Long Term Resource Monitoring Program

Technical Re port 

2004-T001

March 2004

Long Term Resource Monitoring Program 

Outpool Fisheries Analysis
Long Term Resource Monitoring Program Technical Reports 

provide Long Term Resource Monitoring Program 

partners with scientifi c and technical support.

All reports in this series receive anonymous peer review.

Mention of trade names or commercial products does not constitute endorsement

or recommendation for use by the U.S. Department of the Interior, U.S. Geological Survey.
Long Term Resource Monitoring Program 

Outpool Fisheries Analysis

by

John H. Chick and Mark A. Pegg

Final Report submitted to

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603

March 2004
Suggested citation:

Chick, J. H., and M. A. Pegg. 2004. Long Term Resource Monitoring Program outpool fi sheries analysis: Final 

report. U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin. 

March 2004. LTRMP 2004-T001. 21 pp. 

Additional copies of this report may be obtained from the National Technical Information Service, 5285 

Port Royal Road, Springfi eld, VA 22161 (1-800-553-6847 or 703-487-4650). Also available to registered 

users from the Defense Technical Information Center, Attn: Help Desk, 8725 Kingman Road, Suite 0944, Fort 

Belvoir, VA 22060-6218 (1-800-225-3842 or 703-767-9050).
iii

Contents

Page

Preface ................................................................................................................................................v

Abstract................................................................................................................................................1

Introduction..........................................................................................................................................2

Methods................................................................................................................................................3

Fish Sampling ................................................................................................................................3

Statistical Analysis.........................................................................................................................4

Results ................................................................................................................................................6

Electrofi shing.................................................................................................................................6

Habitat Correlations.....................................................................................................................14

Seining .........................................................................................................................................15

Discussion..........................................................................................................................................15

Implications for Long Term Resource Monitoring Program and Future Studies..............................20

References..........................................................................................................................................20
iv

Tables

Number Page

1. Habitat variables routinely collected from each electrofi shing site for the Long Term Resourse 

Monitoring Program ......................................................................................................................4

2. Mean abundance of the 16 species used in community structure analysis....................................5

3. Surface area of aquatic/geomorphic habitat variables as defi ned by the habitat needs 

assessment query tool ....................................................................................................................6

4. Total number of individuals captured using boat electrofi shing....................................................7

5. Mean abundance of the 11 species that contributed more than 70% to the dissimilarity among 

pool subgroups.............................................................................................................................15

Figures

1. Map of the Upper Mississippi River System showing the six reginal trend analysis pools 

monitored by the Long Term Resource Monitoring Program and the eight outpools sampled 

with electrofi shing during 2000.....................................................................................................3

2. Rarefaction curves from electrofi shing data for the six regional trend analysis pools in 2000...12

3. The total number of fi sh captured by electrofi shing from the six regional trend analysis pools 

and eight outpools during 2000 ...................................................................................................12

4. (A) Cluster analysis of fi sh community composition data collected through electrofi shing. ......13

 (B) Nonmetric multidimensional scaling plot of Upper Mississippi River System in three 

dimensions (Fish community composition data).........................................................................13

5. (A) Cluster analysis of fi sh community structure data collected through electrofi shing .............14

 (B) Nonmetric multidimensional scaling plot of Upper Mississippi River System in three 

dimensions (Fish community structure data)...............................................................................14

6. Relations between the distance between pool (river miles) with (A) community structure of 

fi sh, (B) community composition of fi shes, and (C) habitat composition ...................................16

7. Relation between water depth, fl ow, conductivity, vegetation density, presence of woody 

structure, and presence of fl ooded terrestrial vegetation with river mile.....................................17

8. (A) Cluster analysis of fi sh community composition data collected through seining..................18

 (B) Nonmetric multidimensional scaling plot and stress value for Upper Mississippi River 

System pools in two dimensions..................................................................................................18
v

Preface

The Long Term Resource Monitoring Program (LTRMP) was authorized under the Water Resources 

Development Act of 1986 (Public Law 99-662) as an element of the Environmental Management 

Program for the Upper Mississippi River System. The LTRMP is implemented by the Upper Midwest 

Environmental Sciences Center of the U.S. Geological Survey, in cooperation with the fi ve Upper 

Mississippi River System states (Illinois, Iowa, Minnesota, Missouri, and Wisconsin), with guidance 

and Program responsibility provided by the U.S. Army Corps of Engineers. 

The mission of the LTRMP is to provide decision makers with information to maintain the Upper 

Mississippi River System as a viable large river ecosystem given its multiple-use character. The 

longterm goals of the Program are to understand the system, determine resource trends and impacts, 

develop management alternatives, manage information, and develop useful products.
.
Long Term Resource Monitoring Program 

Outpool Fisheries Analysis

Final report to

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603

by

John H. Chick

Illinois Natural History Survey

Great Rivers Field Station

8450 Montclair Ave

Brighton, Illinois 62012

and

Mark A. Pegg

Illinois Natural History Survey

Illinois River Biological Station

704 North Schrader

Havana, Illinois 62644

Abstract: This study was designed to assess whether fi sh community data collected for the Long Term 

Resource Monitoring Program (LTRMP) from six regional trend analysis (RTA) areas of the Upper 

Mississippi River System (UMRS) can be used to make inferences to the system as a whole. Spatial 

coverage of fi sh monitoring for three LTRMP fi eld stations was extended to "outpools" immediately 

above and below RTA pools 4 and 13 and the Open River Reach from June 15 to October 31, 2000. 

Also, we sampled Navigation Pools 19 and 20 using LTRMP electrofi shing methodology in September 

2000. Multivariate statistical analyses were used to group pools on the basis of fi sh community 

composition and community structure. Cluster analysis of community composition and structure 

data revealed two major groups of pools: upper pools (i.e., northern) and lower pools (i.e., southern). 

Navigation Pools 19 and 20 grouped with lower pools in terms of community composition, and with 

upper pools in terms of community structure. Analysis of community composition data yielded four 

subgroups, with La Grange Pool forming its own subgroup. Analysis of community structure yielded 

fi ve subgroups, with La Grange Pool and Pool 8 forming unique subgroups. In general, all outpools 

grouped with the nearest RTA pools for both community composition (no exception) and community 

structure (one exception). Strong correlations between the community composition and structure 

matrices with distance between pools suggest that fi sh communities in relatively close pools are more 

similar than in pools separated by larger distances. Habitat variables measured during electrofi shing 

collections were signifi cantly correlated with spatial variation of fi sh composition and community 

structure, but provided only marginal improvements to correlations with distance between pools alone. 
2

Results of this study lend support to the premise that LTRMP fi sh community data could potentially be 

used to make inferences to the entire UMRS, because current RTA areas are evenly distributed within 

the major pool groupings identifi ed in this study. Nevertheless, further research is needed to resolve 

how fi sh communities in Navigation Pools 19 and 20 and other lower UMRS pools compare to present 

RTA areas.

