Long-term monitoring by the Wisconsin Department of Natural Resources shows efforts to improve Mississippi River water quality appear to be paying off with the return of several important fish and aquatic plant species to at least one major pool.
The latest results come as the Upper Mississippi River Restoration Program celebrates 30 years of large river ecosystem restoration, intensive monitoring and research on the Upper Mississippi.
Program leaders, partners and stakeholders gathered at Riverside Park in La Crosse on August 8 to mark the multi-state achievements, including the rehabilitation of more than 100,000 acres of important fish and wildlife habitat.
The combination of large scale habitat restoration coupled with long-term resource monitoring and research was an untested concept when the program was authorized by Congress in 1986, said Jim Fischer, DNR's Mississippi River basin supervisor. Since then, the program has worked to adapt techniques proven on a smaller scale that restore complex river functions.
Wisconsin DNR's role has involved support for more than 19 major construction projects including work on the Capoli Slough, a cooperative project involving DNR, the U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service and the Iowa Department of Natural Resources. The project protected 10 existing islands and constructed nine new islands totaling 49 acres, compared to the 74 acres of islands present shortly after inundation by Lock and Dam 9 in 1940.
As part of the work, backwater dredging increased water depths for fisheries. Completed in 2014, the project improved fish and wildlife habitat in more than 600 acres of lower Pool 9.
"The Mississippi River is an important commercial shipping waterway yet it also provides critical habitat for a variety of fish and waterfowl," Fischer said. "Over time, wave action and river currents took their toll on the islands until few were left in lower portions of several pools. Loss of the islands and aquatic vegetation resulted in an increase in suspended sediments in the water and heavy silt accumulation in previously important fish habitat."
A similar, multistate effort is now underway in Harper's Slough involving Wisconsin DNR, Iowa DNR and the U.S. Army Corps of Engineers using $16.5 million in federal funds. The Harper's Slough area is used heavily by tundra swans, Canada geese, puddle and diving ducks, black terns, nesting eagles and bitterns and is also significant as a fish nursery area. The project will protect approximately 46 acres of existing islands and construct 52 acres of new islands, said Jeff Janvrin, DNR fisheries biologist.
"These projects are years in the making, with planning and construction often stretching more than a decade," Janvrin said. "However, the positive results are already evident, with the return of species that had been absent for years in some areas."
Upstream in Pool 8, Wisconsin DNR bears responsibility for long-term monitoring of fish, aquatic vegetation and water quality for the Upper Mississippi River Restoration program. There, water quality and fish data have been collected since 1993 and vegetation data since 1998. Results from 2015 indicate work in this area has contributed to reduced suspended solids in the water, the return or expansion of wild rice and wild celery and several fish on the threatened list.
"After a 16 year absence, the survey crews captured a burbot, while Mississippi silvery minnows and yellow bass were found after a 10 year absence," said Andy Bartels, DNR's long term resource monitoring fisheries specialist. "We also documented blue sucker and river redhorse, both on Wisconsin's threatened list, as well as lake sturgeon, which has now been found in six of the last 23 years."
Beyond enhancing the environment, Fischer said the habitat improvements and resulting benefits also contribute to the vitality of the region's economy. The Upper Mississippi River, home to the Upper Mississippi River Wildlife and Fish Refuge, attracts more visitors than the Grand Canyon with tourism and outdoor recreation bringing more than $17 billion into the region and supporting more than 300,000 jobs.
To learn more about the Mississippi River fisheries and habitat survey work, visit DNR.wi.gov and search "Fishing Mississippi."