Field Notes: Trout Stream Updates–Southeastern Minnesota
from MN DNR Conservation Volunteer

Fisheries managers have an old saying: Good fishing begins on the land.

Larry Gates understands that well. As the DNR watershed coordinator for southeastern Minnesota, Gates has been working since the late 1970s to improve the health of the region's 151 trout streams. These coldwater homes to brown, brook, and rainbow trout are "crown jewels," he says.

But what Gates has witnessed during the past decade has him concerned about the future. "Sediment," he says. "I'm seeing much more of it in these trout streams, and that's alarming."
As farmers have converted pastures to row crops, runoff and streambank erosion have increased, Gates says. Thus more sediment enters the streams and covers the gravel runs and riffles that trout need to spawn.

Sediment also covers the aquatic invertebrates trout need to eat. Turbidity levels—a measure of sediment in a stream—exceed state standards for some trout streams, particularly in spring when runoff is heaviest.

"The bottom line is that we're seeing a shift from perennial cover types to more soybeans, which are highly, highly erodible," Gates says. "The change is being driven in large part by federal farm policy, which provides producers with financial incentives to plant certain row crops."

Research by Gyles Randall, a University of Minnesota soil scientist based in Waseca, illustrates the land-use transformation. Analyzing statistical data for a nine-county area in the southeast, Randall found that corn and soybeans occupied 64 percent of crop acreage in 1975 compared with 82 percent in 2001.

During the past two years, DNR fall stream surveys have shown trout populations are declining in some southeastern streams. "There has been a decline in smaller fish, less than 10 inches," says Jason Moeckel, DNR assistant regional fisheries manager in Rochester. "We've also had anglers tell us that they're seeing more sediment and aren't catching as many small fish."
Moeckel says sediment and trout don't mix. "At each life stage, trout are affected by sediment," he says. "Sediment can get in the gills of adult fish, stress them out, and ultimately kill them. Trout eggs can be smothered. The entire aquatic food chain can be disrupted from increased sediment loads."

According to Moeckel, DNR Fisheries plans to play a larger role in measuring sedimentation in southeastern streams, as well as restoring trout habitat such as Mill Creek near Chatfield. "The Mill Creek project was designed and constructed to be a prototype of future habitat improvement projects in the southeast," he says. "One of its key elements was creating a new floodplain to decrease stream power and water depth during periods of high runoff."
Both Moeckel and Gates emphasize that landowners have a critical role in determining healthy watersheds. "Most of the land in the southeast is privately owned," says Gates. "But keep in mind there are a number of conservation programs that landowners can enroll in to improve upland and riparian habitat."

After all, good fishing begins on the land.
For information on private-land conservation programs, contact your local farm service agency office or the DNR farmland wildlife coordinator at 651-259-5230.
Tori McCormick, freelance writer