Key words: Analysis, fi sh community, LTRMP, Mississippi River, navigation pool, trend analysis, 

UMRS 

Introduction

The Long Term Resource Monitoring Program 

(LTRMP) was authorized by the Water Resources 

Development Acts of 1986 and 1999 as an 

element of the U.S. Army Corps of Engineers' 

Environmental Management Program. The primary 

mission of the LTRMP is to provide resource 

managers with the information needed to maintain 

the Upper Mississippi River System (UMRS) as 

a viable multiple-use ecosystem. Four long-term 

goals established for the LTRMP are (1) increasing 

our understanding of how the river ecosystem 

operates, (2) monitoring UMRS natural resources 

status and trends, (3) assisting in the evaluation of 

management alternatives, and (4) managing and 

providing access to resulting data, information, and 

products (U.S. Army Corps of Engineers 1997). 

Standardized monitoring of water quality, aquatic 

vegetation, aquatic invertebrates, and fi shes are key 

components of the LTRMP. 

The vast geographic expanse of the UMRS, 

which includes 1,300 miles of navigable rivers 

and a basin encompassing 190,000 square miles 

including numerous tributaries, presents a major 

challenge to the LTRMP. The design of any 

monitoring program focused on a large ecosystem 

must fi nd a balance between covering enough 

spatial area to allow for system wide inferences and 

the ability to obtain enough detailed information 

to describe and understand the interaction of 

ecosystem components. This challenge is even 

greater when populations and communities of 

organisms are a primary focus of a monitoring 

program, given that population dynamics of 

different species within an ecosystem usually 

operate at several different spatial and temporal 

scales (Wiens 1989; Levin 1992). Therefore, 

monitoring programs designed to track population 

variation of several species need to sample multiple 

spatial subunits appropriate for populations 

operating at small scales, with suffi cient replication 

of subunits to track populations operating at larger 

scales and allow inferences to the entire system.

For a system as spatially extensive as the 

UMRS, it is clear that many species have multiple 

populations within this river-fl oodplain system. 

Because a major goal of LTRMP is to provide 

system wide inferences for the monitored 

components, it is also clear that the monitoring 

design must include substantial spatial coverage. 

The original plans for the LTRMP included sample 

collection from 22 river reaches (U.S. Army 

Corps of Engineers 1997). Logistical constraints, 

however, reduced the number of areas sampled 

from 22 river reaches to 6 regional trend analysis 

areas (RTA; Navigation Pools 4, 8, 13, and 26 

and the Open River Reach on the Mississippi 

River and La Grange Pool on the Illinois River). 

Lubinski et al. (2001) conducted a power analysis 

demonstrating that the present LTRMP design 

provides adequate statistical power to detect 

inter-annual variation for most water quality 

parameters and many fi shes within the six RTA 

areas. Nevertheless, how well these six RTA areas 

refl ect the overall biotic and abiotic conditions of 

the entire UMRS remains unknown. 

This study was initiated to expand the 

spatial coverage of LTRMP fi sheries monitoring 

(specifi cally, electrofi shing and seining) to outpools 

immediately above and below three RTA areas in 

an attempt to provide further insight into the ability 

of LTRMP to make ecological inferences to the 

UMRS as a whole. We present statistical analysis 

of this study, examining spatial variation of 

community composition (the presence or absence 

of species) and community structure (relative 
3

abundance of species) of UMRS fi shes. Four major 

goals are addressed:

1. Determine how sampled pools group based 

on community composition of fi shes.

2. Determine how sampled pools group based 

on community structure of fi shes.

3. Determine where outpools group relative to 

adjacent RTA areas.

4. Determine whether groupings of pools 

based on community composition and 

structure correspond to spatial variation of 

important habitat factors. 

Methods

Fish Sampling

This study extended the spatial coverage of 

fi sh monitoring for three LTRMP monitoring 

locations. Mississippi River navigation 

pools immediately above and below 

RTA pools 4 and 13 and Open River 

Reach (Figure 1) were sampled using 

standard LTRMP electrofi shing 

methodology from June 15 to October 

31, 2000. Throughout this report, these 

areas will be referred to collectively as 

outpools and individually as Pools 3, 

5, 12, 14, 29, and 31 (note: 29 and 31 

are nonpooled river reaches). Standard 

LTRMP monitoring also occurred 

in all six RTA pools (4, 8, 13, 26, 

La Grange, and Open River Reach) 

during 2000 and electrofi shing samples 

were collected from Pools 19 and 20 

by all LTRMP fi sheries personnel on 

September 12 and 13, 2000 (Figure 1). 

We were interested in examining how 

fi sh communities in Pools 19 and 

20 grouped with other UMRS pools 

because Lock and Dam 19 is believed to 

present a barrier to migrations of certain 

fi shes (Kelner and Seitman 2000). Plans 

for this study called for seining in all 

outpools. Unfortunately, this proved to 

be logistically impractical and only was 

accomplished for two outpools (12 and 

14).

Gutreuter et al. (1995) described standard 

LTRMP methodology for electrofi shing and 

seining in detail. Sampling locations were 

selected using a stratifi ed (by habitat type) random 

design (Lubinski et al. 2001). Electrofi shing was 

conducted using pulsed-DC output with two ring 

anodes and the boat hull serving as the cathode 

and voltage and amperage were adjusted for water 

temperature and conductivity to achieve a power 

output of 3,000 W. Two dippers collected fi sh. 

Electrofi shing was conducted along shorelines 

continuously for 15 min at each sample collection 

site. Data on water temperature, depth (average 

for each collection site), conductivity, and habitat 

were collected with each sample (Table 1). Seining 

was conducted using a 10.7-m-long 3-mm-mesh 

bag seine. Seines are fi shed along banks in water 

<1.2 m. One end of the seine was anchored to the 

bank and the other end was deployed perpendicular 

to the bank and swept downstream. All fi sh were 

Figure 1. Map of the Upper Mississippi River System showing the six regional trend 

analysis pools monitored by the Long Term Resource Monitoring Program and the eight 

outpools sampled with electrofi shing during 2000. 
4

identifi ed, measured, and enumerated following 

standard LTRMP protocol (Gutreuter et al. 1995).

Statistical Analysis

We examined spatial variation in fi sh 

community composition and structure among the 

six RTA pools and eight outpools. Community 

composition refers to the presence or absence of 

species, whereas community structure refers to the 

abundance of species as measured by mean catchper-unit-effort (CPUE equals number per 15 min, 

weighted by habitat strata). Separate analyses were 

conducted for electrofi shing and seining data, 

and all analyses were conducted using SAS for 

Windows (SAS Institute, Inc. 1999) and Primer for 

Windows (Primer-E LTD 2001). Our analysis of 

seining data was limited to community composition 

because the power to detect variation in abundance 

of fi shes from LTRMP seining data differs greatly 

among pools (Lubinski et al. 2001).

For both response variables (presence/absence, 

CPUE), we used cluster analysis and nonmetric 

multidimensional scaling (NMDS) to identify 

groupings of pools. These analyses were based 

on a Euclidian distance matrix for community 

composition data, and a Bray-Curtis similarity 

matrix for community structure data. Catch-perunit-effort data were square-root transformed 

to better conform to multivariate normality 

assumptions. This transformation also dampens the 

infl uence of very abundant species for community 

structure analysis (Clarke and Warwick 1994). 

