In a landmark concession that will likely lead to the largest dam-removal effort in U.S. history, an electrical utility company has agreed to destroy four dams on the Klamath River to help migrating salmon and steelhead. The dams won’t be decommissioned until 2020 and there are still regulatory hoops to jump through, but fishermen and environmentalists are delighted by the development. “We’re about to make changes to the Klamath Basin that will be observable from space,” said Craig Tucker of the Karuk tribe, which traditionally fished for salmon [Los Angeles Times].
The Klamath River, which winds through Southern Oregon and eventually reaches California’s Pacific coast, was once home to one of the most vibrant salmon runs in the West. But since the first dam was erected in 1908, the region has been host to a nasty battle over water rights, with wildlife and commercial fishers ultimately bearing the worst scars as regulators were forced to repeatedly close salmon fishing along 700 miles of the Oregon-California coast [Greenwire]. The removal of the dams’ will open 300 miles of river to the salmon.
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Image: flickr / patrickmccully
A study that set out to determine the how many of the fish in our nation’s streams are contaminated with mercury came back with an ominous answer: quite possibly, all of them. Researchers from the U.S. Geological Survey sampled 34 species of fish at 291 stream sites across the country, and found mercury in every single fish they tested. “This study shows just how widespread mercury pollution has become in our air, watersheds, and many of our fish in freshwater streams,” U.S. Interior Secretary Ken Salazar said [Los Angeles Times].
A quarter of the fish had mercury levels that are considered unsafe for people who eat fish regularly, according to the Interior Department. The main source of mercury to most of the streams tested, according to the researchers, is emissions from coal-fired power plants. The mercury released from smokestacks rains down into waterways, where natural processes convert it into methylmercury — a form that allows the toxin to wind its way up the food chain into fish [AP]. But fish with high mercury levels were also found in Western areas that have been mined for gold or mercury.
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Image: flickr / kasperbs
The Chesapeake Bay was once carpeted with oysters, but that was before centuries of overfishing, pollution, and disease took their toll: Today the oyster population has been reduced to less than 1 percent of its historical population. But a new restoration effort has shown unprecedented progress in bringing the bivalves back. In the Great Wicomico River, a tributary of the Bay, researchers have created a 87-acre oyster colony that contains about 185 million oysters.
The Chesapeake’s oyster reefs were destroyed by centuries of watermen towing rakelike metal “dredges” and silted over by dirt flowing from the mid-Atlantic’s farms and growing cities. The final blow came in the mid-20th century: A pair of new diseases killed oysters by the millions. Now, in many places, the bay bottom is a flat expanse of green mud. “Just picture, you know, a clear-cut forest,” said Kennedy Paynter, a biology professor [Washington Post].
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The region today known as Iraq was once known as Mesopotamia, which means “Land Between the Rivers,” and since that ancient time the land between the Euphrates and Tigris rivers has been renowned for its fecund soil and thriving farms. But now the Mesopotamian cradle of civilisation seems to be returning to desert [New Scientist].
Decades of war and mismanagement, compounded by two years of drought, are wreaking havoc on Iraq’s ecosystem, drying up riverbeds and marshes, turning arable land into desert, killing trees and plants, and generally transforming what was once the region’s most fertile area into a wasteland…. “We’re talking about something that’s making the breadbasket of Iraq look like the Dust Bowl of Oklahoma in the early part of the 20th century” [Los Angeles Times], said Adam L. Silverman, a social scientist with the U.S. military.
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The state of Louisiana is losing its coastal wetlands to the Gulf of Mexico, and a new study suggests that conservationists won’t be able to turn the tide. If engineers don’t divert sediment-rich waters from the Mississippi River to help replenish a sinking river delta, about 10 percent of [the] state will slip beneath the waves by the end of this century. However, even if the engineers do try to abate the subsidence, the Mississippi doesn’t carry enough sediment to offset more than a small fraction of that loss, a new analysis suggests [Science News].
Before American settlers subdued the Mississippi and its tributaries, the river periodically overflowed its banks and spilled muddy water, thick with sediment, into surrounding wetlands. But the new study found that the Mississippi and Atchafalaya rivers today carry only half the sediment they did a century ago — between 400 million and 500 million tons a year then, compared with just 205 million tons today. The rest is now captured by more than 40,000 dams and reservoirs that have been built on rivers and streams that flow into the main channels [The Times-Picayune].
So even if Louisiana officials embark on an all-out campaign to restore the marshes through controlled levee breaks and diversion projects that bring back river water, it wouldn’t be enough to save the land–especially since sea levels are rising due to global warming. “We conclude that significant drowning is inevitable” [The Guardian], the study’s authors wrote.
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Cleveland’s Cuyahoga River caught on fire 40 years ago June 22 when oily garbage floating in it was ignited, probably by sparks from a passing train. In turn, the fire sparked the creation of environmental agencies such as the Environmental Protection Agency, along with passage of 1972’s Clean Water Act. And the river, once a dumping ground for industrial waste and an icon for environmental disrepair, today supports more than 60 species of fish along with beavers and various bird species, and serves as an example of environmental restoration.
