MINNESOTA FALLS — Removing the Minnesota Falls dam on the Minnesota River has benefited the upstream fishery as was hoped, according to fish sampling conducted this past season by the Minnesota Department of Natural Resources.
There was a greater diversity of fish species found upstream of the former dam site, and in simple terms, a lot more fish. Fisheries staff counted 300 fish per hour as compared to an average of 150 fish per hour before the dam was removed.
Chris Domeier, assistant fisheries director with the Minnesota Department of Natural in Ortonville, said the improvements documented this summer should only be the first. He anticipates it will take five to 10 years for the upstream portion of the river to truly get back to ‘‘normal.’’
Xcel Energy removed the Minnesota Falls dam last December and January. The 600-foot long, 14.5 foot tall structure had stopped natural fish migration at the site roughly three river miles south of the Granite Falls dam for more than a century.
Lake sturgeon, paddlefish, and flathead catfish are among the fish that had been prevented from naturally migrating upstream of the dam.
Domeier said a paddlefish was spotted (but not netted) during sampling this summer. Sampling and the success of anglers have shown that flathead catfish are now returning to the upstream portion of the river.
He is confident that lake sturgeon have returned, but was not able to confirm it. They are among the fish species that he had not been able to capture through sampling techniques, mainly electro-shocking.
Anglers have already reported catching lots of the smaller, shovelnose sturgeon in the upstream portion of the river. They had only rarely been found upstream while the Minnesota Falls dam was in place.
Anglers have enjoyed more success catching walleyes, whitebass, sauger and smallmouth bass in upstream areas.
Domeier said panfish numbers, mainly bluegill and crappies, seem to be unchanged. He found no signs that the numbers of any species declined.
The sampling revealed that many non-game fish species indicative of an improved aquatic habitat have returned to the upstream portion. Black buffalo, shortnose gar, longnose gar, and sauger have all been documented.
He said another noticeable change was a substantial increase in “river loving’’ species such as gizzard shad, bigmouth buffalo, and river carpsucker.
Perhaps most telling of all, Domeier and DNR fisheries staff involved in the sampling found evidence that a lot more anglers were visiting this portion of the river than before.
The removal of the dam has allowed a free-flowing river to return to an area where it drops about 17-feet in a three-mile stretch. That creates a variety of riffles and rapids that provide ideal spawning habitat for many river fish species.