Environment: Oxygen-depleted dead zones caused by reservoirs killing endangered fish embryos

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Pallid sturgeon embryos are dying in the dead zones of the Missouri River. Photo via Nebraska Games and Parks Commission.

‘We’re basically talking about a living dinosaur that takes 20 years to reach sexual maturity and can live as long as the average human in the U.S.’

Staff Report

FRISCO — A river fish whose genetic lineage goes back ten of million years has survived dramatic climate shifts and other earth-changing events, but may not be able to persist through the age of dam-building.

Oxygen-depleted dead zones between dams in the upper Missouri River Missouri River are preventing pallid sturgeon from reproducing, and there’s no sign things will get better, at least not without a little help from humans. Continue reading

Green groups push EPA to address airline emissions

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A commercial airliner flies over the Sierra Nevada.

Without regs, emissions could triple by 2050

Staff Report

FRISCO — With the EPA set to decide in May whether aircraft carbon pollution endangers public health or welfare, the battle over airline industry emissions in heating up.

Both the EPA and the airline industry have been dragging their feet for years, refusing to address one of the fastest growing sources of greenhouse gas pollutants. This week, six major green groups called on the EPA and the  Federal Aviation Administration to move quickly to set emission standards to curb greenhouse gas pollution from the nation’s aircraft fleet. Continue reading

Study: California’s biggest, oldest trees fading fast

Oaks, stands of dense, small trees becoming dominant

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Redwood trees in California. bberwyn photo.

Staff Report

FRISCO — Hand-written notes from old forest surveys have helped scientists track long-term changes in California forests, including a decline of large trees of up to 50 percent in the Sierra Nevada highlands, the south and central coast ranges and Northern California.

The research team  from the University of California, Berkeley, UC Davis and the U.S. Geological Survey compared unique forest surveys collected by UC Berkeley alumnus Albert Wieslander in the 1920s and ’30s with recent U.S. Forest Service data to show that the decline of large trees and increase in the density of smaller trees is not unique to the state’s mountains. Continue reading

Scientists probe Antarctic ice sheet for climate clues

New data to help inform projections of sea-level rise

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Researchers are exploring Antarctic ice sheets. bberwyn photo.

Staff Report

FRISCO — Drilling deep into Antarctic ice this month, researchers were able for the first time to take a close look at the grounding zone of an ice sheet, where Antarctic ice, land and sea all converge.

Sediment samples from the half-mile bore hole will provide clues about the mechanics of ice sheets and their potential effects on sea-level rise, but the drilling also revealed an unsuspected population of fish and invertebrates living beneath the ice sheet, the farthest south that fish have ever been found. Continue reading

Study explores Greenland Ice Sheet plumbing

A meltwater lake on the surface of the Greenland Ice Sheet. Now researchers are tracking where that water goes, and how it may affect ice sheet movement. Photo courtesy Thomas Nylen, NSF.

A meltwater lake on the surface of the Greenland Ice Sheet. Now researchers are tracking where that water goes, and how it may affect ice sheet movement. Photo courtesy Thomas Nylen, National Science Foundation.

Surface meltwater feeds subglacial lakes

Staff Report

FRISCO — Scientists who recently took a close look at the “plumbing” of the Greenland Ice Sheet say that meltwater from the surface is building up lakes beneath the ice and transporting heat to the bottom of the ice sheet.

The research, led by Cornell University Earth and Atmospheric Sciences researcher Michael Willis, includes groundbreaking findings that give new information about atmospheric warming and its affect on the critical zone at the base of the ice. The warmth provided by the water could make the ice sheet move faster and alter how it responds to the changing climate. The research is detailed in a new paper published online by the journal Nature on Jan. 21. Continue reading

Wildlife: Colorado launches new lynx monitoring effort

A radio-collared lynx in Colorado. Photo courtesy CPW.

A radio-collared lynx in Colorado. Photo courtesy CPW.

SW Colorado field project will assess habitat occupancy, population trends

Staff Report

FRISCO — Colorado biologists have launched an ambitious monitoring program aimed at learning whether the state’s population of reintroduced and native-born lynx is holding steady.

The monitoring will cover more than 5,000 miles in the San Juan Mountains in southwest Colorado, including six wilderness areas: Weminuche, Uncompahgre, Lizard Head, Powderhorn, La Garita Mount Sneffels, and South San Juan. Continue reading

Climate: Melting glaciers adding dissolved carbon to world’s oceans

Scientists eye impacts to high-latitude marine ecosystems

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Melting glaciers, like the Dachstein in Austria, may be a big source of dissolved carbon with the potential to affect downstream ecosystems. bberwyn photo.

Staff Report

FRISCO — As if rising sea levels aren’t enough to worry about, U.S. Geological Survey scientists say melting glaciers may also adding significant amounts of carbon to the oceans, where it’s readily available to microscopic organisms at the base of the food chain.

By 2050, that carbon could total as much as 17 million tons, equal to about half of the annual flux of dissolved organic carbon from the Amazon River, the researchers reported in the journal Nature Geoscience, cautioning that their calculations are subject to revision.

The study aimed to better understand the role glaciers play in the global carbon cycle, especially as climate warming continues to reduce glacier ice stores and release ice-locked organic carbon into downstream freshwater and marine ecosystems. Continue reading

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