SE Minnesota trout face challenges from climate change
Climate change is shrinking the habitat of cold-water fish throughout the U.S.
Mark Reisetter first started trout fishing while attending Luther College in Decorah, Iowa, as a lark.
“I’d follow the (Department of Natural Resources) stocking truck and catch trout with Velveeta,” he said.
The hungry trout were eager to chomp on floppy strands of the processed cheese attached to a lure.
These days, Reisetter is more meticulous about what he uses to lure a trout onto his line. He ties his own flies.
Reisetter moved to Lewiston to take a teaching job. After serving in Vietnam and spending a career teaching, he continued to give guided tours of Southeast Minnesota trout streams.
“I think trout streams were my psychiatrist,” he said.
These days he’s mostly retired from that as well.
“I had a lot of good people come to my door over the years,” he said.
Climate change is shrinking the habitat and stressing populations of cold-water fish in the U.S. The Driftless area, with its spring-fed rivers and streams, is no exception. The region is a unique pocket of the Midwest that supports species of cold-water fish including trout year-round.
Thanks to its unique geology, Southeast Minnesota has more than 700 miles of trout streams.
In other parts of the country, heat has been the main source of recent cold-water fish die-offs and fishing restrictions .
For the trout in Southeast Minnesota, it’s heavier rains that have so far proven to be their biggest climate-related threat, Reisetter said.
The Minnesota Department of Natural Resources stocks hatchery-raised rainbow trout in area streams and rivers. However, brown trout, originally imported from Europe, and brook trout, native to Minnesota, live in Southeast Minnesota waters year-round.
Heavier rains bring sedimentation runoff which affect the health of the streams and rivers where trout live. Heavy sedimentation bury and smother trout eggs in spawning beds and can make it difficult for trout to find food. Poor farming practices on and along the bluffs in Southeast Minnesota led to soil, silt and sand washing off the bluffs into low lying areas. Heavy rain causes the silty banks to wash away and end up in the streams.
That’s why Trout Unlimited Minnesota has focused its efforts on repairing and shoring up stream banks in the region. Reisetter is a volunteer with the organization. Funding from Minnesota’s Legacy Amendment since 2008 has helped the group spend more than $1 million on habitat improvement projects, most of which include grading and repairing stream banks.
In a good year, the organization can stabilize and repair about 10 miles of stream bank, Reisetter said.
But with 700 miles of stream banks, many of them with two sides of impaired banks, there’s easily a century’s worth of work still ahead.
Heavier rains do help replenish the springs that feed cold water into the trout streams. Spring water generally stays at the average air temperature of the year, which for much of the Driftless bluff region is about 48 degrees. That increase in spring-fed cool water is likely helping offset some of the increased temperatures from surface waters, Reisetter said.
“Our springs are emitting more flow,” he said.
That doesn’t mean the trout here will be immune to further effects of climate change, it just means they’re doing alright for now.
“If it gets a lot warmer and that spring water isn’t as cold, that could come to a crashing halt,” Reisetter said.
John Molseed is a tree-hugging Minnesota transplant making his way through his state parks passport. This column is a space for stories of people doing their part (and more) to keep Minnesota green. Send questions, comments and suggestions to firstname.lastname@example.org .