**FINAL BIOLOGICAL OPINION**

**FOR THE UPPER MISSISSIPPI RIVER-ILLINOIS**

**WATERWAY SYSTEM NAVIGATION**

**FEASIBILITY STUDY**

**AUGUST 2004**

Prepared by:

U.S. Fish and Wildlife Service

Rock Island Field Office, Rock Island, Illinois

Marion Suboffice, Marion, Illinois

Twin Cities Field Office, Bloomington, Minnesota

**BIOLOGICAL OPINION FOR THE UPPER MISSISSIPPI RIVER-ILLINOIS WATERWAY
SYSTEM NAVIGATION FEASIBILITY STUDY**

**SUMMARY OF FINDINGS**

In this Biological Opinion, the US Fish and Wildlife Service
(Service)has determined that implementation of the recommended plan
(project) described in the Draft Integrated Feasibility Report and
Programmatic Environmental Impact Statement (EIS) for the Upper
Mississippi River-Illinois Waterway System Navigation Feasibility Study,
dated April 29, 2004, will not jeopardize the continued existence of the
Indiana bat (*Myotis sodalis*), decurrent false aster (*Boltonia
decurrens*), pallid sturgeon (*Scaphirynchus albus*) and Higgins eye
pearlymussel (*Lampsilis higginsii*), but will result in incidental take
of these species. Because it is a plant, take of decurrent false aster
is not prohibited. However, Federal regulations prohibit any commercial
activity involving this species or the destruction, malicious damage or
removal of this species from Federal land or any other lands in knowing
violation of State law or regulation

By letter dated May 28, 2004 the Service concurred with the Biological
Assessment findings that the project is not likely to adversely affect
the bald eagle (*Haliaeetus leucocephalus*), interior least tern
(*Sterna antillarum*), or winged mapleleaf (*Quadrula fragosa*), because
project impacts either will be offset by management actions proposed by
the Corps, or will be negligible.

The subject Feasibility Report states that the overall goal of the
project is articulated in a vision statement defined by Upper
Mississippi River System (UMRS) stakeholders: "To seek long-term
sustainability of the economic uses and ecological integrity of the
Upper Mississippi River System". To support that goal, four additional
ecosystem-specific goals were adopted: 1) maintain viable populations of
native species in situ, 2) represent all native ecosystem types across
their natural range of variation, 3) restore and maintain evolutionary
and ecological processes, and 4) integrate human use and occupancy
within these constraints. This consultation was conducted by an
interagency team which recognized that actions to achieve these goals
will alternately favor and disfavor the species subject to this
consultation, resulting in take where noted, but that the recommended
plan should in the long term contribute to improved ecological integrity
of the UMRS.

The Service considered including the spectacle case (*Cumberlandia
monodonta*) and sheepnose mussel (*Plethobasus cyphyus*), which are
candidate species, in this biological opinion. However, because there is
no listing proposal at this time, they were not included in this
opinion. When they are proposed for listing, the Service will enter into
formal conference with the Corps, as appropriate.

**TABLE OF CONTENTS\
**

BACKGROUND 1

SPECIES COVERED IN THIS CONSULTATION 2

CONSULTATION hISTORY 3

BIOLOGICAL OPINION 5

[1.0 Description of the Proposed Action 5](#__RefHeading___Toc77735368)

**2.0 Indiana bat 12**

**3.0 Decurrent false aster 41**

**4.0 Higgins eye pearlymussel 57**

**5. 0 Pallid sturgeon 90**

**REINITIATION - CLOSING STATEMENT 141**

**Background**

This programmatic (Tier I) consultation considers the systemic impacts
of implementing the recommended plan (project) described in the Draft
Integrated Feasibility Report and Programmatic EIS for the Upper
Mississippi River-Illinois Waterway System Navigation Feasibility Study,
dated April 29, 2004 (USACE 2004a), on listed species as projected over
a 50 year period of analysis. This consultation follows the Final
Biological Opinion for the Operation and Maintenance of the 9-Foot
Navigation Channel on the Upper Mississippi River System (O&M BO),
prepared for Tier I consultation on the effects of operating and
maintaining the existing navigation system. Operation and maintenance of
the navigation system includes impoundment, water level regulation,
dredging and disposal, clearing and snagging, channel \[regulating\]
structures and revetment, tow traffic, fleeting, port facilities, exotic
species, contaminants, recreation, cabin leases; and General Plan Lands
management.

This consultation utilizes a tiered consultation framework with the
consultation resulting in a Tier I biological opinion. All subsequent
projects will be Tier II consultations with Tier II biological opinions
issued as appropriate (i.e., whenever the proposed project will result
in unavoidable adverse effects to threatened and endangered species).
The Tier I Biological Assessment (BA) (USCAE 2004b) and Biological
Opinion (BO) evaluate the effects to listed species at the program or
ecosystem level, and are intended to clarify any effects that may be
insignificant at the site-specific level, but in totality may be
substantial, rise to the level of incidental take, or result in jeopardy
or adverse modification of critical habitat. Specifically, the Tier I
consultation 1) evaluates how the goals of the project will alter
current environmental conditions during and following completion of the
project and how these anticipated changes in environmental conditions
will affect threatened and endangered species occurring within the
action area and 2) assesses whether the future site-specific actions
that are required to meet the project goals will have the potential to
adversely affect individuals within the action area. The Tier II
consultations will evaluate the specific effects that are likely to
occur when a future action is proposed.

To ensure that the exemption of incidental take is appropriately
documented, the Corps of Engineers (Corps) and the Service will
implement a tiered programmatic consultation approach. As individual
projects are proposed under the recommended plan, the Corps shall
provide project-specific information to the Service that 1) describes
the proposed action and the specific area to be affected, 2) identifies
the species that may be affected, 3) describes the manner in which the
proposed action may affect listed species, and the anticipated effects,
4) specifies whether the anticipated effects from the proposed project
are similar to those anticipated in the programmatic BO, 5) estimates a
cumulative total of take that has occurred thus far under the tier I BO,
and 6) describes any additional effects, if any, not considered in the
tier I consultation.

The Service will review the information provided by the Corps for each
proposed project. If it is determined during this review that a proposed
project is not likely to adversely affect listed species, the Service
will complete its documentation with a standard concurrence letter that
refers to this BO, the tier I programmatic document (i.e., it "tiers" to
it), and specifies that the Service concurs that the proposed project is
not likely to adversely affect listed species or designated critical
habitat. If it is determined that the proposed project is likely to
adversely affect listed species or designated critical habitat, then the
Service will complete a tier II BO with a project-specific incidental
take statement within the annual allotted programmatic incidental take.

This consultation was conducted by an interagency Corps of Engineers
(Corps) -- U.S. Fish and Wildlife Service (Service) Consultation Team
composed of representatives of the three Corps Districts (St. Paul,
Minnesota, Rock Island, Illinois, and St. Louis Missouri) and the three
Service Ecological Services Field Offices on the Upper Mississippi River
System (UMRS) (Twin Cities, Minnesota, Rock Island Illinois, and Marion,
Illinois). The Team members cooperated with each other in exchanging
information preparing and reviewing the BA and this BO. Each Team member
took responsibility for one or more species covered in the consultation.
Ultimate responsibility for the content of the Biological Assessment
rests with the Corps, and the ultimate responsibility for the content of
this BO rests with the Service.

The outline for the Biological Assessment was similar to that prepared
for the first referenced consultation and was proposed by the Corps to
ensure that all necessary topics would be addressed and that the need
for additional information would be minimized following completion of
the Assessment. The Corps developed an initial screening matrix in an
attempt to identify all of the potential impacts to listed species for
subsequent assessment.

Oversight of the consultation process was provided by the Service's
Field Office Supervisors and the Corps District Office staff. Conflict
resolution was the primary responsibility of the Field and District
offices. A set of ground rules was jointly developed by the two agencies
to guide the process.

**Species Covered in This Consultation**

This consultation covers the following species: bald eagle (*Haliaeetus
leucocephalus*), interior least tern (*Sterna antillarum*), Indiana bat
(*Myotis sodalis*), decurrent false aster (*Boltonia decurrens*), pallid
sturgeon (*Scaphirynchus albus*), Higgins eye pearlymussel (*Lampsilis
higginsi*), and winged mapleleaf mussel (*Quadrula fragosa*). During
informal consultation, the Interagency Corps-Service Consultation Team
concluded that the pink mucket pearlymussel (*Lampsilis abrupta*),
scaleshell mussel (*Leptodea leptodon*), and fat pocketbook mussel
(*Potamilis capax*) have been extirpated from the UMRS and need not be
addressed. By letter dated May 28, 2004, the Service concurred with the
Corps' findings in its Biological Assessment that the project may
adversely affect the decurrent false aster and pallid sturgeon. However,
the Service disagreed with the scope of adverse effects for the pallid
sturgeon, and did not concur with the Corps that the project would not
adversely affect the Indiana bat and Higgins eye pearlymussel.

The Service considered including the spectacle case (*Cumberlandia
monodonta*) and sheepnose mussel (*Plethobasus cyphyus*), which are
candidate species, in this biological opinion. However, because there is
no listing proposal at this time, they were not included in this
opinion. When they are proposed for listing, the Service will enter into
formal conference with the Corps.

**Consultation History**

July 2, 2003- First meeting with Corps to discuss BA approach and
anticipated schedule.

November 19, 2003 -- Corps transmits draft impacts matrix example for
discussion.

December 22, 2003 -- Corps transmits Navigation Improvement Effects
draft.

December 24, 2003 -- Corps transmits Restoration Measures draft

December 24, 2003 -- Service transmits email acknowledging receipt of
preconsultation material, anticipated review period, and intra-agency
distribution.

January 12, 2004 -- Facsimile receipt of Corps request for species list

January 16, 2004 -- Service provides species list facsimile to Corps.
Advised Corps regarding schedule, and suggested team approach similar to
that used for O&M BA.

January 16, 2004 -- Corps-Service telephone conference call to discuss
schedule request review completion date estimate and set meeting date.

February 11 and 12, 2004 -- Meeting at Rock Island Field Office to
discuss preliminary BA information and ground rules.

March 29, 2004 -- Corps- Service meeting to discuss schedule, delivers
first BA copy.

April 2, 2004 -- Service offices receive BA.

April 22, 2004 -- Service acknowledges receipt of the BA and provides
start date of April 2

April 19, 2004 --Telephone conference with Corps and Service to discuss
Not Likely to Adversely Affect and Likely to Adversely Affect
determinations.

May 28, 2004 -- Letter from Service outlining agreements and
disagreements with BA determinations.

June 3, 2004 -- Meeting with Corps at Twin Cities Field Office to
discuss Service position on determinations, analysis status, and
potential Reasonable and Prudent Measures (RPMs) and Terms and
Conditions.

June 14 and June 17,2004 - Service transmits preliminary draft sections
of the BO for the pallid sturgeon to the Corps for review and comment.

July 1, 2004 -- Service receives letter clarifying conservation measures
proposed for Indiana bats.

Ninety day consultation period ends.

July 2, 2004 - Service transmits preliminary draft sections of the
Biological Opinion for the Higgins eye pearlymussel to the Corps for
review and comment.

July 9. 2004 -- Service transmits preliminary draft Project Description
to the interagency team for review.

July 12, 2004 -- Telephone conference between the Corps and Service

July 13, 2004 -- Corps transmits comments on the project description and
preliminary Biological Opinion sections.

July 19, 2004 -- Corps --Service telephone conversation regarding
acreage estimates for Indiana bats.

August 9, 2004 - Service receives letter clarifying conservation
measures proposed for Indiana bats in response to additional interagency
coordination.

August 12, 2004 -- Draft Biological Opinion provided to the Corps for
review and comment.

August 18, 2004 -- Comments on Draft Biological Opinion received from
Corps.

August 27, 2004 - Final Biological Opinion delivered to the Corps.

**BIOLOGICAL OPINION**

**1.0 Description of the Proposed Action**

The Upper Mississippi River-Illinois Waterway System Navigation
Feasibility Study is an investigation addressing navigation system
improvement and ecological restoration needs for the Upper Mississippi
River and Illinois Waterway system for the years 2000-2050. For the
purpose of this consultation, the Service considers that the action area
includes the study area as described in the project Integrated
Feasibility Report and Programmatic Environmental Impact Statement. This
includes the Upper Mississippi River from Minneapolis, Minnesota to
Cairo Illinois; the Illinois River from Chicago to Grafton, Illinois;
and the navigable portions of the Minnesota, St. Croix, Black, and
Kaskaskia Rivers. The action area also includes those floodplain
portions of Illinois, Missouri, Iowa, Wisconsin and Minnesota bordering
these navigable waters, which totals over 2.6 million acres. As the
proposed actions affect pallid sturgeon populations in the lower
Missouri and lower Mississippi River reaches, the action area also
encompasses these river reaches (see section 5.2 for further
discussion).

This consultation focuses on the recommended plan described in the
Integrated Feasibility Report, and includes a combination of
administrative, operational, and physical construction actions directed
at upgrading the existing navigation system and restoring ecosystem
components associated with the navigation system in the study area. With
the enactment of new authority these actions would include Federal
policy changes, interagency coordinating mechanism or institutional
arrangement modifications, changes in operation of existing facilities,
manipulation of landcover types to change habitat features, and a suite
of construction activities for navigation feature improvement,
navigation structure modification, and ecosystem restoration. The
Integrated Feasibility Report Executive Summary contained the following
features in the recommended plan:

1\. Structural and nonstructural measures to include:

a.  Mooring facilities at Locks and Dams 12, 14, 18, 20, 22, 24 and
    LaGrange.

b.  Switchboats at Locks and Dams 20-25.

c.  New 1,200 foot locks at 20-25, La Grange, and Peoria.

d.  Lock extensions at Locks and Dams 14 through 18.

2\. Administrative measures to include:

a.  Adaptive implementation to include the following decision points and
    congressional oversight:

```{=html}
<!-- -->
```
1.  A notification report at the end of design and before construction
    contract award that presents any new information resulting from
    monitoring river traffic and markets, and the results of any
    improved models and analysis.

2.  An evaluation report upon the development and use of any new and
    widely accepted models concluding with a recommendation to Congress
    whether or not to stop, or delay lock construction.

3.  An updated feasibility report requiring additional authorization
    before proceeding with the final five locks.

```{=html}
<!-- -->
```
b.  Continued study and monitoring of the system to include:

```{=html}
<!-- -->
```
1.  Development of an appointment scheduling system.

2.  Development of a new spatial model.

3.  Collection of demand elasticity data.

4.  Monitoring of traffic delays and patterns.

5.  Monitoring of domestic and global grain market conditions, land use,
    crop yield technology, and developments in China regarding import
    trends.

```{=html}
<!-- -->
```
c.  Land acquisition from willing sellers, up to 35,000 acres for
    ecosystem restoration.

3\. Mitigation for site-specific impacts and system-wide fish
entrainment.

a.  Bank armoring and vegetative stabilization

b.  Regulating works modification.

c.  Reforestation and submerged aquatic vegetation planting

d.  Wood structure placement

e.  Gravel bar placement

f.  Backwater restoration

4\. Ecosystem restoration.

Although the period of analysis for the project is 50 years, the
Executive Summary described ecosystem restoration in the context of an
incremental approach, and outlined the first 15 year increment of the
Alternative D\* framework.

Table 1-1 provides the type and estimated number of ecosystem
restoration measures to be pursued over the entire analysis period and
the first 15 years. This table contains 8 general categories of measures
which subsume over 2300 individual actions recorded in the Environmental
Objectives Workshop report (USACE 2003).

Island building is recommended to address physical processes and restore
habitats lost to inundation and erosion following lock and dam
construction. Islands provide habitat diversity and reduce wind fetch
that generates waves, resuspends sediments and reduces water quality and
aquatic plant growth.

Fish passage, both lateral into the floodplain and longitudinal, is
recommended to restore habitat connectivity that was fragmented by
navigation system construction and floodplain development. Not all
riverine fish are strong swimmers, yet require access to a variety of
habitats to complete their life cycles. One native species, the American
eel, (*Anguilla rostrata*) is catadromous, meaning it must travel from
freshwater to salt water to spawn. Other native species are potadromous
and once traveled long distances in seasonal runs throughout the system
and tributaries. While fish passage may also benefit invasive aquatic
species, the general consensus of river fisheries biologists is that by
restoring access opportunities for all species, native species will be
better able to compete with non-native species.

**Table 1-1. Description of management measures included in the
recommended plan and first 15 year increment.**

+-------------------------------------+-------+------+-------+---------+
| **Management Measures**             | **A   |      | **15  |         |
|                                     | ltern |      | -year |         |
|                                     | ative |      | Impl  |         |
|                                     | D\*** |      | ement |         |
|                                     |       |      | ation |         |
|                                     |       |      | P     |         |
|                                     |       |      | lan** |         |
+-------------------------------------+-------+------+-------+---------+
|                                     | **N   | **   | **N   | **Area  |
|                                     | umber | Area | umber | of      |
|                                     | of**  | of   | of**  | Be      |
|                                     |       | B    |       | nefit** |
|                                     | **    | enef | **    |         |
|                                     | Proje | it** | Proje | **(a    |
|                                     | cts** |      | cts** | cres)** |
|                                     |       | **(  |       |         |
|                                     |       | acre |       |         |
|                                     |       | s)** |       |         |
+-------------------------------------+-------+------+-------+---------+
| **Adaptive Management**             |       |      |       |         |
+-------------------------------------+-------+------+-------+---------+
| **Cultural Res. Management &        |       |      |       |         |
| Mitigation**                        |       |      |       |         |
+-------------------------------------+-------+------+-------+---------+
| **Forest Management**               |       |      |       |         |
+-------------------------------------+-------+------+-------+---------+
| **Real Estate (35,000 acres in MVR  |       |      |       |         |
| and MVS)**                          |       |      |       |         |
+-------------------------------------+-------+------+-------+---------+
| **Ecosystem Management and          | **1,  | **3  | **    | **10    |
| Restoration Measures**              | 010** | 88,2 | 225** | 4,986** |
|                                     |       | 81** |       |         |
+-------------------------------------+-------+------+-------+---------+
| Island Building                     | 91    | 91   | 23    | 23,000  |
|                                     |       | ,000 |       |         |
+-------------------------------------+-------+------+-------+---------+
| Fish Passage                        | 14    |      | 4     |         |
+-------------------------------------+-------+------+-------+---------+
| Floodplain Restoration^1^           | 72    | 118  | 24    | 46,056  |
|                                     |       | ,756 |       |         |
+-------------------------------------+-------+------+-------+---------+
| Water Level Management^2^           | 15    |      | 15    |         |
+-------------------------------------+-------+------+-------+---------+
| Backwater Restoration               | 215   | 124  | 38    | 24,800  |
|                                     |       | ,800 |       |         |
+-------------------------------------+-------+------+-------+---------+
| Side Channel Restoration            | 147   | 14   | 29    | 2,900   |
|                                     |       | ,700 |       |         |
+-------------------------------------+-------+------+-------+---------+
| Wing Dam/Dike Alteration            | 64    | 640  | 19    | 190     |
+-------------------------------------+-------+------+-------+---------+
| Shoreline Protection^3^             | 392   | 38   | 73    | 8,040   |
|                                     |       | ,385 |       |         |
+-------------------------------------+-------+------+-------+---------+

^1^ -- Includes large and small-scale floodplain restoration, dam
embankment lowering, and topographic diversity

^2^ -- Includes pool-scale drawdowns/changing to dam point control at 2
sites/reducing water level fluctuations on the IL River

^3^ -- Included bankline and island protection

Floodplain restoration encompasses a suite of actions from the
relatively passive, such as hydrologic restoration (modified drainage
management) and planting, to large-scale construction of water control
features in existing levees, new levee or berm construction to
facilitate water control, and other earthwork. Larger scale projects and
earthwork are intended to restore elements of hydrology, provide
topographic diversity and allow planting or other manipulation of
landcover to achieve restoration of representative habitat types.

Water level management includes pool-scale drawdowns, moving the pool
control point from mid-pool to the dam to effectively control pool
elevations near the dam, medium scale projects using levees or berms, as
noted above and small scale drawdowns using temporary pumps and control
structures to artificially influence local hydrologic conditions to
achieve selected habitat objectives.

Backwater restoration generally refers to dredging to regain depths and
diversity lost to sedimentation. Dredging may occur with a cutterhead
type dredge with disposal of dredged material on the floodplain, behind
the levee, or elsewhere for beneficial use; or it may occur with a
clamshell bucket or dragline and involve side casting to the shoreline,
to an adjacent location for island construction, or to a barge for
transport and disposal off-site.

Side channel restoration will involve a variety of approaches, depending
on site characteristics. Such approaches include dredging, placement of
stone structures to create scouring flow, notching existing closing
structures to restore flow, and/or dike alterations as subsequently
described. The purpose is to restore habitats lost to channel
maintenance and sedimentation, and improve aquatic habitat diversity for
all life stages of native fish and freshwater mussels.

Wing dam and dike alterations are proposed to restore flow diversity and
beneficially affect sediment distribution. The study area contains over
2,100 wing dams, closing structures, and dikes constructed since the mid
1800s for the express purpose of directing flows to a single main
channel. These structures vary greatly in size and performance depending
on the river reach. They have altered flows and sediment distribution
patterns and contributed to structural homogeneity in aquatic habitats.
Wing dams are most common above St. Louis and are not emergent or
visible above normal pool elevations. Wing dikes are generally found
below St Louis in the Open River and are emergent or visible at the
bankline, and are functional at all river stages.

Shoreline protection generally refers to minimizing further erosion
damage to remaining habitats on islands and the floodplain. This may be
done through traditional bank armoring with riprap, placement of
off-shore revetment, which maintains an area of aquatic habitat between
the bankline and revetment, use of wood pilings, placement of downed
trees, or placement of dredged material.

Administrative Actions

Adaptive management is proposed to address uncertainty in future habitat
conditions and the response to restoration measures of organisms that
rely on those habitats. Adaptive management will require focused
experimental design to evaluate performance of both common and untried
restoration practices. It will require development of both conceptual
and predictive models to facilitate communication and inform restoration
strategy. It will require agencies to modify their planning, regulatory,
and implementation relationships (that is, institutional arrangements)
to provide flexibility and improve response to shifting navigation and
ecosystem needs over time. As the primary administrative action to be
pursued by partner agencies, the adaptive management paradigm requires
that regulatory agencies be active participants in management
experiments that focus on questions critical to threatened and
endangered species survival and habitat restoration programs (Stankey et
al 2003). Provision of authority for ecosystem restoration along with
existing authority for operation and maintenance of the navigation
system will expand Corps capabilities to work outside of the navigation
channel. It will allow the opportunistic use of equipment for small
scale restoration work, and should increase efficiency by reducing
mobilization and demobilization cost and logistics.

Forest Management is the enhancement of the Corps' ongoing Forestry
Program, which is targeted to habitat enhancement. This program is
coordinated with partner natural resource agencies annually. It has been
a relatively small portion of the overall Corps operation and
maintenance program to date. Its enhancement is proposed to build on the
expertise of Corps forestry staff and take advantage of existing
interagency collaboration and coordination mechanisms.

The Corps has proposed to address fleeting through the development of a
fleeting plan in collaboration with industry, the Coast Guard, and the
Service. Originally scheduled later in the implementation phase, the
Corps has agreed to move initiation of the planning process to year one
of the project schedule.

Restoration Response Monitoring and Evaluation was recognized by
stakeholders as an absolute necessity for successful implementation of
adaptive management. Details will be project or measure-specific and are
proposed to be developed by existing field level interagency
coordination teams and vetted through a proposed Science Panel (USACE
2004a).

Conservation Measures

Conservation measures to minimize harm to listed species which are
proposed by the action agency are considered part of the proposed action
and their implementation is required under the terms of the
consultation. The Corps included the following Conservation Measures in
its March 2004 Biological Assessment (USACE 2004b):

Decurrent false aster

Within potential impact zones, the Corps will conduct field surveys for
*B. decurrens*. Survey information would be provided to the Service. If
the species is located, a Tier II BA would be prepared and coordinated
with the Service. Individual plants that would be affected can be
relocated with the Service's approval of the transplant location.

Indiana bat

Any activities that are determined to impact potential Indiana bat
habitat will prohibit tree removal/clearing during the period of April 1
to September 30, unless mist net surveys indicate that no bats are
present and there is no known roosting at the site. If a site is within
a 5-mile radius of hibernacula, the period is April 1 to November 15.

Forest management efforts within the range of the Indiana bat will be
carried out to establish and maintain forest species and size class
diversity in order to ensure a long-term supply of potential Indiana bat
roosting trees.

Current Corps of Engineers operations and maintenance programs will be
evaluated to determine if additional opportunities exist to promote
hardwood regeneration and species diversity in floodplain forests.

Higgins eye pearlymussel

#### 

#### For pool level drawdowns, the following Conservation Measures avoid and minimize impacts to Higgins eye from stranding:

####  

1\. A drawdown will not be implemented that would result in lowering
normal water levels more than 1.5 feet at any of the essential,
secondary, or relocation habitat areas.

2\. A drawdown will not be implemented if pool elevation at the dam is
greater than two feet above the secondary control pool elevation in
excess of 20 days from April 1 to June 15 in the proposed drawdown year.

3 During the drawdown, water levels will be lowered slowly (0.1 to 0.2
foot per day), allowing the escape of native mussels from the dewatered
zone. The rate of drawdown will be commensurate with the proposed level
of drawdown and the location of the drawdown.

4\. Studies may be completed to evaluate the distribution of Higgins eye
in relationship to water depths, the ability of Higgins eye to escape
the dewatered zone, and evaluation of the stranding of mussels with
ongoing pilot pool drawdowns. As additional information is obtained, the
preceding conservation measures will be reviewed and revised, in
coordination with the Service

Pallid sturgeon

None provided in the Biological Assessment.

Interior Least Tern

Because of the potential harassment of Interior least terns during
ecosystem restoration construction activities, the Corps will consult
with the U.S. Fish and Wildlife Service on proposed construction
projects that are scheduled between May 1 and September 30 and are
within 300 feet of a least tern colony. Currently, reoccurring nesting
is known at Marquette Island, Baumgard Island, Brown's Bar and Ellis
Island.

