Fertilizer and zebra mussels

Every week, the Freshwater Society publishes a digest of the best regional, national and international news articles and research on water and the environment. Scan the articles here, then follow the links to their original sources.

BWCA recovering a decade after the blow-down

Ten years after millions of trees blew down in Minnesota’s pristine Boundary Waters Wilderness, the forest is in the midst of a comeback.

It was July 4, 1999, when a huge storm roared across the remote woods, terrifying campers and trapping them in a tangle of uprooted trees that blocked their way out.

These days, you have to do a little work to see the effects of the blowdown.

–Minnesota Public Radio

Chestnut revival could fight climate change

The American chestnut tree, which towered over eastern U.S. forests before succumbing to a deadly fungus in the early 20th century, appears to be an excellent sponge for greenhouse gases, according to a new study.

If scientists can develop a fungus-resistant version of the tree, the chestnut could play a key role in the battle against climate change, Purdue University scientists say.

“Maintaining or increasing forest cover has been identified as an important way to slow climate change,” said Douglass Jacobs, whose chestnut tree study appears in the June issue of Forest Ecology and Management.

–Scientific American

Fertilizer suspected as water pollutant

The water supply in the city of Park Rapids is contaminated with nitrates, and many suspect the source is the fertilizer used on local farm fields.

Park Rapids has had elevated nitrate levels in its water for years. But last April was the first time a city well exceeded 10 parts per million, the threshold for what’s considered safe. The well was shut down.

City administrator Bill Smith says residents aren’t panicking, they are concerned. Nitrate contamination can cause health problems. It’s especially dangerous for infants, who can get something called blue baby syndrome — when nitrates inhibit a baby’s ability to use oxygen.

Smith says some blame local farmers who put tons of nitrogen-based fertilizer on their fields. That includes the R.D. Offutt Company, or RDO — the largest potato grower in the U.S., and the community’s largest employer.

–Minnesota Public Radio

Winnipeg man spends month living on 25 liters of water daily

After a month of living on 25 litres of H20 daily, Kevin Freedman said saving water is still a priority. But handwashing all of his clothing? Not so much.

Freedman spent the month of June limiting his daily water use to 25 litres. That included a few litres for   drinking and the rest for washing, cooking and other necessities.

The experiment meant giving up the shower in favor of a bucket of water, flushing the toilet less often, and washing clothes with carefully doled out portions of hot and cold water.

–Winnipeg Free Press

Groundwater pumping threatens aqueduct

Fearing the main canal carrying drinking water to millions of Southern Californians is sinking again, water officials are monitoring the effects of incessant agricultural pumping from the aquifer that runs under the aqueduct.

Their concern is that the canal, which has sunk six feet in places during California dry spells, will buckle enough to slow delivery of water to parched points south and force costly repairs.

On June 1, the Metropolitan Water District of Southern California and other users of state water signed a $255,000, two-year contract with the U.S. Geological Survey to monitor by satellite the California Aqueduct along a vulnerable 70-mile stretch west of here, between Los Banos and Kettleman City.

–The Associated Press

EPA settles suit over feminization of fish

It took a lawsuit, but the EPA announced the first step toward regulating a chemical that can cause male fish to develop female sex characteristics. The chemical, nonylphenol ethloxylate, is used in cleaning products and detergents.

Studies show that NPEs can change the biology of male fish so they grow female eggs at very low levels, said Albert Ettinger of the Environmental Law and Policy Center, in a statement. “The EPA ignored these studies because there was insufficient evidence of the impact on fish reproduction.”

The EPA issued the “notice of proposed rulemaking” as part of a settlement of the lawsuit brought by the Sierra Club, Environmental Law and Policy Center, UNITE HERE, Pacific Coast Federation of Fisherman’s Associations and Physicians for Social Responsibility filed in October 2007.

Other well-known sources of estrogen and estrogen-mimicking compounds, also called “endocrine disruptors,” are birth control pills, hormone replacements and hormones from livestock operations discharged from wastewater treatment plants.


Farming fish indoors in artificial sea water

Yonathan Zohar beams like a proud parent as he cradles the freshly netted fish in his hands.

He didn’t catch this glistening branzini. He raised it – and thousands more – in large fiberglass tanks at the Columbus Center at the Inner Harbor.

