Great Lakes slowly losing water

DULUTH, Minn., June 22 (UPI) -- Boaters on Lake Superior said the water is so low it appears the world's largest freshwater lake is disappearing.

The lake, which is about 18 inches below average, has dropped nearly 2.5 feet over the past decade and the entire Great Lakes Basin is seeing reduced water levels, CBS News said Friday.

Recreational boaters are moving boats to marinas set in deeper water and commercial shippers are being forced to reduce cargo loads.

A 20 percent less rain has fallen into the lake during the current drought and warmer winter temperatures mean less ice cover and more evaporation. Scientists, however, say they don't know if it is a natural pattern or global warming.

"Within a couple of years, they should be rising again," ecologist Doug Wilcox, branch chief of the U.S. Geological Survey Great Lakes Science Center, told CBS. "If they continue to go lower and lower, that would indicate to me that we're outside the bounds of the natural pattern."

Virus killing Great Lakes fish

ITHACA, N.Y., May 18 (UPI) -- U.S. researchers say a deadly fish virus is reaching epidemic proportions in the Great Lakes.

Paul Bowser, a professor of aquatic animal medicine in Cornell University's College of Veterinary Medicine, said viral hemorrhagic septicemia virus has been identified in 19 species.

Hundreds of thousands of round gobies have died from the disease in the St. Lawrence Seaway and gizzard shad die-offs were reported in Lake Ontario and Lake Erie.

The Wisconsin Department of Natural Resources also has made a presumptive identification of the virus for the first time in the Lake Winnebago chain of inland lakes about 25 miles south of Green Bay near Lake Michigan, the university said Friday in a news release.

Bowser said the virus could have a devastating impact on aquaculture and particularly the channel catfish trade, which constitutes about 80 percent of aquaculture business in the United States.

He said the virus may have originated from an infected marine fish off the Atlantic Coast or from infected bait and fishing equipment.

Antarctic underground lakes to be studied

COLLEGE STATION, Texas, June 5 (UPI) -- A U.S. scientist says the discovery of interconnected lakes miles under Antarctic ice might be one of the most important scientific finds in recent years.

Texas A&M University Oceanography Professor Mahlon "Chuck" Kennicutt II says the National Science Foundation and 11 nations involved in Antarctic research and exploration are considering how to study the unique environments, which include at least 145 lakes under Antarctica's massive ice sheets.

Several of the lakes are immense, and one, Lake Vostok, is similar in size to Lake Ontario -- roughly 5,400 square miles.

"These bodies of water are several miles beneath the ice sheet which took millions of years to form, meaning these lakes have been undisturbed and disconnected from our atmosphere for hundreds of thousands of years," said Kennicutt, a director of the Subglacial Antarctic Lake Environments office, located at the university. "It is highly likely unique microbial communities that we never knew existed are lake residents."

Antarctica is the only continent on Earth that's managed through an international treaty signed by 45 nations representing two-thirds of the world's population. By unanimous consent, Antarctica has been viewed as a continent for science, research and peace.

Antarctica icebergs hold sea life

WASHINGTON, June 22 (UPI) -- Scientists say icebergs in Antarctica serve as hosts for thriving communities of seabirds, phytoplankton and fish.

A report published in the current issue of Science magazine said the icebergs hold trapped terrestrial material, which they release far out at sea as they melt, the National Science Foundation said Friday in a release.

Scientists say the process produces a "halo effect" with significantly increased nutrients, chlorophyll and krill out to a radius of more 2 miles.

Researchers said the icebergs are raising the biological productivity of almost 40 percent of Antarctica's Weddell Sea, and may play a role in global climate regulation by removing carbon from the atmosphere.

The research, funded by The National Science Foundation, was conducted by scientists from the Monterey Bay Aquarium Research Institute, the San Diego Supercomputer Center, Scripps Institution of Oceanography, the University of San Diego and the University of South Carolina.

Study: Icebergs create ocean 'hot spots'

MOSS LANDING, Calif., June 20 (UPI) -- A U.S. study suggests Antarctic icebergs created by global climate change are having a major ecological impact.

The study, led by oceanographer Ken Smith of California's Monterey Bay Aquarium Research Institute, has determined global warming is causing Antarctic ice shelves to split into thousands of free-drifting icebergs in the Weddell Sea.

The floating islands of ice -- some dozens of miles across -- are serving as "hotspots" for ocean life, with thriving communities of seabirds above and a web of phytoplankton, krill and fish below.

