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“Majestic bluffs ... the shining river, winding here and there and yonder, its sweep interrupted at intervals by clusters of 

wooded islands threaded by silver channels”

 — Mark Twain, Life on the Mississippi, 1883, describing the Upper Mississippi River.

Taking the Pulse of a River System: Research on the 

Upper Mississippi River System

Product of the Long Term Resource Monitoring Program

Upper Mississippi River System

Mark Twain raved about the Mississippi River basin as, “the body of the Nation.” The “upper body,” upstream of the 

confluence with the Ohio River, includes commercially navigable reaches and branching tributaries that are recreationally 

and environmentally important. Together they feed and shelter an array of fish and wildlife in their flowing channels, 

floodplain lakes, backwaters, wetlands, and floodplain forests.

Effective river management requires knowledge about factors controlling the dynamics and interactions of important 

ecosystem components. The Long Term Resource Monitoring Program (LTRMP) is the prized diagnostic tool in the 

Environmental Management Program for the Upper Mississippi River System that provides critical information about the 

status and trends of key environmental resources.

Bringing 1890s Maps into the Digital Age

Maps detailing the Mississippi River floodplain about the time of Mark Twain’s book Life on the Mississippi are now updated for 

use with geographical information systems. These georeferenced data of the original Mississippi River Commission maps give 

the best historical picture of the river’s geomorphology and land use/land cover before impoundment of the river in the late 1930s. 

These maps contain detailed information on vegetation cover, water depths, and land elevations and are invaluable resources for 

change analysis and for habitat restoration planning. Island restoration efforts in particular use these maps to help determine where 

islands and higher land features existed historically. Often, remnants of these features lie below the surface of the water, thereby 

decreasing the amount of fill material needed for construction and increasing the likelihood of a successful restoration. (www.umesc.

usgs.gov/data_library.html) 

Contact: Larry Robinson; lrobinson@usgs.gov

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2009–3045

June 2009

1896 1999 2008
Invasive Snail Plays Role in Bird Deaths

Since 2002, up to 65,000 waterbirds have died along the Upper Mississippi River System 

from disease caused by three parasitic trematodes that are carried by the invasive faucet 

snail. Birds can swallow lethal doses of the trematodes while feeding on the faucet snail 

or infected aquatic insect larvae. Lesser scaup, American coots, blue-winged teal, and 

ring-necked ducks comprised the largest numbers of casualties.

Partners in the Long Term Resource Monitoring Program responded to this crisis by 

adding sampling for faucet snails to projects already underway to sample submerged 

vegetation. Knowing the distribution and abundance of this invasive snail alerts managers 

to its potential spread along bird migration routes that include critical habitat for 

waterfowl. Research will continue to search for ways to curtail and mitigate effects of this 

invasive snail and the associated trematodes.

Contact: Jennifer Sauer; jsauer@usgs.gov; Rebecca Cole; rcole@usgs.gov;

James Nissen; james_nissen@fws.gov; Ed Britton; ed_britton@fws.gov

How to Resupply the Banquet

Historically, Weaver Bottoms, located 

near Weaver, Minnesota, attracted thousands 

of migrating swans and ducks each fall to feed on 

aquatic plants. After years of impoundment and increased 

suspended sediments, its smorgasbord of aquatic plants became 

skimpy. In summer 2005, researchers simulated pre-dam, low 

flow conditions by drawing down the water in Pool 5 (including 

Weaver Bottoms). Emergent aquatic plants such as arrowhead 

increased as a result of the drawdown. Submersed aquatic plant 

abundance increased and water clarity improved following the 

drawdowns, however similar improvements were also seen in 

other pools. Ducks have returned in abundance to feed on the 

aquatic plants.

Additional studies are needed to determine the effect of 

drawdowns on these parameters. Continued monitoring will help 

us know: How long will the increase in vegetation persist? What 

frequency of drawdowns is most successful and cost effective? 

Contact: Tim Schlagenhaft; Timothy.Schlagenhaft@state.mn.us 

Walt Popp; Walter.Popp@state.mn.us

NATURAL CORRIDOR

The Upper Mississippi River System forms a nearly continuous natural corridor through the heart of the 

United States for migrating birds as well as fishes and other aquatic life.

Revealing Refueling Stops for Landbirds

Migrating birds use the river’s natural corridor of wetlands, 

backwaters, floodplain forests and adjacent bluffs as they 

travel between southern wintering grounds and northern 

breeding places. Researchers track bird abundance and 

diversity, indices of habitat quality, and patterns of 

migration and stopover behavior.

Locations such as floodplain forests where birds stop to rest and 

feed are being revealed by a combination of field, laboratory, and 

high resolution radar (NEXRAD) techniques. 

This research helps us understand when and how birds use upland 

and bottomland river forest habitats during their migration. With 

this information, agencies can target their land acquisition and 

restoration to important areas of bird use.