The river’s recovery is an inspirational account of how even the most putrid bodies of water could be cleaned up. Indeed, the first time [Cleveland resident] Gene Roberts fell into the Cuyahoga River, he worried he might die. The year was 1963, and the river was still an open sewer for industrial waste. Walking home, Mr. Roberts smelled so bad that his friends ran to stay upwind of him. Recently, Mr. Roberts returned to the river carrying his fly-fishing rod. In 20 minutes, he caught six smallmouth bass. “It’s a miracle,” said Mr. Roberts, 58. “The river has come back to life” [The New York Times].
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China’s recent economic boom has come at the cost of polluted landscapes and newly endangered species, and now a new study explains how another species has been left teetering on the brink of extinction. The endangered Chinese sturgeon live in the East China and Yellow seas and return to China’s Yangtze River to spawn. Construction of dams on the river is thought to have contributed to a decline in the species, and an artificial propagation effort has not resulted in recovery of the fish [AP]. But the new study shows that a chemical called triphenyltin (TPT), which is commonly used in paint, may be the true culprit behind the sturgeon’s decline.
The tin-containing organic compound TPT is extensively used in paints to prevent the fouling of ship hulls and fishing nets. It is also used in fungicide to treat crops in China. A derivative of TPT is also used to eliminate snails in paddy fields [Reuters]. In the study, published in the Proceedings of the National Academy of Sciences, researchers found that river water polluted with the chemical is producing sturgeon with misshapen skeletons and deformed eyes.
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China’s plan to build dams along the Mekong River poses the greatest threat to the river’s future, according to a United Nations report released yesterday. China is constructing a series of eight dams on the upper half of the Mekong as it passes through high gorges of Yunnan Province, including the recently completed Xiowan Dam, which — at 958 feet (292 meters) high — is the world’s tallest. Its storage capacity is equal to all the Southeast Asia reservoirs combined [AP], according to the report.
The Mekong, which is known as the Lancang in China, is an important source of water, food, and jobs for residents in the river basin, and runs through China, Myanmar, Laos, Thailand, Cambodia and Vietnam. It provides a habitat for rare species of bird and marine life. If the dams move ahead, said the report, the consequences will include “changes in river flow volume and timing, water quality deterioration and loss of biodiversity” [AP]. But Chinese Foreign Ministry spokesman Ma Zhaoxu defended the proposed plans, saying China would give equal attention to hydropower development on transnational rivers and ecological protection [Xinhua].
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If global warming trends continue unabated, the Colorado River won’t have enough water to supply the 27 million people who depend on it, according to a new study. Less runoff — the snow and rain that fortify the 1,400-mile river — caused by human-induced climate change could mean that by 2050 the Colorado won’t be able to provide all of its allocated water 60 percent to 90 percent of the time, according to two climate researchers [AP].
The Colorado River flows through seven states in the American Southwest and continues into Mexico. It supplies water to households, businesses, factories, and farms, and is also home to several endangered species of fish. The study’s lead researcher, Tim Barnett, says that the findings indicate that tough decisions will have to be made about who will get less water. Agricultural operations use about 80 percent of the water taken out of the Colorado, Barnett said. He knows the arguments, though: Shorting farms could drive up food prices. Curbing development in cities and suburbs will make developers unhappy. Whatever the case, he said, some decisions need to be made soon. “The actions that need to be taken aren’t going to be fun,” Barnett said. “It’s not going to be life as usual” [AP].
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One-third of China’s Yellow River is no longer fit for any use, and only one-sixth is safe to drink, according to a bulletin released over the weekend by the Chinese government. It reported the results of a 2007 study that surveyed water quality along the 5,464-kilometer-long river, which has become increasingly polluted from booming riverside industries and raw human sewage. Li Xiaoqiang of the Yellow River Conservancy Committee, which ran the study, called for “urgent action” to save the river, and added forlornly: “I wish that a harmony could be achieved between development, utilisation and protection of the river someday” [Telegraph].
The 2007 study monitored the river’s mainstream and its 35 tributaries, with the combined length totaling 13,492.7 km, and found 4,557.6 km, or 33.8 percent of the waterways monitored, to have polluted water classified as type-five negative [XinHua]. The United Nations Environmental Program considers level five water to be unfit for drinking, aquaculture (such as fish farming and oyster farming), agriculture, and industrial use. Only 16.1 percent of the river water was rated level one or two, considered safe for drinking and household use. Of the 4.29 tons of pollution discharged into the river, industry and manufacturing contributed 70 percent and human sewage made up most of the rest, the bulletin reported. Specific pollutants were not reported. Wen Bo of the environmental group Pacific Environment said “It’s not surprising…They are just treating the river as a dumping site. It’s basically a sewage channel for the provinces that share the river” [AP].
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In a new study that’s already generating controversy, researchers tracked more than 1,000 young Pacific salmon on their first journey to the sea, and found that those battling dams on the Columbia River fared no worse than the young fish with an easier path to the sea on Canada’s free-flowing Fraser River. The findings seem to contradict many previous studies about dams: Conservationists have blamed these obstacles for a large share of the shrinking salmon populations in the Pacific Northwest, and engineers have spent billions trying to make the dams less damaging to salmon [Science News].
The study used implanted transmitters to follow the juvenile salmon, called smolts, on their trips downriver, and found that only about 25 percent of smolts in both the Columbia and the Fraser survived the voyage and made it to the ocean. But environmentalists and several salmon biologists pounced on the study, suggesting that industry funding might have biased the results. These critics question the value of comparing the two rivers and say that the study doesn’t even address what many think is the dams’ biggest effect: stressed smolts dying after they reach the ocean [Nature News].
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