State environmental regulators are investigating a fish kill in northwestern Wisconsin.
The Department of Natural Resources said staff have observed dead fish in Isabelle Creek flowing south along County Road C in Ellsworth, a Pierce County village of about 3,300 people 35 miles southeast of the Twin Cities.
As Wisconsin’s lakes warm, researchers say it may be time to rethink efforts to maintain struggling populations of fish like walleye, a coveted trophy fish, a supper club favorite and a staple of Native American diets.
The DNR said staff have visited the site several times since Aug. 17 and seen about 600 dead trout and forage species.
The agency has not identified a cause and says the investigation is ongoing.
The site is downstream of a creamery and two fertilizer facilities.
Art of the Everyday: A recap of July in photos from Wisconsin State Journal photographers
Marlene Miller, a ceramic sculpture artist from Washington, Illinois, left, works on her clay sculpture design of “Jonah and the Whale” with the help of Mark Skudlarek, with Cambridge Wood-Fired Pottery, at right, in preparation for the Midwest Fire Fest at Westside Park in Cambridge, Wis., Friday, July 8, 2022. The sculpture, which will be a permanent art piece in Cambridge, will be fired in a temporary kiln at the park and revealed during the fest at 9 p.m. on July 23. AMBER ARNOLD, STATE JOURNAL
Samantha Gadzinski holds her 4-month-old Arlo, as she picks raspberries with her children Rosie, front, and Ezra, back, at the family's home in Madison, Wis., Wednesday, July 13, 2022. KAYLA WOLF, STATE JOURNAL
Angela Burgette, of Madison, with her son, Thor, 12, at right, learns Bollywood-style dancing from Manisha Bhargava with BollyBeat during a Lakeside Kids event on the rooftop of Monona Terrace in Madison, Wis., Tuesday, July 19, 2022. AMBER ARNOLD, STATE JOURNAL
Tom Jones, Professor of Photography at UW-Madison and a member of the Ho-Chunk Nation, displays a photograph of his cousin from his series called “Strong Unrelenting Spirits,” at his home, a former church, in Prairie du Sac, Wis., Tuesday, July 5, 2022. Another photo from that series by Jones is hanging in the National Portrait Gallery in Washington, DC. AMBER ARNOLD, STATE JOURNAL
(From left top) Nikki Sotka, a middle and high school science teacher in Marinette, Dean Petersen, a plumbing apprentice instructor at Madison Area Technical College and Wendy Stelzer, with KEEP, Wisconsin K-12 Energy Education Program in Stevens Point, look on as instructor Cris Folk, front, solar consultant and retired MATC teacher, holds up a plan to install pole mounted solar panels during MATC’s STEM Educator Solar Institute at the Commercial Avenue campus in Madison, Wis., Wednesday, July 13, 2022. AMBER ARNOLD, STATE JOURNAL
Carter Aguilera, of Cottage Grove, participates in the Keg Toss Throwdown during the Monona Community Festival at Winnequah Park in Monona, Wis., Monday, July 4, 2022. Aguilera won the competition last year during the festival. AMBER ARNOLD, STATE JOURNAL
Alejandro Escalante, left, and his younger brother Leonardo test the water temperature of the fountain on Library Mall under the close watch of their parents, not pictured, on the UW-Madison campus in Madison, Wis., Friday, July 22, 2022. KAYLA WOLF, STATE JOURNAL
Amelia Holland, 7, right, and her brother, Elliott, 5, of Cottage Grove, compete in a water challenge with help from the Monona Fire Department during the Monona Community Festival at Winnequah Park in Monona, Wis., Monday, July 4, 2022. AMBER ARNOLD, STATE JOURNAL
(From left) Carter and Mason Sampson, 5-year-old twins, ride their matching trikes to the store with their mom, Ana, on the North Side in Madison, Wis., Thursday, July 21, 2022. AMBER ARNOLD, STATE JOURNAL
Nyelle Williams paints flowers onto the outside of the "Old Woman in a Shoe" slide at Vilas Park in Madison, Wis., Tuesday, July 12, 2022. The annual painting of the shoe is a Madison School and Community Recreation tradition. KAYLA WOLF, STATE JOURNAL
Rachel Castillon, right, sprays water through a window under guidance from Madison Fire Department firefighter/EMT Cameron Gasaway during a fire attack rotation at CampHERO held at Madison Area Technical College in Madison, Wis., Tuesday, July 26, 2022. KAYLA WOLF, STATE JOURNAL
Capitol tour guide Daina Zemliauskas shuts the Assembly Chamber doors after leading a tour group through the Wisconsin State Capitol in Madison, Wis., Tuesday, July 19, 2022. KAYLA WOLF, STATE JOURNAL
Goodman Waves’ Yaretzy Cuamani competes in the All-City Dive Meet 11-12 girls at Goodman Pool in Madison, Wis., Monday, July 25, 2022. AMBER ARNOLD, STATE JOURNAL
(From left) Monona’s Ashlynn Campbell, Kennadie Rossing, Talia Riemen and Mikayla McQueenie huddle up before competing in the All-City Dive Meet 11-12 girls at Goodman Pool in Madison, Wis., Monday, July 25, 2022. AMBER ARNOLD, STATE JOURNAL