If deemed necessary by the Service, the Corps will conduct a least tern
nesting survey of the construction area. The results of the survey and
details of avoidance measures that will be employed during construction
will be coordinated with the Service.

If a least tern colony is found within 300 feet of the construction
zone, and impacts to the species cannot be avoided, the project will be
conducted when the species is not in the area.

**Literature Cited**

Stankey, G. H., B. T. Bormann, C. Ryan, B. Shindler, V. Sturtevant, R.
N. Clark, and C. Philpot. 2003. Adaptive management and the Northwest
Forest Plan, rhetoric and reality. J. Forestry, Jan./Feb. 2003, pp
40-46.

USACE (U.S. Army Corps of Engineers). 2004a. Draft Integrated
Feasibility Report and Programmatic EIS for the Upper Mississippi
River-Illinois Waterway System Navigation Feasibility Study. U.S. Army
Corps of Engineers, Rock Island District, Rock Island, IL

USACE (U.S. Army Corps of Engineers). 2004b. Biological Assessment of
the Upper Mississippi River -- Illinois Waterway System Navigation
Study. U.S. Army Corps of Engineers, Rock Island, St Paul, and St Louis
Districts. 193pp.

**2.0 Indiana bat *(Myotis sodalis)***

[2.1 Status of the Species]{.underline}

This section presents the biological or ecological information relevant
to formulating the biological opinion. Appropriate information on the
species' life history, its habitat and distribution, and other data on
factors necessary to its survival are included to provide background for
analysis in later sections. This analysis documents the effects of past
human and natural activities or events that have led to the current
range-wide status of the species. Portions of this information are also
presented in listing documents, the recovery plan (USFWS 1983), the
draft revised recovery plan (USFWS 1999), the Final Biological Opinion
for the Operation and Maintenance of the 9-Foot Navigation Channel on
the Upper Mississippi River System (USFWS 2000), and the Biological
Assessment of the Upper Mississippi River-Illinois Waterway System
Navigation Study (USACE 2004) and are referenced accordingly.

[2.1.1 Species/critical habitat description]{.underline}

The Indiana bat *(Myotis sodalis)* was listed as an endangered species
on March 11, 1967 *(Federal Register* 32\[48\]:4001) under the
Endangered Species Preservation Act of October 15, 1966 (80 Stat. 926;
16 U. S. C. 668aa\[c\]). Eleven caves and two mines in six states were
listed as critical habitat on September 24, 1976 (41 FR 41914). These
sites along with other known hibernacula were classified in the Indiana
Bat Recovery Plan as Priority One, containing at least 30,000 bats;
Priority Two, containing 1000 to fewer than 30,000; and Priority Three
with less than 1,000 bats (USFWS 1983). In the 1999 draft revised
Recovery Plan, the Priority Two lower limit was reduced to 500 bats. In
summary, the objectives of the Recovery Plan are to: (1) protect
hibernacula; (2) maintain, protect, and restore summer maternity
habitat; and (3) monitor population trends through winter censuses.

[2.1.2 Life history]{.underline}

The Indiana bat is a medium-sized bat with a head and body length that
ranges from 41 to 49 mm. The fur is described as dull pinkish-brown on
the back, and somewhat lighter on the chest and belly. The ears and wing
membranes do not contrast with the fur. There are no recognized
subspecies. Generally, Indiana bats hibernate from October through April
(Hall 1962, LaVal and LaVal 1980), depending upon local weather
conditions. Figure 2-1 provides a depiction of the annual cycle). They
hibernate in large, dense clusters, ranging from 300 bats per square
foot to 484 bats per square foot (Clawson *et al*. 1980, Clawson, pers.
observ. October 1996 *in* USFWS 2000). Upon arrival at hibernating caves
in August-September, Indiana bats \"swarm,\" a behavior in which large
numbers of bats fly in and out of cave entrances from dusk to dawn, with
relatively few roosting in the caves during the day (Cope and Humphrey
1977). Swarming continues for several weeks and mating occurs during the
latter part of the period. Fat supplies are replenished as the bats
forage prior to hibernation.

![](media/image1.png){width="6.479166666666667in"
height="1.6770833333333333in"}

**Figure 2-1. Indiana Bat Annual Chronology**

Indiana bats tend to hibernate in the same cave at which they swarm
(LaVal et al. 1976), although swarming has occurred at caves other than
those in which the bats hibernated (Cope and Humphrey 1977). During
swarming, males remain active over a longer period of time at cave
entrances than do females (LaVal and LaVal 1980), probably to mate with
the females as they arrive. After mating, females enter directly into
hibernation. A majority of bats of both sexes hibernate by the end of
November \[by mid-October in northern areas (Kurta, pers. observ. June
1997)\], but hibernacula populations may increase throughout the fall
and even into early January (Clawson et al. 1980).

Indiana bats forage over a variety of habitat types but prefer to forage
in and around the tree canopy of both upland and bottomland forest or
along the corridors of small streams.

Bats forage at a height of approximately 2-30 meters under riparian and
floodplain trees (Humphrey et al. 1977). They forage between dusk and
dawn and feed exclusively on flying insects, primarily moths, beetles,
and aquatic insects. Females in Illinois were found to forage most
frequently in areas with canopy cover of greater than 80% (Garner and
Gardner 1992). The species feeds on flying insects, both aquatic and
terrestrial. Diet appears to vary across the range, as well as
seasonally and with age, sex and reproductive status (Murray and Kurta
2002, Lee 1993, Belwood 1979). Murray and Kurta (2002) found that diet
is somewhat flexible across the range and that prey consumed is
potentially affected by regional and local differences in bat
assemblages and/or availability of foraging habitats and prey. For
example, Lee (1993) and Murray and Kurta (2002) found that adult aquatic
insects (Trichoptera and Diptera) made up 25-81% of Indiana bat diets in
northern Indiana and Michigan. However, in the southern part of the
species range terrestrial insects (Lepidoptera) were the most abundant
prey items (as high as 85%) (Lee 1993, Brack and LeVal 1985, LaVal and
Laval 1980, Belwood 1979). Kiser and Elliot (1996) found that
Lepidopterans (moths), Coleopterans (beetles), Dipterans (true flies)
and Homopterans (leafhoppers) accounted for the majority of prey items
(87.9% and 93.5% combined for 1994 and 1995, respectively) consumed by
male Indiana bats in their study in Kentucky. Diptera, Trichoptera,
Lepidoptera, and Coleopterans also comprised the main prey of Indiana
bats in Michigan (Murray and Kurta 2002); however, Hymenopterans (alate
ants) were also taken when abundant.

Reproductively active females and juveniles exhibit greater dietary
diversity than males and non-reproductively active adult females. Lee
(1993) found that reproductively active females eat more aquatic insects
than adult males or juveniles in Indiana. These differences in dietary
demands between age groups, sex and reproductive stage is perhaps due to
higher energy

demands of reproductive females and juveniles. Male Indiana bats
summering in or near a hibernation cave feed preferentially on moths and
beetles.

Adult females store sperm through the winter and become pregnant via
delayed fertilization soon after emergence from hibernation. Young
female bats can mate in their first autumn and have offspring the
following year, whereas males may not mature until the second year.
Limited mating activity occurs throughout the winter and in late April
as the bats leave hibernation (Hall 1962).

Females emerge from hibernation ahead of males; most winter populations
leave by early May. The first maternity colony was found and several
studies of Indiana bat maternity habitat were conducted in the Midwest
region (Cope et al 1974). Females migrate up to 500 km northward (Kurta
& Murray 2002), to form maternity colonies consisting 10 to 100 adults
(Murray & Kurta 2004).

Some males spend the summer near hibernacula in Missouri (LaVal and
LaVal 1980) and West Virginia (Stihler, pers. observ. October 1996, *in*
USFWS 2000). In spring when fat reserves and food supplies are low,
migration is probably hazardous (Tuttle and Stevenson 1977).
Consequently, mortality may be higher in the early spring, immediately
following emergence.

Females may arrive in their summer habitats as early as April 15 in
Illinois (Gardner et al. 1991a, Brack 1979). During this early spring
period, a number of roosts (e.g., small cavities) may be used
temporarily, until a roost with larger numbers of bats is established.
Humphrey et al. (1977) reported that Indiana bats first arrived at their
maternity roost in early May in Indiana, with substantial numbers
arriving in mid-May. Parturition occurs in late June and early July
(Easterla and Watkins 1969, Humphrey et al. 1977) and the young are able
to fly between mid-July and early August (Mumford and Cope 1958, Cope et
al. 1974, Humphrey et al. 1977, Clark et al. 1987, Gardner et al 1991a,
Kurta et al. 1996).

Female Indiana bats exhibit strong site fidelity to summer roosting and
foraging areas, that is, they return to the same summer range annually
to bear their young. Females typically utilize larger foraging ranges
than males (Garner and Gardner 1992). Maternal activity has been
recorded at approximately 233 locations rangewide (Barbara Douglas USFWS
, pers. com.. 2004), by the capture of reproductive females (pregnant or
lactating). The top five States by total records are Indiana (83),
Illinois (38), Iowa (25), Kentucky (21), and Missouri (20). These
states, along with Michigan and Ohio are considered to be the species'
core maternity range.

Male Indiana bats may be found throughout the entire range of the
species. Males appear to roost singly or in small groups, except during
brief summer visits to hibernacula. Males have been observed roosting in
trees as small as 3 inch diameter at breast height (dbh).

The species range includes much of the eastern half of the United
States, from Oklahoma, Iowa, and Wisconsin east to Vermont, and south to
northwestern Florida. The Indiana bat is migratory, and the above
described range includes both winter and summer habitat. The winter
range is associated with regions of well-developed limestone caverns.
Major populations of this species hibernate in Indiana, Kentucky, and
Missouri. Smaller winter populations have been reported from Alabama,
Arkansas, Georgia, Illinois, Maryland, Mississippi, New York, North
Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West
Virginia. More than 85% of the entire known population of Indiana bats
hibernates in only nine caves.

[2.1.3 Population dynamics]{.underline}

Based on censuses taken at all hibernacula, the total known Indiana bat
population is estimated to number about 382,350 bats (Table 2-1). The
most severe declines in wintering populations have occurred in two
states: Kentucky, where 200,200 bats were lost between 1960 and 2001,
and Missouri, where 326,000 Indiana bats were estimated to be lost in
the same period. In Indiana, populations dropped by 50,000 between the
earliest censuses and 1980, but have returned to former levels in recent
years. Currently, almost half of all the hibernating Indiana bats in
existence (approximately 173,100) winter in Indiana.

**Table 2-1.---Size of hibernating populations of the Indiana bat by
region and state, based upon estimates nearest to the year indicated
(Clawson 2002).**

> [1960/1970 1980 1990 2000/2001]{.underline}

*Southern Region*

Alabama 350 350 350 250

Arkansas 15,000 15,000 4,500 2,500

Kentucky 248,100 102,200 78,700 47,900

Missouri 399,000 342,000 150,100 73,000

Tennessee 20,100 20,100 16,400 10,200

[Virginia 3,100 2,500 1,900 1,000]{.underline}

Subtotal 685,650 482,150 251,950 134,850

*Northern Region*

Illinois 14,800 14,800 14,900 19,300

Indiana 160,300 155,200 163,500 173,100

New York 20,200 21,100 26,800 34,900

Ohio 150 3,600 9,500 9,800

Pennsylvania 700 700 400 700

[West Virginia 1,500 1,200 6,500 9,700]{.underline}

Subtotal 197,650 196,600 221,600 247,500

Grand total 883,300 678,750 473,550 382,350

a Not all surveys occurred exactly in the winter indicated. Population
estimates for a

particular period were based on the survey nearest to the year
indicated, either prior to

or subsequent to that year, so that all caves are represented in each
period.

b States with records of fewer than 100 hibernating Indiana bats were
not listed.

c Data were from 1998--1999.

Missouri currently holds the second largest hibernating population of
Indiana bats and Illinois holds the fifth largest hibernating population
(Clawson 2002). Indiana bat populations first were first surveyed in the
late 1950s (Hall 1962). In the decades since then, the total rangewide
population of Indiana bats declined 57% (Clawson 2002). Regional trends
contrast sharply, with the southern states losing approximately 80% over
the survey period, and the northern states gaining 30% (Clawson 2002).

Trees in excess of 16 inch dbh with exfoliating bark are considered
optimal for maternity colony roost sites, but trees in excess of 9 inch
dbh appear to provide suitable maternity roosting habitat (Romme et al.
1995). Cavities and crevices in trees may also be used for roosting. In
Illinois, Gardner et al. (1991) found that forested stream corridors and
impounded bodies of water, were preferred foraging habitats for pregnant
and lactating Indiana bats.

After the summer maternity period, Indiana bats migrate back to
traditional winter hibernacula. Some male bats may begin to arrive at
hibernacula as early as July. Females typically arrive later and by
September the number of males and females are almost equal. Autumn
"swarming" occurs prior to hibernation. During swarming, bats fly in and
out of cave entrances from dusk to dawn, while relatively few roost in
the caves during the day. By late September many females have entered
hibernation, but males may continue swarming well into October in what
is believed to be an attempt to breed with late arriving females.

[2.1.4 Status and distribution]{.underline}

The current status and distribution of the species is described above.
The reasons for listing the species were summarized in the original
Recovery Plan as (1) Hibernating populations in Missouri have shown a
decline over the last seven years despite an intensive cave management
program; (2) The largest known hibernating population at Pilot Knob
Mine, Missouri, continues to be threatened by subsidence (mine
collapse); (3) Kentucky hibernating populations are not protected
adequately and continue to be depressed (USFWS 1983). Clawson (2002)
provided that the hibernating populations in Missouri have continued to
decline, Pilot Knob Mine has undergone continued subsidence to the point
at which it is unsafe to enter for survey, and Kentucky hibernating
populations have also continued to decline. The species' range-wide
trend is described in *Population dynamics*, preceding.

Reasons for Decline

Not all of the causes of Indiana bat population declines have been
determined; the decline of the species at its current rate is unknown.
Although several known human-related factors have caused declines in the
past, they may not solely be responsible for recent declines.

Documented causes of Indiana bat population decline include:

[Disturbance and vandalism]{.underline} - A serious cause of Indiana bat
decline has been human disturbance of hibernating bats during the
decades of the 1960s through the 1980s. Bats enter hibernation with only
enough fat reserves to last until spring. When a bat is aroused, as much
as 68 days of fat supply is used in a single disturbance (Thomas et
al*.* 1990). Humans use (e.g., including recreational cavers and
researchers) near hibernating Indiana bats can cause arousal (Humphrey
1978, Thomas 1995, Johnson *et al.* 1998). If this happens too often,
the bats\' fat reserves may be exhausted before the species is able to
forage in the spring.

Active programs by State and Federal agencies have led to the
acquisition and protection of a number of Indiana bat hibernacula. Of
127 caves/mines with populations \>100 bats, 54 (43%) are in public
ownership or control, and most of the 46 (36%) that are gated or fenced
are on public land. Although such conservation efforts have been
successful in protecting Indiana bats from human disturbance, they have
not been sufficient to reverse the downward trend in many populations.

[Improper cave gates and structures]{.underline} - Some hibernacula have
been rendered unavailable to Indiana bats by the erection of solid gates
in the entrances (Humphrey 1978). Since the 1950\'s, the exclusion of
Indiana bats from caves and changes in air flow are the major cause of
loss in Kentucky (an estimated 200,000 bats at three caves) (USFWS
1999). Other cave gates have so modified the climate of hibernacula that
Indiana bats were unable to survive the winter because changes in air
flow elevated temperatures which caused an increase in metabolic rate
and a premature exhaustion of fat reserves (Richter *et al.* 1993).

[Natural hazards]{.underline} - Indiana bats are subject to a number of
natural hazards. River flooding in Bat Cave, Mammoth Cave National Park,
drowned large numbers of Indiana bats (Hall 1962). Other cases of
hibernacula being flooded have been recorded by Hall (1962), DeBlase *et
al.* (1965), and USFWS (1999). A case of internal cave flooding occurred
when tree slash and debris (produced by forest clearing to convert the
land to pasture) were bulldozed into a sinkhole, blocking the cave\'s
rain water outlet and drowning an estimated 150 Indiana bats (USFWS
1999).

Another hazard exists because Indiana bats hibernate in cool portions of
caves that tend to be near entrances, or where cold air is trapped. Some
bats may freeze to death during severe winters (Humphrey 1978, Richter
*et al.* 1993). Indiana bats are vulnerable to the effects of severe
weather when roosting under exfoliating bark during summer. For example,
a maternity colony was displaced when strong winds and hail produced by
a thunderstorm stripped the bark from their cottonwood roost and the
bats were forced to move to another roost (USFWS 1999).

Suspected causes of Indiana bat decline include:

[Microclimate effects]{.underline} - Changes in the microclimates of
caves and mines may have contributed more to the decline in population
levels of the Indiana bat than previously estimated (Tuttle, *in litt.*
August 4, 1998). Entrances and internal passages essential to air flow
may become larger, smaller, or close altogether, with concomitant
increases or decreases in air flow. Blockage of entry points, even those
too small to be recognized, can be extremely important in hibernacula
that require chimney-effect air flow to function. As suggested by
Richter *et al.* (1993) and Tuttle (*in litt.* August 4, 1998), changes
in air flow can elevate temperatures which can cause an increase in
metabolic rate and a premature exhaustion of fat reserves.

Hibernacula in the southern portions of the Indiana bat\'s range may be
either near the warm edge of the bat\'s hibernating tolerance or have
relatively less stable temperatures. Hibernacula in the North may have
passages that become too cold. In the former case, bats may be forced to
roost near entrances or floors to find low enough temperatures, thus
increasing their vulnerability to freezing or predation. In the North,
bats must be able to escape particularly cold temperatures. In both
cases, modifications that obstruct air flow or bat movement could
adversely impact the species (USFWS 1999).

[Land use practices]{.underline} - The Indiana bats\' maternity range
has changed dramatically since pre-settlement times (Schroeder 1991;
Giessman *et al.* 1986; MacCleery 1992; Nigh *et al.* 1992). Most of the
forest in the upper Midwest has been fragmented, fire has been
suppressed, and native prairies have been converted to agricultural
crops or to pasture and hay meadows for livestock. Native plant species
have been replaced with exotics in large portions of the maternity
range, and plant communities have become less diverse than occurred
prior to settlement. Additionally, numerous chemicals are applied to
these intensely- cropped areas. The changes in the landscape and the use
of chemicals (McFarland 1998) may have reduced the availability and
abundance of the bats\' insect forage base.

In the eastern U. S., the area of land covered by forest has been
increasing in recent years (MacCleery 1992). Whether or not this is
beneficial to the Indiana bat is unknown. The age, composition, and size
class distribution of the woodlands will have a bearing on their
suitability as roosting and foraging habitat for the species outside the
winter hibernation season.

[Chemical contamination]{.underline} - Pesticides have been implicated
in the declines of a number of insectivorous bats in North America (Mohr
1972, Reidinger 1972, Reidinger 1976, Clark and Prouty 1976, Clark *et
al.* 1978, Geluso *et al.* 1976, Clark 1981). The effects of pesticides
on Indiana bats have yet to be studied. McFarland (1998) studied two
sympatric species, the little brown bat *(Myotis lucifugus)* and the
northern long-eared bat *(M. septentrionalis keenii)* as surrogates in
northern Missouri and documented depressed levels of
acetylcholinesterase, suggesting that bats there may be exposed to
sublethal levels of organophosphate and/or carbamate insecticides
applied to agricultural crops. McFarland (1998) also demonstrated that
bats in northern Missouri are exposed to significant amounts of
agricultural chemicals, especially those applied to corn. BHE
Environmental, Inc. (1999) collected tissue and guano samples from five
species of bats at Fort Leonard Wood, Missouri and documented the
exposure of bats to p,p\'-DDE, heptachlor epoxide, and dieldrin.

[2.2 Environmental Baseline]{.underline}

This section is an analysis of the effects of past and ongoing human and
natural factors leading to the current status of the species, its
habitat, and ecosystem within the action area. The purpose is to
describe the current status of the species within the action area and
those factors that have contributed to this state. Factors affecting the
species include those listed previously under Reasons for Decline. Other
factors with the potential to adversely roosting habitat include
pulpwood management by private industry on islands in the Open River
reach, woodlot management and wetland drainage by floodplain landowners,
and land management activities by the States of Missouri and Illinois.

Much of the UMRS corridor represents potential summer habitat for the
Indiana bat. Due to their migratory behavior, Indiana bats likely
traverse or follow the Mississippi and Illinois River corridors en route
to their summer habitats and in returning to their hibernacula. In doing
so,

they may stop and roost temporarily in suitable floodplain trees, or may
select an area to spend the summer in a maternity colony.

[2.2.1 Status of the Indiana bat within the action area]{.underline}

The action area includes the UMRS and its floodplain in 5 states. Two of
these states, Illinois and Missouri, provide hibernacula designated as
critical habitat. Missouri critical habitat consists of 5 caves and 1
mine in counties well outside the action area. However there are 3
counties in the action area containing Priority Three hibernacula. In
Illinois, there are four Priority 2 hibernacula and two Priority 3
hibernacula in or directly adjacent to the action area, one of which is
designated as critical habitat. As noted previously Missouri currently
holds the second largest hibernating population of Indiana bats and
Illinois holds the fifth largest hibernating population (Clawson 2002).

In Illinois, the majority of maternity colonies located have been found
in bottomlands (T.Carter, SIU-C, 2004. Pers com.) roosting habitat in
general contained more bottomland habitat and patches of water (Carter
et al 2002). Surveys indicate that the southern portion of the action
area is providing suitable summer foraging and maternity habitat
(Gardner 1990, Gardner et al 1996, WDH 2002). Indiana bats demonstrate
roost area fidelity (Gardner 1991, Kurta 1996, Gumbert, 2002). In
addition they have been found to establish multiple roost areas within
4.75 kilometers (2.9 miles) of a hibernaculum (Gumbert 2002). As noted
above, one cave which provides critical habitat is located adjacent to
the action area and is within 1.5 miles of the navigation channel. Males
and lactating female Indiana bats have been captured in the action area
in Illinois and Missouri, and tracked to roost trees on islands and the
floodplain (QST 1997, WDHES 2002, Illinois DNR unpublished 1990, Gardner
et al. 1996). The action area contains a variety of habitats where the
species could forage, although there are no recent summer capture
records northward of Henderson County on the Mississippi River and Ford
County, south of the Illinois River. These habitats include floodplain
forest, backwaters, sloughs, and open water. It is likely that Indiana
bats within the project vicinity will forage upon both aquatic and
terrestrial insects near the canopy of floodplain forests. Floodplain
forest adjacent to known hibernacula could provide other key features
necessary to the Indiana bat life cycle (e.g.. swarming) and is
consequently important to viability of the species. We believe it
reasonable that the species may be encountered throughout the
Mississippi River portion of the action area south of Muscatine, Iowa
and throughout the Illinois River portion of the action area downstream
from Marseilles, Illinois.

[2.2.2 Factors affecting the Indiana bat environment within the action
area]{.underline}

Disturbance and vandalism, improper gates natural hazards microclimate
changes, land use in maternity range, and contaminants were discussed in
status of the species, preceding. Acquisition of lands associated with
the 9-Foot navigation Channel Project in the 1930s allowed a shift in
landcover from agriculture to bottomland forest on those lands over the
last seventy years. At this time there are 27,230 acres of forested
lands in the Rock Island District on Pools 17-22, and 37,090 acres of
forested land in the St Louis District from Pool 24 southward. The State
of Illinois owns over 60,000 acres on the Illinois Waterway from the
Peoria Pool to its confluence with the Mississippi, and the bulk of that
is forested. The State of Missouri owns over 23,000 acres on the UMRS
above the Ohio River confluence. The floodplain forests of the UMRS are
dominated by mixes of silver maple communities that occur in even-aged
stands between 50 and 70 years old, and there is limited regeneration of
silver maple or other trees present (UMRCC 2002). Due to this current
condition, about 60 percent of forest lands in Federal ownership on the
UMRS are estimated to provide an average of 40 trees per acre that
provide roost tree structural features such as loose, exfoliating bark,
or are dead or dying trees over 9 inches dbh (Gary Swenson, USACE pers.
com. 2004). Due to limited regeneration and even-age structure, the
long-term maintenance of suitable summer habitat is questionable.
Despite the apparent abundance of seemingly suitable habitat, survey
efforts have been infrequent, and evidence of habitat occupation is
limited to the studies previously noted. It is difficult to determine
the importance of the action area to recovery of the species in the
absence of additional research, but given the life history information
preceding, it is likely that portions of the action area are valuable
maternity habitat and contribute to successful reproduction and
recruitment.

The Final Biological Opinion for the Operation and Maintenance of the
9-Foot Navigation Channel on the Upper Mississippi River System (O&M BO)
outlined a number of navigation-

related factors that may affect the species including impoundment and
water level regulation, dredging and disposal, clearing and snagging,
channel \[regulating\] structures and revetment, tow traffic, fleeting,
port facilities, exotic species, contaminants, recreation, cabin leases,
and General Plan Lands management.

[2.3 Effects of the Action]{.underline}

This section includes an analysis of the direct and indirect effects of
the proposed action on the species and/or its critical habitat and its
interrelated and interdependent activities.

The Upper Mississippi River-Illinois Waterway System Navigation Study
proposes to implement both navigation improvement and ecosystem
restoration actions. The navigation improvement program also contains a
mitigation component for unavoidable adverse impacts to natural
resources of the UMRS.

The proposed action (project) is the implementation of the recommended
plan contained in the Draft Integrated Feasibility Report and
Programmatic EIS for the Upper Mississippi River-Illinois Waterway
System Navigation Feasibility Study (USACE 2004). With the enactment of
additional authorities, this project would include Federal policy
changes, interagency coordinating mechanism or institutional arrangement
modifications, changes in operation of existing facilities, manipulation
of landcover types to change habitat features, and a suite of
construction activities for navigation feature improvement, navigation
structure modification, and ecosystem restoration.