"One important consequence of the increased biological productivity is that free-floating icebergs can serve as a route for carbon dioxide drawdown and sequestration of particulate carbon as it sinks into the deep sea," said Smith.

"While the melting of Antarctic ice shelves is contributing to rising sea levels and other climate change dynamics in complex ways, this additional role of removing carbon from the atmosphere may have implications for global climate models that need to be further studied," he said.

The researchers report in detail in the current issue of the journal Science.

Antarctic losing ability to absorb CO2

SYDNEY, May 18 (UPI) -- Scientists say the Antarctic Ocean is losing some of its ability to absorb carbon dioxide.

A study published Friday in the journal Science says the ocean's carbon dioxide sink has weakened by about 15 percent per decade since 1981, which will lead to higher levels of atmospheric carbon dioxide in the long term.

Paul Fraser of Australia's Commonwealth Scientific and Industrial Research Organization said the ocean is becoming less efficient at absorbing carbon dioxide due to an increase in wind strength from human-induced climate change.

"The increase in wind strength is due to a combination of higher levels of greenhouse gases in the atmosphere and long-term ozone depletion in the stratosphere, which previous CSIRO research has shown intensifies storms over the southern ocean," Fraser said in a news release.

He said the Earth's land and oceans absorb about half of all carbon dioxide emissions from human activities, with the Antarctic Ocean taking up 15 percent of the emissions.

Study: Climate change hurts carbon sinks

LONDON, May 21 (UPI) -- A British-led study has offered the first evidence climate change has weakened one of the Earth's natural carbon sinks.

The four-year study by scientists from the British Antarctic Survey, the University of East Anglia, and the Max-Planck Institute for Biogeochemistry reveals an increase in winds over the Southern Ocean caused by greenhouse gases and ozone depletion has led to a release of stored CO2 into the atmosphere and is preventing further absorption of the greenhouse gas.

Lead author Corinne Le Quere of UEA and BAS said: "This is the first time we've been able to say climate change itself is responsible for the saturation of the Southern Ocean sink. This is serious. All climate models predict that this kind of 'feedback' will continue and intensify during this century.

"The Earth's carbon sinks -- of which the Southern Ocean accounts for 15 percent -- absorb about half of all human carbon emissions. With the Southern Ocean reaching its saturation point, more CO2 will stay in our atmosphere."

The scientists said their findings suggest stabilization of atmospheric CO2 is even more difficult to achieve than previously thought.

The study appears in the journal Science.

Earth's climate close to tipping point

GREENBELT, Md., June 4 (UPI) -- U.S. scientists say human-made greenhouse gases have brought Earth's climate close to critical tipping points, with potentially dangerous consequences.

National Aeronautics and Space Administration scientists, along with researchers from Columbia University's Earth Institute, reached that conclusion from a combination of climate models, satellite data and paleoclimate records.

Tipping points can occur when the climate reaches a state such that strong amplifying feedbacks are activated by only moderate additional warming. The study found only moderate additional climate forcing is likely to set in motion disintegration of the West Antarctic ice sheet and Arctic sea ice.

The study's lead author, James Hansen of NASA Goddard Institute for Space Studies IN Greenbelt, Md., said, "If global emissions of carbon dioxide continue to rise at the rate of the past decade, this research shows there will be disastrous effects, including increasingly rapid sea level rise, increased frequency of droughts and floods, and increased stress on wildlife and plants due to rapidly shifting climate zones."

The complex research appears in the current issue of Atmospheric Chemistry and Physics.

Study: All forests not created equal

BOULDER, Colo., June 25 (UPI) -- A U.S.-led science team has determined forests in northern mid- and upper-latitudes are less effective than tropical forests in reducing global warming.

The study, led by Britton Stephens of the National Center for Atmospheric Research, concluded that intact tropical forests are removing an unexpectedly high proportion of carbon dioxide from the atmosphere, thereby partially offsetting carbon entering the air through industrial emissions and deforestation.

"This research fills in another piece of the complex puzzle on how the Earth system functions," said Cliff Jacobs of the National Science Foundation. "These findings will be viewed as a milestone in discoveries about our planet's 'metabolism.'"

Stephens and colleagues analyzed air samples collected by aircraft around the world for decades and found some 40 percent of the carbon dioxide assumed to be absorbed by northern forests is instead being taken up in the tropics.

"Our study will provide researchers with a much better understanding of how trees and other plants respond to industrial emissions of carbon dioxide, which is a critical problem in global warming," Stephens said. "This will help us better predict climate change and identify possible strategies for mitigating it."

