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Plastic Pollution And The Galapagos Islands | Earth Wise

July 12, 2021 By EarthWise 1 Comment

The proliferation of plastics remains one of the world’s most challenging environmental problems. Plastic pollution can be found in some of the most remote regions of the planet, including atop the world’s tallest mountains and in the deepest depths of the ocean. Even the Galapagos Islands, a volcanic archipelago in the Pacific Ocean, are no exception.

According to a new study by researchers from the University of Exeter, the Galapagos Conservation Trust, and the Galapagos Science Center, plastic pollution has been found in seawater, on beaches, and inside marine animals at the Galapagos Islands.

In the most polluted hotspots, more than 400 plastic particles were found per square metre of beach. The researchers found that only 2% of macroplastic pollution – plastic fragments larger than five millimeters – was identified as coming from the Galapagos islands. All seven of the marine invertebrate species examined – 52% of individuals tested – were found to contain microplastics.

Significant accumulations of plastic were also found in key habitats, including rocky lava shores and mangroves. In fact, plastics were found in all marine habitats at the island of San Cristobal, which is where Charles Darwin first landed in Galapagos.

Most of the plastic pollution in the Galapagos appears to arrive via ocean currents. According to the research team, the highest levels of plastic pollution were found on east-facing beaches, which are exposed to pollution carried across the ocean on the Humboldt Current.

The pristine images of the Galapagos, a world-famous biodiversity haven, might give the impression that the region is protected from plastic pollution. But clearly that is not the case.

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Plastic in Galapagos seawater, beaches and animals

Photo, posted April 12, 2012, courtesy of Ben Tavener via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dust And Himalayan Glaciers | Earth Wise

December 14, 2020 By EarthWise Leave a Comment

Glaciers in the Himalayas have been melting and retreating, as have glaciers around the world. As is the case elsewhere, human-driven climate change is a major factor. But at the lofty heights of the Himalayas, warming temperatures are not the biggest culprit. Black carbon – released into the air by burning fossil fuels or biomass such as plants, trees, and shrubs – darkens the snow and causes it to absorb more of the sun’s heat. A recent study by an international team of scientist has identified another important factor: dust.

An estimated 5 billion tons of desert dust enters the Earth’s atmosphere every year. Dust from places like Saudi Arabia gets picked up by spring winds and gets deposited on the western sides of mountains, where it can make the air 10 times more polluted than most European cities. Dust blows across industrial and desert areas in the Indian subcontinent and the Middle East and lands in the Himalayas. According to the new study, this dust is often the dominant cause of snow melt in those areas.

Desert dust causes snow melt in the same way that black carbon does. Dirty snow absorbs sunlight more easily than clean snow.

Desert dust is a natural part of Earth’s systems, but the amount of it in the atmosphere has steadily increased since the Industrial Revolution, when humans greatly expanded into desert areas and broke through surface crust that held large amounts of dust in place.

There is not much we can do about desert dust, short of eliminating deserts. But the disappearance of the Himalayan ice pack – which sustains over a billion people – can be mitigated by reducing greenhouse gas emissions to address climate change .

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Himalayan glaciers melting because of high-altitude dust

Photo, posted March 13, 2018, courtesy of Sarunas Burdulis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recovering Condors | Earth Wise

August 12, 2020 By EarthWise Leave a Comment

The California condor is the largest North American land bird. Its wingspan is nearly 10 feet and its weight of up to 26 pounds nearly equals that of the trumpet swan, the heaviest native North American bird. California condors can live up to 60 years, making them among the world’s longest-living birds as well. But California condors became extinct in the wild in 1987.

Lead poisoning is the primary threat to condors. The birds are scavengers and feeding on the carcasses of dead animals that contain fragments of lead rifle ammunition is responsible for half of all condor deaths.

Condors historically occupied California’s Sierra Nevada mountains and were known to nest in the cavities of giant sequoia trees. By 1982, the wild population was reduced to just 22 birds, and all of those were eventually trapped and brought into captivity to prevent extinction of the species.

A captive breeding program was undertaken at the Los Angeles Zoo and the San Diego Wild Animal Park. With the success of that program, in 1992 the U.S. Fish and Wildlife Service began releasing condors back into the wild in the mountains of Los Padres National Forest in Southern California. That flock has grown to about 100 birds through both wild reproduction and additional release of captive-bred birds.

The Southern California flock continues to expand its range with birds in 8 California counties and even in Arizona, Utah, and Baja California in Mexico. The total wild population of condors is now estimated to be about 340 birds. Recently, condors have been spotted in Sequoia National Park, a part of its historic range where the birds have been absent for nearly 50 years.

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California Condors Spotted in Sequoia National Park, First Time in Nearly Half a Century

Photo, posted May 20, 2005, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Moving Up And Away | Earth Wise

May 21, 2020 By EarthWise Leave a Comment

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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