totals $8 billion. Modifying the platforms to serve as permanent reefs cuts these costs significantly, especially those associated with hauling, cleaning and disposing of the underwater support structure, which will have thousands of tons of sea-life clinging to it by the time it is removed.

Converting the structure into a permanent reef means making it free of any hydrocarbons or other hazardous materials. But this is still a far cheaper venture than total removal. Studies of oil rigs as underwater habitats have shown them to be some of the most productive in the world. They are 3-dimensional reefs whose open construction allows currents to pass through bringing lots of nutrients.

Over time, more and more oil platforms will be decommissioned. Many may end up remaining as permanent homes for undersea life.

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Rigs to Reefs

Photo, posted August 21, 2011, courtesy of Marianne Muegenburg via Flickr

Earth Wise is a production of WAMC Northeast Public Radio.

Protection From Toxic Algae

March 28, 2019 By EarthWise Leave a Comment

Toxic algal blooms have been a growing problem in recent years associated with warming waters and nutrient-rich agricultural runoff in lakes, rivers, and oceans. In 2014, an algal bloom in Lake Erie left half a million residents of Toledo, Ohio without safe drinking water for three days.

The most common toxic substance released by algal blooms in the lake is called microcystin, which is closely linked to liver cancer and other diseases. Toxicologists measure microcystin and other contaminants using the metric of parts per billion. The EPA recommends that young children not drink water containing more than 0.3 parts per billion and adults no more than 1.6 parts per billion of microcystin.

Scientists at the University of Toledo have been working on developing a biofilter that uses naturally occurring Lake Erie bacteria to remove microcystin released by algal blooms and thereby reduce or eliminate the use of chlorine and other chemicals.

They have successfully isolated a number of types of bacteria that degrade microcystin toxin at a daily rate of up to 19 parts per billion. To their knowledge, such bacteria have not been previously used to fight algal blooms in other parts of the world. Based on the recorded toxin levels in Lake Erie in recent years, the bacteria would be able to effectively remove microcystin from water supplies. None of the 13 bacterial isolates they found have any association with human disease so their use in future water-purifying biofilters should not pose a public health concern.

The researchers are now developing and testing biofilters, which are water filters containing the specialized bacteria that will degrade the toxins from lake water as it flows through the filter.

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