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.

Iowa is getting federal help to eliminate lead water pipes in the state.

The Iowa Department of Natural Resources is working with local water agencies, planning where to prioritize funds.

As part of the Bipartisan Infrastructure Law, cities and towns in Iowa are reducing the number of dangerous lead water lines.

The Iowa Environmental Council's Director of Climate Initiatives Cody Smith said even homes built as recently as 1988 are connected to the local water utility with lead lines - which leaves people at risk, even in Iowa's big cities like Des Moines and Council Bluffs.

"Particularly with the most vulnerable groups, such as unborn babies or young children, they have extreme and outsize risk related to exposure to lead through lead service lines," said Smith. "That can cause higher levels of lead in the blood and lead to developmental issues for children."

The State's Revolving Fund, which is the primary source for water infrastructure updates, has received more than $620 million as part of the Bipartisan Infrastructure Law.

The IEC says more than 700 communities have benefited so far.

Beyond replacing lead pipes and updating water system infrastructure, Smith said Iowa could also benefit from help with what are known as non-point source projects.

"Which is runoff from agricultural fields and from livestock operations that lead to nutrient pollution in source water," said Smith. "And source water is water that's used for drinking water somewhere in the state."

Smith said those strategies can help farmers and local utilities reduce nitrates and other pollutants in the soil.

The Biden administration has a goal of replacing all lead water service lines in the U.S. by 2031.




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Nearly a year after the U.S. Supreme Court left key watersheds unprotected by the Clean Water Act, the Polis administration has designated new protections for some 385 miles across 15 rivers and streams in the Upper and Lower Colorado, Eagle, Yampa and Roaring Fork river basins.

Chad Rudow, water quality program manager with the Roaring Fork Conservancy, said the Outstanding Waters designation is an important tool for protecting drinking water.

"Which means it's protecting the actual quality of the water, and that's the highest level of protection that can be given to a stream within the state of Colorado," he said.

The designation aims to protect existing high-quality waterways from any future degradation, including pollution from development, mining, oil and gas extraction, and other uses. It does not affect any existing uses in the watershed, so long as they don't degrade current water quality.

The designation, which won unanimous approval by the Colorado Water Quality Control Commission in late August, comes after years of work done by conservation groups.

Carrie Sandstedt, senior officer with The Pew Charitable Trusts, said protections are still needed for many streams in the state, and added that protecting water quality is critical not only for drinking water but also healthy wildlife habitat and ecosystems.

"This designation not only protects rivers and streams, it also protects their associated wetlands. It helps preserve important plant life and other species critical for healthy freshwater habitats," she said.

The designation also protects one of the state's biggest economic drivers. A recent study found that Colorado's river basins generated nearly $11 billion in outdoor recreation spending in 2019. Rudow noted clean water is essential for swimming, rafting and other activities across the Roaring Fork Valley.

"We have the second longest contiguous reach of Gold Medal water in our watersheds, so that's high-quality fishing streams. People come from all over the world, literally, to go fly fishing," he explained.

World Water Week is underway, as leaders forge discussions on the global water crisis. Supply issues aren't as urgent in North Dakota, but that doesn't mean conservation is an afterthought.

Dani Quissell - executive director of the North Dakota Water Education Foundation - said the state is lucky to sit on a more predictable water supply, namely the Missouri River, when compared to elsewhere in the U.S.

But she acknowledged that droughts in recent years serve as a reminder for state & local governments, and residents, to not take this precious resource for granted.

At home, she said basic conservation tips still apply.

"Being mindful on when we're letting the tap run where you're filling a pitcher," said Quissell, "and then you walk away for a minute to go let the dog out or something, keeping in mind that that water is running over and right down the drain."

She said that mindfulness should also come into play with other daily practices, like brushing your teeth.

As for policymakers, Quissell encouraged strong communication across various agencies - to ensure water supplies are prioritized when mapping out commercial and residential development.

Surging demand and uneven regulations have plagued western states as key water sources dry up.

Quissell argued that North Dakota closely monitors water use around the state. As climate change threats take shape, she said that has to be the approach moving forward.

"It's a mindset to have in wet periods and dry periods," said Quissell. "I think you build those habits over the long term. I think it's important to be thinking about being a good steward of the resource to have available for our children and our grandchildren."

Agriculture is one sector that has come under scrutiny for how it uses up water for food production. But Quissell said innovation and technology have helped to address that problem.

For homeowners irrigating their lawns, she urged them to run sprinklers at dusk or pre-dawn. That way, the water won't quickly evaporate in the midday heat.



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