“This is a happy moment here,” says Zohar, director of the Center of Marine Biotechnology at the University of Maryland Biotechnology Institute. “Green fish, as good as it gets. Clean, environmentally friendly, sushi-quality fish, delivered to the restaurant a few hours after harvesting.”

Zohar and his team of scientists and technicians have been laboring for years to perfect techniques for captive breeding and rearing of fish as quickly and cleanly as possible. For marine species like branzini, otherwise known as European seabass, they make artificial sea water, then recycle nearly all of it, filtering out waste and even capturing methane to offset some of the energy used in raising the fish in captivity.

–The Baltimore Sun

EPA identifies ‘high hazard’ coal ash dumps

The Environmental Protection Agency has released a list of 44 “high hazard potential” coal ash waste dumps across the country. The “high hazard” rating applied to sites where a dam failure would most likely result in a loss of human life, the environmental agency advisory said, but did not assess the structural integrity of the dam or its likelihood of failure.

The list was compiled as part of the agency’s inventory of coal ash sites after more than a billion gallons of ash broke through a dam at the Tennessee Valley Authority’s Kingston Fossil Plant west of Knoxville last December. An engineering analysis of the failure cited design problems like the height of the ash, among other factors.

The list identifies disposal sites in 10 states, including 12 in North Carolina, 9 in Arizona and 7 in Kentucky. There were no Minnesota sites on the list.

–The New York Times

DNR approves zebra mussel filter for Snail Lake

Snail Lake looks more like a puddle than a lake these days.

Blame it on zebra mussels.

A combination of drought conditions and a water source cut off because of the invasive species means the Shoreview lake is almost 5 feet below its normal levels.

The rub is that, under ideal conditions, much of the lake averages only 6 feet deep.

This summer, the water has receded 50 to 60 feet from shore in some spots, and navigating anything bigger than a canoe means running the risk of running aground — often.

But a first-of-its-kind plan might refill the lake by next June.

–The St. Paul Pioneer Press

Zebra mussels found in 3 Minnesota lakes

Minnesotans received bad news on the invasive species front: Three new lakes have been invaded by zebra mussels, small mollusks that can dramatically alter the ecology of a lake.

The invasive mollusks were found in Lake Le Homme Dieu in Alexandria, Pike Lake near Duluth and Lake Rebecca near Hastings.

DNR officials say heavy infestations of zebra mussels can kill native mussels, impact fish and interfere with recreation. Dead zebra mussels often mean masses of sharp shells on beaches.

“These new infestations are reason for concern,” said Jay Rendall, DNR invasive species prevention coordinator. “I don’t think we will entirely stop their spread. That will be unrealistic, so our program is aimed at curbing the spread.”

Rendall said Minnesota appears to be doing a good job at reducing the spread of the mollusks. He said in 1992, three states — Wisconsin, Michigan and Minnesota — “all had a few infested waters.”

Since then, Wisconsin’s list of zebra-mussel-infested waters has grown to 100 and Michigan’s has reached 240. Minnesota still has only several dozen zebra-mussel infested waters.

–The St. Paul Pioneer Press

Milfoil found in Lake Florida near Spicer

Eurasian watermilfoil has been discovered growing in Lake Florida, five miles west of Spicer, the Minnesota Department of Natural Resources announced.

Eurasian watermilfoil has now been discovered in 213 lakes and eight rivers or streams in Minnesota.

The nonnative, invasive aquatic plant was discovered near a public water access by a local angler, who reported it to the DNR. The discovery was verified by a DNR fisheries biologist.

Eurasian watermilfoil can form dense mats of vegetation and crowd out native aquatic plants, clog boat propellers, and make water recreation difficult.

–Minnesota DNR news release

Sheep chew up invasive weeds

In between rows of grapevines at a Mendocino County farm in California, dozens of sheep are milling about, munching on the grass and weeds.

Sarah Cahn Bennett, co-owner of the family-owned Navarro Vineyards in Philo, Calif., says they began using the flock of 70 in June to keep the vineyard trimmed and minimize the work of tractors and manual labor.

Grazing vineyards is just one application of a growing niche industry that is harnessing the eating power of animals to control invasive weeds, maintain lawns and clear fire-prone grasses. The animals are an alternative to using machinery that burns up fossil fuels or herbicides that, in some cases, can seep into groundwater.

–USA Today