Tag Archives: ocean temperature

Sturgeon search

Scientists use satellites, underwater robot to study Atlantic sturgeon migrations

More than a century ago, an estimated 180,000 female Atlantic sturgeon arrived from the coast in the spring to spawn in the Delaware River and fishermen sought their caviar as a lucrative export to Europe. Overfishing contributed to steep population declines, however, and today numbers have dwindled to fewer than 300 adults.

Researchers at the University of Delaware and Delaware State University are using satellites, acoustic transmitters, an underwater robot and historical records to pinpoint the ocean conditions that the fish prefer during migrations — and potentially help fishermen avoid spots where they might unintentionally catch this endangered species. (more…)

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Sea Floor Samples Help Explain Arid Southwest

Surface-dwelling algae adjust their biochemistry to surface temperatures. As they die and sink to the bottom, they build a sedimentary record of sea-surface temperature across millennia. Brown’s work on surface temperatures, coupled with work from Texas A&M on rainfall and weather patterns, has helped chart the wetter, lake-filled geological history of the currently arid American West.

During the last ice age, the landscape of the American West was very different. Where now there are deserts and salt flats in the Southwest and Great Basin regions, there once were giant lakes and wetlands. The Great Salt Lake, for example, is a tiny remnant of the prehistoric Lake Bonneville, which at one time covered almost 20,000 square miles. (more…)

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Greenland Glacier Loses Ice

Greenland glacier loses ice island twice the size of Manhattan

An ice island twice the size of Manhattan has broken off from Greenland’s Petermann Glacier, according to researchers at the University of Delaware and the Canadian Ice Service. The Petermann Glacier is one of the two largest glaciers left in Greenland connecting the great Greenland ice sheet with the ocean via a floating ice shelf.

Andreas Muenchow, associate professor of physical ocean science and engineering in UD’s College of Earth, Ocean, and Environment, reports the calving on July 16, 2012, in his “Icy Seas” blog. Muenchow credits Trudy Wohleben of the Canadian Ice Service for first noticing the fracture. (more…)

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Global Warming Refuge Discovered Near At-Risk Pacific Island Nation of Kiribati

Ocean currents may mitigate warming near handful of equatorial islands

Scientists predict ocean temperatures will rise in the equatorial Pacific by the end of the century, wreaking havoc on coral reef ecosystems.

But a new study shows that climate change could cause ocean currents to operate in a way that mitigates warming near a handful of islands right on the equator.

Those islands include some of the 33 coral atolls that form the nation of Kiribati. This low-lying country is at risk from sea-level rise caused by global warming. (more…)

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Fish of Antarctica Threatened By Climate Change

A Yale-led study of the evolutionary history of Antarctic fish and their “anti-freeze” proteins illustrates how tens of millions of years ago a lineage of fish adapted to newly formed polar conditions – and how today they are endangered by a rapid rise in ocean temperatures.

“A rise of 2 degrees centigrade of water temperature will likely have a devastating impact on this Antarctic fish lineage, which is so well adapted to water at freezing temperatures,” said Thomas Near, associate professor of ecology and evolutionary biology and lead author of the study published online the week of Feb. 13 in the Proceedings of the National Academy of Sciences. (more…)

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Sea Change – Penguins Provide Window into Shifting Antarctic Ecosystem

What’s the best way to study the Antarctic’s ecosystem? Follow the penguins.

Scientists are tracking penguins on land, under the sea, and even from space to unravel the environmental dynamics in the West Antarctic Peninsula as the region experiences climate change.

“We’re not just down there bird watching,” said Matthew Oliver, assistant professor of oceanography in UD’s College of Earth, Ocean, and Environment. “This is a concerted effort to put the whole ecosystem together.” (more…)

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NASA Sees Repeating La Niña Hitting its Peak

La Niña, “the diva of drought,” is peaking, increasing the odds that the Pacific Northwest will have more stormy weather this winter and spring, while the southwestern and southern United States will be dry.

Sea surface height data from NASA’s Jason-1 and -2 satellites show that the milder repeat of last year’s strong La Niña has recently intensified, as seen in the latest Jason-2 image of the Pacific Ocean, available at: https://sealevel.jpl.nasa.gov/images/ostm/20120108P1.jpg. (more…)

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