tortoises

Solar Power And Water | Earth Wise

August 8, 2023 By EarthWise Leave a Comment

Solar power is a prime example of clean energy, but it does not come without complications and potential problems. One problem that has arisen in the Californian desert is the effect on scarce water supplies. Solar farms don’t use up water when they are operating but they consume it when they are being built.

One of the densest areas of solar development in North America is in a corridor along Interstate 10 near Palm Springs, California. Multiple utility-scale solar projects are underway near the small town of Desert Center. The projects are being built on public land overseen by the Department of Interior’s Bureau of Land Management. The location is ideal for solar power projects: endless sunshine, nearby transmission lines to distribute power, and a major highway for easy transportation of construction materials.

The problem is that during construction of the solar farms, the law requires developers to reduce the amount of dust being generated that can otherwise spread health problems like Valley Fever. Preventing dust from flying requires water and lots of it.

The water comes from groundwater and building the solar farms is drying up local wells and emptying the aquifer that is part of the Chuckwalla Valley Groundwater Basin. For the people who live in Desert Center and adjacent areas, this is a serious problem. It is also a problem for the desert ecosystem that supports palo verde and ironwood trees as well as endangered desert tortoises.

This isn’t an easy problem to solve. Seven approved new utility-scale solar projects in the area will provide enough electricity to power 2 million homes. But having enough water to build those projects won’t be easy.

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Solar Is Booming in the California Desert, if Water Issues Don’t Get in the Way

Photo, posted October 16, 2017, courtesy of UC Davis College of Engineering via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Genetic Variation And Survivability | Earth Wise

January 21, 2021 By EarthWise Leave a Comment

A massive but unintended experiment in animal conservation has revealed an unexpected result. Thousands of desert tortoises moved to a translocation site in Nevada had a greater chance of surviving if they had lots of genetic variation.

From 1997 to 2014, over 9,000 Mojave desert tortoises were moved to a 39-square-mile translocation site in the Ivanpah Valley. The tortoises were either abandoned pets or were displaced by developments in suburban Las Vegas and by solar farms in the desert.

The U.S. Fish and Wildlife service took blood samples to screen for diseases and marked each animal before releasing them into the site, enabling them to be tracked in later surveys.

When the researchers compared tortoises that lived or died over the same time period after being relocated to the site, they found that survivors averaged 23% greater heterozygosity than those that perished. Heterozygosity is a measure of genetic variation. Like most organisms, tortoises have two copies of their entire genome, with one from each parent. The more those copies differ from each other, the higher the organism’s heterozygosity.

Researchers are not really sure why greater genetic variation is linked to survival rates. Potentially, individuals with higher heterozygosity have more genomic flexibility. It is the case that tortoises with more genetic variation have a better chance of having at least one copy of a gene that works really well in stressful or new environments.

Human activity and the changing climate are increasing the need to relocate plants and animals. Often the chances for success in doing this are not good, so anything we can learn about things that increase the chances for survival can be very important.

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UCLA study of threatened desert tortoises offers new conservation strategy

Photo, posted August 23, 2016, courtesy of the Bureau of Land Management California via Flickr. Photo by Dana Wilson, BLM.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost of Cleaning Up Ocean Plastic | Earth Wise

October 7, 2020 By EarthWise Leave a Comment

Small island developing states increasingly find themselves with large amounts of plastic waste. A recent study looked at the financial cost for removing it.

Aldabra Atoll is a UNESCO World Heritage Site in the Seychelles. It is the world’s second-largest coral atoll and is the home of 307 species of animals and plants, including the largest population of giant tortoises in the world. Aldabra has been called one of the wonders of the world and one of the crown jewels of the Indian Ocean.

Last year, a team from the University of Oxford and the Seychelles Island Foundation, spent five weeks removing litter that had washed up on Aldabra’s shores. In total, they removed 25 tons of plastic litter which, to their surprise, was dominated by waste from the fishing industry. The researchers now estimate that over 500 tons of litter remain on the island, 83% of which consists of buoys, ropes, nets, and, of all things, over 300,000 individual flipflops. This is the largest accumulation of plastic waste reported for any single island in the world.

According to the study, the cost to clean up the entire island would be nearly $5 million, requiring 18,000 person-hours of labor. A project of this magnitude is beyond the capacity of non-profit organizations like the Seychelles Islands Foundation.

The plastic pollution in Aldabra is related to the fishing industry in Seychelles, which provides tuna to high-income markets around the world. The research highlights how even remote highly protected island ecosystems are impacted by global pollution and how difficult and costly it is to remedy.

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Millions of dollars to clean up tuna nets and flip flops from island state

Photo, posted December 27, 2016, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Food Waste And Wildlife

February 3, 2016 By WAMC WEB

We have talked quite a bit about food waste and in particular its impact on world hunger and on the economy. The world wastes more than $750 billion worth of food each year and 1.6 billion tons of food is left in fields, sent to landfills or scattered about the landscape. Another 7 million tons of fishery discards are dumped in the sea.