The study is reported in Science magazine.

Geologists to discuss historic ice core

TALLAHASSEE, Fla., April 26 (UPI) -- An Antarctic core with unprecedented geological detail of the Ross Ice Shelf will be featured during a U.S. international geology meeting.

Geologists, students and educators from Germany, Italy, New Zealand and the United States will meet at Marine Geology Research Facility at Florida State University next Tuesday through Friday. The facility is the U.S. repository for geological material from the Southern Ocean.

The core was extracted during the recent Antarctic summer from a record 4,214 feet below the sea floor beneath Antarctica's Ross Ice Shelf, the Earth's largest floating ice body. Laced with sediment dating to about 10 million years, the core suggests the Ross Ice Shelf retreated and advanced perhaps as many as 50 times during the last 5 million years in response to climate changes, said facility curator Matthew Olney.

He said such signs of fluctuations are critical since the Ross Sea ice is a floating extension of the even bigger West Antarctic Ice Sheet -- an area so unstable scientists foresee its collapse from global warming. Such a collapse could raise sea levels worldwide by a catastrophic 20 feet.

The core was featured in the March edition of the journal Nature.

Glaciers moving faster than expected

LONDON, June 6 (UPI) -- British scientists have determined hundreds of previously unstudied glaciers on the Antarctic Peninsula are flowing faster than expected.

The British Antarctic Survey said that movement adds to sea level rise caused by climate warming that's already producing increased summer snow melt and ice shelf retreat across the Antarctic Peninsula.

Using satellite data, scientists tracked the flow rate of more than 300 glaciers and found a 12 percent increase in glacier speed from 1993 to 2003. The observations -- similar to recent findings from coastal Greenland -- indicate the increased speed is caused by melting of the lower glaciers, which flow directly into the sea. As they thin, the buoyancy of the ice can lift the glaciers from their rock beds, allowing them to slide faster.

The research is detailed in the Journal of Geophysical Research.

Unexpected marine biodiversity discovered

HAMBURG, Germany, May 21 (UPI) -- German researchers have reported finding 585 new species of crustaceans in the depths of the Southern Ocean.

The discovery came during three sampling expeditions set up as part of the Antarctic benthic deep-sea biodiversity project. The discovery of unexpected levels of biodiversity challenge assumptions that deep sea diversity is depressed in that area.

Angelika Brandt and colleagues from the University of Hamburg collected biological specimens and environmental data from different regions between 2,500 and 21,000 feet under the surface of the Weddell Sea and adjacent areas.

The Weddell Sea is an important source of deep water for the rest of the ocean and provides a possible route for species to enter the deep water. In line with that fact, the team reported finding deep-sea creatures also found in adjacent shelf communities and other oceans.

They identified 674 species of isopod -- a diverse order of crustaceans -- of which more than 80 percent were new to science.

The discovery is reported in the current issue of the journal Nature.

420 million years of CO2 are analyzed

NEW HAVEN, Conn., April 2 (UPI) -- U.S. geologists have found the sensitivity of Earth's climate to changes in the greenhouse gas carbon dioxide has been consistent for 420 million years.

A popular predictor of future climate sensitivity is the change in global temperature produced by each doubling of CO2 in the atmosphere. The study confirmed that during 420 million years, each doubling of atmospheric CO2 translated to an average global temperature increase of about 5 degrees Fahrenheit.

The scientists used 500 data points in the geological records as "proxy data" -- indirect measurements of CO2.

"Proxy data ... are a measure of the effects of CO2," said study co-author Jeffrey Park, a professor of geology and geophysics at Yale who created the computer simulations for the project. "While we cannot actually measure the CO2 that was in the atmosphere millions of years ago, we can measure the geologic record of its presence."

Led by Dana Royer, assistant professor of Earth and Environmental Sciences at Wesleyan University, the researchers simulated 10,000 variations in the carbon-cycle processes and evaluated the variations for a range of atmospheric warming conditions.

The study is detailed in the journal Nature.

Study: Earth's 4th largest lake shrinking

LONDON, April 17 (UPI) -- British scientists have determined the Aral Sea is drying so rapidly it has shrunk by two-thirds in fewer than 50 years.

The University College London study shows the shrinkage has left two separate lakes where the world's fourth largest lake once existed. And researchers say humans -- including Genghis Khan and the White Huns -- have negatively affected the lake's fortunes for centuries.