We limited the community structure analysis to 

16 species for which electrofi shing had power 

0.80 to detect a 20% interannual abundance 

change in at least one habitat strata of an RTA pool 

based on the Lubinski et al. (2001) power analysis 

of LTRMP components (Table 2). This somewhat 

conservative criterion was adopted to help ensure 

that the patterns of relative abundance used in these 

analyses refl ect true ecological patterns rather than 

sampling artifacts. Hybrids and fi sh not identifi ed 

to species were omitted from all analyses.

Three criteria were used to determine the 

subgrouping level in our cluster analysis. First, we 

used rarefaction curves from the six RTA pools 

to visually determine the minimum number of 

individuals needed to reach the asymptote of the 

rarefaction curve (i.e., the sampling effort needed 

to adequately describe species composition). 

Acceptable subgrouping levels should not isolate 

undersampled pools because this isolation 

could have resulted from a sampling artifact. 

Table 1. Habitat variables routinely collected from each electrofi shing site for the Long Term Resource Monitoring 

Program (Gutreuter et al. 1995).

Habitat factor Units Explanation

Secchi cm Measurement of water transparency in cm

Conductivity S/cm Conductivity measured to the nearest 1 S/cm

Flow m/sec Rate at which the water is fl owing given in m/sec

Temperature C Temperature of the water in C

Depth m Water depth in fractions of meters

Emergent/Submersed vegetation 0, 1, 2, 3 0 = 0% coverage; 1 = 1–19% coverage; 

2 = 20–49% coverage; 3 = 50% coverage

Vegetation density 0, 1, 2 0 = no veg; 1 = sparse; 2 = dense

Substrate 1, 2, 3, 4 1 = silt; 2 = silt/clay/little sand; 3 = sand/mostly sand; 

4 = gravel/rock/hard clay

Woody structure pres/abs presence or absence of woody structure

Revetment pres/abs presence or absence of shoreline revetment

Inlet/Outlet pres/abs presence or absence on an inlet/outlet channel to a backwater lake

Flooded terrestrial vegetation pres/abs presence or absence of fl ooded terrestrial vegetation
5

Second, we calculated the mean and range of 

Euclidian distance (community composition) 

and Bray-Curtis similarity (community structure) 

between consecutive years for each RTA pool 

using LTRMP data from 1994 to 2000. Many 

of the differences between consecutive years in 

community composition and structure data from 

LTRMP electrofi shing can be attributed to sampling 

artifacts (i.e., electrofi shing does not sample all the 

species present in a pool each year). Therefore, the 

critical Euclidean distance for deriving robust pool 

groupings should be greater than the range of these 

year-to-year differences. Finally, we accepted only 

subgrouping levels that produced groups that were 

easily illustrated using NMDS in either two or three 

dimensions with a stress value < 0.05. Stress value 

is a measure of "goodness-of-fi t" for NMDS with 

small values indicating a better fi t than large stress 

values (Clarke and Warwick 1994). Because seining 

data were available only for a small subset of pools, 

we determined subgrouping using NMDS criteria 

alone.

Because cluster analysis and NMDS are 

data exploration techniques, we used analysis 

of similarity (ANOSIM) to test for signifi cant 

variation in fi sh community composition and 

structure among groups. Analysis of similarity 

is analogous to univariate ANOVA in that it tests 

for signifi cant differences among groups. Unlike 

ANOVA, however, ANOSIM uses Monte Carlo 

simulation to determine signifi cance rather than 

probability inferences from an assumed statistical 

distribution. Nonetheless, our use of ANOSIM 

here is clearly a post-hoc test and results should be 

interpreted with caution. Also, we used similarity 

breakdown analysis (Clarke and Warwick 1994; 

SIMPER procedure in Primer-E LTD 2001) to 

determine the contribution of species to BrayCurtis dissimilarity between community structure 

groupings. 

Finally, we used the electrofi shing data to 

determine whether variation in fi sh community 

composition and structure among pools 

corresponded with variation in habitat factors. Two 

Table 2. Mean abundance (square root # / 15 min) of the 16 species used in community structure analysisa. 

Upper Mississippi River System Navigation Pool

Speciesb 3 4 5 8 12 13 14 19 20 LG 26 29 OR 31

Gizzard shad 7.50 6.30 3.53 2.18 3.45 4.12 2.94 2.61 2.74 6.98 4.51 3.23 5.36 4.14 

Emerald shiner 7.13 3.99 1.77 2.34 3.93 3.99 1.69 6.85 6.96 1.08 1.49 1.72 2.46 1.26 

Common carp 2.07 2.23 2.19 1.18 2.23 2.30 2.30 2.11 1.79 2.76 2.46 1.99 1.20 1.71 

Bluegill 0.52 2.97 3.09 6.28 3.19 3.00 3.76 1.48 0.17 1.75 0.84 0.05 0.09 0.08 

Freshwater drum 1.44 0.67 0.56 0.34 0.82 0.97 0.91 1.86 1.46 1.50 0.95 1.26 1.22 0.97 

Largemouth bass 0.05 1.43 1.21 2.66 1.88 2.27 2.24 1.22 0.12 1.23 0.26 0.00 0.04 0.02 

Spotfi n shiner 1.91 1.06 1.12 2.62 1.18 1.14 0.21 1.21 1.53 0.00 0.10 0.08 0.00 0.00 

Bullhead minnow 1.16 0.75 0.89 3.08 2.03 1.46 0.89 0.81 0.36 0.11 0.13 0.00 0.01 0.02 

White bass 1.45 0.63 0.39 0.45 0.76 0.76 0.41 0.89 0.72 1.63 0.49 0.69 0.72 0.46 

Channel catfi sh 0.26 0.09 0.12 0.09 0.58 0.69 0.38 1.77 0.55 1.17 0.71 0.74 0.83 0.69 

Black crappie 0.08 0.92 0.90 0.95 0.43 1.14 1.01 0.10 0.08 0.37 0.06 0.02 0.00 0.00 

Smallmouth buffalo 0.22 0.20 0.15 0.23 0.84 0.24 0.12 0.22 0.63 1.68 0.59 0.08 0.42 0.40 

Shorthead redhorse 0.82 1.16 1.18 0.91 0.55 0.28 0.12 0.13 0.07 0.12 0.06 0.08 0.04 0.00 

Smallmouth bass 0.92 0.73 0.98 0.65 0.46 0.06 0.18 0.10 0.05 0.00 0.00 0.01 0.02 0.00 

Silver redhorse 0.14 0.84 1.09 0.84 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Bigmouth buffalo 0.02 0.10 0.19 0.00 0.42 0.41 0.15 0.13 0.00 1.05 0.16 0.01 0.17 0.10 

a

Samples were collected from June 15 through October 31, 2000. LG = La Grange Pool of the Illinois River. OR = Open River 

Reach. Note: Pools 29 and 31 are open river reaches. 

