degradation

Biosurfactants And Oil Spills | Earth Wise

August 22, 2023 By EarthWise Leave a Comment

About 400 million gallons of oil leaks into the ocean every year. This is a major source of environmental pollution. Oil contains many hazardous compounds that are toxic or mutagenic for marine organisms.

When oil spill incidents occur, large quantities of chemical dispersants, sometimes as much as millions of gallons, are applied to dissolve oil slicks, prevent oil from reaching coastlines, and enhance the dispersion of the oil in the water. The hope for doing this is that microbial oil degradation will be enhanced as a result. Certain microorganisms present in the water can feed on crude oil components and break them down into harmless substances.

A study at the University of Stuttgart in Germany in 2015 showed that chemical dispersants in fact can slow down microbial oil degradation and therefore inhibit water purification. The oil components need to be broken down sufficiently for them to be bioavailable to microorganisms. The study found that dispersants were not accomplishing this.

A new study by the same group along with researchers from the University of Tubingen in Germany and the University of Georgia has found that using biosurfactants rather than chemical dispersants stimulates different microbial oil degraders with respect to their growth and activity and can enhance our ability to deal with oil spills. Treating the water with the biosurfactant rhamnolipid rather than any of the generally-used dispersants provided much higher rates of microbial breakdown of oil components.

The hope is that this work can lead to the development of effective and environmentally friendly approaches to combatting oil spills.

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Biosurfactants might offer an environmentally friendly solution for tackling oil spills

Photo, posted June 11, 2010, courtesy of Deepwater Horizon Response via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Decreasing Forest Area Per Capita | Earth Wise

September 7, 2022 By EarthWise Leave a Comment

Over the past 60 years, global forest area has decreased by 315,000 square miles, an area about twice the size of California. Combined with global population growth over that period, this has resulted in more than a 60% decline in global forest area per capita.

The continuous loss as well as degradation of forest affects the integrity of forest ecosystems and reduces their ability to generate and provide essential services and sustain biodiversity. It impacts the lives of at least 1.6 billion people worldwide – primarily in developing countries – who depend upon forests in multiple ways.

According to the new study published in the journal Environmental Research Letters, forest losses have been occurring primarily in lower-income countries in the tropics while forest gains have occurred in higher-income countries in the mid-latitudes or extratropics.

More than half of the world’s forest losses were in Brazil, home to the Amazon rainforest. In the past 60 years, that country has had a net loss of 170,000 square miles of forest. While most high-income countries had net forest gains, Canada actually had a net loss of about 11,000 square miles of forest.

Economic growth has a stronger association with net forest gain than with net forest loss. Therefore, the study highlights the need to strengthen the support given to lower income countries, especially in the tropics, to help improve their capacity to minimize or curtail their forest losses. To help address this ongoing displacement of forest losses to lower income countries, higher-income nations need to reduce their dependence on imported tropic forest products.

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New study finds global forest area per capita has decreased by over 60%

Earth Wise is a production of WAMC Northeast Public Radio.

Declining Bird Populations | Earth Wise

June 16, 2022 By EarthWise Leave a Comment

A study by scientists from multiple institutions around the world including Cornell University has found that significant declines in bird populations are taking place across the planet. Loss and degradation of natural habitats, direct overexploitation of many species, and climate change are driving the bird population declines.

According to the study, approximately 48% of existing bird species worldwide are known or suspected to be undergoing population declines. The populations of 39% of bird species appear to be stable. Only 6% of birds have increasing populations.

A study in 2019 determined that nearly 3 billion breeding birds have been lost in the U.S. and Canada over the past 50 years. The new study shows that the same patterns of population decline and extinction are happening globally. According to the study, there are now the first signs of a new wave of extinctions of continentally distributed bird species.

The ultimate fate of bird populations is strongly dependent on stopping the loss and degradation of habitats. Habitat loss is generally driven by human demand for resources. Reducing the human footprint on the natural world is what is needed. Birds are a highly visible indicator of environmental health, and their declining populations signal a much wide loss of biodiversity and threats to human health and wellbeing.

There is a global network of bird conservation organizations trying to prevent further loss of bird species and bird abundance. Keeping track of the situation is essential and there is growing participation by the public in bird monitoring. But ultimately, it depends on governments and society in general to support sustainable resource use and learn how to share the planet with nature.

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Global Bird Populations Steadily Declining

Photo, posted January 9, 2022, courtesy of Martien Brand via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rising Seas And Wastewater Leakage | Earth Wise

April 28, 2021 By EarthWise Leave a Comment

Global mean sea level has risen nearly 9 inches since 1880, with over two inches of that over just the last 25 years. The rising water level is primarily due to two factors: additional water in the oceans coming from melting glaciers and ice sheets; and the thermal expansion of seawater as it warms. Climate models estimate that over the course of the century, global sea levels will rise at least a foot even if efforts to reduce greenhouse gas emissions are quite successful and, in the worst case, levels could rise as much as 8 feet.

Faced with this situation, the greatest concerns are, initially, increasing amounts of coastal flooding and erosion and, as things get worse, inundation of coastal regions making many places uninhabitable and creating millions of climate refugees.