Patrick Austin and Anson Mackay of the college's Environmental Change Research Center deduced changes in the Central Asian lake by investigating changes in fossils and the chemical makeup of the water.

They determined the current regression is largely due to the diversion of the Amu Darya and Syr Darya -- one of the irrigation strategies of the former Soviet Union that has led to the loss of 90 percent of the lake's fish species and more than 250 species of plankton.

The study, conducted with colleagues from Kazan State University and the University of Nottingham, appears in this month's issue of the journal Quaternary Research.

Lake Superior nitrates continue to rise

MINNEAPOLIS, May 31 (UPI) -- Lake Superior's nitrate levels are rising and scientists say the lake is about 2.7 percent of the way toward having unsafe drinking water.

The University of Minnesota study found the complexity of the causes underlying the increase in nitrates that's been under way for more than a century makes it difficult to predict when the lake's water might become unhealthy.

Nitrate is a component of agricultural fertilizer and is generated by fossil fuel combustion. Lake Superior's nitrate level has increased about five-fold since the early 1900s, researchers said, and the increase has been steady.

"It's puzzling because it doesn't reflect post-World War II increases in fertilizer and fossil fuel or the Clean Air Act of 1972," said Professor Robert Sterner, lead author of the study. "It's much more complex than that."

Sterner says factors include the vast size of the lake and conversion of other forms of nitrogen within the lake in decaying plant matter and sewage into nitrate.

The research is available online in the journal Geophysical Research Letters.

Deadly fish virus reaches Wisconsin lake

OSHKOSH, Wis., May 14 (UPI) -- State biologists weren't sure how a deadly fish virus would affect the fish population of Wisconsin's Lake Winnebago system.

Fishermen feared the virus, which has killed hundreds of sheepshead, would kill the lake system's most popular game fish, the walleye.

"I'm worried because, inevitably, it'll wipe out fish," Randy Vandezande, who fishes about 75 days a year, told the Milwaukee Journal Sentinel.

The virus, viral hemorrhagic septicemia, was found in Lake Huron in 2005. In 2006, it had spread to Lake Erie and then to an inland New York lake, the Journal Sentinel reported.

"There are a lot of anglers who fish in Lake Erie and Lake Huron and also in Winnebago," Mike Staggs, fisheries director for the state Department of Natural Resources told the Journal Sentinel. "If anything, it underscores the fact of just how detrimental it is when invasive species are transported into other lakes."

Virus poses great danger to fish

SEATTLE, April 30 (UPI) -- Scientists fear a virus that is killing fish in the Great Lakes could endanger freshwater fish elsewhere in the United States.

Viral hemorrhagic septicemia kills fish in much the same way as the virus that has decimated elm trees in the United States. said Jim Winton, chief of fish health at the U.S. Geological Survey in Seattle.

� "VHS is the most important and dangerous fish viruses known worldwide," Winton said. "Its discovery in our fresh water is ... potentially catastrophic."

The virus resulted in large fish kills last year that struck at least 20 species in the Great Lakes, USA Today reported Monday. Scientists fear the disease will return this summer when water in the lakes warms, Winton said.

� The United States and Canada are restricting the transport of fish and live bait and having boaters wash their boats when moving them between the Great Lakes. In addition, Michigan has closed hatcheries that produce three important sport fish: walleye, northern pike and muskellunge.

The virus likely originated in the Atlantic Ocean, near New Brunswick, Canada, near the start of the St. Lawrence River shipping route that leads to the Great Lakes.

Missouri officials want to contain mussels

KANSAS CITY, Mo., May 28 (UPI) -- Wildlife officials in Missouri are trying to get boaters to help stop the spread of invasive zebra mussels through the region's lakes and rivers.

While the Eurasian mussels have already spawned massive colonies in Kansas' El Dorado Reservoir and in Missouri's Lake of the Ozarks, wildlife officials are asking boaters to check their vehicles for the invasive animals, The Kansas City Star said Monday.

"We're very concerned about the possibility of accidentally transferring them into other bodies of water," said Brian Canaday, a Missouri Department of Conservation official.

The mussels are thought to have entered the region's waterways on the hulls of ships. Thorough checks by boaters are considered the most effective way to prevent further infestations elsewhere.

"The big message is, clean out the boats and the trailers," Canaday said.

Each female zebra mussel has the ability to lay more than 1 million eggs Such rampant breeding abilities already have inflicted billions of dollars of damage throughout the region, the Star said.