b

Common names for fi shes follow Robins et al. (1991).
6

Table 3. Surface area (hectares) of aquatic/geomorphic habitat variables as defi ned by the habitat needs assessment query 

tool for Upper Mississippi River Navigation Pools 4-26 and open river reaches (29, OR, 31).a

Area (ha) of aquatic/geomorphic habitat type

Pool MNC MCB TWZ SCH TCH TRC CFL CFS CIM TIS CTF TOC

4 1,093 448 12 463 2 97 10,320 1,567 408 1,848 8,438 24,695

5 337 536 22 278 0 59 155 733 2,178 863 6,025 11,187

8 627 603 21 510 1 30 1,125 1,573 4,024 2,966 3,478 14,957

12 596 1,506 26 740 20 4 401 545 864 1,446 1,645 7,794

13 1,569 1,141 20 789 105 32 1,242 1,902 3,556 2,414 8,494 21,262

14 561 2,127 22 599 4 24 668 0 0 1,357 3,107 8,470

19 1,350 5,273 30 1,527 1 93 868 1,282 1,069 2,297 14,033 27,823

20 574 1,728 39 545 4 200 23 0 0 786 4,829 8,727

26 1,467 2,875 28 1,483 14 51 409 0 245 2,530 18,663 27,764

a

Habitat variables were the main navigation channel (MNC), main channel border (MCB), tailwater (TWZ), 

secondary channel (SCH), tertiary channel (TCH), tributary channel (TRC), contiguous fl oodplain lake (CFL), 

contiguous fl oodplain shallow aquatic area (CFS), contiguous impounded area (CIM), terrestrial island (TIS), 

contiguous terrestrial fl oodplain (CTF), and total contiguous habitat area (TOC). Data were not available for 

Pool 3, La Grange Pool of the Illinois River, or open river reaches 29 and 31.

sources of habitat data available for comparisons 

were those measured directly in the fi eld with each 

electrofi shing collection (Table 1) and a suite of 

aquatic or geomorphic variables quantifi ed for 

the habitat needs assessment (HNA) query tool 

that were available for a subset of pools (Table 3; 

DeHaan et al. 2000; Koel 2001). For both sets of 

habitat variables, normalized (mean = 0, standard 

deviation = 1) Euclidean distance matrices were 

calculated and Mantel tests were used to determine 

correlations with both the Euclidian matrix from 

fi sh community composition data and the BrayCurtis similarity matrix from community structure 

data. A canonical Mantel test (Clarke and Warwick 

1994; BioEnv procedure in Primer-E LTD 2001) 

was used to determine the combination of habitat 

variables that would provide the greatest correlation 

with community data. Because many habitat 

variables can co-vary with latitude, we included 

distance in river miles (relative to Navigation 

Pool 3) in both habitat data sets to help determine 

whether correlations with habitat refl ect covariation 

with the distance between pools. For La Grange 

Pool, distance was the sum of river miles between 

Pools 3 and 26, and river miles between Pool 26 

and La Grange Pool. We also used a Mantel test 

to examine whether habitat similarity (normalized 

Euclidian distance matrix for all habitat features 

measured in the fi eld) was correlated with distance 

between pools.

Results

Electrofi shing

A total of 118,139 fi shes were collected 

comprising 100 species (Table 4). The species 

with the greatest overall abundance were gizzard 

shad, emerald shiner, bluegill, and common carp, 

which together accounted for over 71% of the total 

catch. The mean number of species captured in a 

pool was 49, ranging from 38 to 60. Rarefaction 

curves suggest that sampling suffi cient to collect 

at least 5,000 fi shes is needed to do an adequate 

job of describing community composition within 

a given pool or reach (Figure 2). Because fewer 

than 5,000 fi shes were collected from several of the 

outpools (Figure 3), we rejected any subgrouping 

level that isolated these undersampled pools in our 

cluster analysis of community composition and 

community structure data.
7

Table 4. Total number of individuals captured using boat electrofi shing from regional trend analysis pools and outpoolsa. 

Upper Mississippi River System Navigation Poolsb

Species 3 4 5 8 12 13 14 19 20 LG 26 29 Gizzard shad 7,802 7,539 2,954 868 895 1,385 711 149 375 7,806 2,947 478 Emerald shiner 7,479 7,487 3,158 942 2,136 2,121 526 2,896 1,772 788 1,121 167 Bluegill 57 746 1,268 2,375 691 630 966 254 8 1,164 564 17 Common carp 527 533 571 212 403 414 349 124 131 1,870 596 245 

Spotfi n shiner 625 298 413 1,437 178 143 16 60 108 0 107 1 Mimic shiner 47 173 15 1,076 616 568 48 85 60 0 0 0 Largemouth bass 3 240 232 572 242 376 270 81 8 573 47 0 Bullhead minnow 194 171 161 927 444 256 123 48 15 16 50 0 White bass 250 231 33 43 84 89 35 24 57 1,254 54 22 Freshwater drum 253 79 54 43 90 93 81 86 151 552 260 65 Orangespotted sunfi sh 8 1 0 5 379 363 261 55 3 37 407 2 Shorthead redhorse 128 323 259 482 115 76 40 3 2 22 6 1 River shiner 1 7 43 402 223 194 18 230 68 0 4 2 Smallmouth buffalo 22 23 16 16 76 16 7 8 71 766 79 2 Bigmouth buffalo 1 9 32 0 40 29 9 2 1 684 30 4 

Threadfi n shad 0 0 0 0 0 0 0 0 0 173 14 3 Channel catfi sh 28 10 10 6 48 68 29 58 18 317 90 47 

Smallmouth bass 155 176 211 158 58 13 17 4 4 1 0 4 

Black crappie 7 130 158 100 30 104 96 21 2 154 8 5 Channel shiner 0 0 0 0 0 2 0 64 140 0 179 121 

Silver redhorse 12 175 221 198 1 4 16 0 0 1 0 0 

River carpsucker 15 6 7 1 16 36 100 5 29 109 31 13 

Golden redhorse 4 50 247 98 10 1 6 0 0 8 0 0 
8

Rock bass 11 93 137 155 20 3 2 0 0 0 0 0 Sauger 45 53 36 61 84 56 16 3 2 41 2 1 White crappie 11 12 6 6 112 35 101 7 1 80 16 1 Spotted sucker 0 60 119 85 27 19 21 3 0 0 0 0 Flathead catfi sh 25 14 14 14 21 10 14 23 30 76 32 26 Shortnose gar 7 1 0 6 8 9 5 7 20 43 67 36 Red shiner 0 0 0 0 0 0 0 1 17 10 3 50 Yellow perch 3 132 52 22 2 10 1 0 0 0 0 0 Walleye 35 35 44 24 16 18 34 0 2 2 2 0 Logperch 26 71 33 46 5 9 2 3 1 10 2 0 Skipjack herring 0 0 0 0 0 0 0 0 4 156 13 3 Brook silverside 0 7 13 20 40 52 5 0 0 6 8 8 Pugnose minnow 1 46 36 95 11 8 0 0 0 0 0 0 Golden shiner 0 0 4 67 40 71 7 1 0 4 0 0 Goldeye 0 0 0 0 1 0 0 0 1 0 3 106 Silver chub 38 12 1 0 21 18 14 8 2 16 33 0 Spottail shiner 1 9 30 32 26 24 24 1 0 0 0 0 Green sunfi sh 17 8 5 25 3 0 0 0 1 16 51 1 Silverband shiner 0 0 0 0 0 0 0 0 12 6 3 87 Grass carp 0 0 0 0 0 0 0 0 7 104 8 1 Johnny darter 5 7 7 77 13 1 5 0 0 0 0 0 Black buffalo 0 0 0 0 1 4 0 1 2 62 18 3 