Members of the Tosa Crew soccer team, of Wauwatosa, from left, Owen Schmidt, Owen Plier, London DeCarlo and Wes Adams do the "Lambeau Leap" prior to the friendly featuring FC Bayern Munich and Manchester City at Lambeau Field in Green Bay, Wis., Saturday, July 23, 2022. KAYLA WOLF, STATE JOURNAL
FC Bayern Munich's Serge Gnabry, left, and Manchester City's Joshua Wilson-Esbrand go after the ball during a friendly at Lambeau Field in Green Bay, Wis., Saturday, July 23, 2022. KAYLA WOLF, STATE JOURNAL
Otis Van de Camp cheers while sitting on the shoulders of his dad Tim Van de Camp during the second half of a friendly featuring FC Bayern Munich and Manchester City at Lambeau Field in Green Bay, Wis., Saturday, July 23, 2022. KAYLA WOLF, STATE JOURNAL
Parkcrest coaches Maddie Gerhardt, left, and Sophie Bell cheer on swimmer Eddy Reaser, not pictured, in the 100-meter freestyle during the first day of swimming at the All-City Swim Meet at Ridgewood Pool in Madison, Wis., Thursday, July 28, 2022. This year marks the 60th anniversary of the All-City Swim Meet, which has grown from a half-day event with fewer than 150 swimmers, to a three-day meet with more than 2,000 competitors. KAYLA WOLF, STATE JOURNAL
Kayakers float down Badfish Creek near Leedle Mill Road in Stoughton, Wis., Wednesday, July 20, 2022. Clark Conway, not pictured, the owner of Drift Away Paddle Company, helped launch the kayakers at Badfish Creek State Wildlife Area where they started their three-hour trip. This is Conway's seventh season offering rentals and shuttle services for trips down the lower Yahara River and Badfish Creek. "Business really got crazy after the pandemic," Conway said. KAYLA WOLF, STATE JOURNAL
Two-time World Youth chess champion Awonder Liang, 19, in Madison, Wis. Saturday, July 2, 2022. JOHN HART, STATE JOURNAL
Members of the Forward Marching Band, including Junko Yamaguchi, right, perform for visitors to the 2022 Festival Foods Lights the Isthmus event at Breese Stevens Field in Madison, Wis. Saturday, July 2, 2022. JOHN HART, STATE JOURNAL
Visitors to the 2022 Festival Foods Lights the Isthmus event at watch a fireworks display to cap the event at Breese Stevens Field n Madison, Wis. Saturday, July 2, 2022. JOHN HART, STATE JOURNAL
High school and middle school students enrolled in a rowing class offered through the Mendota Rowing Club carry a four person craft toward Lake Mendota during a first day of the week-long training program in Madison, Wis. Monday, July 11, 2022. The classes, which continue through the summer, offer participants the opportunity to learn the basics of rowing, teamwork and physical fitness via dry land exercises and on-the-water training. JOHN HART, STATE JOURNAL
Enjoying sunny skies and warm temperatures, a family of cousins from three different states share a group paddle board outing on the waters of Monona Bay near Brittingham Park in Madison, Wis. Monday, July 18, 2022. Pictured from left are Caroline Klessig of Madison, Gabe Zinser of Littleton, Colo., Ryan Cray of Madison, Grace Zinser of Littleton, Colo., Virginia Pendleton of St. Paul, Minn. and Scott Labot of St. Paul, Minn. JOHN HART, STATE JOURNAL
Mark Henneger, left, and Casey Healy compete in a friendly game of horseshoes during a gathering with a close group of classmates from the 1975 Madison East graduating class at Yahara Place Park in Madison, Wis. Wednesday, July 20, 2022. The group of men typically meet several times a week for a variety of activities, including bocce ball, pickleball, golf, and card playing. JOHN HART, STATE JOURNAL
Members of IBEW Local 159, including John Zwettler, foreground, and Mikek Stassi, behind, work to inspect, repair and prepare light displays for this year’s Holiday Fantasy in Lights event at the union headquarters in McFarland, Wis. Thursday, July 28, 2022. From April to November each year, a group of mostly-retired union members volunteer their time once or twice a week to check lights, weld broken components and create new features for the popular drive-through seasonal display at Olin Park. JOHN HART, STATE JOURNAL
Lena Nyhus, 10, prepares to show her shorthorn beef steer as the 2022 Dane County Fair opens at the Alliant Energy Center in Madison, Wis. Thursday, July 21, 2022. JOHN HART, STATE JOURNAL
Madisyn Tritz-Reefe of the Stoughton Trailblazers 4H club tends her poultry entries during the opening day of the 2022 Dane County Fair in Madison, Wis. Thursday, July 21, 2022. JOHN HART, STATE JOURNAL
Janiyah Denton, 9, dances during the Think Like A DJ: Varsity Program at the Theresa Terrace Neighborhood Center in Madison, Wis., Wednesday, July 27, 2022. Denton won a t-shirt in the dance competition portion of the event. KAYLA WOLF, STATE JOURNAL