They came to this stretch of river downstream of Granite Falls not for the weather, but to see how this stretch of river had responded to running free for those seven years. Low water levels on the Minnesota River this fall provided the perfect opportunity to see any changes.
Aadland and Domeier are with the Minnesota Department of Natural Resources, and played roles in the removal of the former Minnesota Falls dam, a 600-foot-wide, 14.5-foot-tall structure that had created a reservoir of water for a hydro-electric generation system that operated until 1961. Aadland has built an international reputation for his work in restoring river habitat when dams are removed. Domeier, the DNR’s fisheries supervisor in Ortonville, shares Aadland’s interest in restoring aquatic ecosystems.
In some ways, they found themselves traveling back in time over 10,000 years when exploring the waters they helped unleash. They guided their kayaks through whitewater rapids churning around large, rounded boulders in places, some of the rocks equal in weight and size to the cattle they saw grazing along portions of the stretch they paddled.
“I think they are from the River Warren,” said Aadland of the large boulders. They are too large to have been moved by the Minnesota River, which is but a small remnant of the glacial River Warren, he explained.
What it all meant, he said, is that thanks to the removal of the dam, flow velocities on this stretch of the river have allowed it to scour away much of the silt and sediment that had slowly stacked up, year-by-year, ever since the Minnesota Falls dam plugged this waterway over a century ago.
Like pulling away a blanket, sand and gravel bars that lay covered by sediment since the era of steamboats are now exposed to the light of day.
Most important, the channel under the river’s flow is once again cleaned of sediment and consists largely of stone and gravel, ideal habitat for a variety of invertebrates and other aquatic organisms.
The best of these organisms: sauger, shovelnose sturgeon, paddlefish, flathead catfish and other native fish species, including black and smallmouth buffalo fish and blue suckers. They are among 39 native fish species that had been blocked from this stretch of river with the construction of the Minnesota Falls dam. A few years ago, Aadland was able to document the return of at least 12 of the 39 species. He’s hoping to do additional work to see if more have returned.
The return of blue suckers, a species of concern in the Minnesota River, is especially encouraging to Aadland. The native fish favors fast-moving waters and is a sign of improved water conditions.
“What’s remarkable, though, is the number of species that we’ve documented that weren’t here,” said Aadland. The ability of these fish to re-establish themselves in just seven years is really good news, he noted.
The fish are attracted to a stretch of river that could be considered prime real estate for them. The Minnesota River drops 17 feet from the dam at Granite Falls to the site of the former Minnesota Falls dam, a distance of roughly six to seven river miles. That makes this area one of the best in terms of tumbling waters and rock riffles. The riffles provide critical spawning habitat for many fish species, lake sturgeon among them.
“You can count on one hand the number of rock riffles from Granite Falls to St. Paul,’’ said Domeier of the Minnesota River, which is not otherwise known for rapids and whitewater. He and Aadland can now see the day when lake sturgeon, essentially absent from the Minnesota River in modern times, will be found spawning in these rapids downstream of Granite Falls. Lake sturgeon were returned upstream to Big Stone Lake several years ago, and are responding well to their re-introduction, said Domeier. He is confident they will migrate downstream into the Minnesota River and return to these waters.
With the removal of the Minnesota Falls dam, a 250-mile stretch of the Minnesota River now runs free from Granite Falls to the confluence with the Mississippi River. That makes it one of the longest, free-running stretches of river in the state.
The two paddlers carried cameras and notebooks to document the changes they witnessed on the stretch of river they explored. They regretted not having fishing poles or the opportunity to fish these spots. Domeier noted that the pools scoured below the rapids they paddled were certain to hold walleye and sauger. They’d be the perfect spots to do some vertical jigging.
Their paddle convinced them that this stretch of water is also perfect for those who enjoy paddling fast- and free-flowing waters.
Most of all, they were pleased to see the greatly improved aquatic habitat in this stretch. After being complimented for creating these improvements, Domeier was quick to say the credit belongs to the river itself. “We wanted to free it, we didn’t want to create it.”
"fish" - Google News
October 03, 2020 at 10:00PM
https://ift.tt/2EWw8mE
Fish are returning to fast-flowing stretch of Minnesota River with removal of dam - West Central Tribune
"fish" - Google News
https://ift.tt/35JkYuc
https://ift.tt/3feFffJ
Bagikan Berita Ini
0 Response to "Fish are returning to fast-flowing stretch of Minnesota River with removal of dam - West Central Tribune"
Post a Comment