Pumpkinseed 0 5 5 23 1 44 29 2 0 0 0 0 

Upper Mississippi River System Navigation Poolsb

Species 3 4 5 8 12 13 14 19 20 LG 26 29 

Table 4. Continued 
9

Spotted bass 0 0 0 0 0 0 0 0 0 0 0 22 Quillback 22 21 17 6 5 2 1 0 0 3 1 0 Longnose gar 5 6 3 9 11 7 4 4 17 6 3 0 Bowfi n 3 3 6 11 7 12 17 6 0 7 2 1 River redhorse 1 41 6 26 0 0 0 0 0 0 0 0 Northern pike 0 19 18 11 4 7 9 0 0 0 0 0 Blue sucker 2 6 6 1 3 0 0 0 46 0 1 0 Bighead carp 0 0 0 0 0 0 0 0 3 57 0 0 Western mosquitofi sh 0 0 0 0 0 0 0 0 4 3 50 0 Yellow bass 0 0 0 2 0 5 1 0 0 41 0 0 Warmouth 0 0 0 1 3 4 6 2 0 19 14 0 Silver carp 0 0 0 0 0 0 0 0 2 37 0 1 Mooneye 0 12 1 3 1 1 2 1 2 0 0 10 Sand shiner 1 3 0 3 0 0 0 18 24 0 11 0 Silver lamprey 5 3 14 5 4 1 0 0 0 0 0 0 Blue catfi sh 0 0 0 0 0 0 0 0 0 0 0 6 Weed shiner 0 0 0 26 0 0 0 0 0 0 0 0 Highfi n carpsucker 0 0 0 1 18 0 2 0 1 2 0 0 Goldfi sh 0 0 0 0 0 0 0 0 0 23 0 0 Slenderhead darter 4 4 3 3 0 0 0 1 1 1 0 0 Bluntnose minnow 11 0 0 0 0 0 1 0 0 1 0 0 Inland silverside 0 0 0 0 0 0 0 0 0 0 0 2 Spotted gar 0 0 0 0 0 0 0 0 0 6 5 0 

Upper Mississippi River System Navigation Poolsb

Species 3 4 5 8 12 13 14 19 20 LG 26 29 

Table 4. Continued 
10

Mud darter 0 0 1 8 1 0 2 0 0 0 0 0 Yellow bullhead 0 0 0 0 0 0 2 0 0 10 0 0 Chestnut lamprey 0 1 1 2 0 0 1 0 0 0 0 1 Fathead minnow 2 0 0 5 3 0 0 0 0 0 0 0 Miss. silvery minnow 0 0 0 0 0 6 2 0 0 0 0 0 American eel 0 0 0 0 0 0 0 0 0 0 0 1 Tadpole madtom 0 0 0 3 3 1 1 1 0 0 1 0 White sucker 0 3 3 2 1 0 0 0 0 0 0 0 Black bullhead 0 1 0 0 1 0 0 0 0 6 0 0 Blacktail shiner 0 0 0 0 0 0 0 0 0 0 0 0 Blackstripe topminnow 0 0 0 0 0 0 0 0 0 2 0 0 River darter 0 0 0 1 1 0 1 1 1 0 0 1 Western sand darter 0 0 2 3 0 0 0 0 1 0 0 0 Burbot 4 1 0 0 0 0 0 0 0 0 0 0 Grass pickerel 0 0 0 0 3 0 1 0 0 1 0 0 Paddlefi sh 0 0 0 0 0 0 0 0 3 0 0 0 Redear sunfi sh 0 0 0 0 0 0 0 0 0 4 0 0 Freckled madtom 0 0 0 0 0 0 0 2 0 0 0 0 Longear sunfi sh 0 0 0 0 0 0 0 0 0 0 0 0 

Stonecat 0 0 0 0 0 0 1 0 0 0 0 0 

Brown bullhead 0 0 0 0 0 0 0 0 0 2 0 0 Blackspotted topminnow 0 0 0 0 0 0 0 0 0 0 0 0 Central munminnow 0 0 0 2 0 0 0 0 0 0 0 0 

Upper Mississippi River System Navigation Poolsb

Species 3 4 5 8 12 13 14 19 20 LG 26 29 

Table 4. Continued 
11

Speckled chub 0 0 0 0 0 0 0 2 0 0 0 0 Trout perch 2 0 0 0 0 0 0 0 0 0 0 0 Banded darter 0 1 0 0 0 0 0 0 0 0 0 0 Brook stickleback 0 0 0 1 0 0 0 0 0 0 0 0 Blackside darter 0 0 0 1 0 0 0 0 0 0 0 0 Striped bass 0 0 0 0 0 0 0 0 0 0 0 1 Striped mullet 0 0 0 0 0 0 0 0 0 0 0 0 Species richness 46 52 49 60 56 49 53 43 46 55 44 40 Total catch 17,905 19,097 10,686 10,855 7,296 7,418 4,058 4,357 3,228 17,165 6,943 1,568 Total samples 72 83 84 72 63 63 51 21 31 126 77 25 

aSamples were collected from June 15 through October 31, 2000. bLG = La Grange Pool of the Illinois River. OR = Open River Reach. Note: Pools 29 and 31 are open river reaches. Common names for fi shes follow R*The shaded bars are intended only as an aid to reading the table. 

Upper Mississippi River System Navigation Poolsb

Species 3 4 5 8 12 13 14 19 20 LG 26 29 

Table 4. Continued 
12

Figure 2. Rarefaction curves from electrofi shing data for the six regional trend analysis pools in 2000. At least 5,000 

individuals, it seems, should be sampled to adequately describe fi sh community composition (i.e., to reach the rarefaction 

curve asymptote). 

Figure 3. The total number of fi sh captured by electrofi shing from the six regional trend analysis pools and eight outpools 

during 2000. The horizontal line depicts the minimum number of individuals (5,000) needed to be sampled to adequately 

describe community composition (see Figure 2).
13

Cluster analysis of community composition 

data revealed two major groupings of pools: upper 

and lower pools (Figure 4A). Twenty-eight species 

were captured only within lower pools and 18 only 

within upper pools. The average Euclidian distance 

between consecutive years at an RTA pool was 

3.60, and ranged from 3.16 to 4.47. Therefore, we 

chose 5.0 as our subgrouping distance, resulting 

in four subgroups: all upper pools, La Grange 

Pool, the Open River Reach and Pools 29 and 

31, and Pools 19, 20, and 26 (Figure 4A). These 

four groups were illustrated by NMDS in three 

dimensions with a stress value = 0.02 (Figure 4B). 

