ST. PAUL, Minn. -- In some Minnesota lakes, invasive species are limiting the growth of a popular fish, according to a new study of the effects on walleye.

University of Minnesota researchers say the culprits are zebra mussels and spiny waterflea. They found in lakes where these are present, they can reduce the growth size of walleye from 12% to 14%. The species take away zooplankton, a food source for the fish.

Jeff Forester, executive director of the group Minnesota Lakes and Rivers Advocates, said the findings should spur stronger action by the state to prevent the spread of these species.

"What we've been doing -- this kind of emphasis on education and personal responsibility -- that's not getting it done," he said. "I think it's slowed the spread, but it certainly hasn't stopped it."

Forester said he'd like to see the state adopt more stringent boat-inspection policies, such as making it a requirement for people getting an operator's license. The Department of Natural Resources said that, in coordination with local governments, it conducted more than 500,000 watercraft inspections last year, a record number.

Walleye is a favorite fish for anglers and many resorts rely on its popularity for business. Forester acknowledged that it's a difficult balance for the state because boats are helping to spread these species, but many lake communities are dependent on water recreation.

"How do we use the lakes in such a way that they're protected for the future," he said, "and we're protecting the resource, which is not the lake itself, but the quality of life and the economics."

One of the lakes in the study, Mille Lacs Lake, has seen many controversies surrounding walleye fishing in recent years. The DNR has enforced strong limits for anglers so the walleye population can rebound. Some of those restrictions have been slowly lifted as walleye makes a comeback in the popular lake.

The study is online at springer.com.

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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A new report finds pollution violations at wastewater treatment plants have been a problem in more than half of Idaho's communities.

The Idaho Conservation League's annual study of the state's sewage treatment plants says 58% violated Clean Water Act standards during 2023.

Will Tiedemann, the regulatory conservation associate with the Idaho Conservation League, said his organization didn't find much change between 2022 and 2023.

"It was kind of the status quo as continued from last year," said Tiedemann. "There were still a significant number of facilities across Idaho who violate. And of that, you know, it's usually ten, eleven, twelve facilities who make up the lion's share of that."

Tiedemann said his organization continued to study not just violations but loads over limits, or the severity of the violation.

Three facilities, in Driggs, Parma and Preston, accounted for about a third of total violations. On the positive side, 47 cities and towns did not report any violations in 2023.

Tiedemann said violations typically occur because of elevated levels of phosphorous or nitrogen from an excess of nutrients.

He noted that excess nutrients can create problems for water bodies, such as algae blooms.

"There are real world consequences," said Tiedemann, "for the environment and for recreation and for human health."

Tiedemann said violations occur more often in smaller communities - and there's a reason for that.

"Large cities in Idaho have a tax base to where they can have more advanced treatment systems," said Tiedemann. "They have more things to treat but they kind of have an outsized availability of resources to address that. But lots of smaller towns in Idaho don't always. They have limited budgets."

The Biden Administration is investing $105 million in water conservation and efficiency projects meant to shore up drought resilience, including more than $5.5 million for projects in Larimer, Montezuma, Montrose and Otero counties.

Zachary Hoylman, assistant state climatologist, said protecting water resources now and in the future will be critical for the nation's farmers and ranchers.

"Conservation is a really important piece of building resiliency," Hoylman explained. "Especially in an era of increasing variability in the climate system and longer term changes to the climate system."

The projects will optimize water deliveries to agricultural users, mitigate the risks of ditch failures by installing pipes, and install smart water meters. Shovel-ready projects in 11 states including Colorado are projected to save more than 111,000 acre-feet of water annually. One acre-foot is equal to more than 325,000 gallons of water, enough to cover a football field with one foot of water.

Hoylman pointed out there are many benefits to improving water transport efficiencies but it is also important to consider broader impacts. If you transport water by pipe instead of by ditch, it may be more efficient but it could also be taking water away from wetlands and waterfowl habitat.

"We can't only think about the human, socio-economic system," Hoylman argued. "There is really important feedback between the way that we divert water and the implications for ecology and ecosystems as a whole."

The investment taps funding allocated in the Bipartisan Infrastructure Law passed in 2021. The Bureau of Reclamation is investing a total of $8.3 billion over five years for water infrastructure projects, including rural water, water storage, conservation and conveyance, nature-based solutions, dam safety, water purification and reuse, and desalination.


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