Conservation measures to minimize harm to listed species which are
proposed by the action agency are also considered part of the proposed
project and their implementation is required under the terms of the
consultation. The Corps included the following Conservation Measures by
reference in its March 2004 Biological Assessment:

-   Any activities that are determined to impact potential Indiana bat
    habitat will prohibit tree removal/clearing during the period of
    April 1 to September 30, unless mist net surveys indicate that no
    bats are present and there is no known roosting at the site. If a
    site is within a 5-mile radius of hibernacula, the period is April 1
    to November 15.

-   Forest management efforts within the range of the Indiana bat will
    be carried out to establish and maintain forest species and size
    class diversity in order to ensure a long-term supply of potential
    Indiana bat roosting trees.

-   Current Corps of Engineers operations and maintenance programs will
    be evaluated to determine if additional opportunities exist to
    promote hardwood regeneration and species diversity in floodplain
    forests.

Through subsequent correspondence during consultation, the agency also
provided the following conservation measure:

-   Tree removal, timber stand improvement, and other activities
    determined to affect potential Indiana bat habitat will be conducted
    in a manner that does not adversely alter the character or habitat
    suitability of subject sites. Site boundaries will be determined in
    collaboration with the Service, respective State, and other resource
    experts as necessary.

Short term local impacts to individual Indiana bats in the action area
during construction activity described below are expected to be
outweighed by the long term landscape level benefits of proposed
ecosystem restoration measures. Improved forest species diversity and
structural diversity would be expected to contribute to a long term
supply of suitable roost trees. Restoration measures directed at aquatic
habitat improvement should contribute to the species' forage base.

[2.3.1 Direct effects]{.underline}

[2.3.1.1 Navigation improvements]{.underline}

Navigation improvements with the potential to affect Indiana bats were
screened and provided in BA Table 1 (USACE 2004). Effects would be
realized as injury or direct mortality to adults and young bats from
roost tree toppling by navigation-induced erosion, casual mooring, or
fleeting; tree removal for bank shaping and armoring; and energetic
stress from increased foraging and searching for new suitable foraging
areas, roost areas, and roost trees by pregnant females. These effects
would be likely to contribute to lower reproductive success in the
action area, if roosting and foraging areas are limited at the project
or site-specific scale. Clearing for construction staging, or other
landcover modification close to hibernacula could alter site
characteristics by reducing available roost trees, changing foraging
patterns or distances, and affecting fat accumulation for swarming bats,
and consequently, reducing over-winter survival, resulting in
unquantified take of Indiana bats. Activities occurring near hibernacula
during the swarming period may also affect mating success, and thus
reproductive success of the population.

The proposed conservation measures, however, are anticipated to minimize
the level of exposure and the extent of impact such that neither
reproductive success nor survival will be appreciably affected. First,
the proposed conservation measures include restricting activities to
periods when bats are not likely to be using the area. This will reduce,
if not eliminate, nearly all direct exposure to project impacts. Second,
the proposed conservation measures also include maintaining the
character of project sites in terms of Indiana bat habitat suitability.
Thus, we expect that despite alterations of habitat will occur in
conjunction with navigation improvement projects, the suitability of the
targeted sites will not be reduced. Although the Corps may not be
successful in maintaining the character of the site every time, based on
past experiences, we fully expect that through Tier II consultations
exceptions will be rare. Third, the closest known hibernacula to a lock
site is on the Illinois Waterway, where no additional lock work is
currently proposed; therefore, the likelihood of impact to swarming and
hibernating bats from navigation improvement is extremely low, and
therefore, discountable.

Most of the large-scale navigation improvements which would require
staging areas and forest clearing for new construction are located in
the mid to lower portions of the UMRS, where Indiana bats have been
collected. Table 2-2 provides the projected permanent and temporary
clearing for navigation improvements, and the approximate date range for
clearing and replanting temporary staging areas (USACE 1998). This
acreage represents about 0.0005

percent of the total 269,404 acres of forested habitat from Pool 17
southward on the Mississippi and Peoria Pool southward on the Illinois
River.

**Table 2-2. Forest clearing for navigation improvements.**

  ---------------- ----------- ----------- ---------- ---------- ------------
                   Permanent   Temporary   Total      Clear NST  Replant NLT

  Lock and Dam 20  15 ac                   15.0       2011       n/a

  Lock and Dam 21  8 ac        4.5 ac      12.5       2008       2021

  Lock and Dam 22  22 ac                   22.0       2005       n/a

  Lock and Dam 24              5.8 ac      5.8        2008       2021

  Lock and Dam 25  24 ac                   24.0       2005       n/a

  Peoria L & D                 12.5 ac     12.5       2011       2026

  LaGrange L & D   24 ac       19 ac       43         2008       2022

  Total                                    134.8                 
                                           acres                 
  ---------------- ----------- ----------- ---------- ---------- ------------

While it may be possible to avoid most direct impacts to roosting areas
and maternal colonies by scheduling construction/clearing during the
non-hibernation season, it is unlikely that all direct impacts will be
avoided over the 50 year project period. In addition, tree clearing and
general silvicultural practices as part of forest management scheduled
during the hibernation period can still alter the characteristics of
suitable habitat (roost areas), rendering them unavailable to pregnant
bats demonstrating roosting area and/or roost tree fidelity upon
emergence in the spring. We anticipate that very few instances will
arise where adverse effects will be unavoidable. In those instances
where unavoidable, reproduction, numbers, or distribution of Indiana
bats within the action area are not likely to be appreciably reduced due
to the implementation of the conservation measures proposed.

[2.3.1.2 Mitigation]{.underline}

Mitigation planning for impacts associated with incremental increases in
navigation traffic fall into four major biological areas -- fishery,
submersed aquatic plants, bank erosion, and backwater-side channel
sedimentation. Fishery mitigation measures include large woody debris
anchors, backwater improvements, dike alterations, and fish passage.
Submerged aquatic plant mitigation measures include modification of
river regulation to improve habitat conditions, backwater/side channel
habitat protection and restoration and revegetation. Bank erosion
mitigation measures include such structural measures as offshore
revetments, bank protection, or vegetative/bioengineered protection.
Mitigation for backwater/side channel sedimentation measures includes
offshore revetment, drop structures, closure structures, bank
protection, barrier island construction, and dredging.

At the programmatic scale, mitigation measures associated with erosion
and bank protection have the potential to impact Indiana bats through
removal of bankline trees during bank shaping activity. Per the proposed
conservation measures, the Corps will coordinate with State and Federal
resource agencies to evaluate site characteristics and suitability, and
will develop site-specific project plans to preserve site suitability.
We anticipate that only in a very few instances will adverse effects be
unavoidable. In these situations, it is unlikely that an entire bat
colony will be affected and activities would be limited to removal of a
few trees. Furthermore, it is extremely unlikely that any such project
would be implemented if maternity activity is verified. Thus, although
we anticipate that a few individuals may be harmed, we do not expect the
reproduction, numbers or distribution of Indiana bats will be
appreciably reduced from mitigation activities.

Because mitigation measures proposed to date are similar to the
ecosystem restoration component of the Upper Mississippi River-Illinois
Waterway System Navigation Study, these actions are evaluated
subsequently in greater detail in the Ecosystem Restoration section of
this biological opinion.

[2.3.1.3 Ecosystem restoration]{.underline}

Restoration projects are proposed to alter and improve habitat
conditions on up to an estimated 96,500 acres on the Mississippi River
(below Rock Island) and Illinois River portions of the study area. This
acreage is considered "area of influence," as individual project
footprints may be smaller, actions should positively influence habitat
quality within a larger contiguous area or area of influence. This
figure represents approximately 36 percent of the total forested acreage
from Pool 17 southward on the Mississippi and Peoria Pool southward on
the Illinois. The estimated annual average acreage of forested habitat
associated with ecosystem restoration work is 511 acres. Descriptions of
proposed ecosystem restoration measures are summarized in *Project
Description* preceding, pages 7 - 12. Generally speaking we anticipate
that activities associated with ecosystem restoration will not
appreciably affect reproduction, numbers, or the distribution of Indian
bats within the action area. Proposed conservation measures include
mechanisms to avoid direct exposure to impacts and ensure site
suitability and characteristics are maintained. Therefore, potential
impacts (as specifically described below) to Indiana bats from actions
implemented per the ecosystem restoration component of the project are
expected to be minor. Portions of the action area fall within a five
mile radius of known hibernacula; however, these hibernacula are well
removed from the action area by topography and are not expected to fall
within the boundaries of proposed ecosystem restoration measures. Thus,
we anticipate that the likelihood of impact to swarming or hibernating
bats from ecosystem restoration activities is extremely low and
therefore discountable.

Island Building

Island building is primarily a process of dredging and placement of
dredged material for the express purpose of restoring an eroded feature
or providing wind and wave protection to reduce sediment resuspension,
improve water clarity, provide bathymetric diversity necessary to
provided habitat for a range of aquatic life stages, and provide the
topographic diversity necessary to provide a range of terrestrial
habitats representative of the specific river reach. No detectable
effects to Indiana bats would be expected during island construction.
Over the project life, some islands would be expected to be planted with
preferred species or be allowed to reforest naturally. This would be
expected to contribute to long-term forest species diversity and
structural diversity beneficial to forest-dwelling bats, including the
Indiana bat.

Fish Passage

Fish passage involving reestablishment of lateral hydraulic connectivity
could involve tree removal and construction-related disturbance during
the non-hibernation period. In the portion of the action area where
Indiana bats may be found, reestablishing lateral connectivity is likely
to involve deployment and operation of standard construction equipment
to modify flood control levees and channels. Alteration of foraging
habitat or roosting area characteristics via tree removal and disruption
of foraging would adversely affect the Indiana bat on a temporary basis,
as modification of forested habitat is expected to be insignificant with
implementation of the proposed conservation measures. No effects to
Indiana bats are anticipated from fish passage construction at lock and
dam facilities, as no forested habitat will be involved in the projects.

Floodplain Restoration

Floodplain restoration, as described previously, includes a range of
passive measures to restore and manage representative ecotypes, as well
as aggressive construction measures typical of floodplain development
and flood control projects. These activities occurring in close
proximity to maternal roost trees or roosting areas would be expected to
influence reproductive success, resulting in take of the species, if
sufficient alternative roosting habitat is unavailable. Floodplain
restoration includes timber stand improvement, clearing for grassland
restoration, or other landcover modification that has the potential to
affect area characteristics close to hibernacula and could alter site
characteristics by reducing available roost trees and changing foraging
patterns or distances, also resulting in take. Grassland restoration
typically involves periodic burning to control undesirable species and
woody encroachment. Burning on federally owned General Plan Lands below
Rock Island is typically carried out by Service Refuge personnel
following detailed burn plans, under the Refuge Comprehensive
Conservation Plan. Of the average combined estimate of 3000 acre per
year acreage target, Refuge staff indicates that about 10% or 300 acres
of that would occur in the vicinity of bottomland forest or forested
wetland habitat in the action area (Tim Julison, USFWS, pers. comm.
2004). Another 1200 acre General Plan tract managed by the State of
Missouri is being converted to open wetland and is being managed with a
combination of herbicide, burning, and mechanical means to control
canary grass invasion and promote native wetland vegetation. Burning on
State-managed lands in the action area is minimal and has been confined
to about 150 acres in Iowa on Pool 17 to favor oak regeneration over
silver maple, and set back invasive canary grass. In Illinois, burning
is rare on the floodplain, involving about 300 acres directed at
managing willow encroachment in wetland units as necessary. Burning on
the U.S. Forest Service Inageh Unit of the Shawnee National Forest
currently involves up to 300 acres annually; however, future plans
include reduction in burn frequency as bottomland hardwood restoration
goals are achieved (Steve Widowski, pers. comm. 2004).

Water Level Management

Water level management includes both small and large-scale drawdowns to
expose and consolidate sediment, stimulate valuable vegetation, and
simulate natural river processes. In addition, water level management
includes moving navigation pool regulation on Pools 16 and 25 from hinge
point to dam point control, resulting in an estimated 1500 additional
acres of inundation in the lower third of each of these two navigation
Pools. Pool 16 is northward of recent Indiana bat collection, and moving
its control point is therefore not anticipated to affect the species.
Inundation of additional acreage in Pool 25 has the potential to
increase stress and mortality on trees in the lower pool, and will thus
contribute to the total number of snag trees available to roosting bats.
Moving the control point will change the seasonal water surface profiles
in a way that is anticipated to reduce regeneration potential in the
lower navigation pool and improve regeneration potential in the upper
navigation pool; therefore, the long term net effect on total available
habitat may be undetectable. Thus we believe it will have no net effect
on the species, after the initial increase in available roost trees.

Backwater Restoration

Backwater restoration will primarily involve dredging and dredged
material placement, some of which may be used for island construction,
and some of which may be used to create topographic diversity beneficial
to a variety of terrestrial plants and animals. Dredged material
placement often involves the deployment of standard construction
equipment at the target locations and has the potential to modify or
destroy roosting areas. This would place increased energetic demands on
displaced bats, and, depending on the season and location, affect
maternity success. Impacts to roost trees are expected to be minimized
through implementation of the proposed conservation measures and
maintenance of site characteristics.

Side Channel Restoration

Side channel restoration may potentially affect Indiana bats where
construction activities involve shoreline work, construction equipment
access, and roost tree removal. Such effects would be minor, temporary,
and localized. There is no guarantee that suitable roost trees existing
along banklines can be avoided for all projects, resulting in
displacement of roosting individuals.

Implementation of the proposed conservation measures and maintenance of
overall site suitability is expected to minimize effects to roost area
characteristics.

Wing Dam and Dike Alteration

Wing dam and dike alteration is anticipated to be primarily performed by
waterborne equipment and has minimal potential to affect Indiana bats
because forested habitats will not be affected.

Island and Shoreline Protection

Island and shoreline protection potentially affecting roost trees is
proposed over a total length of 148 miles in this same portion of the
study area. This bankline total includes that work proposed to offset
navigation-induced erosion (mitigation) and that work proposed to
protect or restore shorelines and islands as part of the ecosystem
component. Impacts would be expected in the form of tree removal during
bank shaping and preparation for rock placement. Effects to bats would
be realized in the form of increased energetic demand from primary roost
tree displacement.

Administrative actions

Administrative actions are not anticipated to affect the Indiana bat,
and are anticipated to facilitate the timely implementation of the
conservation measures proposed. In addition, implementation of the
adaptive management approach may contribute to the recovery of the
species by filling in knowledge gaps through project monitoring and
performance evaluation.

Interrelated and Interdependent Actions

Interrelated and interdependent actions associated with the proposed
project include

Port and facility development resulting from increased navigation system
capacity. Such future development would have no independent utility
apart from improved system capacity and could adversely affect the
Indiana bat. The water-dependent location of such facilities could place
them in riparian areas commonly used by the Indiana bat. Large-scale
clearing for port facility construction could render previously unknown
individual roost trees or an entire roosting area unsuitable for
continued occupation by male bats or a maternal colony. Displacement
effects would be the same as those noted previously in *Direct Effects*,
preceding. Implementation of the proposed conservation measures is
expected to minimize adverse effects to the species, and for those
avoidable adverse effects, the Tier II consultation process described
previously will be initiated.

Indirect Effects

Under the subject consultation the Service considers fleeting to be an
indirect effect, since the improved navigation project may alter
efficiencies in fleet locations and sizes, and thereby result in
additional fleeting activity. Such activity is reasonably certain to
occur as evidenced by permits sought/issued in the Rock Island District
of the Corps. Fleeting and temporary casual mooring present the
potential to alter bankline habitat characteristics by girdling and
toppling trees during the hibernation period (i.e., adversely altering
the suitability of roosting and foraging habitat) and has the potential
to cause direct mortality through toppling during the non-hibernation
and maternity period.

Other indirect effects are anticipated to arise from administrative
actions proposed in the recommended plan, primarily partner agencies'
adoption of the adaptive management paradigm, in short "learning by
doing," and provision of additional Corps authority for ecosystem
restoration. It is likely that all effects to listed species subject to
this consultation cannot be foreseen at this time. Through Tier II
consultations, the Corps will ensure the expected level of impact to
Indiana bat will be minimal and will do this by ensuring the character
of the habitat will not be reduced. And, in the rare cases where this is
unavoidable, the Corps is committed to working with the Service to
ensure impacts do not rise to the level of adversely affecting
reproduction, numbers, or distribution of the Indiana bat. As part of
the adaptive management approach, predictive models are proposed to be
developed in the implementation phase of the recommended plan, and will
necessarily involve elements of listed species life history. The Service
expects that further collaboration among partner agencies to develop,
test, and validate assumptions used in such models will result in
modifications to the recommended plan that contribute to listed species
recovery.

[2.3.1.4 Summary]{.underline}

Potential impacts of the recommended plan on Indiana bats involve the
cascade of effects resulting from displacement from summer roost trees
and roost areas. These effects could include adult mortality from
increased energy demands from searching for and establishing new
territories, increased inter and intraspecific competition, and
increased exposure to predation. Increased energy demands would also be
expected to result in slower prenatal development or abortion, delayed
parturition, slower postnatal development, delayed weaning and volancy,
and increased juvenile predation risk. These effects would all
contribute to decreased recruitment of Indiana bats, a species of known
low fecundity. Both navigation improvement and ecosystem restoration
actions proposed to be implemented are to be undertaken over a 50 year
period and intended to achieve restoration and maintenance of ecological
processes representative of large river ecosystems. Implementation of
the proposed conservation measures will minimize the potential localized
adverse effects of individual project actions on Indiana bats.

The disturbance frequency for construction of navigation improvements or
ecosystem restoration would be expected to be low, occurring over one
multi-year period within the 50 year period of analysis at any given
location in the project area. Certain restoration-related habitat
maintenance activities such as burning must by necessity be carried out
during the non-hibernation period in some locations, and may be expected
to occur infrequently on up to 300 acres annually in the portion of the
study area where bats are known to roost.

Areas proposed for clearing or new lock construction would be either
permanently deforested or require post--project planting which would not
restore site character or entirely regain pre-project habitat values
before the end of the 50 year analysis period. The severity of
disturbance will be highly variable by site and action (navigation
construction or ecosystem restoration) selected. Disturbance severity
for navigation improvements is expected to reach a peak between 2008 and
2034 based on the proposed schedule for new lock and lock extension
construction (USACE 2004b). Disturbance from navigation improvements or
ecosystem restoration will involve separate activities at sites
spatially distant from each other within the action area. The effects of
existing human activity, equipment operation, and navigation traffic on
Indiana bats at and around each lock and dam site are unknown.
Therefore, the effects of additional personnel and machinery during lock
improvement would not be detectable. However, implementation of the
proposed conservation measures is expected to limit the exposure of
Indiana bats to disturbance from lock construction

Tree toppling due to additional navigation-induced erosion, fleeting or
casual mooring, as well as removal for construction area staging lock
expansion, mitigation of erosion impacts, or ecosystem restoration
during the non-hibernation season may result in mortality to roosting
Indiana bats. Prescribed burning, while an infrequent floodplain
ecosystem management practice on the UMRS, may result in burning of
occupied roost trees outside of the hibernation period (April 1 --
September 30). Smoke generated during prescribed burns could also cause
roosting bats discomfort or death. Burning may cause an individual
roosting bat to abandon a traditionally used roost tree, or a group of
bats to abandon a traditional roosting area, thereby requiring a search
for and establishment of a new roosting area. Such a requirement in turn
would be expected to increase energetic demands, exposure to inter and
intra-specific competition, and exposure to predation while searching
unfamiliar habitat, resulting in harm or harassment of individual bats.

No direct effects on hibernacula, or designated critical habitat are
foreseen from implementation of the recommended plan.

Tree removal activities include: clearing of up to 134.8 acres for
navigation improvements, bank stabilization work throughout the lower
two thirds of the action area totaling approximately 784,000 feet or 148
miles, and various ecosystem restoration projects involving standard
construction techniques and silvicultural (forest management) practices
affecting up to approximately 96,500 acres of all landcover classes in
the lower portions of the action area over 50 years, or about 1930 acres
annually (USCOE, Henry DeHaan, pers. comm., from tables 6-24, and 14-4
in the Feasibility Report). Of this total acreage, an estimated 10% or
193 acres of forested habitat would be included in implementation of the
recommended plan on an average annual basis. Silvicultural practices
will generally be directed at uneven-age management and will ultimately
benefit the Indiana bat through improved forest structure and species
diversity. If bankline work was conservatively estimated to include a
strip of forest 50 feet wide, the area associated with 148 linear miles
totals approximately 900 acres over the life of the plan, or about 18
acres annually.

[2.4 Cumulative Effects]{.underline}

Cumulative effects include the effects of State, local or private
actions that may occur in the action area. Future Federal actions that
are unrelated to the proposed action are not considered in this section
because they require separate consultation pursuant to section 7 of ESA.
State-owned and managed lands in the action area in Illinois comprise
about 61,000 acres. Actions potentially affecting Indiana bats on these
lands are limited to timber stand improvement (TSI) work directed at
uneven age management, which should be beneficial to the species.
Uneven-age forest management should provide a continuous supply of
suitable roost trees over the long-term. Burning on State lands in the
action area is minimal, unscheduled, and estimated to involve no more
than 450 acres. Burning on private lands is unscheduled and occurs on an
as-needed basis, primarily to control willow invasion of managed
wetlands. State and private activities in the action area involve lands
managed for wildlife, and focus on management for moist soil plants and
wetland landcover. As roost trees in Illinois occur in highly fragmented
bottomland forests close to water (Carter et. al. 2002), and maintenance
of wetland landcover within the action area contributes to interspersion
of forest and wetland habitats, the effects of current wetland
management on Indiana bats should be beneficial. The current acreage and
extent of active timber management that occurs on State lands is not
known at this time. Private landowners on the Illinois River have
actively enrolled in the USDA Conservation Reserve and Enhancement
Program and have planted 3,300 acres of trees on former agricultural
land, which is anticipated to benefit Indiana bats as future roosting
and foraging habitat. Enrollment in the riparian buffer practice totals
over 20,000 acres in Illinois and includes grasses, shrubs, and trees
planted to stabilize streambanks and benefit aquatic life. Improved
water quality and resultant increase in aquatic life will improve the
insect forage base for Indiana bats. Enrollment in the new 2004
bottomland tree practice (CP 31) under the Conservation Reserve Program
has just begun, with State-wide targets of 75,000 acres each for
Missouri and Illinois. It is thus anticipated that, overall, private
landowners will contribute to restoring landcover beneficial to the
Indiana bat through their participation in USDA programs.

The Service is unaware of any other non-Federal actions that are
reasonably certain to occur which may affect the Indiana bat. We are
aware that that floodplain lands in private ownership associated with
floodplain restoration contain approximately 7 percent forested lands;
however, private management initiatives are unknown and their impact
cannot be quantified at this time. Unforeseen non-Federal actions in the
floodplain of the Illinois and Upper Mississippi Rivers will likely
require Federal review under Section 404 of the Clean Water Act or
Section 10 of the Rivers and Harbors Act. Given appropriate
environmental

coordination, impacts to the Indiana bat can be avoided. Therefore, any
cumulative effects due to non-Federal actions are considered to be
negligible.

[2.5 Conclusion]{.underline}

After reviewing the current status of the Indiana bat, the environmental
baseline for the action area, the effects of the proposed action, and
the cumulative effects, it is the Service's biological opinion that the
proposed action is not likely to jeopardize the continued existence of
the Indiana bat, and is not likely to destroy or adversely modify
designated critical habitat.

The proposed project is not expected to affect hibernating activities or
habitat. Implementation of the recommended plan, however, presents the
potential to affect summer habitat for both female and male Indiana
bats. In addition, small portions of the action area fall within a 5
mile radius of some hibernacula, and thus would be expected to support
swarming activity in the fall. Although infrequent and likely to be
minimized by the conservation measures proposed, it is likely that
adverse impacts to the individuals of the species cannot be avoided
entirely over the project life, and take will occur. Potential impacts
to Indiana bat habitat from 7 navigation improvement projects range from
clearing 5.8 acres to 43 acres on a single-event basis. Potential
impacts from the ecosystem restoration component to forested areas
presenting potential roosting habitat features are estimated to occur on
a maximum of 511 acres distributed over multiple project sites annually.
Based on the preceding estimates of the small percentage of total
forested habitat affected, and conservation measures proposed by the
action agency, it is expected that adverse impact to Indiana bats will
be minimized but, due to the unknown distribution of roosting bats on a
site-specific basis, not avoided entirely. Because site specific adverse
impacts to Indiana bats are likely in only a few instances, we believe
implementation of the recommended plan will not appreciably reduce
reproduction, numbers, or distribution of Indiana bats within the action
area or appreciably reduce the likelihood of recovery of the species
over 50 years. Critical habitat for the Indiana bat has been designated
at Blackball Mine; however, implementation of the recommended plan does
not affect that site and no destruction or adverse modification of that
critical habitat is expected.

[2.6 Incidental Take Statement]{.underline}

[2.6.1 Introduction]{.underline}

Section 9 of the ESA and Federal regulations pursuant to section 4(d) of
the ESA, prohibits the take of endangered and threatened species,
without special exemption. Take is defined as to harass, harm, pursue,
hunt, shoot, wound, kill, trap, capture or collect, or attempt to engage
in any such conduct. Harm is further defined by the Service to include
significant habitat modification or degradation that results in death or
injury to listed species by significantly impairing behavioral patterns,
including breeding, feeding, or sheltering. Harass is defined by the
Service as intentional or negligent actions that create the likelihood
of injury to listed species to such an extent as to significantly
disrupt normal behavioral patterns which include, but are not limited
to, breeding, feeding or sheltering. Incidental take is defined as take
that is incidental to, and not the purpose of, the carrying out of an
otherwise lawful activity. Under the terms of Section 7(b)(4) and
Section 7(o)(2), taking that is incidental to and not intended as part
of the

agency action is not considered to be prohibited taking under the Act
provided that such taking is in compliance with the terms and conditions
of this Incidental Take Statement.