Analysis of similarity revealed signifi cant 

differences between the two major groupings 

(Global R = 0.83; P = 0.001), and among the four 

subgroups (Global R = 0.95; P = 0.001). 

As with community composition, cluster 

analysis based on community structure of fi shes 

revealed two major subgroups of pools, upper 

and lower. In this analysis, however, Pools 19 and 

20 grouped with the upper pools rather than the 

lower pools (Figure 5A). Six species accounted 

for more than 70% of the dissimilarity between 

upper and lower pool groupings. Upper pools were 

characterized by greater abundance of emerald 

shiner, bluegill, largemouth bass, bullhead minnow, 

and spotfi n shiner relative to lower pools. Lower 

pools had greater abundance of gizzard shad 

compared with upper pools.

The mean Bray-Curtis similarity value for 

consecutive years in RTA pools was 85.7 (range 

from 74.4 to 92.6; Figure 5A). We chose a 

Figure 4. (A) Cluster analysis 

of fi sh community composition 

data collected through 

electrofi shing. The lower solid 

line and two dashed lines 

indicate the mean and range 

of Euclidean distance for 

consecutive years in regional 

trend analysis pools. The 

upper solid line indicates the 

subgrouping level (Euclidean 

distance of 5) resulting in four 

subgroups (circled). 

(B) Nonmetric multidimensional 

scaling plot of Upper 

Mississippi River System in 

three dimensions. The four 

subgroups from the cluster 

analysis are circled. 
14

The mean Bray-Curtis similarity value for 

consecutive years in RTA pools was 85.7 (range 

from 74.4 to 92.6; Figure 5A). We chose a 

Bray-Curtis value of 70 for our subgrouping 

distance, producing fi ve subgroups: Pools 26, 

29, and 31 and the Open River Reach (subgroup 

A); La Grange Pool (subgroup B); Pools 3, 19, 

and 20 (subgroup C); Pools 4, 5, 12, 13, and 

14 (subgroup D); and Pool 8 (subgroup E). 

Nonmetric multidimensional scaling illustrates 

these fi ve subgroups in three dimensions with a 

stress value = 0.03 (Figure 5B). Eleven species 

contributed more than 70% to the dissimilarity 

among subgroups (Table 5). Pool 8 (subgroup 

E) had the greatest abundance of black crappie, 

bullhead minnow, bluegill, largemouth bass, and 

spotfi n shiner. La Grange Pool (subgroup B) 

had the greatest abundance of bigmouth buffalo, 

common carp, smallmouth buffalo, and white bass. 

Subgroup C had the greatest abundance of emerald 

shiner and freshwater drum. Analysis of similarity 

revealed signifi cant differences between upper and 

lower pool groupings (Global R = 0.67; P = 0.001) 

and among the fi ve subgroups (Global R = 99; 

P = 0.001).

Habitat Correlations

Strong correlations between community 

composition (r = 0.80) and structure (r = 0.63) 

Figure 5. (A) Cluster analysis 

of fi sh community structure 

data collected through 

electrofi shing. The lower solid 

line and two dashed lines 

indicate the mean and range 

of Bray-Curtis similarity for 

consecutive years in regional 

trend analysis pools. The 

upper solid line indicates the 

subgrouping level (Bray-Curtis 

similarity = 70) resulting in fi ve 

subgroups (circled). 

(B) Nonmetric multidimensional 

scaling plot of Upper 

Mississippi River System in 

three dimensions. The fi ve 

subgroups from the cluster 

analysis are circled. 
15

matrices with distance between pools suggest 

that fi sh communities in relatively close pools 

are more similar than pools separated by larger 

distances (Figures 6A–6B). Also, habitat similarity 

was correlated (r = 0.74) with distance between 

pools (Figure 6C) and most of the habitat variables 

measured during electrofi shing sampling showed 

longitudinal variation (Figure 7). These habitat 

variables were signifi cantly correlated with both 

community composition (r = 0.75; P = 0.0001) 

and community structure (r = 0.64; P = 0.0010). 

The canonical Mantel procedure revealed 

that the strongest correlations (r = 0.90) with 

community composition were with a habitat matrix 

composed of distance between pools, water depth, 

conductivity, vegetation density, and the frequency 

of woody structure presence. The strongest 

correlations (r = 0.73) for community structure 

were with a habitat matrix composed of distance 

between pools, fl ow, vegetation density, frequency 

of woody structure presence, and the frequency of 

fl ooded terrestrial vegetation presence. Note that 

these correlations are only marginal improvements 

over correlation with distance between pools alone.

Mantel tests revealed signifi cant correlations 

between HNA variables with both community 

composition (r = 0.46; P = 0.0083) and community 

structure (r = 0.37; P = 0.0225). Nevertheless, 

correlations with distance between pools alone 

were stronger (r = 0.79; r = 0.69) and the canonical 

Mantel procedure was unable to add any HNA 

habitat variables that could more than trivially 

improve these correlations. 

Seining

A total 115,820 fi shes from 81 species were 

captured. The species with the greatest overall 

abundance were emerald shiner, mimic shiner, 

river shiner, bluegill, bullhead minnow, and gizzard 

shad. Together, these six species accounted for 

over 80% of the total catch. Cluster analysis of 

seining data revealed two major groupings of 

pools: upper (4, 8, 12, 13, and 14) and lower pools 

(26, La Grange, and Open River Reach; Figure 8A). 

These two groupings were illustrated in two 

dimensions by NMDS with a stress value = 0.01 

(Figure 8B). Of the 81 species captured, 13 species 

were captured only in the lower pools and 30 only 

in the upper pools. Nevertheless, several of the 

species captured only in the upper pools, including 

bigmouth buffalo, bowfi n, quillback, and walleye, 

are known to be established in the lower pools. 

Thus, at least some of the difference in community 

composition between upper and lower pools 

refl ects sampling artifacts. 

Table 5. Mean abundance (square root # / 15 min) of the 11 species that contributed more than 70% to the dissimilarity among pool 

subgroups identifi ed through cluster and non-metric multidimensional scaling analysis of electrofi shing community structure data. 

Subgroups and UMRS Pools

Speciesb

A

26–31

B

La Grange

C

3, 19, 20

D

4, 5, 12 , 13, 14

E

8

Black crappie 0.02 0.37 0.09 0.88 0.95a

Bluegill 0.26 1.75 0.72 3.20 6.28

Bigmouth buffalo 0.11 1.05 0.05 0.25 0.00

Bullhead minnow 0.04 0.11 0.78 1.20 3.08

Common carp 1.84 2.76 1.99 2.25 1.18

Emerald shiner 1.73 1.08 6.98 3.07 2.34

Freshwater drum 1.10 1.50 1.59 0.79 0.34

Gizzard shad 4.31 6.98 4.28 4.07 2.18

Smallmouth buffalo 0.37 1.68 0.35 0.31 0.23

Spotfi n shiner 0.04 0.00 0.94 0.94 2.62

White bass 0.59 1.63 1.02 0.59 0.45

a

The maximum abundance for each species are in bold.

b

Common names for fi shes follow Robins et al. (1991).
16

Figure 6. Relations between the distance between pools (river miles) with (A) community structure of fi sh (Bray-Curtis similiarity), (B) 

community composition of fi shes (Euclidian distance), and (C) habitat composition (normalized Euclidian distance). Plotted are all possible 

pairwise comparisons among the six regional trend areas and outpools. 