Recently, computer modeling studies have focused on an additional imminent problem: the flooding of coastal wastewater infrastructure, which includes sewer lines and cesspools.

A new study by the University of Hawaii at Manoa is the first to provide direct evidence that tidally driven groundwater inundation of wastewater infrastructure is already occurring in urban Honolulu. The study shows that higher ocean water levels are leading to wastewater entering storm drains and the coastal ocean. The result is degradation of coastal water quality and ecological health.

The researchers used chemical tracers to detect groundwater discharge and wastewater present at multiple low-lying areas during spring tides. During high tides, storm drains become channels for untreated wastewater to flood streets and sidewalks.

People tend to think of sea-level rise as a future problem, but there are already serious effects going on today that are only going to get worse.

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Sea-level rise drives wastewater leakage to coastal waters

Photo, posted August 23, 2011, courtesy of Eric Tessmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Decline In Wildlife | Earth Wise

October 14, 2020 By EarthWise Leave a Comment

According to a new report released by the World Wildlife Fund, global populations of mammals, birds, amphibians, reptiles, and fish have declined by 68% in less than half a century.

The report presents a comprehensive overview of the state of the natural world based on the tracking of almost 21,000 populations of more than 4,000 vertebrate species between 1970 and 2016.

The report shows that the main cause of the dramatic decline in species populations on land is habitat loss and degradation, which includes deforestation driven by food production. Additional factors include land-use change and the use and trade of wildlife.

Wildlife populations found in freshwater habitats have suffered a decline of 84%, which is the steepest decline in any biome.

Insect populations have declined rapidly in many places, but most of the information about insects comes from a small number of countries in the northern hemisphere. There is very little information from large parts of the world, such as Africa, South America, and Asia, where land-use change and agricultural expansion are happening fast. What happens to insects matters a lot to humanity. Insects play central roles in the world’s ecosystems as waste processors, pollinators, predators, and prey.

The report is clear evidence of the damage human activity is doing to the natural world. Threats to the integrity of ecosystems endanger humans and all of nature. This is especially apparent in the midst of a global pandemic. It is now more important than ever to take coordinated global action to halt and reverse the loss of biodiversity and wildlife populations across the globe.

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Living Planet Report reveals 68% decline in global wildlife populations since 1970

Photo, posted May 7, 2020, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Beavers And The Warming Arctic | Earth Wise

August 5, 2020 By EarthWise Leave a Comment

Beavers have a remarkable ability to transform landscapes. Using their sharp teeth, they fell trees and shrubs and build dams, which cause small valleys to fill with water and form new lakes. Some of these lakes measure five or ten acres in size, or even more. And beavers are very efficient builders; they often build their dams at precisely those points where can they have the greatest effect with the least effort.

Scientists studying beaver activity in the Arctic regions of Alaska have found that the changing climate is leading to a substantial increase in beaver populations and their effect on the landscape.

In 2018, researchers found that the beavers living in a 7,000 square-mile area in northwest Alaska had created 56 new lakes in just five years. Thanks to rising temperatures, more and more habitats offer the shrubs that beavers need for food and building material. In addition, the lakes, which used to freeze solid, now offer beaver-friendlier conditions. Also, beavers are not hunted as intensively as in the past.

The scientists were surprised that beavers have seized the opportunity so intensively. There is basically an exponential growth in beaver dams. This is actually a worrisome situation. Forming all these new lakes degrades ice-rich permafrost in the area. In the Kotzebue region of Alaska, the overall water area has increased by more than 8% over the past 17 years, and roughly two-thirds of that is due to beavers.

The degradation of the Arctic’s permafrost is a dangerous situation and it appears that anyone who wants to predict its future has to keep the activity of beavers in mind.

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Beavers gnawing away at the permafrost

Photo, posted June 23, 2018, courtesy of Becky Matsubara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Degraded Permafrost In The Arctic

July 11, 2019 By EarthWise Leave a Comment

Permafrost is defined as rock or soil that has been at or below the freezing point of water for two or more years. Most of it is located in high latitudes in and around the Arctic and Antarctic regions. Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.

Permafrost can contain many different materials including bedrock, sediment, organic matter, water and ice. Because of the presence of organic matter, permafrost is potentially the source of significant methane emissions if it thaws and the trapped biomass begins to rot.

A recent study looked at the results of 30 years of aerial surveys and extensive ground mapping of an area of Canada’s high Arctic polar desert known as the Eureka Sound Lowlands. This area has an extremely cold climate and the permafrost there is over 1/3 of a mile thick. It has long been assumed that this landscape was stable.

Research led by McGill University in Montreal has found that this is not the case. The increases in summer air temperatures seen in recent years are initiating widespread changes in the landscape.

A particular landform known as a retrogressive thaw slump that forms when ice within permafrost melts and the land slips down is widely occurring in the area. The absence of vegetation and layers of organic soil in these polar deserts make permafrost in the area particularly vulnerable to increases in summer air temperatures.

The research indicates that despite the cold polar desert conditions that characterize much of the high Arctic, the interaction between ice-rich permafrost systems and climate factors is complex and the links between global warming and permafrost degradation are not well understood.

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