The measures described below are non-discretionary, and must be
undertaken by the Corps so that they become binding conditions of any
grant or permit issued to an applicant, as appropriate, for the
exemption of Section 7(o)(2) to apply. The Corps has a continuing duty
to regulate the activity covered by this Incidental Take Statement. If
the Corps (1) fails to assume and implement the terms and conditions, or
(2) fails to require an applicant to adhere to the terms and conditions
of the Incidental Take Statement through enforceable terms that are
added to the permit or grant document, the protective coverage of
Section 7(o)(2) may lapse. In order to monitor the impact of incidental
take, the Corps must report the progress of the action and its impact on
the species to the Service as specified in the Incidental Take
Statement, pursuant to 50 CFR § 402.14(i)(3).

[2.6.2 Extent of take anticipated]{.underline}

Incidental take of Indiana bats is expected to be in the form of injury,
death, harm, or harassment of individuals. Given the conservation
measures proposed by Corps, we do not anticipate any direct take of
Indiana bats to occur where their presence is verified. Furthermore, as
the Corps is committed to maintaining the suitability of potentially
occupied sites, we do not anticipate that indirect take resulting from
habitat alterations during the inactive season will result in loss of
individuals. However, as our survey methodologies and information
regarding the exact location of individual bats at any one moment is
imprecise, we cannot ensure that the conservation measures proposed will
avoid altering habitat currently being used by individuals. However, we
believe following suitable survey protocols, considering past and
present survey efforts and their results, habitat suitability of the
area, etc., will greatly minimize the chances of concluding not present
when indeed they are present. This is especially true for maternity
colonies as the number of bats in a given area would be greater than for
solitary males, and hence, reproductive females are more likely to be
caught. Moreover, as the proposed action will span 50 years and will
entail actions that occur within seemingly suitable habitat, we are
reasonable certain that incidental take of a few individuals over the
term of the project is likely.

Due to programmatic nature of the project, we are unable to determine
where and when this take will occur. Furthermore, we also anticipate
that incidental take of Indiana bats will be difficult to detect because
(1) dead or injured bats are rarely discovered due to the bat's small
body size; and (2) the number of bats occupying a particular area at a
particular time is highly variable and difficult to determine. Thus, it
is appropriate to use a surrogate to monitor the level of take that
occurs. The Service typically uses the areal extent of potential
roosting habitat affected as a surrogate to monitor the level of take.
Such monitoring, described at the end of this section, typically
quantifies the actual versus projected amount of habitat harvested, and
number of live or dead bats encountered, and age, sex, and reproductive
status of live bats handled.

This incidental take statement is based on several single event
clearings not to exceed an aggregate 135 acres for navigation
improvement (see Table 2), and annualized timber stand improvement and
tree removal activities occurring during ecosystem restoration work on
an average of 193 acres, bankline work on approximately 18 acres, and
prescribed burning on a maximum of 300 acres, for a total forest impact
of about 511 acres annually. Since the level of incidental take of
Indiana bats cannot be adequately quantified, incidental take will be
estimated by the loss or abandonment of roost trees potentially occupied
by Indiana bats that are contained within the total 511 acres of
forested habitat estimated to be affected annually. These estimates of
habitat alterations are described in the *Direct Effects Summary*
preceding. The proposed conservation measures will ensure that every
effort to identify maternity activity and maternity roosts is taken,
this estimate is based on the removal of other undiscovered roost trees
used by male bats. Because males roost solitarily or in small groups, we
believe that few individuals are likely to be exposed to impacts. Given
the proposed conservation measures, we anticipate that the anticipated
level of habitat alteration is likely to result in the take of less than
20 bats per year. Management activities on project lands that would
significantly increase the number of acres of tree removal or burning
during the non-hibernation season would be considered to affect this
determination and would require reinitiation of consultation.

[2.6.3 Effect of the take]{.underline}

In the accompanying biological opinion, the Service determines that this
level of expected take is not likely to result in jeopardy to the
species or destruction or adverse modification of critical habitat.

[2.6.4 Reasonable and prudent measures]{.underline}

To ensure that the anticipated level of incidental take is commensurate
with the take that occurs per the proposed action, the Corps of
Engineers (Corps) and the Service is implementing a tiered programmatic
consultation approach. This approach utilizes a tiered consultation
framework with the subject consultation resulting in this Tier I
biological opinion. All subsequent projects will be Tier II
consultations with Tier II biological opinions issued as appropriate
(i.e., whenever the proposed project will result in unavoidable adverse
effects to threatened and endangered species).

As individual projects are proposed under the recommended plan, the
Corps shall provide, for any action that may affect Indiana bats,
project-specific information to the Service that (1) describes the
proposed action and the specific area to be affected, (2) identifies the
species that may be affected, (3) describes the manner in which the
proposed action may affect listed species, and the anticipated effects,
(4) specifies whether the anticipated effects from the proposed project
are similar to those anticipated in the programmatic BO, (5) estimates a
cumulative total of take that has occurred thus far under the tier I BO,
and (6) describes any additional effects, if any, not considered in the
tier I consultation. If it is determined that the proposed project may
affect the Indiana bat, the Corps will provide this information in a
tier II BA to document anticipated effects of the subject action.

The Service will review the information provided by the Corps for each
proposed project. If it is determined during this review that a proposed
project is not likely to adversely affect listed species, the Service
will complete its documentation with a standard concurrence letter and
specifies that the Service concurs that the proposed project is not
likely to adversely affect listed species or designated critical
habitat.. If it is determined that the action is likely to adversely
affect listed species or designated critical habitat and these effects
are commensurate with those contemplated in the programmatic BO, then
the Service will complete a tier II BO with a project-specific
incidental take statement within the annual allotted programmatic
incidental take, and project specific Reasonable and Prudent Measures
and Terms and Conditions, if appropriate.

The Service believes the following reasonable and prudent measures are
necessary and appropriate to minimize impacts of incidental take of the
Indiana bat:

1\. Protect those portions of swarming areas (5-mile radius around
hibernacula), maternity colonies, and male home range (2 mile radius
around roost trees or capture sites) on Project (fee title or General
Plan) lands by establishing management areas and prescriptions that
focus ecosystem restoration measures compatible with Indiana bat
management.

2\. Where evidence of possible maternal colonies (lactating females or
juveniles prior to August 15) is discovered, in addition to preserving
the character of the site, the Service and appropriate state will be
notified to determine the feasibility of project deferral, relocation,
or modification. Recommendations for further site monitoring will be
developed in cooperation with the Service and appropriate state.

Terms and Conditions

In order to be exempt from the prohibitions of Section 9 of the Act, the
Corps of Engineers must comply with the following terms and conditions.
These terms and conditions are non-discretionary.

RPM 1.

1\. Management area establishment and prescriptions will be reflected in
site-specific planning documents that include, but not be limited to,
detailed pre and post-project monitoring, site suitability enhancement,
and post-project land use (types and levels of recreation) management.

2\. Monitor snag (standing dead or dying trees over nine inches diameter
at breast height (dbh)) retention through routine forest inventory on
project lands. If there exists an average of less than 6 snags per acre,
manually create additional snags greater than 9 inches dbh. This is
intended to maintain a supply of suitable roost trees.

3\. Where feasible, conduct prescribed burning activities on fee title
or General Plan lands during the period October 1 to March 31 unless
within a 5-mile radius of a known hibernacula and then the dates are
from November 15 to March 31.

RPM 2.

1\. Wherever tree removal is proposed to occur, first evaluate the site
potential for roosting habitat. If roosting habitat characteristics are
evident, employ more detailed survey methods (such as mist netting) to
further evaluate site use by Indiana bats.

2\. If site investigations or monitoring activities result in the
discovery of maternity sites on Project lands, roost areas used by
maternity colonies will be protected by establishing a zone centered on
the maternity roosting area. The actual area will be determined by a
combination of topography, known roost tree locations, proximity of
permanent water, and a site-specific evaluation of the habitat
characteristics associated with the colony. Protective measures shall be
established by developing a management strategy in cooperation with the
Service and the appropriate state. Strategies may include such things as
survey/monitoring plans, site enhancement plans, and land use plans.

######## Requirements for Monitoring and Reporting of Incidental Take of Indiana Bats

######## Federal agencies have a continuing duty to monitor the impacts of incidental take resulting from their activities \[50 CFR 402.14(i)(3)\]. In doing so, the Federal agency must report the progress of the action and its impact on the species to the Service as specified below. 

1.  Supply the Service with an annual report, due by January 31 of each
    following year, that specifies:

```{=html}
<!-- -->
```
a.  the amount of suitable habitat harvested in the current year and the
    total harvested since issuance of the BO,

b.  progress and results of any terms and conditions that were required,
    identified by site-specific project,

c.  the number of live or dead Indiana bats encountered, and

d.  age, sex, and reproductive status of live bats handled.

```{=html}
<!-- -->
```
2.  Care must be taken in handling dead bat specimens that are found on
    project lands to preserve biological material in the best possible
    condition.

3.  Any dead specimens found should be placed in plastic bags and
    refrigerated as soon as possible following discovery.

4.  The finding of any dead specimen should be reported immediately to
    the Service's Rock Island Field Office.

Closing

The reasonable and prudent measures, with their implementing terms and
conditions, are designed to minimize the impact of incidental take that
might otherwise result from the proposed action. If, during the course
of the action, this level of incidental take is exceeded, such
incidental take represents new information requiring reinitiation of
consultation and review of the reasonable and prudent measures provided.
The Federal agency must immediately provide an explanation of the causes
of the taking and review with the Service the need for possible
modification of the reasonable and prudent measures.

**Literature Cited**

Barbour, R.W. and W.H. Davis. 1969. Bats of America. Univ. Press of
Kentucky, Lexington. 286 pp.

Beauvais, S.L., J.G. Wiener, and G.J. Atchison. 1995. Cadmium and
mercury in sediment and burrowing mayfly nymphs (*Hexagenia*) in the
Upper Mississippi River, USA. Arch. Environ. Contam. Toxicol. 28,
178-183.

Belwood, J. J. 1979. Feeding ecology of an Indiana bat community with
emphasis on the endangered Indiana bat, Myotis sodalis. M. S. Thesis,
Univ. Florida, Gainesille, FL, 103 pp.

BHE Environmental, Inc. 1999. 1998 Annual report: implementation of
reasonable and prudent measures and terms and conditions in the
biological opinion for BRAC implementation at Fort Leonard Wood. Unpubl.
Rept. 3D/E Group of BHE Environmental, Inc., Cincinnati, OH. 199 pp. +
app.

Bowles, J.B. 1982. Results of monitoring of Indiana bat maternity sites
in south-central Iowa. Unpubl. Report to IA Cons. Comm.

Brack, V., Jr. 1979. Determination of presence and habitat suitability
for the Indiana bat (Myotis sodalis) and gray bat (Myotis grisescens)
for portions of three ditches, Big Five Levee and Drainage District,
Union and Alexander Counties, Illinois. U.S. Army Corps of Engineers,
St. Louis, MO. 23 pp.

Brack, V., and R. K. LaVal. 1985. Food habits of the Indiana bat in
Missouri. J. of Mammalogy, 66:308-315.

Brack, V., Jr., K. Tyrell, and K. Dunlap. 1991. A 1990-1991 winter cave
census for the Indiana bat (*Myotis sodalis*) in non-priority 1
hibernacula in Indiana. Ind. Fed. Aid Proj. E-1-6, Study No. 18. Ind.
Dept. Nat. Resources., Indianapolis. 45 pp.

Carter, T.C., S.K. Carroll, J.E. Hoffmann, J.E.Gardner, and G.A.
Feldhamer. 2002. Landscape analysis of roosting habitat in Illinois.
*In* The Indiana bat: biology and management of an endangered species
(A. Kurta and J. Kennedy, eds.). Bat Conservation International, Austin,
Texas. 253 pp.

Clark, D.R., Jr. 1981. Bats and environmental contaminants: a review.
USDI Fish and Wildlife Service Special Scientific Report. Wildlife No.
235. 27 pp.

Clark, D.R., Jr., R.K. LaVal, and D.M. Swineford. 1978. Dieldrin-induced
mortality in an endangered species, the gray bat ((Myotis grisescens).
Science 199:1357-1359.

Clark, D.R., Jr., and R.M. Prouty. 1976. Organochlorine residues in
three bat species from four localities in Maryland and West Virginia,
1973. J. Pestic. Monitor. 10:44-53.

Clawson, R. L., R. K. LaVal, M. L. LaVal, and W. Caire. 1980. Clustering
behavior of hibernating Myotis sodalis in Missouri. J. Mammalogy,
61:245-253.

Clawson. R.L.. 2002. Trends in population size and current status. *In*
The Indiana bat: biology and management of an endangered species (A.
Kurta and J. Kennedy, eds.). Bat Conservation International, Austin,
Texas. 253 pp.

Cope, J. B., A. R. Richter, and R. S. Mills. 1974. Concentrations of the
Indiana bat, Myotis sodalis, in Wayne County, Indiana. Proc. Indiana
Acad. Sci. 83:482-484

Cope, J. B., and S. R. Humphrey. 1977. Spring and autumn swarming
behavior in the Indiana bat, Myotis sodalis. J. of Mammalogy, 58:93-95.

DeBlase, A.F., S.R. Humphrey, and K.S. Drury. 1965. Cave flooding and
mortality in bats in Wind Cave, Kentucky. J. Mamm., 46:96.

Easterla, D. A., and L. C. Watkins. 1969. Pregnant Myotis sodalis in
northwestern Missouri. J. of Mammalogy, 50:372-373.

EMTC (Environmental Management Technical Center). 1998. Ecological
status and trends of the Upper Mississippi River System. USGS/EMTC

Gardner, J. E., J. D. Garner, and J. E. Hofmann \-\-\-\-\--. 1990.
Combined progress reports: 1989 and 1990 investigations of Myotis
sodalis (Indiana bat) distribution, habitat use, and status in Illinois.
Progress report for the U.S. Dept. of the Interior, Fish and Wildlife
Service, Twin Cities, MN. 19 pp.

Gardner, J. E., J. D. Garner, and J. E. Hofmann 1991. Summer roost
selection and roosting behavior of Myotis sodalis (Indiana bat) in
Illinois. Final report. Illinois Natural History Survey, Illinois Dept.
of Conserv. Champaign, IL. 56 pp.

Gardner, J. E., J. E. Hofmann, and J. D. Garner. 1996. Summer
distribution of the federally endangered Indiana bat (Myotis sodalis) in
Illinois. Trans. Illinois St. Acad. Sci. 89, 187-196.

Garner, J.D. and J.E. Gardner. 1992. Determinations of summer
distribution and habitat utilization of the Indiana bat (*Myotis
sodalis*) in Illinois. Final Report: Project E-3. End. Sp. Act Sec. 6
Rpt. Il. Dept. Cons., Springfield, IL.

Geluso, K.N., J.S. Altenbach, and D.E. Wilson. 1976. Bat mortality:
pesticide poisoning and migratory stress. Science 194:185-186.

Giessman, N., T.W. Barney, T.L. Haithcoat, J.W. Meyers, and B.
Massengale. 1986. Distribution of forestland in Missouri. Trans.
Missouri Acad. Sci. 20:5-14.

Goolsby, D.A and W.E. Pereira. 1996. Pesticides in the Mississippi
River. In: Mead, R.H. ed. 1996. Contaminants in the Mississippi River,
1987-92. U.S. Geol. Surv. Circ. 1133. pp87-101. Denver, CO.

Gumbert, M. W., J.M. O'Keefe, and J.R. MacGregor. 2002 Roost fidelity in
Kentucky. *In* The Indiana bat: biology and management of an endangered
species (A. Kurta and J. Kennedy, eds.). Bat Conservation International,
Austin, Texas. 253 pp.

Hall, J.S. 1962. A life history and taxonomic study of the Indiana bat,
*Myotis sodalis*. Reading Publ. Mus. Art., Gallery Publ. 12:1-68.

Hassell, M.D. and M.J. Harvey. 1965. Differential homing in *Myotis
sodalis*. Am. Midl. Nat. 74:501-503

Humphrey, S.R. 1978. Status, winter habitat, and management of the
endangered Indiana bat, *Myotis sodalis*. Florida Scientist 41:65-76.

Humphrey, S. R., and J. B. Cope. 1977. Survival rates of the endangered
Indiana bat, Myotis sodalis. J. of Mammalogy, 58:32-36.

Humphrey, S. R., A. R. Richter, and J. B. Cope. 1977. Summer habitat and
ecology of the endangered Indiana bat, Myotis sodalis. J. of Mammalogy,
58:334-346.

ILDNR (Illinois Department of Natural Resources). 1990. Unpublished
internal memorandum and site record sheet of bat capture. 6 pp.

Jacobson, R.B., and A.T. Primm. 1997. Historical land-use changes and
potential effects on stream disturbance in the Ozark Plateaus, Missouri.
U.S. Geol. Surv. Water-Supply Paper 2484, Denver, CO. 85pp.

Johnson, S.A., V. Brack, Jr., and R.E. Rolley. 1998. Overwinter weight
loss of Indiana bats (*Myotis sodalis*) from hibernacula subject to
human visitation. Am. Midl. Nat. 139:255-261.

Kennedy, J. and S. Ducummon. 1999. 1999 Winter bat survey in Pilot Know
Mine, Iron County, Missouri. Unpubl. Rept. to the U.S. Fish and Wildlife
Service, Columbia, MO. 12pp.

Jacobson, R.B., and A.T. Primm. 1997. Historical land-use changes and
potential effects on stream disturbance in the Ozark Plateaus, Missouri.
U.S. Geol. Surv. Water-Supply Paper 2484, Denver, CO. 85pp.

Kiser, J. D., and C. L. Elliott. 1996. Foraging habitat, food habits,
and roost tree characteristics of the Indiana bat (Myotis sodalis)
during autumn in Johnson County, Kentucky. Final report,Kentucky Dept.
of Fish and Wildl. Resources, Frankfort, KY. 65 pp.

Kurta, A. 1980. Status of the Indiana bat, *Myotis sodalis*, in
Michigan. Mich. Acad. 13:31-36.

Ladd, D. 1991. Reexamination of the role of fire in Missouri oak
woodlands. *In:* G.V. Burger, J.E. Ebinger, and G.S. Wilhelm, eds., pp.
67-80. Proceedings of the Oak Woods Management Workshop, Eastern IL
Univ., Charleston, IL.

LaVal, R.K. and M.L. LaVal. 1980. Ecological studies and management of
Missouri bats, with emphasis on cave-dwelling species. MO Dept. of Cons.
Terrestrial Series 8:1-53.

Lee, Y. 1993. Feeding ecology of the Indiana bat *Myotis sodalis*, and
resource partitioning with *Myotis keenii* and *Myotis lucifugus*. M.S.
Thesis, U. of Tenn., Knoxville.

MacCleery, D.W. 1992. American forests - a history of resiliency and
recovery. USDA Forest Service publ. FS-540. Forest History Society,
Durham, NC. 58 pp.

Marbut, C.F. 1896. Surface features of Missouri. MO Geol. Surv. Rept.
10-14-109.

McFarland, C.A. 1998. Potrential agricultural insecticide exposure of
Indiana bats (*Myotis sodalis*) in Missouri. Unpubl. M.S. thesis, U. of
MO - Columbia. 256 pp.

Meade, R.H., ed. 1995. Contaminants in the Mississippi River, 1987-92.
U.S. Geol. Surv. Circ. 1133. Denver, CO

Mohr, C.E. 1972. The status of threatened species of cave-dwelling bats.
Bull. Nat. Speleol. Soc. 34:33-37.

Moore, G.F. 1998. Plant communities of Effigy Mounds National Monument
and their relationship to presettlement vegetation. M.S. Thesis, U. of
WI, Madison.

Mumford, R. E., and J. B. Cope. 1958. Summer record of Myotis sodalis in
Indiana. J. of Mammalogy, 39:586-587.

Murray, S. W., and A. Kurta. 2002. Spatial and temporal variation in
diet. *In* The Indiana bat: biology and management of an endangered
species (A. Kurta and J. Kennedy, eds.). Bat Conservation International,
Austin, Texas. 253 pp.

Murray, S. W., and A. Kurta. 2004. Nocturnal activity of the endangered
Indiana bat (Myotis sodalis). J. Zool., Lond. (2004) 262, 1-10.

Myers, R.F. 1964. Ecology of three species of Myotine bats in the Ozark
Plateau. Unpubl. Ph.D. Dissertation, Univ. of Missouri-Columbia,
Columbia, MO 210 pp.

Nelson, J.C., A. Redmond, and R.E. Sparks. 1994. Impacts of settlement
on floodplain vegetation at the confluence of the Illinois and
Mississippi Rivers. Transactions of the IL St. Acad. Sci. (1994). Vol.
87, Nos. 3 and 4, pp. 117-133.

Nelson, J.C.. And R.E. Sparks. 1997. Forest compositional change at the
confluence of the Illinois and Mississippi Rivers. Trans. Il. St. Acad.
Sci. Vol. 91, Nos. 1 and 2, pp. 33-46. Reprinted by the U.S.G.S., Envl.
Mgmt. Tech. Cent., Onalaska, WI. September 1998. LTRMP 98-R011. 14 pp.

Nigh, T.A., W.L. Pflieger, P.L. Redfearn, W.A. Schroeder, A.R.
Templeton, and F.R. Thompson, III. 1992. The biodiversity of Missouri -
definition, status, and

recommendations for its conservation. Biodiversity Task Force, Jefferson
City, MO. 53 pp.

QST Environmental, Inc. 1997. Indiana bat (Myotis sodalis) survey on
Cottonwood Island, Marioa and Lewis Counties, Missouri. Prepared for the
U. S. Army Corps of Engineers Rock Island District. 10 pp plus
appendices.

Reidinger, R.F. 1972. Factors influencing Arizona bat population levels.
Unpubl. Ph.D. dissert., U. of AZ, Tucson. 172 pp.

Reidinger, R.F. 1976. Organochlorine residues in adults of six
southwestern bat species. J. Widl. Manag. 40:677-680.

Richter, A.R., S.R. Humphrey, J.B. Cope and V. Brack, Jr. 1993. Modified
cave entrances: thermal effect on body mass and resulting decline of
endangered Indiana bats (*Myotis sodalis*). Conserv. Biol. 7:407-415.

Romme. R.C., K. Tyrell, and V. Brack, Jr. 1995. Literature summary and
habitat suitability index model: components of summer habitat for the
Indiana bat, *Myotis sodalis*. Report submitted to the IN Dept. Nat.
Res., Div. Wildl., Bloomington, IN by 3D/Environmental Services, Inc.,
Cincinnati, OH. Fed. Aid Proj. E-1-7, Study No. 8. 38pp.

Saur, C. O. 1920. The geography of the Ozark highland of Missouri. Geog.
Soc. of Chicago Bull. No. 7. U. of Chicago Press, Chicago. 187 pp.

Schmauch, S. and M. Tuttle. 1998. Pilot Knob Mine site evaluation.
Unpubl. Rept. to the U.S. Fish and Wildlife Service, Columbia, MO. 5pp.

Schroeder, W.A. 1981. Presettlement Prairie of Missouri. MO Dept. of
Cons., Jefferson City, MO. 35 pp.

Steingraeber, M.T., T.R. Schwartz, J.G. Wiener, and J.A. Lebo. 1994.
Polychlorinated biphenyl congeners in emergent mayflies from the Upper
Mississippi River. Envl. Sci. and Tech. 8:707-714.

Steingraeber, M.T. and J.G. Wiener. 1995. Bioassessment of contaminant
transport and distribution in aquatic ecosystems by chemical analysis of
burrowing mayflies (*Hexagenia*). Regulated Rivers: Research and
Management 11:201-209.

Thomas, D.W., M. Dorais, and J.M. Bergeron. 1990. Winter energy budgets
and cost of arousals for hibernating little brown bats (*Myotis
lucifugus*). J. Mamm. 71:475-479.

Thomas, D. W. 1995. Hibernating bats are sensitive to non-tactile human
disturbance. J. Mamm. 76:940-946.

UMRC (Upper Mississippi River Conservation Committee). 2002. Upper
Mississippi and Illinois River floodplain forests, desired future and
recommended actions. Upper Mississippi River Conservation Committee,
Rock Island Illinois. 35 pp.

USACE (U.S.Army Corps of Engineers) 1992. Natural Resource Management
Operational Management Plan, Mississippi River. U.S. Army Corps of
Engineers, Rock Island District, Rock Island, IL.

USACE (U.S. Army Corps of Engineers). 1998. Identification of potential
commercial navigation related bank erosion sites. Interim report for the
UMR-IWW System Navigation Study.

USACE (U.S. Army Corps of Engineers). 1998. Site-specific habitat
assessment. Interim report No. 7 for the UMR-IWW System Navigation
Study.262pp

USACE (U.S. Army Corps of Engineers). 1999. Tier I of a two-tiered
biological assessment - operation and maintenance of the Upper
Mississippi River navigation project within the

St. Paul, Rock Island, and St. Louis Districts. Mississippi Valley
Division, Vicksburg, MS. 111 pp. plus appendices.

USACE (U.S. Army Corps of Engineers). 2004a. Draft Integrated
Feasibility Report and Programmatic EIS for the Upper Mississippi
River-Illinois Waterway System Navigation Feasibility Study. U.S. Army
Corps of Engineers, Rock Island District, Rock Island, IL

USACE (U.S. Army Corps of Engineers). 2004b. Biological Assessment of
the Upper Mississippi River -- Illinois Waterway System Navigation
Study. U.S. Army Corps of Engineers, Rock Island, St Paul, and St Louis
Districts. 193pp.

USFWS (U.S. Fish and Wildlife Service). 1983. Recovery Plan for the
Indiana Bat. Twin Cities, MN. 23 pp.

USFWS (U.S. Fish and Wildlife Service). 1999. Agency Draft Indiana Bat
(*Myotis sodalis*) Revised Recovery Plan. Fort Snelling, MN. 53 pp.

USFWS (US Fish and Wildlife Service) 2000. Biological Opinion for the
Nantahala and Pisgah National Forests Land and Resource Management Plan,
Amendment 5, on the Indiana bat. Asheville Ecological Services Field
Office, Asheville, North Carolina.89 pp.

USFWS (US Fish and Wildlife Service) 2002. Biological Opinion, for the
Monongahela National Forest Amended Land and Resource Management Plan.
West Virginia Field Office, Elkins, West Virginia. 25 pp.