B

C

A
17

Figure 7. Relation between water depth, fl ow, conductivity, vegetation density, presence of woody structure, and presence of fl ooded terrestrial 

vegetation with river mile (relative to Pool 3). All habitat measures were collected at the electrofi shing sites sampled in 2000. 
18

Discussion

Our analysis of both the community 

composition and community structure of fi shes 

in the UMRS each yielded two major pool 

groups, upper and lower. Two previous studies 

also classifi ed UMRS pools into upper and 

lower reaches based on habitat variables (U.S. 

Geological Survey 1999; Koel 2001). It is likely 

that geographic range limitations of fi shes, habitat 

factors, and possibly historical barriers have all 

infl uenced the fi sh composition and community 

structure differences between upper and lower 

pools. Our analysis also revealed four or fi ve 

subgroups of pools. Based on the strength of our 

analysis of similarity tests (i.e., Global R values) 

and NMDS plots, these subgroupings may present 

a more accurate description of the similarity of 

community composition and structure among 

the UMRS pools sampled. Although there were 

clear differences between the upper and lower 

pool groups based on community structure and 

community composition, it is clear that more 

spatial structure exists in this system than a simple 

dichotomy of upper and lower pools. 

Results from this study should be interpreted 

with caution because the data available for analysis 

were limited to 1 year (covariation of communities 

cannot be addressed) and essentially one sampling 

Figure 8. (A) Cluster analysis 

of fi sh community composition 

data collected through seining. 

Major pool groupings (upper and 

lower) are noted. (B) Nonmetric 

multidimensional scaling plot 

and stress value for Upper 

Mississippi River System pools in 

two dimensions. The two major 

groups from the cluster analysis 

are easily identifi able. 
19

gear, an electrofi shing boat. Lubinski et al. (2001) 

reported that among all gears used in the LTRMP, 

electrofi shing generally had the greatest statistical 

power to detect trends across all species and habitat 

types. Nevertheless, boat electrofi shing does not 

sample all species within the UMRS equally 

well. For example, electrofi shing is conducted 

near the shoreline and will not be effective for 

species that primarily occupy offshore habitats. 

Because of the limitations of boat electrofi shing, 

seining was included in the plans for this study to 

provide additional information on the small fi sh 

community. Unfortunately, we found seining to be 

logistically untenable to conduct in all outpools, 

but the limited seining data collected showed 

major pool groupings (upper and lower pools) 

consistent with our analysis of electrofi shing data. 

Given the vast spatial extent of the UMRS and the 

great diversity of habitat types and fi sh species it 

contains, it is unlikely that any single study could 

fully address both the patterns and causes of spatial 

variation of fi sh communities within this system. 

We feel the present study provides a useful fi rst 

step in addressing this issue.

In general, outpools tended to group with 

adjacent RTA pools. Outpools 5, 12, 14, 29, 

and 31 were within the same subgroups as 

their adjacent RTA pools (4, 13, and the Open 

River Reach). These results, and our habitat 

correlation analysis, suggest a strong negative 

relation between the distance among pools and 

similarity of fi sh community composition and 

structure. In other words, our results suggest fi sh 

communities in adjacent UMRS pools and reaches 

tend to be similar. The exception to this trend, 

the subgrouping of outpools 3, 19, and 20 in our 

community structure analysis, may have arisen as a 

result of similarity in habitat features or low sample 

sizes in Pools 19 and 20. La Grange Pool was a 

unique subgroup for both community composition 

and structure analyses, which was an expected 

result for this tributary RTA pool. Pool 8 was a 

unique subgroup in terms of community structure. 

This RTA pool had the greatest abundance of 

centrarchid species, which may be related to the 

relatively greater abundance of aquatic vegetation 

found in this pool (Figure 7). 

Our attempts to correlate spatial variation of 

fi sh communities with habitat data were hindered 

by the confounding of habitat similarity and 

distance between pools. Both the composition 

and community structure of fi shes should vary 

as a function of distance between pools because 

of zoogeography, immigration and emigration, 

source-sink dynamics and similar histories of 

large scale disturbances such as major fl oods and 

droughts (Drake 1990, 1991; Hamrick and Nason 

1996; Pullium 1996). Because habitat similarity 

was also correlated with distance between pools, 

it is diffi cult to determine the infl uence of habitat 

on fi sh communities independent of the spatial 

demographic processes listed above. To gain a 

better understanding of the infl uence of habitat 

on fi sh communities, future studies could attempt 

to account for both spatial proximity and habitat 

variation by selecting pairs of study pools that are 

relatively close together, but differ substantially 

in specifi c habitat measures. Also, future analyses 

could devise an index of historic habitat alterations 

for each RTA and outpool to assess if fi sh 

community variation correlates with this index. 

This study was not able to resolve where 

Navigation Pools 19 and 20 fi t within the UMRS 

as a whole. Pools 19 and 20 were similar to lower 

pools in terms of community composition, but 

similar to upper pools with regard to community 

structure. Electrofi shing collections from Pools 

19 and 20 differed from all other pools in that all 

data were collected over a period of 2 days, rather 

than over a period of 5 months. It is interesting, 

however, that Pools 19 and 20 grouped together 

in both the community composition and structure 

analyses because Lock and Dam 19 is known to 

be a barrier to migratory fi shes such as skipjack 

herring (Kelner and Seitman 2000). Despite 

this barrier, this study suggests the overall fi sh 

communities with Pools 19 and 20 are relatively 

similar. An important caveat to this study is that 

only three UMRS pools below Pool 14 were 

sampled (19, 20, and 26), whereas seven upper 

UMRS pools were sampled (3, 4, 5, 8, 12, 13, and 

14). Studies including a greater number of lower 

UMRS pools might improve our understanding of 

spatial variation of fi sh communities.
20

Implications for Long Term Resource 

Monitoring Program and Future Studies

Current RTA areas are evenly distributed within 

the major pool groupings identifi ed in this study 

(i.e., three RTA areas in upper pool group, three 

RTA areas in the lower group), which supports the 

premise that LTRMP fi sheries data can be used to 

make inferences to the entire UMRS. Subgroupings 

of outpools with nearby RTA pools and the 

importance of distance between pools in habitat 

correlations suggest that fi sh community data from 

RTA pools should at least be relevant to other 

nearby UMRS pools. Furthermore, these results 

suggest that expanding LTRMP fi sh monitoring to 

pools adjacent to current RTA areas would yield 

minimal additional information. Further research 

is needed to resolve how fi sh communities within 

Navigation Pools 19 and 20 and other lower UMRS 

pools compare to current RTA areas. Future studies 

in this area should (1) address covariation of 

community measures through time, (2) examine 

additional pools and reaches in the lower portion 

of the system, and (3) further examine relations 

between fi sh communities and habitat features 

using experimental designs that specifi cally 

account for the confounding of habitat similarity 

and distance between pools.

