MINNEAPOLIS -- Just as humans need clean air to breathe, lakes need healthy oxygen levels to provide habitat for fish species. But a new study said in Minnesota and around the world, freshwater lakes are in trouble with temperatures on the rise.

The research, published in the journal Nature, looked at nearly 400 lakes across the globe, including more than 80 in Minnesota.

It concluded, driven by climate change and warming temperatures, lake oxygen levels are declining as much as nine times faster than oceans.

Kristen Blann, freshwater ecologist for The Nature Conservancy, said if mitigation efforts aren't prioritized, Minnesota lakes and fish could look a lot different in the coming years.

"What we end up with is the opportunistic generalists that can survive extremes and poor conditions, and we'll lose many of the species that we most appreciate for the unique ecosystems that they represent," Blann explained.

For example, lake trout could be affected because they need cold water with ample oxygen levels to survive. And with other research that puts Minnesota among the fastest-warming states, Blann pointed out it creates a greater sense of urgency, as habitats could see dramatic change much sooner.

Gretchen Hansen, assistant professor in the Department of Fisheries, Wildlife and Conservation Biology at the University of Minnesota and a co-author of the study, said there's another side effect to worry about.

"As lakes warm, the bacteria that can live in those oxygen-depleted waters are bacteria that produce methane," Hansen noted. "And so, the lakes will produce even more greenhouse gases, contributing even more to global climate change."

Blann added The Nature Conservancy is working with the state and other partners on programs to protect the watersheds feeding into freshwater lakes, to help make them more resilient.

"The more we can minimize the amount of exposed soil, and concrete and pavement, the healthier those watersheds will be," Blann asserted.

A key example she cited is conservation work in agriculture to reduce nutrient runoff from farm fields. Meanwhile, Minnesota researchers plan to take a more detailed look at declining oxygen levels in lakes around the state.

A new, high-tech wastewater treatment incinerator, used in only a few states, is on the wish list for one Michigan city.

Former state Representative - now Mayor of Warren - Lori Stone is asking her former colleagues in the Environment, Great Lakes and Energy Subcommittee for up to $100 million to upgrade her city's wastewater treatment system.

Warren's current plant was built in 1957 and serves over 137,000 residents. The new incinerator would oxidize organic matter contained in the sludge.

Warren Wastewater Treatment Plant Director Donna Dordeski said the old system is failing.

"One of the hearths of the furnace collapsed and failed, and we couldn't use it any longer until repairs had been completed," said Dordeski. "So, from the beginning - and all the waiting, getting the contractors and repairs completed - it took four months."

Dordeski said they're approaching the final steps of getting permits for the project. And they're still seeking funds, at the state and federal levels - including infrastructure grants that may be available.

The city has around 500 miles of sanitary sewer pipes to ensure its wastewater is treated and disposed of properly. Dordeski said when the current system breaks down, it affects local residents. Trucks have to pick up and carry sludge back and forth through their neighborhoods to nearby landfills.

"That's a 24-hour operation," said Dordeski. "We usually have several trucks. Its a continuous process, five days a week, where we process the sludge and those trucks have to be nearby, available, be loaded, exchanged for a new one. So, that's what has to happen when our incinerator is not operational."

Michigan has 95 wastewater treatment plants.

Warren's mayor believes if the new incinerator is approved, the city will have the opportunity to be the proving ground as a pilot program for this technology.




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As Wyoming and other states grapple with shrinking Colorado River water levels - new research pinpoints how much water is being diverted to feed cattle, to sprawling desert cities, and the river's 40 million other stakeholders.

The stakes are high in a time of persistent and widespread drought.

Brian Richter - president of Sustainable Waters - said if Upper Basin states can't deliver the volume of water required under a century-old agreement, Lower Basin states could force the issue with what's known as a compact call.

"The likely result would be that the Upper Basin states, including Wyoming, would be forced to use less water," said Richter, "so that more water could be flowing into Lake Powell and downstream into the Lower Basin."

Researchers found that in Upper Basin states, cattle-feed crops soak up 90% of all irrigation water - which is three times the amount that goes to all cities, towns, commercial and industrial uses combined.

Just 19% of the Colorado River feeds the wetlands and riparian areas wildlife depend on.

Richter noted that cities in Utah and along Colorado's Front Range are at risk because they have very low priority for accessing water under the 1922 Colorado River Compact.

Despite calls for closing off spigots used exclusively for cattle feed, Richter said blaming any single user is counter-productive.

"Farmers and ranchers are growing the things that people want, and are willing to pay a necessary price for," said Richter. "So they are just responding to consumer demands."

He said he believes the new data could be an important tool for Colorado River stakeholders as they work to build a long term plan to bring the total use of water back in balance with what nature provides.

Richter said right now, water use is at least 10% to 15% over that limit.

"We need a long range plan that says how much water do we want to use in the cities? How much water do we want to use on the irrigated farms? How much are the industries going to need?" said Richter. "And until we do that long range plan, we are just going to be reacting to these water shortages on a year-by-year basis."




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Colorado lawmakers are considering legislation to restore protections to key waters and wetlands struck down by the U.S. Supreme Court last year in a decision leaving more than half of the nation's water supply at risk of industrial pollution.

Margaret Kran-Annexstein, director of the Colorado chapter of the Sierra Club, said House Bill 1379 is in sync with Colorado voters, pointing to a recent survey which found nearly nine in 10 voters want to limit damage and pollution from development, industry and mining on wetlands and streams.

"Recent polling has found that massive majorities of Coloradans, whether they are Democrat, Republican or Independent, really support common sense water protections that would happen under this bill," Kran-Annexstein reported. "I think we can all agree that clean water is a necessity."

A coalition of conservation groups support the measure to create a permitting program for responsible development through the Colorado Department of Health and Environment.

Last month, Sen. Barb Kirkmeyer, R-Brighton, introduced an alternative proposal supported by the homebuilding industry, which would require a new division and staffing in the Department of Natural Resources.

Kran-Annexstein stressed clean, reliable water resources drive the economy and are vital for the health of communities. She believes the high court's ruling, claiming some waterways do not have significant connections to watersheds, was a win for corporate polluters who want to avoid permitting.

"In Colorado we know that there are a lot of streams and rivers and wetlands that run dry for certain parts of the year," Kran-Annexstein pointed out. "This ruling said that those waterways don't deserve protections and they don't count, just because they are seasonal."

Mountain states like Colorado are the source of drinking water for some 40 million Americans living in downslope states and Kran-Annexstein said the House bill is an opportunity to pass important and necessary protections after last year's Supreme Court decision.

"This decision left half of the waters across the United States unprotected by the Clean Water Act," Kran-Annexstein emphasized. "And really left it to states to make their own laws to protect state waters. And now it is the responsibility of states to step up and close that gap."