WDH Ecological Services. 2002. Endangered species investigation. Bat
survey report. Indiana and gray bats (Myotis sodalis and Myotis
grisescens) \[for the\] Proposed Lee Island Project, Holcim (US) Inc.
Prepared for Holcim (US) Inc. Chesterfield Missouri. 11 pp plus
appendices.

Yin, Y. 1999. Flooding and forest succession in a modified stretch along
the Upper Mississippi River. Regulated Rivers: Research and Management,
14:217-225. Reprinted

by U.S.G.S. Upper Midwest Envl. Sci. Cent., La Crosse, WI. Jan. 1999.
LTRMP 99-R002. 9 pp.

Yin, Y. and J.C. Nelson. 1995. Modifications of the Upper Mississippi
River and their effects on floodplain forests. Nat. Biol. Surv., Envl.
Mgmt. Tech. Cent., Onalaska, WI. Feb. 1995. LTRMP 95-T003. 17 pp.

Yin, Y., J.C. Nelson, and K.S. Lubinski. 1997. Bottomland hardwood
forests along the Upper Mississippi River. Natural Areas Journal 17(2):
164-173. Reprinted by U.S.G.S. Envl. Mgmt. Tech. Cent., Onalaska, WI.
Nov. 1997. LTRMP 97-R025. 10pp.

**Personal Communication**

Carter, T. 2004. Associate Scientist, Southern Illinois University.
Telephone conversation with Bob Clevenstine, Rock Island Field Office,
U. S. Fish and Wildlife Service, Rock Island Illinois.

DeHaan, H. 2004. Geomorphologist, U. S. Army Corps of Engineers, Rock
Island District. Telephone conversation with Bob Clevenstine, Rock
Island Field Office, U. S. Fish and Wildlife Service, Rock Island
Illinois.

Douglas, B. 2004. Fish and wildlife biologist, U. S. Fish and Wildlife
Service, Elkins Field Office, Elkins West Virginia.. Telephone
conversation and email with Bob Clevenstine. Rock Island Field Office,
U. S. Fish and Wildlife Service, Rock Island Illinois.

Julison, T. 2004. Refuge Operation Specialist, U. S. Fish and Wildlife
Service, Port Louisa National Wildlife Refuge. Telephone conversation
with Bob Clevenstine, Rock Island Field Office, U. S. Fish and Wildlife
Service, Rock Island Illinois.

Swenson, G. 2004. District forester, U. S. Army Corps of Engineers, Rock
Island District. Telephone conversation with Bob Clevenstine, Rock
Island Filed Office, U. S. Fish and Wildlife Service, Rock Island
Illinois.

Widowsky, S. 2004. U. S. Forest Service. Shawnee National Forest.
Telephone conversation with Bob Clevenstine, Rock Island Field Office,
Rock Island Illinois.

**3.0 Decurrent false aster *(Boltonia decurrens)***

[3.1 Status of the Species]{.underline}

This section presents the biological and ecological information relevant
to formulating the biological opinion. Appropriate information on the
species' life history, its habitat and distribution, and other data on
factors necessary to its survival, is included to provide background for
analysis in later sections. This analysis documents the effects of all
past human and natural activities or events that have led to the current
status of the species. Portions of this information are also presented
in listing documents, the recovery plan (USFWS 1990), the Final
Biological Opinion for the Operation and Maintenance of the 9-Foot
Navigation Channel on the Upper Mississippi River System (USFWS 2000)
(O&M BO), and the Biological Assessment of the Upper Mississippi
River-Illinois Waterway System Navigation Study (USACE 2004).

[3.1.1 Species/critical habitat description]{.underline}

*Boltonia decurrens* is an early successional species that requires
either natural or human disturbance to create and maintain suitable
habitat. Its natural habitat is wet prairies, shallow marshes, and
shores of open rivers, creeks, and lakes (Schwegman and Nyboer 1985). In
the past, the annual flood/drought cycle of the Illinois River provided
the natural disturbance required by this species. Annual spring flooding
created open, well-lit habitat and reduced competition by killing other
less flood-tolerant, early successional species. Field observations
indicate that in \"weedy\" areas without disturbance, the species is
eliminated by competition within 3 to 5 years (USFWS 1990). No critical
habitat has been designated for the decurrent false aster at this time,
although the Recovery Plan identified ten Illinois populations and two
Missouri populations that should be protected.

[3.1.2 Life history]{.underline}

*Boltonia decurrens* is a perennial plant of open wetland habitats. It
reproduces vegetatively and sexually. Vegetative production of one or
more basal rosettes occurs during the fall. Rosettes bolt the following
spring; plants flower and set seed (achenes) from late August to early
October. Smith *et al.* (1998) found that populations of *B. decurrens*
increased in size at three sites studied on the Illinois River following
the flood of 1993, with the greatest increase occurring at the two sites
which had the most severe flooding. These results suggest that the
removal of competing species by flood waters may be an important factor
in maintaining populations of *B. decurrens* in the floodplain. *B.
decurrens* has high light requirements for growth and achene germination
(Smith *et al.* 1993, Smith *et al.* 1995), and shading from other
vegetation is thought to contribute to its decline in undisturbed areas.

*Boltonia decurrens* exhibits a number of morphological adaptations for
life on the floodplain. Stoecker et *al.* (1995) found *B. decurrens* to
be extremely tolerant when maintained under conditions of root -zone
saturation. All plants in the flood treatment replicate survived to the
end of the study at 56 days. The formation of aerenchyma, a common plant
adaptation to flooding which allows diffusion of oxygen from aerial
shoots to maintain root metabolism, was extensive, increasing in
adventitious roots from 26% of root cross-section area in non-flooded
plants to 49% in flooded plants (Stoecker *et al.* 1995)*.* Achenes of
*B. decurrens* are morphologically structured for flotation and
therefore presumably are adapted for dispersal on river currents. Smith
and Keevin (1998) found that germination was not significantly reduced
in achenes floated for 4 weeks, and 20% of achenes floated under
conditions of simulated wave action were still floating after 4 weeks.
These data indicate that achenes have the potential for long distance
dispersal on water.

Smith and Keevin (1998) found that achenes of *B. decurrens* will not
germinate in the dark. Achenes, which were covered with as little as 0.2
in. of sediment, did not germinate; therefore, if achenes are deposited
by flood water and subsequently covered by a shallow layer of sediment,
it is unlikely they will germinate. Natural or human disturbance of the
soil, exposing the achenes to light, would be required for germination.
Sediment type may also be an important factor in achene germination and
long-term survival of populations. *B. decurrens* has been observed
growing on a variety of soil types (Schwegman and Nyboer 1985, Smith
1991); however, laboratory studies (Smith *et al.* 1995) comparing
achene germination and growth on two soil types, silty clay (6.7% sand,
53.3% silt, and 40% clay) and loamy sand (80% sand, 16.7% silt and 3.3%
clay) indicate that germination and seedling growth were significantly
greater on sand than on clay. These laboratory results suggest that the
silt and clay sediment being deposited by flood events on the Illinois
River (Lee and Stall 1976) is not ideal for germination and growth. Soil
type may thus be important in determining the distribution pattern of
this species.

Field monitoring by Schwegman and Nyboer (1985) suggested prolific
achene production. *B. decurrens* produces about 50,000 achenes per
individual, and, based on achene viability, an average plant is capable
of producing about 40,000 seedlings under optimal conditions for
germination (Smith and Keevin 1998). Fall seedlings overwinter and bolt
and flower the following spring and summer. Spring seedlings, however,
may either bolt and flower the same year or overwinter as small rosettes
which bolt and flower the following year (Smith 1991). In areas where
seedling production is low or nonexistent, *B. decurrens* populations
can be maintained by basal rosette production. In fact, few seedlings
are found in established populations (Moss 1997, Smith 1991). Seedling
establishment is expected to be low due to the small achene size, the
high light and temperature requirements for germination, and specific
soil texture and microtopography requirements for germination and
seedling growth (Baskin and Baskin 1988, Smith *et al.* 1995).

[3.1.3 Population dynamics]{.underline}

During the consultation for the O&M BO, the species was considered to be
stable ((Dr. Marian Smith, Southern Illinois University - Edwardsville.
*in litt*. to Gerry Bade December 4, 1999). The Recovery Plan states
that the species will be considered recovered after 12 stable
populations have been protected by purchase, easement or cooperative
management agreement. Following recent surveys, the number of
populations had increased from 14 to 26 in 2002, but the number of
individuals had decreased from over one million to an estimated 378,887
plants (Smith 2002). Given the fecundity of the species noted above and
the long-term viability of achenes (Baskin and Baskin 2002) it is likely
that wide variation will be the norm in the interannual numbers of
individual plants within each known population. In the absence of other
information, it is likely that the overall rangewide population of the
species is stable within the species' natural range of variability,
under current river management conditions.

[3.1.4 Status and distribution]{.underline}

The status of the species is described above under Population dynamics.

Reasons for Decline and Listing

Habitat destruction and modification have been identified as the primary
factors in the decline of the species, particularly of natural marshes,
wet prairies, and shoreline habitats. Wetlands have been drained and
converted to other uses, heavy siltation has buried suitable habitats,
and construction of levee systems has altered the flooding regimes
necessary for reduction of competition and prevented the dispersal of
seeds to potential habitat. (USFWS 1990, Schwegman and Nyboer 1985,
Smith et *al.* 1993, Stoecker *et al.* 1995, Smith *et al.* 1998, Smith
and Keevin 1998). The decurrent false aster was listed as a threatened
species by the Service on November 14, 1988 (53 FR 45861). It is a
floodplain species that occurs along a 250 miles section of the lower
Illinois River and nearby parts of the UMR (Schwegman and Nyboer 1985,
USFWS 1990). Analysis of 19^th^ century habitat data taken from
herbarium sheets indicates that *B. decurrens*' natural habitat was the
shores of lakes and streams in the Illinois River floodplain and the
Mississippi River floodplain in the vicinity of its confluence with the
Illinois River. It ranged along a 250 mile stretch between LaSalle,
Illinois, and St. Louis, Missouri. A disjunct population at Cape
Girardeau, Missouri, was reported in 1976, 120 miles downstream of St.
Louis (Schwegman and Nyboer 1985), but it has not been found since.

Range-wide Status

The action area encompasses the entire range of *B. decurrens*. The
present distribution of the aster is essentially unchanged. Determining
the status of an early successional species such as the decurrent false
aster is difficult. Such species typically display a "boom and bust"
phenomenon as colonies invade newly suitable sites, become dominant, and
then decline as succession overcomes them. Determining a total
population for the species is difficult because individual populations
may change dramatically from year to year; some increasing, some
decreasing, new ones appearing and old ones disappearing depending on
site conditions. Several notable populations include Riverlands
Environmental Demonstration Area, Spatterdock Bottoms and Columbia
Bottoms in St. Charles County, Missouri; and Rice Lake in Fulton County,
and Worley Lake in Tazewell County, Illinois (Dr. Marian Smith, Southern
Illinois University - Edwardsville. *in litt*. to Gerry Bade December 4,
1999; *ibid*. January 28, 2000.). No new threats to the species since
preparation of the Recovery Plan are known at this time.

[3.2 Environmental Baseline]{.underline}

This section is an analysis of the effects of past and ongoing human and
natural factors leading to the current status of the species, its
habitat, and ecosystem within the action area. The purpose is to analyze
the effects on the species at the action level. Factors affecting the
species include

habitat destruction and degradation due to water level regulation,
impoundment, channel maintenance, and wetland and shoreline development.

[3.2.1 Status of the decurrent false aster in the action
area]{.underline}

The action area encompasses the entire range of *B decurrens*, therefore
its status within the action area is as described above.

[3.2.2 Factors affecting the decurrent false aster environment within
the action area]{.underline}

Habitat destruction and modification have been noted as the main reasons
for the decline of the species (Schwegman and Nyboer, 1985). Shore
habitats have been modified by heavy siltation and altered flood
regimes. Prolonged flooding during the growing season appears to be a
limiting factor (USFWS 1990). Figure 3-1 illustrates the shift in
seasonal river stages over the historic period. We are unaware of any
research that has been specifically done to discern the relative
contribution of natural factors such as climate and precipitation versus
human factors such as upland and urban development, stormwater runoff,
wetland drainage, and field tiling to this change in the hydrograph.

![](media/image2.wmf){width="4.001388888888889in"
height="3.0006944444444446in"}

**Figure 3-1. River stage records at the Copperas Creek gauge (Sparks et
al. 1998).**

While flooding benefits *B. decurrens* through seed dispersal and
reduction of competition (Smith et al. 1998), summer flooding of
recently germinated plants can be lethal depending on the depth and
duration of the event. Mature plants are capable of withstanding
saturated soils and display morphologic adaptions to maintain root
metabolism under such conditions (Stoecker et al. 1995).

The 2000 O&M BO noted factors attributable to the 9-Foot Navigation
Project that also affect the species: impoundment and water level
regulation, dredged material disposal, channel regulating structures and
bank revetment, fleeting, recreation, cabin leases, and General Plan
Land management. These are summarized as follows:

[Impoundment]{.underline} - The initial impoundment of the Illinois
River by navigation dams Locks and Dam 26 on the UMR; La Grange Lock and
Dam, Peoria Lock and Dam, Starved Rock Lock and Dam and Marseilles Lock
and Dam on the Illinois River) within the historic range of the aster
created a series of pools. The pooling of the Illinois River resulted in
the inundation of shoreline habitat. Historic collections indicate that
shoreline habitat was utilized by *B. decurrens* (USFWS 1990). The
acreage of shoreline habitat lost during the initial inundation by the
navigation pools has not been quantified. It should be noted, however,
that "new" shoreline would have been created or shifted to a higher
elevation when the river was impounded.

Maintenance of navigation pools on the Illinois River has resulted in
stable water levels during low-flow periods while locks and dams have
had little effect on water stages during high water events. During
low-flow periods prior to lock and dam construction, especially during
drought years, the river would have receded, providing additional
shoreline habitat for *B. decurrens.* The magnitude of impact would
depend on many factors including the timing and duration of shoreline
dewatering and availability of a seed bank.

[Dredging and Disposal]{.underline} - Dredged material is usually
removed from the navigation channel in the impounded reaches of the UMRS
by a government or contractor-owned hydraulic cutterhead dredge and is
discharged to placement sites by floating pipeline. In the Open River,
it has been more common to use a hydraulic dustpan dredge that is
sidecast, or discharged directly to adjacent channel border habitats.
The government also uses its own mechanical dredging capability and
contractors to perform smaller operations. Material is usually
mechanically dredged by a clamshell bucket and placed on a deck barge
for transport to a disposal site.

In the impounded or pooled reaches of the river system, dredged material
was usually placed along the shoreline or occasionally in landward sites
located in close proximity to the dredging site. Depending upon
location, hydraulically or mechanically dredged material is placed 1)
linearly along the shoreline for bankline stabilization or to rejuvenate
recreational beaches that have eroded, or 2) placed in open water in
channel border habitats, or 3) on sites landward of the shore to improve
site suitability for planting or regeneration of desirable tree species,
or 4) on land or behind levees for beneficial use stockpiles. Previous
shoreline and upland placement may have destroyed populations of *B.
decurrens* or rendered the habitat unsuitable for recolonization.
However, the magnitude of impact cannot be quantified due to a lack of
historical data.

[Channel Structure/Revetment]{.underline} - Past activities related to
the construction of channel training structures and revetment have
likely affected *B. decurrens* or its habitat. Such modification
included bankline grading and placement of stone (covering habitat) for
bank revetment, wingdams, and closure structures. Maintenance of
existing structures where shoreline modification has occurred may also
have affected the species. The magnitude of these impacts cannot be
quantified due to a lack of historical data. Other effects of channel
regulating structures, such as redistribution of flows and sediment, may
have changed overbank flooding and seed dispersal patterns at specific
locations.

[Fleeting]{.underline} - Development of existing fleeting areas required
various levels of habitat modification, including placement of on-shore
deadmen. Operation of heavy equipment and soil disturbance may have
affected B*. decurrens* to an unknown degree. Other unregulated fleeting
or casual mooring areas involving the use of shoreline trees for mooring
has resulted in girdling, killing and toppling of trees which would
provide marginal opportunity for achene exposure and germination.
However, such effects would be expected to be short-lived and overcome
by consequent shoreline erosion and/or succession at the forest edge.

[Recreation]{.underline} - Development of existing recreation-related
facilities required various levels of habitat modification including
grading of shoreline areas, construction of boat ramps and docks,
placement or riprap and bank revetment, and dredging access channels and
harbors. The level of impact to *B. decurrens* or its habitat is unknown
due to a lack of historical data.

[General Plan Land Management]{.underline} - Corps of Engineers' General
Plan (GP) Lands in the St. Louis District include Riverlands
Environmental Demonstration Area (EDA) managed by the Corps, Dresser
Island/Spatterdock Bottoms managed by the Corps, Horseshoe Lake managed
in part by the Corps and the State of Illinois) and Batchtown, Calhoun
and Gilbert Lake Divisions and the Portage Island Group of the Mark
Twain National Wildlife Refuge managed by the Service. *B. decurrens*
occurs in the Gilbert Lake Division, Horseshoe Lake, the EDA and Dresser
Island/Spatterdock Bottoms. In the past, certain maintenance activities
such as grading and filling, bank stabilization, mowing and drainage
ditch clean-out may have impacted the aster on these areas. The
magnitude of these impacts is unknown due to a lack of historical data.
No previous Section 7 consultation has ever been conducted for these
activities.

[3.3 Effects of the Action]{.underline}

This section includes an analysis of the direct and indirect effects of
the proposed action on the species and its interrelated and
interdependent activities. Factors to be considered include proximity of
the action distribution timing nature of the effect duration disturbance
frequency disturbance intensity and disturbance severity. The action is
the recommended plan and its components described in Section 1,
preceding.

The Upper Mississippi River-Illinois Waterway System Navigation Study
proposes to implement both navigation improvement and ecosystem
restoration actions. The navigation improvement program also contains a
mitigation component for unavoidable adverse impacts to natural
resources of the UMRS.

This Tier I biological opinion for the decurrent false aster evaluates
the effects of these actions from a programmatic scale. Site-specific
impacts will be evaluated during the Tier II planning process for
specific projects and Tier II biological opinions provided to the U.S.
Army Corps of Engineers for those projects that are likely to adversely
affect the decurrent false aster. As the range of the species is limited
to the Illinois River and counties below its confluence with the
Mississippi, site-specific actions on the UMR above Mississippi river
mile 221 are not likely to affect the species.

The action area includes the entire known range of *B. decurrens*;
therefore, implementation of the recommended plan and its construction
components is expected to kill individual plants by clearing, crushing,
or burial (USACE 2004), and is likely to affect individuals and colonies
of both known and unknown populations as a result of both navigation
improvements and floodplain restoration. Due to the distribution of
actions within the action area, the majority of populations exist in
managed and monitored locations that will remain unaffected by
navigation improvement or ecosystem restoration, although they are found
within part of the action area defined in the Feasibility Study. The
timing of actions such as drawdown, water level management, and other
floodplain restoration or management actions is commonly directed at
enhancing the establishment and survival of moist soil species, and
would be expected to benefit *B. decurrens*. The nature of adverse
effect is noted above and is likely to involve localized impacts of
short duration to individuals within colonies, or burial of achenes that
prevents germination. Disturbance frequency will vary with the plan
component. Construction frequency for any particular navigation or
ecosystem feature would be expected once at a given location over the 50
year period of analysis. Management action frequency for water level
manipulation and moist soil management would be annual. Typical burning
rotations are approximately every four years, based on Service
management activity. The effect and intensity of disturbance depends on
the life stage of *B. decurrens* at the site. Water level management or
drawdowns would be expected to be beneficial and open up the soil
surface seed bank to germination. Burning to reduce woody species
invasion would be expected to kill mature *B. decurrens* present in the
subject burn unit. If burning were conducted in the spring, late fall,
or winter, it would have little impact on the species and clearing would
be beneficial (T. Keevin pers. com. 2004). Given the relative fecundity
of *B. decurrens* described previously, it is likely that the recovery
of a colony from a prescribed burn would be rapid.

Short term impacts to individual *B. decurrens* during construction
activity are expected to be outweighed by the long term benefits of
floodplain restoration. Improved water level control, wetland
restoration, and easement or acquisition of interest in the Illinois
River portion of the action area will contribute to *B. decurrens*
Recovery Plan objectives for habitat protection and management.

[3.3.1 Direct effects]{.underline}

[3.3.1.1 Navigation improvements]{.underline}

Continued impoundment and proposed changes in river regulation will not
cause any additional impacts to the species or its habitat, i.e. no
additional habitat will be lost due to inundation. Consequently, the
impacts of impoundment will not threaten the survival and recovery of
the species over the life of the project. The future impacts of water
level regulation are not anticipated to change, as the regulatory
capacity of the wicket gate dams at Peoria and LaGrange will not be
altered with the addition of new lock structures. Currently, the effects
of wicket gate raising and lowering create drops and spikes respectively
in the tailwaters of these dams. Dam operations will be the same as in
the past, i.e. stabilization of water levels during low flows and little
or no affect on high flows. While natural seasonal low water levels have
been eliminated by impoundment, high water and flood events will
continue to provide part of the habitat disturbance on which the species
depends. Consequently, the impacts of water level regulation will not
threaten the survival and recovery of the species over the life of the
project.

Tow traffic effects on *B. decurrens* are limited to tow-induced bank
erosion. Approximately 88,795 meters of bankline in the Peoria through
Pool 26 portion of the Illinois were identified as susceptible to bank
erosion, and two locations within the erosional areas are adjacent to
*B.* *decurrens* records (USACE 2004). Proposed mitigation for bank
erosion includes bank armoring. Bank armor construction activities may
adversely affect individuals by crushing or burial, but long term site
stability should be beneficial to the species.

Dredging and dredged material placement will become tools for ecosystem
management as well as channel maintenance under the recommended plan.
Both the St Louis District and the Rock Island District have dredged
material placement coordination processes in place. Prior to the
discharge of any dredged material, interagency teams meet to determine
the preferred placement site for the dredged material. These teams are
composed of representatives of the appropriate State and Federal
agencies. The U.S. Fish and Wildlife Service, along with representatives
of the affected State(s), participate in these teams. Additionally,
appropriate Federal and State agency representatives are coordinated
with concerning endangered species. Although these teams strive to
preclude impacts from dredged material placement, there is a potential
that *B. decurrens* may occur at sites where seed has settled but the
plant has not yet sprouted. Potential impacts of dredged material
placement can be avoided or minimized through appropriate coordination
with the Service and States. Tier II Section 7 Consultation will be
conducted as necessary.

Channel regulating structures and revetments present a potential to
adversely affect decurrent false aster populations that occur on
bankline areas where habitat modification would occur. Such modification
would include bankline grading and placement of stone (covering habitat)
for bank revetment, wingdams, and closure structures. Maintenance of
existing structures where shoreline modification would occur may also
affect the species. There is also a potential that bank grading and
associated activities could create conditions suitable for the
establishment of new populations of *B. decurrens* due to habitat
disturbance. Current construction practices for off-bank revetment,
chevron dikes, and bendway weirs do not involve terrestrial habitat
destruction and construction is done from the river without terrestrial
staging areas.

Potential impacts of constructing and maintaining channel structures and
revetment can be avoided through appropriate coordination with the
Service. Tier II Section 7 Consultation will be conducted as necessary.
Therefore, construction and maintenance of channel structures and
revetment will not threaten the survival and recovery of the species
over the life of the project.

[3.3.1.2 Mitigation]{.underline}

The recommended plan contains 20 sites recommended for mitigation of
lost backwaters and side channels on the Illinois Waterway between the
Dresden and Alton Pools. Proposed mitigation involves placement of
channel closing structures, bank protection, and/or dredging. The
effects of these actions are similar to those described in the preceding
section on navigation improvements.

[3.3.1.3 Ecosystem Restoration]{.underline}

Restoration projects are proposed to alter and improve habitat
conditions on up to an estimated 32,000 acres in the Illinois River
portions of the study area. Descriptions of proposed ecosystem
restoration measures are summarized in *Project Description* preceding.
The conservation measure described previously will allow the action
agency to develop site-specific plans that reduce the potential adverse
effects to *B. decurrens*. We anticipate that few instances will arise
where adverse effects will be unavoidable, and that where unavoidable,
reproduction, numbers, or distribution of *B. decurrens* will be
appreciably reduced.

Island Building

Island building is primarily a process of dredging and placement of
dredged material for the express purpose of restoring an eroded feature
or providing wind and wave protection to reduce sediment resuspension,
improve water clarity, provide bathymetric diversity necessary to
provided habitat for a range of aquatic life stages, and provide the
topographic diversity necessary to provide a range of terrestrial
habitats representative of the specific river reach. New or restored
island sites may present shoreline areas suitable for colonization by
*B. decurrens*, and depending on flood frequency may contribute to the
total population of the species.

Fish Passage

Fish passage involving reestablishment of lateral hydraulic connectivity
could involve tree removal and construction-related disturbance that
could open up sites for temporary establishment of *B. decurrens*
colonies. This benefit would be expected to be temporary.

Floodplain Restoration

Floodplain restoration, as described previously includes a range of
passive measures to restore and manage representative ecotypes, as well
as aggressive construction measures typical of floodplain development
and flood control projects. These activities occurring in close
proximity to maternal roost trees or roosting areas would be expected to
influence reproductive success, resulting in take of the species.
Floodplain restoration includes timber stand improvement, clearing for
grassland restoration, or other landcover modification that has the
potential to open up soil surfaces and either expose *B. decurrens* seed
or provide open substrate for its colonization depending on flood
frequency.

Water Level Management

Water level management includes both small and large-scale drawdowns to
expose and consolidate sediment, stimulate valuable vegetation, and
simulate natural river processes. Pool-wide drawdowns are seen as
feasible on the Illinois Waterway due to river and floodplain
morphometry. However, off-channel or backwater drawdowns that expose
sediment for seasonal establishment of moist soil species could benefit
*B. decurrens* and add additional seed sources if not new
self-sustaining populations.

Backwater Restoration

Backwater restoration will primarily involve dredging and dredged
material placement, some of which may be used for island construction,
and some of which may be used to create topographic diversity beneficial
to a variety of terrestrial plants and animals. Dredged material
placement often involves the deployment of standard construction
equipment at the target locations and has the potential to destroy
existing *B. decurrens* colonies as well as open up new substrate for
colonization.