Contact: Pat Heglund; Patricia_Heglund@fws.gov

Eileen Kirsch; ekirsch@usgs.gov
Tips to Count Mussels

Freshwater mussels are the largest group of endangered animals 

in North America. Threats come from many sources including (1) 

changes in flow patterns within rivers, (2) increases in sediment 

loads, (3) chemical contaminants within rivers, and (4) invasive 

species. Conservation attempts have been thwarted by lack of such 

basic tools as an inexpensive and efficient way to estimate the 

presence and abundance of mussels in large rivers. 

Identifying Limits on

Fish Abundance in Backwaters

Habitat enhancement efforts along the Upper 

Mississippi River often focus on off-channel 

areas because of their ecological and recreational 

importance and degraded condition. Using 10 years 

of monitoring data, researchers compared fish diversity 

and abundance of various size classes of bluegill, black 

crappie, and largemouth bass in 42 off-channel areas. Of all 

environmental factors examined, they found that small fishes 

and large bluegill depend most on aquatic vegetation to flourish, 

probably because vegetation provides the habitat necessary for 

invertebrates that these fish need for food and hiding places 

from predators. Large black crappies and largemouth bass were 

less dependent on vegetation, probably because they are top 

predators which use other fish for food.

Contact: Brent Knights; bknights@usgs.gov

MANAGERS’ TOOLBOX

Research can give river managers the tools they need to meet today’s challenges.

Looking at Oxygen and Primary Production

Primary production (the growth of algae and aquatic plants) 

is a key component of floodplain river ecosystems, ultimately 

determining the abundance of its fish and waterfowl, and 

regulating dissolved oxygen concentrations needed for 

favorable fish habitats. Researchers asked how connectivity to 

the main channel and vegetation abundance affect dissolved 

oxygen and nutrient concentrations in the backwaters, 

particularly as they relate to fish and vegetation abundance. 

They found that nitrogen concentrations were higher in the 

main channel or in backwaters with strong flow connections 

to the river. Phosphorus levels were higher in backwater sites. 

Abundance of vegetation and water depth dictated dissolved 

oxygen dynamics more than connectivity. Knowing the link 

between nutrients and primary production can help managers 

evaluate nutrient problems in backwaters and other offchannel areas.

Contact: Jeff Houser; jhouser@usgs.gov 

Bill Richardson; wrichardson@usgs.gov

John Sullivan; john.sullivan@wisconsin.gov

Researchers used computer simulations to evaluate various 

sampling designs for small (e.g., island construction) and 

large scale projects (e.g., pool-wide drawdowns). Their 

results have identified sampling designs that produce more 

accurate estimates of abundance with less effort than standard 

techniques. These designs can be used by managers to survey 

sites suggested for restoration projects and help to assess the 

effects of habitat restoration projects on mussels.

Contact: Teresa Newton; tnewton@usgs.gov; 

Dave Smith; drsmith@usgs.gov
OTHER ON-GOING WORK:

1. Asian Carp in the Mississippi River: Their impact 

on native fish species and predicted dispersal 

within the system

2. Investigate effects of newly completed 

rehabilitation projects (Lake Chautauqua National 

Wildlife Refuge, Banner Marsh State Fish and 

Wildlife Area) in La Grange Pool in the Illinois 

River on fish production 

3. Developing indicators of southern bottomland 

hardwood forest condition within the Upper 

Mississippi River ecosystem 

4. Assessment of high-resolution digital imagery for 

vegetation mapping and software-based vegetation 

classification

5. Development of survey methods to spatially map 

mussel assemblages

6. Experimental and comparative approaches 

to determine factors supporting or limiting 

submersed aquatic vegetation in the Illinois River 

and its backwaters 

AND THE LIST GOES ON....

For more information, go to www.umesc.usgs.gov/ltrmp.html — perhaps the world’s best source of ecological data on 

large rivers.

Congress declared the Upper Mississippi River System as a nationally significant ecosystem and a nationally significant 

commercial navigation system — the only river in the United States to receive this dual recognition. The Long Term 

Resource Monitoring Program was created over 20 years ago as part of the Environmental Management Program (EMP). 

The LTRMP consists of a comprehensive program of monitoring, research, and data management that provides critical 

information about the status and trends of key resources. The LTRMP information is used extensively by resource 

managers, planners, administrators, scientists, academics, legislators, and the general public for improved understanding, 

problem solving, and informed decision-making about issues important to the UMRS. 

The LTRMP partnership:

This fact sheet is second in a series highlighting work done under the LTRMP. See: Leake, L., and Johnson, B., 2006, 

Taking the pulse of a river system: First 20 years: U.S. Geological Survey, Fact Sheet 2006-3098. 

http://pubs.usgs.gov/fs/2006/3098/pdf/FS2006-3098.pdf 

For Program information contact Dr. Barry Johnson, USGS, LTRMP Science Director at 608-783-6451.

U.S. Army Corps of Engineers