monitoring programs

There has been a great deal of interest in the plight of monarch butterflies in this country. Monarchs’ population and migratory habits are closely watched, and many people have been planting milkweed in their gardens to help their caterpillars. But other butterfly species have received much less attention despite the fact that many butterfly populations are in decline.

A groundbreaking new study has provided comprehensive answers about the status of butterflies in America. Over the past 20 years, the contiguous US has lost 22 percent of its butterflies.

The study is based on over 12 million individual butteries counted in 77,000 surveys across 35 monitoring programs from 2000 to 2020. Three hundred forty-two butterfly species in total were analyzed. Thirty three percent showed statistically significant declines while less than 3% displayed statistically significant increases. Overall, 13 times as many species decreased as increased.

Why are butterfly populations crashing? Experts point to a combination of factors: habitat loss as land in converted for agriculture or development, climate change, and pesticide use. It is not clear which factor is most important and may well vary by location. Pesticide use – especially neonicotinoids – has been shown to play a particularly lethal role in studies.

Insects including butterflies play a huge role in supporting life on earth. They pollinate plants, feed birds and many other creatures in the food web. Nature collapses without them. And butterflies are clearly in trouble.

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See How Butterflies Are Surviving, or Not, Near You

Photo, posted August 9, 2016, courtesy of Rachel Larue/Arlington National Cemetery via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Groundwater is the water found underground in the cracks and spaces in soil, sand, and rock. It is held in aquifers and bubbles up naturally into springs, streams, and rivers, but also is pumped out for use by people. Groundwater provides almost half the drinking water in the U.S. and is a main source of water for agriculture.

The world’s supply of groundwater is steadily declining. The combination of climate change and human population growth is increasingly diminishing groundwater.

A study by the Desert Research Institute published in the journal Nature Communications has mapped the global permanent loss of aquifer storage capacity for the first time. Computer modeling with advanced machine learning techniques has provided a detailed picture of the world’s groundwater situation.

The study found that global aquifer storage capacity is disappearing at a rate of 10 miles a year, about the size of 7,000 Great Pyramids of Giza. The loss of groundwater storage is permanent, forever reducing the amount of water that can be captured and stored because the pumping of groundwater can cause the ground surface above to sink, collapsing the space where water can be stored.

About 75% of this subsidence is occurring over cropland and urban regions. The United States, China, and Iran account for most of the global groundwater storage loss but many other places in the Middle East and Asia are experiencing significant groundwater withdrawal as well.

Most regions of the world do not have monitoring programs for groundwater pumping. The study underscores the need to better understand this issue on a global scale and take appropriate action before it is too late.

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Scientists Map Loss of Groundwater Storage Around the World

Photo, posted August 7, 2015, courtesy of NRCS Oregon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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The American butterfly census

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Groundwater loss

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