Side Channel Restoration

Side channel restoration may potentially affect *B. decurrens* where
construction activities involve shoreline work and construction
equipment access. Such effects would be minor, temporary, and localized.

Wing Dam and Dike Alteration

Wing dam and dike alteration is anticipated to have the same effects
noted previously in *Mitigation* and *Navigation Improvements*.

*Island and shoreline protection* potentially affecting bankline
individuals or colonies of *B. decurrens* is proposed over a total
length of 41 miles in this same portion of the study area. This bankline
total includes that work proposed to offset navigation induced erosion
and that work proposed to protect or restore shorelines and islands as
part of the ecosystem component.

Interrelated and Interdependent Actions

The recommended plan contains a suite of administrative, operational,
and construction activities that are directed at navigation improvement
and ecosystem restoration throughout the UMRS. An interrelated activity
is an activity that is part of the proposed action and depends on the
proposed action for its justification. Such things as timber management
and General Plan Land management are all interrelated to both the
operation and maintenance of the 9-Foot Navigation Channel Project and
implementation of the recommended that integrates these government
functions with the ecosystem restoration component of the plan.

The St. Louis District has recently completed an Action Plan for *B.
decurrens* on Corps of Engineers General Plan lands within the St. Louis
District (USACE 1998). Development of the Action Plan was a joint effort
between the U.S. Fish and Wildlife Service and the Corps of Engineers
with participation from Dr. Marian Smith (Southern Illinois University -
Edwardsville), an expert on the species. The action plan included a
monitoring protocol and initial census, evaluation of management
techniques, training of site personnel to identify the species,
development of an education and outreach program, development of land
management objectives, and development of a pre-action checklist for
project implementation. The next step is to implement the plan and to
incorporate a management protocol into the Corps' Operational Management
Plan for the area.

Consistent with the Action Plan, the St. Louis District has completed
Phase I (Monitoring Protocol), an initial census of the Environmental
Demonstration Area, to determine the locations and general population
sizes of *B. decurrens* (USACE *in litt*. to Gerry Bade, November 3,
1999). Similar management possibilities exist on other Corps lands, U.S.
Fish and Wildlife Service refuge lands, and lands owned and/or managed
by the Missouri Department of Conservation and the Illinois Department
of Natural Resources. Implementation of this Action Plan will provide
benefits to the species and enhance the potential for its survival and
recovery.

An interdependent activity is an activity that has no independent
utility apart from the action under consultation. The future need for
additional fleeting areas is unknown. However, potential impacts of
development of fleeting areas can be avoided through appropriate
coordination with the Service. Tier II Section 7 Consultation will be
conducted as necessary. Therefore, fleeting will not threaten the
survival and recovery of the species over the life of the project.

Indirect Effects

[Navigation]{.underline} - Tow traffic was projected to affect
approximately 88,795 meters of shoreline on the Illinois River,
necessitating mitigation in the form of bank protection. Increased
traffic is not expected to increase the amount of susceptible bankline.

[Port facilities]{.underline} - The future need for additional port
facilities is unknown. However, potential impacts of development of port
facilities can be avoided through appropriate coordination with the
Service. Tier II Section 7 Consultation will be conducted as necessary.
Therefore, development of port facilities will not threaten the survival
and recovery of the species over the life of the project.

[Exotic species]{.underline} - The future effects of introduced exotic
species on *B. decurrens* cannot be predicted at this time. Given the
species life history, it would be possible for disease or insects to
exploit whole colonies at a time, but their ability to spread to other
colonies within a population or to the disjunct populations throughout
the species range is unknown. While unquantified, the presence of buried
achenes in the floodplain seedbank suggests a measure of resilience to
such events. The species ability to compete with invasive plant species
is unknown; therefore, the potential effect of exotic species cannot be
forecast at this time.

[Contaminants]{.underline} - The effects of contaminants on *B.
decurrens* have not been researched; however, it is considered
vulnerable to herbicide use in low-lying marginal lands for crop weed
control (USFWS 1990). Implementation of the recommended plan is not
anticipated to contribute to current contaminant loading in the action
area. Non-point source contaminants introduced from stormwater or
agricultural runoff may be positively influenced by achievement of some
floodplain restoration objectives, but watershed or upland
treatment/restoration measures are beyond the scope of this study.
Therefore, the effects of contaminants on *B. decurrens* cannot be
quantified at this time.

[Recreation effects]{.underline} - The future need for additional
government-operated recreational facilities is unknown. However,
potential impacts of development of recreational facilities can be
avoided through appropriate coordination with the Service. Tier II
Section 7 Consultation will be conducted as necessary. Therefore,
development of recreational facilities will not threaten the survival
and recovery of the species over the life of the project. Development on
private lands adjacent to ecosystem restoration projects is also an
indirect effect, but is addressed subsequently in Cumulative Effects.

Other indirect effects are anticipated to arise from administrative
actions proposed in the recommended plan, primarily partner agencies'
adoption of the adaptive management paradigm, in short "learning by
doing," and provision of additional Corps authority for ecosystem
restoration. It is likely that all effects to listed species subject to
this consultation cannot be foreseen at this time. As part of the
adaptive management approach, predictive models are proposed to be
developed in the implementation phase of the recommended plan, and will
necessarily involve elements of listed species life history. The Service
expects that further collaboration among partner agencies to develop,
test, and validate assumptions used in such models will result in
modifications to the recommended plan that contribute to listed species'
recovery Adaptive management requires a more responsive approach to
problems and opportunities as they arise and agency regulatory processes
can limit responsiveness.

The recommended plan calls for additional authority for ecosystem
restoration and will allow the use of Corps channel maintenance
capabilities for restoration work in off-channel areas. Because channel
maintenance priorities are dictated seasonally by the dynamics of river
hydraulics and sediment transport, it will not be possible to predict
where specific actions will occur on an annual basis, or on a basis that
permits total avoidance of impact to the decurrent false aster. It is
likely that although the long term effects of ecosystem restoration will
be beneficial, logistically advantageous use of channel maintenance
equipment could adversely affect individual plants and colonies on a
site-specific basis.

Species response to the proposed action

Smith (2002) identified 26 populations holding an estimated 378,887
individuals in the action area, down from over million individuals in
2001. Elsewhere in the species range, recent monitoring of 28 colonies
associated with a highway relocation project in Madison and St Clair
counties, Illinois, resulted in summary estimates ranging from one
flowering plant to over one million. Eighty percent of the colonies had
higher populations in 2003 than in 2002 (Ketzner et al, 2004). The
subject highway project lies within the technical study area boundary
but would not be affected by implementation of the recommended plan.
Populations existing on Federal and state lands are already receiving
management consideration. Ecosystem restoration on those lands, as well
as water level management improvements on the system that mimic the
natural hydrograph, would be expected to elicit a positive response from
*B. decurrens*. The life history previously discussed for *B. decurrens*
demonstrates fairly specific conditions (soil type, temperature, light)
necessary for establishment and persistence in the wild that may be
interpreted as sensitivity to change; however, the species is actually
dependent on change in the form of periodic disturbance to open new
areas for colonization and seed dispersal. Research indicated that
factors other than fecundity are responsible for the threatened status
of *B. decurrens*; therefore, from a reproductive potential standpoint,
the species may be considered very resilient to disturbance. It would be
expected to respond positively to appropriately-timed moist soil
management and water level management that provide open substrate for
germination. As a pioneer or fugitive species dependent on ecosystem
disturbance, *B. decurrens* is not a likely representative of ecosystem
equilibrium at the individual population or microhabitat scale, and
recovery rate may not be a meaningful metric in assessing its response
to the recommended plan. Colonies within populations are generally known
to only persist for 3 to 5 years. However, it is a representative of the
continued existence of dynamic natural processes on a landscape scale,
as it is dependent on periodic flooding to reduce competition and
disperse seed to newly available habitat. Two goals of the recommended
plan are to maintain viable populations of native species in situ; and
represent all native ecosystem types across their natural range of
variation. Any improvement in water level management on the Illinois
River and restoration of portions of its floodplain would be expected to
maintain conditions necessary for the continued viability of *B.
decurrens*.

[3.4 Cumulative Effects]{.underline}

Cumulative effects include the effects of State, local or private
actions that have occurred in the action area. Future Federal actions
that are unrelated to the proposed action are not considered in this
section because they require separate consultation pursuant to section 7
of ESA.

Changes in the Illinois river hydrograph illustrated in Figure 1 are due
in part to the construction operation and maintenance of the navigation
system, in part to altered hydrology from wetland drainage and
agricultural activity (ditching and tiling), and in part to development
throughout the upper Illinois River watershed. No estimate of the
relative contribution of each factor to discharge represented on the
hydrograph has been made, but it is reasonable to conclude that
development will continue, and that unstable water levels will continue
to dictate vegetation success in the floodway of the Illinois River.
Likewise, although programs exist for wetland restoration on private
lands, that agriculture will remain a dominant and determining factor in
floodplain hydrology and landcover.

Some non-Federal actions in the floodplain of the Illinois and Upper
Mississippi Rivers will likely require Federal review under Section 404
of the Clean Water Act (CWA) or Section 10 of the Rivers and Harbors
Act. Ecosystem restoration may induce the development of adjacent
agricultural properties for outdoor sporting purposes, including wetland
restoration, moist soil management, and general conversion of row crop
landcover to forest or grassland wildlife habitat. Such conversion would
be expected to be beneficial to *B. decurrens*. Examples of non-Federal
actions currently underway on the Illinois River floodplain that could
be beneficial are those restoration projects undertaken by the Nature
Conservancy at Emiquon, a 7000 acre site formerly known as Wilder Farms
in Fulton County, and Spunky Bottoms, a 2026 acre site in Brown County,
opposite the USFWS Meredosia National Wildlife Refuge (The Nature
Conservancy 2004a & b). Also, a consortium of non-profit organizations
has acquired the former Hennepin Drainage and Levee District and is in
the process of reestablishing elements of the natural hydrology and
native plant communities on approximately 2600 acres of floodplain near
Hennepin Illinois (The Wetlands Initiative, 2004).

It is possible that unauthorized activities or activities not requiring
Federal review under the CWA could adversely affect the aster or its
habitat. While some population exist on private lands, it is impossible
to determine the magnitude of any such impacts in the absence of
comprehensive surveys of all private lands within the species range.

[3.5 Conclusion]{.underline}

After reviewing the current status of *B. decurrens*, the environmental
baseline for the action area, the effects of the proposed action, and
the cumulative effects, it is the Service\'s biological opinion that the
proposed action is not likely to jeopardize the continued existence of
the species. No critical habitat has been designated for this species;
therefore, none will be affected.

[3.6 Incidental Take Statement]{.underline}

Sections 7(b)(4) and 7(o)(2) of ESA do not apply to the incidental take
of listed plant species. However, protection of listed plants is
provided to the extent that ESA requires a Federal permit for removal or
reduction to possession of endangered plants from areas under Federal
jurisdiction, or for any act that would remove, cut, dig up, or damage
or destroy any such species on any other area in knowing violation of
any regulation of any State or in the course of any violation of a State
criminal trespass law.

Conservation Recommendations

Section 7(a)(1) of ESA directs Federal agencies to utilize their
authorities to further the purposes of ESA by carrying out conservation
programs for the benefit of endangered and threatened species.
Conservation recommendations are discretionary agency activities to
minimize or avoid adverse effects of a proposed action on listed species
or critical habitat, to help implement recovery plans, or to develop
information.

1\. The St. Louis District and the U.S. Fish and Wildlife Service
developed an action plan for managing and protecting populations of *B.
decurrens* on the Riverlands - Environmental Demonstration Area (EDA).
The action plan included a monitoring protocol and initial census,
evaluation of management techniques, training of site personnel to
identify the species, development of an education and outreach program,
development of land management objectives, and development of a
pre-action checklist for project implementation. Implementation of this
action plan is hereby recommended.

2\. The Corps should provide assistance to the Service towards recovery
of the species by assembling and providing all its *B. decurrens* survey
data in GIS format. In addition, we request the Corps' participation in
updating the recovery plan and participation in related recovery
actions.

**Literature Cited**

Baskin, C.C. and J.M. Baskin. 1988. Germination ecophysiology of
herbaceous plant species in a temperate region. Amer. J. Bot.
75:286-305.

Baskin, C.C. and J.M. Baskin. 2002. Achene germination ecology of the
federally threatened floodplain endemic Boltonia decurrens. Am. Midl.
Nat. 147:16-24.

Ketzner, D. P. Marcum, A. Plocher, D. Keene, and R. Larimore. 2004.
Results from the decurrent false aster (Boltonia decurrens) recovery
project -- FAP 999 (New Mississippi River Crossing, Relocated I-70 and
I-64 Connector) and FAP 14 (Il Route 3 Relocation), Madison and St Clair
Counties, Illinois -- 2003. Illinois Natural History Survey, Center for
Wildlife Ecology, Champaign, Illinois. 15 pp.

Lee, M.T., and J.B. Stall. 1976. Sediment conditions in backwater lakes
along the Illinois River - Phase 2. Il. St. Wat. Surv. Contract Report
176B. 63 pp.

Moss, J. 1997. Stage-based demography of the threatened floodplain
species *Boltonia decurrens*. M.S. Thesis, Southern Illinois University,
Edwardsville, IL.

Nature Conservancy, The. 2004a. The Emiquon Project.
http.//nature.org/wherewework/northamerica/state/Illinois/preserves/art1112.html.

Nature Conservancy, The 2004b. Spunky Bottoms.
http.//nature.org/wherewework/northamerica/state/Illinois/preserves/art1113.html

Schwegman, J.E. and R.W. Nyboer. 1985. The taxonomic and population
status of *Boltonia decurrens* (Torr. & Gray) Wood. Castanea 50:112-115.

Smith, M. 1991. Life history research for decurrent false aster. Il.
Dept. Cons. Contract Report, Springfield, IL. 26 pp.

Smith, M. 2002. Year 2002 inventory of decurrent false aster (*Boltonia
decurrens*) U.S. Army Corps of Engineers, Rock Island District, final
report. 5pp.

Smith, M., T. Brandt, and J. Stone. 1995. Effects of soil texture and
microtopography on germination and seedling growth in *Boltonia
decurrens* (Asteraceae), a threatened floodplain species. Wetlands
15:392-396.

Smith, M. and T. Keevin. 1998. Achene morphology, production and
germination, and potential for water dispersal in *Boltonia decurrens*
(decurrent false aster), a threatened floodplain species. Rhodora
100:69-81.

Smith, M., T. Keevin, P. Mettler-McClure, and R. Barkau. 1998. Effects
of the flood of 1993 on *Boltonia decurrens*, a rare floodplain plant.
Regulated Rivers: Research and Management 14:191-202.

Smith, M., Y. Wu, and O. Green. 1993. Effects of light and water-stress
on photosynthesis and biomass production in *Boltonia decurrens*
(Asteraceae), a threatened species. Am. J. Bot. 80:854-864.

Stoecker, M.A., M. Smith, and E.D. Melton. 1995. Survival and aerenchyma
development under flooded conditions of *Boltonia decurrens*, a
threatened floodplain species and Conyza canadensis, a widely
distributed competitor. Am. Midl. Nat. 134:117-126.

USACE (U.S. Army Corps of Engineers). 1998. Action plan for managing and
protecting populations of *Boltonia decurrens*. 3 pp.

\_\_\_\_\_. 2004. Biological Assessment of the Upper Mississippi
River-Illinois Waterway System Navigation Study. 193pp.

\_\_\_\_\_. 1999. Tier I of a two-tiered biological assessment -
operation and maintenance of the Upper Mississippi River navigation
project within the St. Paul, Rock Island, and St. Louis Districts.
Mississippi Valley Division, Vicksburg, MS. 111 pp. plus appendices.

\_\_\_\_\_. In litt. Correspondence to Gerry Bade, U.S. Fish and
Wildlife Service, Rock Island, IL. November 3, 1999.

USFWS (U.S. Fish and Wildlife Service). 1990. Decurrent false aster
recovery plan. U.S. Fish and Wildlife Service. Twin Cities, MN. 26 pp.

USFWS (U.S. Fish and Wildlife Service). 2000. Final Biological Opinion
for the operation and maintenance of the 9-Foot navigation channel on
the upper Mississippi River system. 240pp.

Wetlands Initive, The. 2004. The Hennepin & Hopper Lakes Project.
<http://www.wetlands-initiative.org/pages/page28.html>

**Personal Communication**

Keevin, T. 2004. Senior Scientist, U. S. Army Corps of Engineers, St
Louis District. Telephone conversation with Bob Clevenstine, Rock Island
Field Office, U. S. Fish and Wildlife Service, Rock Island Illinois.

**4.0 Higgins eye pearlymussel (*Lampsilis higginsii*)**

[4.1 Status of the Species]{.underline}

This section presents the biological or ecological information relevant
to formulating the biological opinion. Appropriate information on the
species' life history, its habitat and distribution, and other data on
factors necessary to its survival, is included to provide background for
analysis in later sections. This analysis documents the effects of all
past human and natural activities or events that have led to the current
status of the species. Portions of this information are also presented
in listing documents, the recovery plan (USFWS 2004), the Final
Biological Opinion for the Operation and Maintenance of the 9-Foot
Navigation Channel on the Upper Mississippi River System (USFWS 2000),
and the Biological Assessment of the Upper Mississippi River-Illinois
Waterway System Navigation Study (USACE 2004).

# 

[4.1.1 Species /critical habitat description]{.underline}

The Higgins Eye Pearlymussel Recovery Plan identifies ten Essential
Habitat Areas (EHAs) that are important for the recovery of the species
(U.S. Fish and Wildlife Service 2004). The ten Essential Habitat Areas
are: 1) the St. Croix River near Interstate (River Mile 47.5 - 48.5), 2)
the St. Croix River at Hudson, Wisconsin (River Mile 16.2 - 17.6), 3)
the St. Croix River at Prescott, Wisconsin (River Mile 0 -- 0.2), 4) the
Wisconsin River near Muscoda, Wisconsin (Orion), 5) the UMR at Whiskey
Rock, at Ferryville, Wisconsin, Pool 9 (River Mile 655.8 - 658.4), 6)
the UMR at Harpers Slough, Pool 10 (River Mile 639.0 - 641.4), 7) the
UMR Main and East Channels at Prairie du Chien, Wisconsin, and
Marquette, Iowa, Pool 10 (River Mile 633.4 - 637), 8) the UMR at
McMillan Island, Pool 10 (River Mile 616.4 - 619.1), 9) the UMR at
Cordova, Illinois, Pool 14 (River Mile 503.0 - 505.5), and 10) the UMR
at Sylvan Slough, Quad Cities, Illinois, Pool 15 (River Mile 485.5 -
486.0). In addition, the original recovery plan described the following
nine secondary habitats: 1) Guttenberg, Iowa, Pool 11 (River Mile 613),
2) Cassville, Wisconsin, Pool 11 (River Mile 607), 3) Dubuque, Iowa,
Pool 12 (River Mile 580); (4) Adam Island (vicinity), Iowa, Pool 14
(River Mile 507); (5) Rapids City, Illinois, Pool 14 (River Mile 496);
(6) Lower Sylvan Slough, Illinois, Pool 16 (River Mile 482); (7)
Andalusia Slough, Illinois, Pool 16 (River Mile 473); (8) Barkis Island,
Illinois, Pool 17 (River Mile 444); and (9) Jonas Johnson Island,
Illinois, Pool 17 (River Mile 439) (U.S. Fish and Wildlife Service
2004).

[4.1.2 Life history]{.underline}

Higgins eye occurs most frequently in medium to large rivers with
current velocities of 0.5 to 1.5 feet per second and in depths of 2 to
20 feet (U.S. Fish and Wildlife Service 2004). It tends to be found in
water with dissolved oxygen greater than 5 parts per million (ppm) and
calcium carbonate levels greater than 50 ppm. The species is correlated
with a firm, coarse sand substrate (Hornbach *et al.* 1995). Higgins eye
usually is found in large, stable mussel beds with relatively high
species and age diversity. Hornbach *et al.* (1995) concluded Higgins
eye seemed to be associated with areas of higher mussel species richness
and generally higher mussel population densities.

The reproductive cycle of Higgins eye is typical of the family Unionidae
(Cummings and Mayer 1992). Males discharge sperm into the surrounding
water; females obtain the sperm as they siphon water for food and
respiration. Eggs are fertilized in gill sacs (marsupia) in the female;
fertilized eggs are retained in the marsupia until they mature into
glochidia and are released. The mantle edge near the posterior shell
resembles a small swimming fish that is postulated to attract predator
fish. Gill tissue containing glochidia protrudes between the mantle
flaps. When a fish attacks the gill tissue, glochidia are released, thus
enhancing the probability that glochidia will come into contact with a
host fish. Released glochidia attach themselves to the gills of host
fish. Successfully attached glochidia mature and excyst from hosts\'
gills as juvenile mussels; they settle to the substrate and become
sedentary in the substrate, if it is suitable. The species is
bradytictic (i.e., a long-term breeder) retaining developing glochidia
throughout the year, except for the period following glochidia release.
Glochidia are carried in the gill marsupia through winter and released
the following spring or summer (Baker 1928, Holland-Bartels and Waller
1988).

Holland-Bartels and Waller (1988) tested 15 species of UMR fish and
reported walleye (*Stizostedion vitreum*) and largemouth bass
(*Micropterus salmoides*) as the most successful host fish for Higgins
eye, as determined by glochidial persistence and maturation to juvenile
stage on the fish. Subsequent studies (Gordon 2001) found smallmouth
bass (*Micropterus dolomieui*) to be a suitable host as well.

[4.1.3 Population dynamics]{.underline}

Population dynamics are described below under Status and distribution.

[4.1.4 Status and distribution]{.underline}

The Higgins eye pearlymussel (*Lampsilis higginsii*) was listed as an
endangered species by the U.S. Fish and Wildlife Service (Service) on
June 14, 1976 (Federal Register, 41 FR 24064). The major reasons for
listing Higgins eye were the decrease in both the abundance and range of
the species. As stated in the recovery plan (U.S. Fish and Wildlife
Service 2004), Higgins eye was never abundant, and Coker (1919)
indicated it was becoming increasingly rare around the turn of the last
century. The fact that there were few records of live specimens from the
early 1900s until the enactment of the Endangered Species Act in 1973
was a major factor in its listing in 1976 (U.S. Fish and Wildlife
Service 2004). A variety of factors have been listed as affecting
Higgins eye over time including commercial harvest; impoundment from the
federal 9-Foot Channel Project; channel maintenance dredging and
disposal activities; changes in water quality from municipal,
industrial, and agricultural sources; unavailability of appropriate
glochidial hosts; exotic species; and disease (U.S. Fish and Wildlife
Service 2004).

Distribution

The historical distribution of Higgins eye is not known with certainty.
While never considered an abundant species, it is believed to have been
distributed widely, inhabiting the Upper Mississippi River (UMR) main
stem from just north of St. Louis, Missouri, to Minneapolis-St. Paul,
Minnesota (Coker 1919). It also was found in several UMR tributaries
including the Ohio, Illinois, Sangamon, Iowa, Cedar, Wapsipinicon, Rock,
Wisconsin, Black, Minnesota, and St. Croix Rivers (U.S. Fish and
Wildlife Service 2004). The range of Higgins eye has been reduced
significantly from its historical distribution and now includes the UMR
upstream of Lock and Dam 22 near Hannibal, Missouri, the lower St. Croix
River between Wisconsin and Minnesota, the lower Wisconsin River,
Wisconsin, and the lower Rock River in Illinois (U.S. Fish and Wildlife
Service 2004). Based on work done by Cawley (1996), the known range of
Higgins eye has been extended 98 miles to the south and 82 miles to the
north of the range described in the 1983 recovery plan, based solely on
the collection of dead specimens. However, since 1980, live Higgins eye
have not been collected on the UMR downstream of Lock and Dam 19, though
a single fresh dead specimen was collected in Pool 22 in the late 1980s
(U.S. Fish and Wildlife

Major Threats

The single most significant threat to Higgins eye appears to come from
zebra mussels (*Dreissena polymorpha*), a nonindigenous species
introduced into the United States from the Black and Caspian Seas (U.S.
Fish and Wildlife Service 2000). Zebra mussels were introduced into Lake
St. Clair in the mid 1980s from discharge of ship ballast water. The
species is now reproducing and invading North America\'s lakes and
rivers. Zebra mussels invaded the Illinois River from Lake Michigan
through the Chicago Sanitary and Ship Canal; once in the Illinois River,
they quickly invaded the UMR. The invasion from Lake Michigan probably
resulted from zebra mussel veligers drifting downstream through the
canal system to the Illinois River. However, because zebra mussels
attach to hard objects/substrates, they readily attach to the hulls of
boats including commercial tows and recreational boats navigating on the
Illinois and Mississippi Rivers and are consequently transported by
these vessels. Unfortunately, the ability of zebra mussels to attach to
boat hulls and associated equipment provided the critical vector for
upstream transport on the UMRS by large commercial and recreational
boats. All EHAs for Higgins eye are located in the UMR and tributaries
upstream of the confluence of the Illinois River (U.S. Fish and Wildlife
Service 2004). Today, zebra mussels are found in all EHAs, with the
exception of the Interstate EHA on the St. Croix River.

Zebra mussels can decimate native mussels in waters where they become
establish and reach high densities (U.S. Fish and Wildlife Service
2000). They affect native mussels directly by attaching to the shells of
the native species and impairing feeding and filtering functions,
preventing valve closure, and causing shell deformation. Zebra mussels
may also indirectly harm native mussels by competing for food resources
and changing the water chemistry, i.e., decreasing dissolved oxygen
levels and increasing ammonia levels (U.S. Army Corps of Engineers
2004a). Furthermore, zebra mussels can prevent recolonization of native
mussels in formerly suitable habitats and prevent their burrowing into
substrate by forming an impenetrable layer on the bottom (U.S. Fish and
Wildlife Service 2000).

