Fish, wildlife stand to benefit
IDNR fisheries
biologist studies
mitigation projects
By Larry Myhrelfentfish@msn.com | Posted: Thursday, November 06, 2008
ONAWA, Iowa — With progress, often comes sacrifice.
That certainly has been the case with the channelization of the Missouri River from Sioux City downstream. What was sacrificed was wildlife and fisheries habitat.
For more than 50 years, fish and wildlife populations have seen reductions. Now, efforts are being made to mitigate some of those losses.
The U.S. Army Corps of Engineers has been working on various backwater sites all along the Missouri River.
Helping measure the success of these projects in the Siouxland area is Iowa Department of Natural Resources Fisheries Biologist Van Sterner.
“We have a contract with the Corps to monitor these sites to see how they perform,” he said from his office in Onawa.
“We are monitoring work at the Tieville/Decatur complex, Louisville Bend, California Bend and Tyson Island,” he said. “These are all sites where the Corps has done work under the mitigation project.”
What has been learned is that off channel habitat is very important to many species of Missouri River fish.
“There’s a lot of research that shows species richness increases with connectivity to the main channel,” Sterner says. “Many of these fish are flood plain dependent, whether it be for spawning or as a nursery.”
With the exception of Decatur Lake, all of the off channel sites are backwater or dredged channels which do not support fish life over the winter.
“It’s amazing how quickly these fish find these areas,” he said.
The IDNR established the Missouri River office at Onawa in 2005. Sterner, a University of South Dakota graduate, had been working as a Fisheries Tech 2 in Decorah before being promoted.
The Corps contracted for the study with the IDNR and is also working with three other crews in Missouri, Kansas and Nebraska.
“We are approaching over 200,000 fish caught in our study,” Sterner said. “Fifty-seven species have been captured.
Most of these fish have been young of the year or smaller fish due to the shallow waters that have been sampled.
What are the most common big river fish being sampled?
“We see a lot of gizzard shad, a lot of carpsucker and buffalo,”Sterner said. “We have caught bighead carp, bullheads, bigmouth buffalo, channel catfish, largemouth bass, paddlefish, sauger, skipjack herring, shortnosed gar, silver carp, walleye, white and black crappies, perch, freshwater drum, blue suckers and, of course, shiner minnows.”
The IDNR’s contract with the Corps expires in March of next year.
Sterner said they have done very little survey work on the main channel because their primary focus has been on the mitigation sites.
“We are not sure of the status of an additional contract with the Corps,” Sterner said. “But hopefully we will have enough time to do a riverwide sampling of channel and flathead catfish and growth rates.
“From what little work we have done on the channel and from our off channel work, there appears to be no shortage of reproduction,” he continued. “There are all kinds of small catfish out there but that doesn’t seem to equate into bigger fish. I don’t know if there’s some kind of bottleneck preventing them from growing up or just poor growth rates. These are issues we need to look into.”
Another game fish of interest is the smallmouth bass.
“We did 40 smallmouth bass samples from the Big Sioux to below the Winnebago boat ramp in 2007,” Sterner said. “We saw catch rates as high as 156 fish per hour which rivals any smallmouth fishery we have in Iowa. Size structure was dominated by two younger year classes age one and two, but we saw fish up to 18 inches. Abundance decreased as we went downstream.”
Mitigation work will never restore the river to what is was before channelization, but so far the work that has been done appears promising.
Sterner’s studies, and others like his, will help the Corps move forward to help fish and wildlife along the river.
That certainly has been the case with the channelization of the Missouri River from Sioux City downstream. What was sacrificed was wildlife and fisheries habitat.
For more than 50 years, fish and wildlife populations have seen reductions. Now, efforts are being made to mitigate some of those losses.
The U.S. Army Corps of Engineers has been working on various backwater sites all along the Missouri River.
Helping measure the success of these projects in the Siouxland area is Iowa Department of Natural Resources Fisheries Biologist Van Sterner.
“We have a contract with the Corps to monitor these sites to see how they perform,” he said from his office in Onawa.
“We are monitoring work at the Tieville/Decatur complex, Louisville Bend, California Bend and Tyson Island,” he said. “These are all sites where the Corps has done work under the mitigation project.”
What has been learned is that off channel habitat is very important to many species of Missouri River fish.
“There’s a lot of research that shows species richness increases with connectivity to the main channel,” Sterner says. “Many of these fish are flood plain dependent, whether it be for spawning or as a nursery.”
With the exception of Decatur Lake, all of the off channel sites are backwater or dredged channels which do not support fish life over the winter.
“It’s amazing how quickly these fish find these areas,” he said.
The IDNR established the Missouri River office at Onawa in 2005. Sterner, a University of South Dakota graduate, had been working as a Fisheries Tech 2 in Decorah before being promoted.
The Corps contracted for the study with the IDNR and is also working with three other crews in Missouri, Kansas and Nebraska.
“We are approaching over 200,000 fish caught in our study,” Sterner said. “Fifty-seven species have been captured.
Most of these fish have been young of the year or smaller fish due to the shallow waters that have been sampled.
What are the most common big river fish being sampled?
“We see a lot of gizzard shad, a lot of carpsucker and buffalo,”Sterner said. “We have caught bighead carp, bullheads, bigmouth buffalo, channel catfish, largemouth bass, paddlefish, sauger, skipjack herring, shortnosed gar, silver carp, walleye, white and black crappies, perch, freshwater drum, blue suckers and, of course, shiner minnows.”
The IDNR’s contract with the Corps expires in March of next year.
Sterner said they have done very little survey work on the main channel because their primary focus has been on the mitigation sites.
“We are not sure of the status of an additional contract with the Corps,” Sterner said. “But hopefully we will have enough time to do a riverwide sampling of channel and flathead catfish and growth rates.
“From what little work we have done on the channel and from our off channel work, there appears to be no shortage of reproduction,” he continued. “There are all kinds of small catfish out there but that doesn’t seem to equate into bigger fish. I don’t know if there’s some kind of bottleneck preventing them from growing up or just poor growth rates. These are issues we need to look into.”
Another game fish of interest is the smallmouth bass.
“We did 40 smallmouth bass samples from the Big Sioux to below the Winnebago boat ramp in 2007,” Sterner said. “We saw catch rates as high as 156 fish per hour which rivals any smallmouth fishery we have in Iowa. Size structure was dominated by two younger year classes age one and two, but we saw fish up to 18 inches. Abundance decreased as we went downstream.”
Mitigation work will never restore the river to what is was before channelization, but so far the work that has been done appears promising.
Sterner’s studies, and others like his, will help the Corps move forward to help fish and wildlife along the river.
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