Flood deals blow to trout
Monday, July 01, 2013 4:13 AM
The flash flooding that devastated much of Houston County and southeastern Fillmore County during June 22 and 23 also dealt a blow to Minnesota's trout fishing industry.
Anna Nelson, Cam Mitchell and Jason Roloff weigh trout at the Minnesota DNR Fish Hatchery near Lanesboro following flooding that affected most of southeast Minnesota. Workers at the hatchery had to sort thousands of fish before they were able to calculate how many fish they lost. ANTON ADAMEK/BLUFF COUNTRY READER
While many residents and farmers assessed damage to property and crops, staff members at the Lanesboro State Fish Hatchery were scrambling to sort thousands of trout. Thousands more either escaped into nearby streams or died from stress or being washed out of the water. As the state's largest of five cold-water fish hatcheries, the impact of the flooding will be seen throughout the state. Locally, anglers will also need to deal with stream environments that were radically changed in just a few hours that early Sunday.
The Lanesboro Hatchery has long been a source of quality brown and rainbow trout stock for Minnesota. In fact, 100 percent of the state's brown trout comes from the hatchery, which they maintain through a brood stock. Lanesboro also provides rainbow yearlings across most of the state. Including all the fingerlings and yearlings, the hatchery had 160,000 trout pre-flood. That number was dramatically reduced when floodwaters moved in around 2:35 a.m. Hatchery supervisor Pat Schmidt lives on-site and became aware of nearby Duschee Creek flooding its banks around that time.
"By 3 a.m. water was coming out of some of the buildings. I lost track of time after that," Schmidt recalled. As he moved equipment out of the way, he called his workers in early. "The water came up quickly and by 3:15 a.m. it was probably at its peak," he said, estimating the water level at up 10 feet. "I never was aware of having water coming through the hatchery before this."
As dawn broke, workers started arriving from the steep hills surrounding the hatchery. Flooded roads had forced them to descend from Inspiration Point. When the waters had receded, workers immediately started sorting.
"I was hoping we wouldn't lose too many of the brood stock. I knew we would lose a lot of fingerlings," Schmidt shared.
After calling in help from the Lanesboro Area Fisheries office, Trout Unlimited and Lake City Area Fisheries office, around 20 people separated fish by species and size for almost three straight days. Then the hatchery's staff began evaluating how many fish they had lost. By weighing a sample of certain trout and getting a trout-per-pound value, the staff weighed all the fish and divided by that sample value. The numbers were large.
They lost 6,000 rainbow yearlings, 5,000 brown yearlings and 300 of their brood trout. Taking into account the numerous fingerlings lost, the hatchery lost roughly 74,000 fish. Although overall significant, Schmidt said there won't be big reductions seen in individual stocking locations. "We can't replace fish that were scheduled to be stocked, but we can recover over time." There was enough of the brood stock left to provide eggs for next year.
Schmidt noted the problems aren't over for the trout. Floodwaters were high in turbidity, which irritates the trout's gills and stresses them. Water contamination could also cause disease among the remaining stock. Schmidt said he was thankful their outdoor yearling pool didn't have any fish in it as that would have increased their losses.
Beside the fish losses, the hatchery experienced flooding damage in their offices and nursery incubators. Replacement and recovery will be the focus of the hatchery in the months to come.
The hatchery fish that lived to escape into Duschee Creek and other streams were greeted by an environment undergoing extreme changes. After the waters receded closer to their original levels, Area Fisheries Supervisor Steve Klotz did a rough assessment of stream conditions and the environment.
"There is damage on all of the watersheds," he stated. "There is a lot of infrastructure damage. The roads are a mess. The whole valley is a mess." Most of the damage he surveyed was in Houston County and stream valleys south of Highway 16.
Klotz ran through a list of what he had seen. Several bridges were destroyed, making roads impassable. Stream bank erosion, mass wasting off hillsides and tree debris in the streams contributed to the diversion of the water.
"There are some streams which weren't there before and some channels which aren't where they used to be," Klotz explained. Stream bed scouring, where rock is cleaned off the bottom, was common. This, Klotz explained, impacts invertebrates that the trout depend on for feeding. "Now it looks like someone took a vacuum and cleaned it out," he remarked.
The DNR has worked on many of the streams over the years, sloping eroded banks, building fish hides for trout to cover under and rip-rapping shorelines with rock. Klotz said from what he could tell some is still there and some of it was gone.
"The DNR will assess the damage. We may go in and do some spot fixes and remove debris," he stated. Despite the extreme changes in the streams' environment, Klotz said he wasn't too surprised in what had happened.
"Some of the rainfall totals were pretty incredible," he said adding, "With conservation practices as bad as they have been, it creates a situation where this happens."
He specifically noted that most of the CRP land is gone and much marginal farmland has been plowed that would contribute to these severe effects. "I hope that when we consider conditional use permits for campgrounds in flood plains, we remember what happened here. People need to be careful about land use and development."
Klotz remained optimistic about the short-term future of the streams and trout population. He cited the 2007 flood as a precedent. "There were a lot of fish left in the streams. I don't know how they lived through it, but I'm expecting there will be more fish than what you would guess," he stated. Walking the streams right now he said he didn't see many fish, because he assumed most were hiding.
A complete assessment of the streams won't be completed until September or October. This is because Klotz and the DNR use an electrofishing technique, which requires cooler water temperatures.
Ironically, Klotz expects next year's fish population to be much larger than in years past. The clean gravel, which came from scouring, makes ideal places for spawning. "They can make up numbers in a couple years pretty quick," he said.
Expert trout angler Heath Sershen, who is the director of operations at the National Trout Center in Preston, said 2007 flooding in Winona was followed by several productive years. "As tragic as it is now, I'm hoping that the years to come will be really good seasons," Sershen stated.
Klotz said there may be a one year lag in numbers of what is catchable size, but that formal DNR judgments would only come in the fall.
"It's kind of a neat opportunity to see what happened to the streams," shared Klotz. "Habitats were created and habitats were destroyed. It might make you have to relearn your favorite place."
Sershen said he noticed that many overall features have changed in the streams. "The watershed has an ability to take what comes through and adapt," he commented. "You might go out to your favorite hole and see it's a run, but a new hole might be close by."
Recovering from the recent flooding may be easier for the trout and stream environments, which have dealt with worse. However, for those humans who were affected by the recent floods, it won't make recovery any easier. Learning how to adapt like nature may be a lesson well learned.