Concerning potential impacts to Higgins eye, a reconnaissance study by
the U.S. Army Corps of Engineers predicted that zebra mussels may
adversely affect approximately 1,700 acres of prime Higgins eye habitat
and eventually eliminate 573,000 individuals, or 83 percent of the total
known population in EHAs and secondary habitat areas (U.S. Army Corps of
Engineers 2003). A loss of this magnitude occurred at the Prairie du
Chien EHA, Wisconsin, in UMR Pool 10. Studies by the Corps of Engineers
in the East Channel reference site found the native mussel community
decimated by zebra mussels (U.S. Army Corps of Engineers 2004a). Zebra
mussels were first collected in 1993, averaging two individuals per
square meter. Density increased to over 10,000 individuals per square
meter by 1996 (Figure 4-1), and a precipitous decline in native mussels
followed (Figure 4-2). In particular, catch per unit effort of Higgins
eye declined from nearly 1.0 individual per minute in 1995 to less than
0.1 individual per minute in 2000 through 2003 (Figure 4-3).

![](media/image3.wmf){width="5.997916666666667in"
height="2.998611111111111in"}

**Figure 4-1. Zebra mussel abundance in the East Channel at Prairie du
Chien, Wisconsin. Source: U.S. Army Corps of Engineers (2004a).**

![](media/image4.wmf){width="5.997916666666667in"
height="2.9993055555555554in"}

**Figure 4-2. Native mussel densities in the East Channel at Prairie du
Chien, Wisconsin. Source: U.S. Army Corps of Engineers (2004a).**

![](media/image5.wmf){width="5.497916666666667in" height="3.375in"}

**Figure 4-3. Catch per unit effort of Higgins eye pearlymussels
(*Lampsilis higginsii*) at the East Channel Reference Site within the
Prairie du Chien Essential Habitat Area, Pool 10, Upper Mississippi
River, Wisconsin. Source: Unpublished 2003 data from the U.S. Army Corps
of Engineers.**

A major factor contributing to zebra mussel distribution and abundance
on the UMR, and consequently the current status of Higgins eye, is the
operation and maintenance of the 9-Foot Channel project authorized by
Congress in the Rivers and Harbors Act of 1927. In April 2000, the
Service issued a final Biological Opinion for the Operation and
Maintenance of the 9-Foot Navigation Channel Project on the Upper
Mississippi River System (UMRS) in Illinois, Iowa, Minnesota, Missouri,
and Wisconsin (U.S. Fish and Wildlife Service 2000). In that biological
opinion, we concluded that continued operation and maintenance of the
9-Foot Channel Project for an additional 50 years is likely to
jeopardize the continued existence of Higgins eye due to upstream
transport of zebra mussels by commercial barge transportation using the
project. Our jeopardy opinion included a Reasonable and Prudent
Alternative (RPA) to avoid jeopardizing the species. The RPA required
the Corps of Engineers to:

1 Conduct a Higgins eye relocation feasibility analysis and prepare a
Higgins eye Relocation Plan.

2\. Conduct a zebra mussel reconnaissance study to determine the
necessary measures, projected costs, and likelihood of success in
controlling zebra mussels in the UMR.

The biological opinion also included the following Reasonable and
Prudent Measures (RPMs) to minimize incidental take:

1\. Implement a monitoring program for Higgins eye and other unionids in
the UMR.

2\. Investigate opportunities to protect live Higgins eye individuals
with essential habitat areas in the UMR during the interim period
between issuance of the biological opinion and implementation of the
relocation phase.

3\. Minimize upriver distribution of zebra mussels by commercial
navigation through locks and dams in the UMRS.

The Corps of Engineers is implementing the reasonable and prudent
alternatives and measures identified in the biological opinion (U.S.
Army Corps of Engineers 2004a). To assist in their effort, the Corps of
Engineers established an interagency Mussel Coordination Team (MCT) with
a Partnership Agreement signed by agency heads of the U.S. Army Corps of
Engineers, St. Paul and Rock Island Districts; the U.S. Fish and
Wildlife Service; the U.S. Geological Survey; the National Park Service;
the U.S. Coast Guard; and the Departments of Natural Resources from
Minnesota, Wisconsin, Iowa, and Illinois. The purpose of the MCT is to
work cooperatively with the Corps of Engineers to coordinate and plan
relevant mussel studies and projects, share information on the
management of native mussel resources, and control nonindigenous
mussels. The status of these efforts is summarized below (U.S. Army
Corps of Engineers 2004a):

1\. Zebra Mussel Management -- The Corps of Engineers conducted a
reconnaissance study to evaluate potential zebra mussel management
measures (U.S. Army Corps of Engineers 2003). The study concluded that
there are potentially feasible zebra mussel control alternatives, which
may be in the federal interest to pursue, and recommended a \$2.1
million feasibility study be undertaken.

2\. The Corps of Engineers and the MCT are conducting pilot projects to
protect adult Higgins eye within EHAs by annually removing zebra mussels
from individuals. The pilot projects are being conducted at the
following locations in the UMR: Pool 10 (Harpers Slough), Pool 11
(Cassville), and Pool 14 (Cordova). Over 600 Higgins eye have been
collected and annually cleaned of zebra mussels.

3\. The Corps of Engineers developed a Higgins eye relocation action
plan in collaboration with the MCT (U.S. Army Corps of Engineers 2002).
The objective of this relocation effort is to establish a minimum of
five new and viable populations of Higgins eye with a minimum of 500
individuals in the UMR and/or tributaries un-infested or with low-level
infestations of zebra mussels. With the goal of achieving five viable
populations, relocation efforts are being attempted at 10 UMR sites:
Pools 2, 3, 4 and 17; Rock River in Illinois; Cedar, Iowa, and
Wapsipinicon Rivers in Iowa; Wisconsin River in Wisconsin, and a site to
be determined. A variety of relocation methods are being employed
including adult relocation, release of glochidia inoculated free-ranging
wild and hatchery fish, direct release of juveniles, and raising
subadults in cages for 2 to 3 years prior to placement at a final
relocation site. Over 500 age 3 subadults grown in cages have been
placed in Pools 3 and 4 at their final relocation site, and
approximately 8,500 age 1 and 2 subadults presently are being grown in
cages. Nearly 500 adults have been moved to relocation sites in UMR
Pools 2 and 3. Over 17,000 fish, each capable of producing around 70
juvenile Higgins eye, have been held in open bottom cages or released at
the relocation sites from 2000 to 2004 The stocking should be completed
by 2007, with augmentation thereafter. The plan includes a long-term
monitoring program to assess the viability of these new populations.

4\. A long-term program to monitor trends in abundance and distribution
of Higgins eye and other native mussels in EHAs and secondary habitats
has been ongoing since 2000. Seven to eight areas are sampled annually.
Trends in abundance and distribution of zebra mussels in the UMRS are
also being collected at these areas. Zebra mussel veliger densities are
being monitored on the UMR main stem from above the head of navigation
in Minneapolis, Minnesota, to Pool 24 and all major tributaries.

Since 2000, there are also positive observations on the status of
Higgins eye. In 2003, a significant drop in zebra mussel densities was
observed at the Prairie du Chien EHA; less than 100 individuals per
square meter were found in quantitative samples (Figure 4-1).
Conversely, the abundance of native mussels increased slightly in 2002
and 2003 (Figure 4-2). With respect to Higgins eye at the Prairie du
Chien EHA, only one live individual was collected in each year in 1999
and 2000 (U.S. Army Corps of Engineers 2004a). However, in 2003, six
Higgins eye were collected resulting in slightly higher catch per unit
effort (Figure 4-3). Equally important in 2002 and 2003, the percentage
of individuals and species collected that were less than 30 millimeters
long increased, showing evidence of recent recruitment (Figure 4-4).

![](media/image6.wmf){width="5.999305555555556in"
height="3.298611111111111in"}

**Figure 4-4. Native mussel recruitment in the East Channel at Prairie
du Chien, Wisconsin. Source: U.S. Army Corps of Engineers (2004a).**

Conservation Status

The range of Higgins eye has been reduced significantly from its
historical distribution and now includes the UMR upstream of Lock and
Dam 22 near Hannibal, Missouri, the St. Croix River between Wisconsin
and Minnesota, the Wisconsin River, Wisconsin, and the lower Rock River
in Illinois (U.S. Fish and Wildlife Service 2004). In the 1990s, the
total population of Higgins eye in EHAs and secondary habitats was
estimated to be 697,758 before the zebra mussel invasion; today, the
population may have declined to 182,611 Higgins eye based on adverse
effects from zebra mussels (U.S. Army Corps of Engineers 2003).

We are cautiously optimistic that the status of Higgins eye
reproduction, numbers and distribution improved since 2000 due to (1) a
decrease in abundance of zebra mussels in many areas of the UMRS; (2) an
increase in recruitment at the Prairie du Chien EHA (U.S. Army Corps of
Engineers 2004a); and (3) observed recruitment of Higgins eye in UMR
Pool 16 (Helms 2000). Our optimism since 2000 is also based on
successful Higgins eye propagation and relocation activities of the
Corps of Engineers and MCT (Mussel Coordination Team 2003). Furthermore,
we remain hopeful that funding will be provided to the U.S. Army Corps
of Engineers to initiate the Zebra Mussel Management Feasibility Study,
and implement feasible measures in a timely manner (U.S. Army Corps of
Engineers 2003).

Conservation Needs

Clearly, the immediate conservation needs for Higgins eye focus on
reducing adverse effects from zebra mussels. Priority Task 1.1 of the
revised recovery plan is to assess and limit the impact of zebra mussels
on Higgins eye (U.S. Fish and Wildlife Service 2004). In order to
achieve the immediate goal of reclassifying Higgins eye to threatened
status and long term goal of species recovery, at least five identified
EHAs must contain reproducing, self-sustaining populations of Higgins
eye that are not threatened by zebra mussels. The five EHAs must include
the Prairie du Chien HHA and at least one EHA each in the St. Croix
River and in UMR Pool 14 (U.S. Fish and Wildlife Service 2004). To
achieve these goals, it is critical that the Corps of Engineers initiate
the Zebra Mussel Management Feasibility Study and implement feasible
control measures in a timely manner (U.S. Army Corps of Engineers 2003).
It is likewise critical for the Corps of Engineers and MCT to continue
their efforts to propagate and relocate Higgins eye.

[4.2 Environmental Baseline]{.underline}

This section is an analysis of the effects of past and ongoing human and
natural factors leading to the current status of the species, its
habitat, and ecosystem within the action area. The purpose is to analyze
the effects on the species at the action level.

[4.2.1 Status of the Higgins eye pearlymussel within the action
area]{.underline}

As the action area overlaps completely the range of Higgins eye, thus
its status in the action area is similar to that described in the Status
of the Species section. Currently, the greatest threats to Higgins eye
and other native mussels of the UMRS are from nonindigenous species.
Zebra mussels must be effectively managed, or their abundance and
distribution controlled by natural forces (i.e. predation, diseases,
habitat limitations), so that their effects no longer threaten the
survival and recovery of Higgins eye. It is critical that the Corps of
Engineers initiate the Zebra Mussel Management Feasibility Study and
implement feasible control measures in a timely manner (U.S. Army Corps
of Engineers 2003).

We are seriously concerned that additional nonindigenous species like
the quagga mussel and back carp may become established in the UMRS over
the next 50 years. However, we remain cautiously optimistic for the
survival and recovery of Higgins eye. Our optimism is directly related
to both the decreasing abundance of zebra mussels in some portions of
the UMRS since 2000, and recent evidence of recruitment of Higgins eye
at the Prairie du Chien EHA and in UMR Pool 16. We are also optimistic
that implementation of the Reasonable and Prudent Alternative from the
previous biological opinion will establish five new and viable
populations of Higgins eye in the UMRS outside the threat of zebra
mussels, and control upstream transport of zebra mussels (and
potentially quagga mussels) over the next 50 years. In addition,
construction of habitat restoration projects under EMP and other
authorities to restore the ecological health of the UMRS will improve
habitat conditions for Higgins eye and other native mussels. Likewise,
efforts to conserve native mussels and facilitate public education and
outreach will provide positive benefits to Higgins eye and other
species. Therefore, reproduction, numbers and distribution of Higgins
eye should continue to improve over the next 50 years if zebra mussels
and other harmful noninvasive species can be managed, or fail to reach
harmful densities.

Distribution

The range-wide distribution of Higgins eye is contained within the
action area for the Upper Mississippi River-Illinois Waterway System
Navigation Study and is described in the preceding section on Status of
the Species.

[4.2.2 Factors affecting the Higgins eye pearlymussel environment within
the action area]{.underline}

Historically, the commercial harvest of native freshwater mussels in the
UMRS peaked during the pearl button period of the 1920s and later during
the cultured pearl era in the late-1980s and early 1990s (U.S. Fish and
Wildlife Service 2004). Other than harvest activities such as brailing
that may have influenced the entire mussel community, little is known
regarding the direct impacts of commercial harvest on Higgins eye.
Mathiak (1979), based on observations he made at a commercial clamming
operation, concluded that hundreds of Higgins eye had probably been
harvested in 1975 before the species was placed on the endangered
species list (U.S. Fish and Wildlife Service 2004). Commercial harvest
of mussels could result in some accidental mortality of Higgins eye.
Incidental extraction from the substrate, sorting, and return of Higgins
eye, especially for nondiscriminating collection methods such as
brailing, could produce some Higgins eye mortality and/or abortion of
the glochidia. In addition, misidentification of Higgins eye with
similarly appearing commercially allowed species such as hickory nut
(*Obovaria olivaria*) could result in mortality of Higgins eye. The five
Upper Mississippi River States (Iowa, Illinois, Minnesota, Missouri, and
Wisconsin) have regulated mussel harvest since the latter portion of the
pearl button era in the late 1930s (Waters 1980) and are continuing to
revise the regulations to strive for uniformity among the States, and
protect species of state and federal concern such as Higgins eye (U.S.
Fish and Wildlife Service 2004).

Since construction of the 9-Foot Channel Project approximately 70 years
ago, the UMR continues to adjust from a riverine to a reservoir system.
It is likely that adverse impacts to Higgins eye and other native
mussels occurred from construction, operation and maintenance of the
original 9-Foot Channel Project, and the thousands of channel training
structures preceding it for commercial navigation purposes; however, the
extent and magnitude of the impacts are largely unknown and occurred
nearly a century ago (U.S. Fish and Wildlife Service 2000). Although
effects of the original navigation projects likely reduced the
reproduction, numbers and distribution of Higgins eye to some degree,
the species seemed to be stabilizing by 1993 and discussions by the
Higgins Eye Recovery Team focused on revising the recovery plan and
recovering the species (U.S. Fish and Wildlife Service 2004).

Unfortunately, the recent invasion of the exotic zebra mussel
significantly changed this scenario. Due to upstream transport by
commercial barge traffic and recreational craft, zebra mussels are now
found throughout the UMR and have had significant adverse impacts on
Higgins eye and other native freshwater mussels (U.S. Fish and Wildlife
Service 2000). The crash of native mussels at the Prairie du Chien EHA,
and observations of native mussel declines elsewhere, unequivocally
indicate that zebra mussels are a significant threat to native
freshwater mussels in the UMRS, including Higgins eye (U.S. Fish and
Wildlife Service 2004).

It is likely that zebra mussels will continue to adversely affect
Higgins eye in the foreseeable future until adequate control measures
are implemented, or their abundance and distribution are significantly
reduced by natural forces (i.e. predation, diseases, habitat
limitations). The Corps of Engineers predicted that without implementing
measures to effectively manage zebra mussels on the UMRS, the population
of Higgins eye at EHAs and secondary habitats may decline from 697,758
in the 1990s before zebra mussels invaded the UMRS to 120,227 by 2015
(U.S. Army Corps of Engineers 2003).

Lake Pepin (UMR Pool 4) was one of the first areas in the upper reaches
of the UMR to become infested with zebra mussels, probably due to its
natural lake-like character; it is now a major source population of
zebra mussels and their veligers. In addition to the UMR, zebra mussels
have developed a self-sustaining population within the lower St. Croix
River (R. Rowse, U.S. Fish and Wildlife Service, 2004, personal
communication). Recreational boat traffic using these and other infested
waters may transport zebra mussels to uninfested headwater lakes of the
UMR, the St. Croix River, the Wisconsin River, or any of the other
tributary watersheds (U.S. Army Corps of Engineers 2004a).

Currently, a critical area for Higgins eye and other native mussels is
the segment of the UMR upstream of the middle of Lake Pepin (UMR Pool 4)
to the head of navigation in Minneapolis, Minnesota. Currently, this
reach contains few zebra mussels, has no known upstream source of
veligers (with the exception of the lower St. Croix River which enters
in UMR Pool 3), has a diverse native mussel community that is recovering
from previous water quality impacts from the Twin Cities metro area, and
contains several propagation and relocation sites for Higgins eye
(Mussel Coordination Team 2003). In 2003, zebra mussels were discovered
in Lake Ossawinnamakee in central Minnesota. This lake is less than 10
miles from the Mississippi River near Brainerd, Minnesota, an area of
heavy recreational boat use (U.S. Army Corps of Engineers 2004a). From
this location, zebra mussels may eventually find their way into one of
the headwater lakes of the UMR, establishing a critical source
population of zebra mussels and their veligers for the UMR including the
Twin Cities metro area. The risk-based zebra mussel modeling that will
be done as part of the Zebra Mussel Feasibility Study will provide a
better understanding of zebra mussel population dynamics in the UMRS,
including risks from overland transport.

Unfortunately, it is likely that another nonindigenous species harmful
to native mussels will invade the UMRS over the next 50 years such as
the quagga mussel (*Dreissena bugensis*). Quagga mussels are similar to
zebra mussels in appearance, reproductive strategy, ability to attach to
objects in the water, and adverse effects to native mussels. They are
well established in the lower Great Lakes and the St. Lawrence Seaway; a
specimen was found in the UMR near St. Louis, Missouri (see Internet
site
[www.entryway.com/seagrant/feb97q.jpg](http://www.entryway.com/seagrant/feb97q.jpg)).
Like zebra mussels, quagga mussels could invade the UMRS from Lake
Michigan through the Chicago Sanitary and Ship Canal and be transported
upstream on commercial tows and recreational craft to important Higgins
eye habitats. Another nonindigenous species that could affect Higgins
eye in the future is the black carp (*Mylopharyngodon piceus*), an Asian
species that was recently found in the UMR at River Mile 273 below Lock
and Dam 24 (R. Maher, Illinois Department of Natural Resources, 2004,
personal communication). The primary foods of black carp are mollusks
and crustaceans.

On a more positive note, since the mid 1980s construction of habitat
restoration/enhancement projects has been active on the UMRS. The goals
of these projects are to reverse the decline of habitat and species
since the 9-Foot Channel Project was constructed nearly 70 years ago.
These projects include island construction, fish passage, floodplain
restoration, water level management, backwater restoration, side channel
restoration, wing dam/dike alteration, island and shoreline protection,
increases in topographic diversity, forest management, and other
ecosystem restoration.

Currently, the largest habitat restoration/enhancement program on the
UMRS is the Upper Mississippi River System Environmental Management
Program (EMP); it is anticipated that 132,804 acres of habitat will be
restored over the next 10 years (U.S. Army Corps of Engineers 2004b, in
press). Overall, the goal of these projects is to enhance/restore
habitat for a variety of species, including native freshwater mussels.
Conservation measures to avoid and minimize impacts to Higgins eye have
been implemented on these site-specific projects in the past. These
conservation measures included employing best management practices
during project construction, modifying project features, or abandoning
the project. We assume that these measures will be used for future
projects under EMP and other authorities to avoid impacts to Higgins
eye. To date, no habitat projects constructed under EMP have adversely
affected Higgins eye. However, given the large number of habitat
projects proposed for construction in the future, it is likely that a
few Higgins eye may be adversely affected by one or more of these
habitat projects. However, we believe that there is a net benefit to
Higgins eye and other native mussels from restoration of the UMRS
ecosystem through construction of habitat enhancement/restoration
projects over the next 50 years.

Actions to conserve Higgins eye dramatically increased since 2000.
Activities and accomplishments of the Corps of Engineers and the MCT in
propagation and relocation of Higgins eye has led to similar
conservation activities for other native mussels including the federally
endangered winged mapleleaf (*Quadrula fragosa*). In 2004, the Upper
Mississippi River Conservation Committee released a Conservation Plan
for Freshwater Mussels of the Upper Mississippi River System (Upper
Mississippi River Conservation Committee 2004). Public outreach efforts
have also increased since 2000 with the development of the Internet web
site Freshwater Mussels of the Upper Mississippi River System
(<http://midwest.fws.gov/mussel>), and numerous news articles and
releases on mussel conservation activities. A partnership of state and
federal biologists recently revised and reprinted the popular booklet
Freshwater Mussels of the Upper Mississippi River (Bob Hay, Wisconsin
Department of Natural Resources, 2004 personal communication).
Activities to conserve native mussels, and efforts to educate the public
on the importance of our native mussels, controlling nonindigenous
species, and maintaining/restoring aquatic habitats will continue in the
foreseeable future and benefit Higgins eye and other native mussels of
the UMRS.

[4.3 Effects of the Action]{.underline}

This section includes an analysis of the direct and indirect effects of
the proposed action on the species and/or its critical habitat and its
interrelated and interdependent activities.

The Upper Mississippi River-Illinois Waterway System Navigation Study
proposes to implement both navigation improvement and ecosystem
restoration actions. The navigation improvement program also contains a
mitigation component for unavoidable adverse impacts to natural
resources of the UMRS.

This Tier I biological opinion for Higgins eye evaluates the effects of
these actions from a programmatic scale. Site-specific impacts will be
evaluated during the Tier II planning process for specific projects and
Tier II biological opinions provided to the U.S. Army Corps of Engineers
for those projects that are likely to adversely affect Higgins eye. As
no recent records of live Higgins eye have been recorded below Lock and
Dam 19 (U.S. Fish and Wildlife Service 2004), any site-specific actions
on the UMR downstream of Lock and Dam 19 are not likely to affect the
species.

The following Standards and Guidelines were proposed by the Corps of
Engineers in their Tier I Biological Assessment (Corps of Engineers
2004a) for use in avoiding/minimizing adverse impacts to Higgins eye and
developing subsequent Tier II Assessments for specific projects. This
process essentially follows the current Section 7 consultation process
between the Corps and the Service. As a result of continued
consultation, the Corps of Engineers and Service modified the original
Standards and Guidelines as follows:

1\. The suitability of aquatic habitat for Higgins eye, including
consideration of current range, and existing mussel surveys in the
project area will be reviewed to assess the presence of and impacts to
Higgins eye in the direct and secondary impact zones of site-specific
actions.

2\. Site-specific mussel surveys will be completed where there is
insufficient information on habitat suitability and mussel distribution
in the impact zone to make presence/impact determinations.

3\. If the preliminary Biological Assessment concludes that the proposed
action is likely to adversely affect Higgins eye, conservation measures
will be incorporated, to the extent feasible, into the proposed action
to avoid (no effect determination) impacts, or minimize impacts so that
the anticipated effects will be insignificant or discountable.
Conservation measures may include employing best management practices
during project construction, modifying project features, or abandoning
the project. In the case of water level management, specific
conservation measures have been identified in the section on water
regulation.

If the final Tier II Biological Assessment concludes that project
actions are likely to adversely affect Higgins eye despite the
conservation measures identified in 3 above, formal consultation will be
initiated and a Tier II biological opinion will be issued.

[4.3.1 Direct effects]{.underline}

[4.3.1.1 Navigation improvements]{.underline}

Potential effects to Higgins eye from navigation improvements are
summarized in Table 1 of the Tier I BA (USACE 2004b). At the
programmatic scale, adverse effects to Higgins eye from

navigation improvements are anticipated to be similar to those described
in the biological opinion for the 9-Foot Channel Project (U.S. Fish and
Wildlife Service 2000).

A major issue with navigation improvements is the resulting increase in
tow traffic on the UMRS over the next 50 years and subsequent
environmental effects. Two approaches were used by the Corps of
Engineers to address potential impacts of increased navigation traffic
on native mussels (U.S. Army Corps of Engineers 2004a). In the first
approach, laboratory studies were conducted to determine the effects of
navigation traffic-induced changes in velocity and suspended solids on a
variety of freshwater mussel physiological parameters. In the second
approach, a bioenergetics model was developed to predict the effects of
increased sediment loads on the threeridge mussel (*Amblema plicata*).
The threeridge is a heavy-shelled species with similar life history to
Higgins eye, and hence, is an appropriate surrogate for determining
potential impacts to the species. The results of both the physiological
study and the bioenergetics model indicate that the effects of increased
tow traffic resulting from the proposed action would likely have minimal
effects on native mussels (U.S. Army Corps of Engineers 2004a). Thus, we
anticipate that reproduction, numbers and distribution of Higgins eye
within the action area will not be appreciably altered by the expected
increase in tow traffic.

Numerous fleeting and terminal facilities are located in the action
area. Fleeting areas are typically constructed within main channel
border habitats. Towboats maneuvering within fleeting areas cause
resuspension of sediments, or direct contact with the bottom in shallow
areas. In addition, fleeting areas and terminals often require periodic
dredging, which disturbs bottom sediments. In addition, contaminated
sediments may be resuspended and transferred downstream. Consequently,
fleeting activities may adversely affect Higgins eye located in the
action area of new fleeting/terminal facilities through direct contact
with propellers/hulls, from dredging and disposal activities, or from
increased sedimentation and resuspension of contaminants.

The Corps completed a Fleeting Analysis (USACE 2000) as part of the
Navigation Study in order to determine if fleeting is likely to increase
as a result of increased navigation traffic. The Corps concluded that no
new fleeting areas are expected as a result of improvements to the
navigation system. The Service disagrees with this assessment. While it
is uncertain as to whether construction of additional fleeting areas
will be necessary, there will be more barges moving throughout the UMRS
(U.S. Army Corps of Engineers 2004a). In addition, with implementation
of navigation improvements, tow lockage will become more efficient. For
these reasons, there will likely be increased movement of barges into
and out of some existing fleeting and terminal areas, or expansion of
existing facilities to accommodate increased usage, either of which
could adversely affect Higgins eye in the action area. However, although
we anticipate that a few individuals may be harmed, we do not expect the
reproduction, numbers or distribution of Higgins eye populations within
UMRS will be appreciably reduced.

