swamps

Protecting Wetlands | Earth Wise

March 28, 2023 By EarthWise Leave a Comment

Wetlands are distinct ecosystems that are flooded or saturated by water, either permanently or seasonally. They include mangroves, marshes, swamps, forested wetlands, bogs, wet prairies, and vernal pools. The feature that most wetlands share is soil or substrate that is at least periodically saturated with or covered by water.

Wetlands are some of the most threatened ecosystems in the world. While wetlands can be affected by a variety of natural stressors, including erosion, droughts, and storms, human activities have been the major driver of wetland decline.

But according to a new study by researchers from McGill University in Canada, the global loss of wetland areas since 1700 has likely been overestimated. The research team calculated that the area of wetland ecosystems around the world has declined 21-35% since 1700 as a result of human activities – far less than the 50-87% decline estimated in other studies. The study’s focus beyond regions with historically high wetland losses and its avoidance of possibly misleading extrapolations likely resulted in the lower estimate.

According to the study, which was published in the journal Nature, more than 2.1 million square miles of wetlands have been lost during the past 300 years – an area roughly the size of India. The five countries with the highest wetland losses are the United States, China, India, Russia and Indonesia.

But discovering that fewer wetlands have been historically lost than previously thought gives researchers a second chance to protect wetlands. The findings of the study will help researchers prioritize global conservation and restoration actions.

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A second chance to protect wetlands

Photo, posted February 2, 2005, courtesy of Jan Tik via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Harvesting Fresh Water From Ocean Air | Earth Wise

January 19, 2023 By EarthWise Leave a Comment

Roughly three-quarters of the world population has access to a safely managed water source. That means that one-in-four people do not have access to safe drinking water. Even in the wealthy United States, persistent drought in the west is creating problems in places like Phoenix, Arizona.

Water is plentiful on Earth but more than 99% of it is unusable by humans and many other living things because it is saline, frozen, or inaccessible. Only about 0.3% of our fresh water is found in the surface water of lakes, rivers, and swamps.

There is an almost limitless supply of fresh water in the form of water vapor above the oceans, but this source is untapped. Researchers at the University of Illinois have been evaluating the feasibility of a hypothetical structure capable of capturing water vapor from above the ocean and condensing it into fresh water.

Existing ways to obtain fresh water like wastewater recycling, cloud seeding, and desalination have met only limited success and present various problems with regard to cost, environmental impact, and scalability.

The researchers have proposed hypothetical large offshore structures measuring 700 feet by 300 feet to capture water vapor that is continually evaporating from the ocean in subtropical regions. Their modeling concluded that such structures could provide fresh water for large population centers in the subtropics. Furthermore, climate projections show that the amount of water vapor over the oceans will only increase over time, providing even more fresh water supply.

This is only a theoretical study at this point, but the researchers believe it opens the door for novel infrastructure investments that could address global water scarcity.

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Researchers propose new structures to harvest untapped source of fresh water

Photo, posted June 28, 2009, courtesy of Nicolas Raymond via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Ivory-Billed Woodpecker | Earth Wise

May 24, 2022 By EarthWise Leave a Comment

The ivory-billed woodpecker was the largest woodpecker in the US. They were once relatively common, stretching from the Carolinas through the southeast and across to Texas. Their numbers started to drop sharply in the 19th century because of habitat loss and overhunting. Many were taken as valuable specimens; some were even eaten by poverty-stricken people.

The last widely accepted sighting was way back in 1944. For years, the birds were listed as critically endangered with only infrequent and entirely anecdotal reports of sightings. Last year, the U.S. Fish and Wildlife Service finally declared the species extinct.

A multiyear field study by avian researchers from multiple institutions has recently reported that the ivory-billed woodpecker may in fact still exist in a remote swampy region of Louisiana.

The three-year effort to find the woodpecker involved scientists trudging through the remote site to observe birds and take audio recordings. Unmanned trail cameras taking time-lapse photos and a drone were used to capture images. Several members of the team report that they observed the birds. Some photographic images and videos appear to show ivory bills. Based on characteristic markings visible in some of the photos, the birds do appear to be the ivory bill and not, for example, the fairly common but similar looking pileated woodpecker.

The birds are scarce, live in a tough, swampy habitat, and actively avoid getting near people. They live high in trees and are very difficult to spot, much less get clear photographs of. From all indications, however, reports of the demise of the ivory-billed woodpecker may have been premature.

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Back from the dead? Elusive ivory-billed woodpecker not extinct, researchers say

Photo, posted May 3, 2008, courtesy of Michael McCarthy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.