References

Clarke, K. R. and R. M. Warwick. 1994. Change in 

marine communities: an approach to statistical 

analysis and interpretation. Plymouth Marine 

Laboratories, Plymouth, United Kingdom.

DeHaan, H. C., T. J. Fox, C. E. Korschgen, 

C. H. Theiling, and J. J. Rohweder. 2000. 

Habitat needs assessment GIS query tool for 

the Upper Mississippi River users manual. 

U.S. Geological Survey, Upper Midwest 

Environmental Sciences Center, La Crosse, 

Wisconsin. 96 pp.

Drake, J. A. 1990. Communities as assembled 

structures: do rules govern patterns? Trends in 

Ecology and Evolution 5:159–164.

Drake, J. A. 1991. Community assembly mechanics 

and the structure of an experimental species 

ensemble. American Naturalist 137:1–26.

Gutreuter, S., R. Burkhardt, and K. Lubinski. 1995. 

Long Term Resource Monitoring Program 

procedure: fi sh monitoring. National Biological 

Service, Environmental Management Technical 

Center, Onalaska, Wisconsin. LTRMP 95-

P002-1. 42 pp + Appendixes A–J.

Hamrick, J. L., and J. D. Nason. 1996. 

Consequences of dispersal in plants. Pages 

203–236 in O. E. Rhodes, R. K. Chesser, and 

M. H. Smith, editors. Population dynamics in 

ecological space and time. The University of 

Chicago Press, Chicago. 

Kelner, D E., and B. E. Seitman. 2000. Relic 

populations of the ebony shell, Fusconaia 

ebena (Bivalvia : Unionidae), in the upper 

Mississippi River drainage. Journal of 

Freshwater Ecology 15:371–377.

Koel, T. M. 2001. Classifi cation of Upper 

Mississippi River pools based on contiguous 

aquatic/geomorphic habitats. Journal of 

Freshwater Ecology 16:159–170.

Levin, S. A. 1992. The problem of pattern and 

scale in ecology. Ecology 73:1943–1967.

Lubinski, K, R. Burkhardt, J. Sauer, D. Soballe, 

and Y. Yin. 2001. Initial analyses of change 

detection capabilities and data redundancies in 

the Long Term Resource Monitoring Program. 

U.S. Geological Survey, Upper Midwest 

Environmental Sciences Center, La Crosse, 

Wisconsin, September 2001. LTRMP 2001-

T001. 23 pp + Appendixes A–E.

Primer-E LTD. 2001. Primer for Windows Version 

5.2.4. Plymouth Marine Laboratory, Plymouth, 

United Kingdom.

Pullium, H. R. 1996. Sources and sinks: empirical 

evidence and population consequences. Pages 

45–69 in O. E. Rhodes, R. K. Chesser, and 
21

M. H. Smith, editors. Population dynamics in 

ecological space and time. The University of 

Chicago Press, Chicago. 

Robins, C. R., R. M. Bailey, C. E. Bond, J. R. 

Brooker, E. A. Lachner, R. N. Lea and W. B. 

Scott. 1991. Common and scientifi c names of 

fi shes from the United States and Canada. 5th 

edition. Special Publication (20). American 

Fisheries Society, Bethesda, Maryland. 183 pp.

SAS Institute, Inc. 1999. The SAS System for 

Windows. Release 8.01. Cary, North Carolina.

U.S. Army Corps of Engineers. 1997. Upper 

Mississippi River System - Environmental 

Management Program Report to Congress. 

Public Review Draft.

U.S. Geological Survey. 1999. Ecological status 

and trends of the Upper Mississippi River 

System 1998: A report of the Long Term 

Resource Monitoring Program. U.S. Geological 

Survey, Upper Midwest Environmental 

Sciences Center, La Crosse, Wisconsin. April 

1999. LTRMP 99-T001. 236 pp.

Wiens, J. A. 1989. Spatial scaling in ecology. 

Functional Ecology 3:385-397.

23

REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

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Washington, D.C. 20503

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE

January 2004

3. REPORT TYPE AND DATES COVERED

4. TITLE AND SUBTITLE Long Term Resource Monitoring Program Outpool Fisheries Analysis 5. FUNDING NUMBERS

6. AUTHOR(S) John H. Chick1 and Mark A. Pegg2

7. PERFORMING ORGANIZATION NAME AND ADDRESS

1

Illinois Natural History Survey, Great Rivers Field Station, 8450 Montclair Avenue, Brighton, Illinois 62012

2

Illinois Natural History Survey, Illinois River Biological Station, 704 North Schrader, Havana, Illinois 62644

8. PERFORMING ORGANIZATION

 REPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

 U.S. Geological Survey 

 Upper Midwest Environmental Sciences Center

 2630 Fanta Reed Road

 La Crosse, Wisconsin, 54603

10. SPONSORING/MONITORING

 AGENCY REPORT NUMBER

2004-T001

11. SUPPLEMENTARY NOTES

12a. DISTRIBUTION/AVAILABILITY STATEMENT

Release unlimited. Available from National Technical Information Service, 5285 Port Royal Road, Springfi eld, VA 22161 (1-

800-553-6847 or 703-487-4650). Also available to registered users from the Defense Technical Information Center, Attn: Help 

Desk, 8725 Kingman Road, Suite 0944, Fort Belvoir, VA 22060-6218 (1-800-225-3842 or 703-767-9050).

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words) 

Abstract: This study was designed to assess whether fi sh community data collected for the Long Term Resource Monitoring Program (LTRMP) from six regional trend 

analysis (RTA) areas of the Upper Mississippi River System (UMRS) can be used to make inferences to the system as a whole. Spatial coverage of fi sh monitoring for three 

LTRMP fi eld stations was extended to “outpools” immediately above and below RTA pools 4 and 13 and the Open River Reach from June 15 to October 31, 2000. Also, we 

sampled Navigation Pools 19 and 20 using LTRMP electrofi shing methodology in September 2000. Multivariate statistical analyses were used to group pools on the basis of 

fi sh community composition and community structure. Cluster analysis of community composition and structure data revealed two major groups of pools: upper pools (i.e., 

northern) and lower pools (i.e., southern). 

14. SUBJECT TERMS

Analysis, fi sh community, LTRMP, Mississippi River, navigation pool, trend analysis, UMRS 

15. NUMBER OF PAGES

 28 pp.

16. PRICE CODE

17. SECURITY CLASSIFICATION

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19. SECURITY CLASSIFICATION

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20. LIMITATION OF ABSTRACT
.

The Long Term Resource Monitoring Program (LTRMP) for the Upper Mississippi River 

System was authorized under the Water Resources Development Act of 1986 as 

an element of the Environmental Management Program. The mission of the LTRMP 

is to provide river managers with information for maintaining the Upper Mississippi 

River System as a sustainable large river ecosystem given its multiple-use character. 

The LTRMP is a cooperative effort by the U.S. Geological Survey, the U.S. Army Corps 

of Engineers, and the States of Illinois, Iowa, Minnesota, Missouri, and Wisconsin.