The Corps has proposed to develop a Systemic Barge Fleeting Plan for the
UMRS (U.S. Army Corps of Engineers 2004a). However, the details of this
plan remain unknown, and therefore, it is uncertain as to the extent it
will address impacts associated with fleeting, including impacts to
Higgins eye. The Service supports development of the Systemic Barge
Fleeting Plan for the UMRS in a timely manner

Nonindigenous Species

The purpose of the navigation improvements is to accommodate and
facilitate increased tow traffic within UMRS (U.S. Army Corps of
Engineers 2004a). Additional tows resulting from proposed navigation
improvements will transport additional zebra mussels upstream on the
UMRS to Higgins eye populations and habitats unless effective control
measures are implemented. As discussed in the Status and Environmental
Baseline sections, the Corps of Engineers is implementing the Reasonable
and Prudent Alternative (RPA) described in the biological opinion for
the 9-Foot Channel Project (U.S. Fish and Wildlife Service 2000, U.S.
Army Corps of Engineers 2003, 2004a). At this time, we assume, that (1)
the Corps of Engineers will initiate the Zebra Mussel Management
Feasibility Study; (2) the study will develop one or more feasible
control measures; and (3) these measures will be implemented in a timely
manner to prevent upstream transport of zebra mussels (and potentially
quagga mussels) by commercial navigation on the UMRS, including any
projected increases in navigation traffic as a result of the proposed
action. The feasibility study will also address recreational craft using
the 9-Foot Channel Project, a much more likely vector of transport to
the St. Croix River and other tributaries.

As discussed in the Environmental Baseline section, a critical area for
Higgins eye and other native mussels is the segment of the UMR upstream
of the middle of Lake Pepin (UMR Pool 4) to the head of navigation in
Minneapolis, Minnesota. Currently, this reach contains few zebra
mussels, has no known upstream source of veligers (with the exception of
the lower St. Croix River which enters in UMR Pool 3), has a diverse
native mussel community that is recovering from previous water quality
impacts from the Twin Cities metro area, and contains several
propagation and relocation sites for Higgins eye (Mussel Coordination
Team 2003). As a result of the proposed navigation improvements, the
current traffic level of 5 tows per day at Lock and Dam 3 will increase
to 8 tows per day; however, any increase in tow traffic will not occur
before 2030 (U.S. Army Corps of Engineers 2004a). Considering the small
incremental increase in tow traffic, that any increase in tow traffic is
not projected to occur before 2030 above Lock and Dam 3, and efforts to
control zebra mussel distribution and abundance over the next 10 to 15
years, we anticipate that the status of zebra mussels in the UMRS over
the next 50 years will not be detectably influenced by navigation
improvements proposed in the Upper Mississippi River-Illinois Waterway
System Navigation Study. Hence, further impacts on Higgins eye from
zebra mussels are not anticipated to result from the navigation
improvement program. However, it is critical that the Corps of Engineers
initiate the Zebra Mussel Management Feasibility Study and implement
feasible control measures in a timely manner (U.S. Army Corps of
Engineers 2003).

[4.3.1.2 Mitigation]{.underline}

Mitigation planning for impacts associated with incremental increases in
navigation traffic fall into four major biological areas -- fishery,
submersed aquatic plants, bank erosion, and backwater-side channel
sedimentation. Fishery mitigation measures include large woody debris
anchors, backwater improvements, dike alterations, and fish passage.
Submerged aquatic plant mitigation measures include modification of
river regulation to improve habitat conditions, backwater/side channel
habitat protection and restoration and revegetation. Bank erosion
mitigation measures include such structural measures as offshore
revetments, bank protection, or vegetative/bioengineered protection.
Mitigation for backwater/side channel sedimentation measures includes
offshore revetment, drop structures, closure structures, bank
protection, barrier island construction, and dredging. The level and
schedule of mitigation will be commensurate with the level and schedule
of navigation improvements.

At the programmatic scale, most of the mitigation measures identified
above have the potential for long-term beneficial impacts to Higgins eye
by improving habitat conditions for the species and/or habitat
conditions for fish host species. One mitigation measure that would be
beneficial to the species is providing offshore lock waiting areas,
therefore keeping waiting traffic away from mussel beds. This may
include either mooring cells or buoys. However, it is likely that a few
mitigation projects will be constructed on the UMRS over the next 50
years that adversely affect a few Higgins eye by burial from disposal of
dredged material, rip rap or other construction materials, by contact
with dredging equipment during construction, or changes to existing
habitat conditions (flow velocity, scour and erosion). Per the proposed
Standards and Guidelines, the Corps of Engineers will coordinate with
State, and Federal resource agencies to develop site-specific project
plans, including the placement of the structures, location of dredging
and material placement, and evaluating expected changes in velocity,
scour, and sediment patterns on Higgins eye. We anticipate that only in
a very few instances will adverse effects be unavoidable. In these
situations, it is unlikely that an entire bed or population of Higgins
will be affected. Furthermore, it is extremely unlikely that any such
project would be implemented if the viability of an EHA were to be
threatened. Thus, although we anticipate that a few individuals may be
harmed, we do not expect the reproduction, numbers or distribution of
Higgins eye populations within UMRS will be appreciably reduced from
mitigation activities.

Because mitigation measures proposed to date are similar to the
ecosystem restoration component of the Upper Mississippi River-Illinois
Waterway System Navigation Study, these actions are evaluated in greater
detail in the Ecosystem Restoration section of this biological opinion.

[4.3.1.3 Ecosystem restoration]{.underline}

Implementation of the Upper Mississippi River -- Illinois Waterway
System Navigation Study would result in a variety of navigation and
ecosystem actions. From a habitat perspective, the combined effect of
implementing the ecosystem restoration component of the study would
benefit approximately 400,000 acres of UMRS floodplain habitat and 2,500
miles of main stem and tributary channels resulting in significant
improvements to the quality and sustainability of the ecological health
of the UMRS (U.S. Army Corps of Engineers 2004a). From a programmatic
scale, improving the ecological health of the UMRS will also
significantly benefit native mussels including Higgins eye from water
quality improvements, reduction in erosion/sedimentation and increased
opportunities for movement of host fish between navigation pools,
reaches and tributaries of the UMRS.

The Upper Mississippi River -- Illinois Waterway System Navigation Study
includes ecosystem management actions that are intended to reverse the
decline of habitat and species within the UMRS proposed in these
documents and studies. Specific actions include island construction,
fish passage, floodplain restoration, water level management, backwater
restoration, side channel restoration, wing dam/dike alteration, island
and shoreline protection, topographic diversity improvements, forest
management, and other ecosystem restoration measures. Overall, the goal
of these actions is to enhance/restore habitat on the UMSR for a variety
of species, including native freshwater mussels.

Table 9 of the Tier I BA summarizes the potential impacts to Higgins eye
from ecosystem restoration actions (USACE 2004b). Conservation measures
to avoid and minimize impacts to Higgins eye have been implemented on
similar projects in the past. These conservation measures included
employing best management practices during project construction,
modifying project features, or abandoning the project. To date, resource
agencies have successfully eliminated adverse effects in all but one
instance[^1]. However, given the large number of habitat projects
proposed for construction in the future under the Upper Mississippi
River -- Illinois Waterway System Navigation Study, it is likely that
Higgins eye may be adversely affected in the future by one or more
habitat projects depending on where the specific project is located and
if Higgins eye are in the action area. The anticipated effect associated
with these restoration actions are described below.

Island Building

Many islands were present when the lock and dam system was completed
(U.S. Army Corps of Engineers 2004a). In some areas islands have been
lost to erosion, and in other areas they have grown as a result of
sedimentation. Island building includes constructing islands from
sediment (sand, clay, or silt) dredged from the bottom of the river to
replace islands eroded by waves and river current. Islands may also be
constructed in open water areas to create sheltered off-channel habitat
to promote backwater communities. Past experience has led to designs
that can protect large areas (\>1,000 acres) with as little as 30 acres
of island. Island building can have an added benefit of protecting and
establishing deepwater habitat, which provides important habitat for
fish and mussels.

Island restoration is most needed in the upper pooled reaches where
island erosion is most pronounced, but will apply system-wide to create
wave breaks, protect bank lines, store dredged sediments, and create new
side channels or off-channel habitat elsewhere, but particularly in the
middle Mississippi River.

Construction of islands will improve habitat for Higgins eye and other
native mussels by reducing wind fetch and waves which will decrease
sediment resuspension and increase water quality in the project area.
Islands will also facilitate environmental conditions in the project
area that promote the growth and abundance of aquatic vegetation. Beds
of aquatic vegetation also decrease sediment resuspension in the project
area. However, it is likely that a few islands will be constructed on
the UMRS over the next 50 years that adversely affect a few Higgins eye
by burial from disposal of dredged material, rip rap or other
construction materials, by contact with dredging equipment during
construction, or changes to existing habitat conditions (flow velocity,
scour, erosion). Per the proposed Standards and Guidelines, the Corps of
Engineers will coordinate with State, and Federal resource agencies to
develop site-specific project plans, including the placement of the
structures, location of dredging and material placement, and evaluating
expected changes in velocity, scour, and sediment patterns on Higgins
eye. We anticipate that only in a very few instances will adverse
effects be unavoidable. In these situations, it is unlikely that an
entire bed or population of Higgins will be affected. Furthermore, it is
extremely unlikely that any such project would be implemented if the
viability of an EHA were to be threatened. Thus, although we anticipate
that a few individuals may be harmed, we do not expect the reproduction,
numbers or distribution of Higgins eye populations within UMRS will be
appreciably reduced from island building activities.

Fish Passage

Native mussels like Higgins eye require a host fish for glochidia
transformation (Mussel Conservation Team 2003). Prior to construction of
navigation locks and dams with the 9-Foot Channel Project, host fish for
native mussels had relatively unimpeded access to the entire basin
stream network (U.S. Army Corps of Engineers 2004a). Natural barriers
such as rapids and falls were the primary determinant of the
distribution of fish stocks at that time. Now, navigation dams on the
UMRS restrict upstream fish movement during most portions of a given
year. Technical fishways, such as fish ladders, and naturalistic bypass
channels through spillways are the primary techniques considered as
ecosystem restoration measures under the Upper Mississippi River --
Illinois Waterway System Navigation Study, although some benefits may be
gained from modified dam operation as well. The major benefit to Higgins
eye and other native mussels is increased opportunity for seasonal
movement of host fish between navigation pools and reaches of the UMRS,
and hence, allowing genetic exchange and population reestablishments in
currently unoccupied areas.

Improved fish passage may facilitate more rapid upward movement of
nonindigenous species such as the black carp, which might prey on small
Higgins eye and other native mussels. However, the current navigation
system is not a complete barrier to upstream migration and even if the
proposed fish passage actions do not occur, nonindigenous black carp
will probably disperse upstream and adversely affect mussels over the
next 50 years.

The overall effect of improving fish passage, and improved system
connectivity, has the potential to greatly improve the overall fishery
of the UMRS and distribution of native mussels including Higgins eye.
Increased movement of fish throughout the system increases both the
probability of host fish availability, especially walleye, a preferred
host species for Higgins eye (Holland-Bartels and Waller, 1988), and
improves the opportunity for dispersal of Higgins eye throughout the
Upper Mississippi River (U.S. Army Corps of Engineers 2004a). However,
it is likely that a few fish passage projects constructed on the UMRS
over the next 50 years may adversely affect a few Higgins eye by burial
from disposal of dredged material, rip rap or other construction
materials, by contact with dredging or other equipment during
construction, or changes to existing habitat conditions (flow velocity,
scour, erosion). Per the proposed Standards and Guidelines, the Corps of
Engineers will coordinate with State, and Federal resource agencies to
develop site-specific project plans, including the placement of the
structures, location of dredging and material placement, and evaluating
expected changes in velocity, scour, and sediment patterns on Higgins
eye. We anticipate that only in a very few instances will adverse
effects be unavoidable. In these situations, it is unlikely that an
entire bed or population of Higgins will be affected. Furthermore, it is
extremely unlikely that any such project would be implemented if the
viability of an EHA were to be threatened. Thus, although we anticipate
that a few individuals may be harmed, we do not expect the reproduction,
numbers or distribution of Higgins eye populations within UMRS will be
appreciably reduced from fish passage activities.

Floodplain Restoration

Floodplain habitats throughout the UMRS have been altered for many
reasons (U.S. Army Corps of Engineers 2004a). In northern river reaches,
dams spread water across low elevation floodplain areas and greatly
increase aquatic habitat connectivity in the floodplain. Floodplain
restoration in the north includes a mix of protecting some areas with
islands, connecting isolated backwaters, and restoring tributary
channels. In southern river reaches, the floodplain is much more
developed for crop production and flood protection and is thus much more
isolated from the river. Floodplain restoration in southern reaches will
include a mixture of water level manipulation in management areas,
wetland/habitat management in leveed areas (e.g., Wetlands Reserve
Program, Conservation Reserve Program, etc.), and restoration of
agricultural areas to aquatic, floodplain forest, and prairie habitats.

Providing connectivity to previously isolated floodplain areas will
increase flowing secondary channel habitat suitable for Higgins eye and
other native mussels. However, it is likely that a few floodplain
restoration projects constructed on the UMRS over the next 50 years may
adversely affect a few Higgins eye by burial from disposal of dredged
material, rip rap or other construction materials, by contact with
dredging or other equipment during construction, or changes to existing
habitat conditions (flow velocity, scour, erosion). Per the proposed
Standards and Guidelines, the Corps of Engineers will coordinate with
State, and Federal resource agencies to develop site-specific project
plans, including the placement of the structures, location of dredging
and material placement, and evaluating expected changes in velocity,
scour, and sediment patterns on Higgins eye. We anticipate that only in
a very few instances will adverse effects be unavoidable. In these
situations, it is unlikely that an entire bed or population of Higgins
will be affected. Furthermore, it is extremely unlikely that any such
project would be implemented if the viability of an EHA were to be
threatened. Thus, although we anticipate that a few individuals may be
harmed, we do not expect the reproduction, numbers or distribution of
Higgins eye populations within UMRS will be appreciably reduced from
floodplain restoration activities.

Water Level Management Activities

Large river ecosystems such as the UMRS are characterized by seasonal
cycles of flood and drought (or low flow) (U.S. Army Corps of Engineers
2004a). A variety of ecological functions and processes are linked to
this cycle. Development of water resources for hydropower or navigation
typically alters and disrupts these natural cycles. In the UMRS, the
flood stage of the hydrograph is relatively unaltered, but low flows
have been eliminated to support commercial navigation. Water level
management has the potential to be a powerful ecosystem restoration
measure to improve the long-term habitat quality of the UMR for a
variety of species, including Higgins eye. Pool-wide and/or system-wide
drawdowns are being proposed in the Upper Mississippi River -- Illinois
Waterway System Navigation Study to promote aquatic vegetation,
consolidate sediments, improve water quality, and modify flow
distribution. These actions will enhance habitat conditions for Higgins
eye by improving water quality, cleaning substrate through scouring,
improving overall productivity, improving conditions for host fish
species, and other ecological benefits. However, these drawdowns could
adversely affect Higgins eye during the drawdown phase primarily by
stranding individuals.

#### For pool level drawdowns, the following Conservation Measures are proposed by the Corps of Engineers in their Tier I BA to avoid impacts to Higgins eye from stranding (U.S. Army Corps of Engineers 2004a):

####  

1\. A drawdown will not be implemented that would result in lowering
normal water levels more than 1.5 feet at any of the essential,
secondary, or relocation habitat areas.

2\. A drawdown will not be implemented if pool elevation at the dam is
greater than two feet above the secondary control pool elevation in
excess of 20 days from April 1 to June 15 in the proposed drawdown year.

3\. During the drawdown, water levels will be lowered slowly (0.1 to 0.2
foot per day), allowing the escape of native mussels from the dewatered
zone. The rate of drawdown will be commensurate with the proposed level
of drawdown and the location of the drawdown.

4\. Studies may be completed to evaluate the distribution of Higgins eye
in relationship to water depths, the ability of Higgins eye to escape
the dewatered zone, and evaluation of the stranding of mussels with
ongoing pilot pool drawdowns. As additional information is obtained, the
preceding conservation measures will be reviewed and revised, in
coordination with the Service. For example, a study may find that
Higgins eye are found at depths greater than 1.5 feet at a particular
EHA, thereby facilitating a deeper drawdown at that location.

We believe that the following water level management scenarios may
affect but are not likely to adversely affect Higgins eye: 1) drawdowns
outside the current range of Higgins eye (i.e. UMR downstream of Lock
and Dam 19); 2) minor drawdowns within existing Corps operational
constraints (i.e., current drawdown zone during operation of the 9-Foot
Channel Project); and, 3) drawdowns implemented with the above
Conservation Measures. Other drawdowns of larger scope may adversely
affect a few Higgins eye and other native mussels by stranding. In
addition, drawdowns will likely involve dredging to maintain
recreational and/ commercial navigation access during the event.
Depending on the location of these dredge cuts, a few Higgins eye and
other mussels may be adversely affected by burial from disposal of
dredged material, rip rap or other construction materials, by contact
with dredging or other equipment during construction, or changes to
existing habitat conditions (flow velocity, scour, erosion). Per the
proposed Standards and Guidelines, the Corps of Engineers will
coordinate with State, and Federal resource agencies to develop
site-specific project plans, including the placement of the structures,
location of dredging and material placement, and evaluating expected
changes in velocity, scour, and sediment patterns on Higgins eye. We
anticipate that only in a very few instances will adverse effects be
unavoidable. In these situations, it is unlikely that an entire bed or
population of Higgins will be affected. Furthermore, it is extremely
unlikely that any such project would be implemented if the viability of
an EHA were to be threatened. Thus, although we anticipate that a few
individuals may be harmed, we do not expect the reproduction, numbers

or distribution of Higgins eye populations within UMRS will be
appreciably reduced from water level management activities.

Backwater Restoration

Many UMRS backwaters have been degraded by excessive amounts of sediment
emanating from the basin, tributaries, and main stem sources (U.S. Army
Corps of Engineers 2004a). The degradation results from loss of depth,
poor sediment quality, poor water quality, and sediment resuspension
that blocks sunlight required by aquatic plants. Remedial action can be
in the form of backwater dredging, or water level management actions
discussed above. Backwater dredging typically consists of dredging
channels with fingers extending from the main dredge cut to a depth of 6
to 8 feet deep. Earlier projects have dredged about 20 acres, which
provides enough habitat for fish from larger areas to concentrate during
winter and other harsh climate conditions. The sediment resulting from
the dredging portion of the project can be used to enhance aquatic areas
with islands or to augment terrestrial areas with increased topographic
diversity and elevation, which promotes the growth of oaks and other
mast tree species.

The overall effect of backwater restoration will improve habitat for
Higgins eye and other native mussels through increased plant growth,
which in turn will result in decreased sediment resuspension and
increased water quality in the project area (U.S. Army Corps of
Engineers 2004a). However, some backwater restoration measures may
adversely affect a few Higgins eye in the project area from placement of
structures on individuals; dredging in backwaters, and hence digging up,
injuring and killing specimens found in these locations; drawdowns to
consolidate sediments and increase plant growth; and from resulting
changes in velocity, scour, and sediment patterns. Per the proposed
Standards and Guidelines, the Corps of Engineers will coordinate with
State, and Federal resource agencies to develop site-specific project
plans, including the placement of the structures, location of dredging
and material placement, and evaluating expected changes in velocity,
scour, and sediment patterns on Higgins eye. We anticipate that only in
a very few instances will adverse effects be unavoidable. In these
situations, it is unlikely that an entire bed or population of Higgins
will be affected. Furthermore, it is extremely unlikely that any such
project would be implemented if the viability of an EHA were to be
threatened. Thus, although we anticipate that a few individuals may be
harmed, we do not expect the reproduction, numbers or distribution of
Higgins eye populations within UMRS will be appreciably reduced from
backwater restoration activities.

Side Channel Restoration

Side channels provide off-channel habitat that shields fish and other
animals from the harsh conditions of the main channel. In braided
channel habitats of the northern river reaches, side channels are
numerous and provide an assortment of habitat conditions. Farther south,
side channels are typically larger and more uniform in their
configuration.

Side channels have been degraded by sedimentation and channelization.
Where sedimentation is the issue, restoration includes dredging the
upper and lower connections similar to what is done in backwaters.
Restoration in response to channelization typically involves modifying
channel regulating structures to increase connectivity between the main
and secondary channels. In both cases, work within the side channel may
include constructing barbs to alter flow patterns or

augmenting woody debris piles or other structures. Side channel
restoration will be common throughout the UMRS.

The overall effect of side channel restoration will be to increase and
improve available habitat for both Higgins eye and fish species that
serve as glochidial hosts for the mussel. However, construction of these
projects over 50 years may adversely affect a few Higgins eye. The
direct and secondary impacts of side channel restoration activities on
Higgins eye and other native mussels can be grouped into three
categories -- impacts from direct structure placement to restore side
channels; impacts of dredging to restore side channels; and impacts of
changes in velocity, scour, and sediment patterns resulting from side
channel restoration actions. Per the proposed Standards and Guidelines,
the Corps of Engineers will coordinate with State, and Federal resource
agencies to develop site-specific project plans, including the placement
of the structures, location of dredging and material placement, and
evaluating expected changes in velocity, scour, and sediment patterns on
Higgins eye. We anticipate that only in a very few instances will
adverse effects be unavoidable. In these situations, it is unlikely that
an entire bed or population of Higgins will be affected. Furthermore, it
is extremely unlikely that any such project would be implemented if the
viability of an EHA were to be threatened. Thus, although we anticipate
that a few individuals may be harmed, we do not expect the reproduction,
numbers or distribution of Higgins eye populations within UMRS will be
appreciably reduced from side channel restoration activities.

Wing Dam and Dike Alteration

Wing dams and dikes are prominent channel regulating structures common
in main channel habitats. In northern river reaches, most wing dams are
artifacts of earlier channel management efforts for the navigation
project. Wing dams provide important habitat in channel border areas. In
southern river reaches, and especially the middle Mississippi River
reach, wing dikes are very prominent features of the channel
environment. These structures are used to concentrate flow in the main
channel in order to reduce the need for dredging. They were often
constructed in groups called dike fields. These areas are depositional
zones that often fill from the bank outward toward the channel.
Notching, lowering their profile, or altering their angle to the channel
are some actions that can be used to increase habitat diversity through
the creation of new scour holes, sandbars, and flow refugia. When wing
dike alteration is done on the dike field level, or in association with
new structure placements, new side channels, islands, and off-channel
areas can be created. The practice has met with great success in the
middle Mississippi River.

Dike alteration will be an important component of the restoration of the
middle Mississippi River reach and will have beneficial application
elsewhere in the system. The overall effect of channel regulating
structure alteration will be to increase and improve available habitat
for both Higgins eye and fish species that serve as hosts for the
species. However, construction of these projects over 50 years may
adversely affect a few Higgins eye. The direct and secondary impacts of
channel regulating structure alteration activities on Higgins eye and
other native mussels can be grouped into two categories -- impacts from
direct structure placement and impacts of changes in velocity, scour,
and sediment patterns resulting from channel structure alterations. Per
the proposed Standards and Guidelines, the Corps of Engineers will
coordinate with State, and Federal resource agencies to develop
site-specific project plans, including the placement of the structures,
location of dredging and material placement, and evaluating expected
changes in velocity, scour, and sediment patterns on Higgins eye. We
anticipate that only in a very few instances will adverse effects be
unavoidable. In these situations, it is unlikely that an entire bed or
population of Higgins will be affected. Furthermore, it is extremely
unlikely that any such project would be implemented if the viability of
an EHA were to be threatened. Thus, although we anticipate that a few
individuals may be harmed, we do not expect the reproduction, numbers or
distribution of Higgins eye populations within UMRS will be appreciably
reduced from wing dam and dike alterations.

Island and Shoreline Protection

Island and shoreline erosion are natural processes that characterize
dynamic rivers. In the UMRS, shoreline erosion may also in some areas,
be affected by commercial and recreational boats and by wind-generated
waves in the impounded system. Shoreline erosion may affect Higgins eye
by burial of individuals and beds over time from eroded material, or
changing habitat conditions as existing islands and shorelines are
eroded that may have provided or protected mussel habitat.

Island and shoreline protection includes measures to protect the
existing aquatic and terrestrial features of the river. Typical measures
include riprapped shorelines, but more environmentally compatible
measures including offshore revetments, plantings (bioengineering), low
gradient slopes, rock groins, and others are being incorporated along
with traditional measures. These measures may also be used to alter the
overflow portions of the dams. Priority erosional areas have been mapped
and can be targeted for protection. This measure is viewed as a habitat
protection measure that maintains existing conditions to the extent
possible.

The overall effect of protecting islands and shorelines from erosion
will be to increase and improve available habitat for both Higgins eye
and fish species that serve as glochidial hosts. However, construction
of these projects over 50 years may adversely affect a few Higgins eye.
The direct and secondary impacts to Higgins eye from island and
shoreline protection activities can be grouped into three categories --
impacts from direct placement of dredged material, rip rap, vanes,
groins, revetment, and bioengineering material on individuals; dredging
for construction material and access to the site and hence digging up,
injuring and killing specimens found in these locations; and from
resulting changes in velocity, scour, and sediment patterns. Per the
proposed Standards and Guidelines, the Corps of Engineers will
coordinate with State, and Federal resource agencies to develop
site-specific project plans, including the placement of the structures,
location of dredging and material placement, and evaluating expected
changes in velocity, scour, and sediment patterns on Higgins eye. We
anticipate that only in a very few instances will adverse effects be
unavoidable. In these situations, it is unlikely that an entire bed or
population of Higgins will be affected. Furthermore, it is extremely
unlikely that any such project would be implemented if the viability of
an EHA were to be threatened. Thus, although we anticipate that a few
individuals may be harmed, we do not expect the reproduction, numbers or
distribution of Higgins eye populations within UMRS will be appreciably
reduced from island and shoreline protection measures.

Topographic Diversity

When the dams were put into operation, the floodplain water table
elevation was increased in many areas. The result in the terrestrial
plant communities was the elimination of flood intolerant tree species
that require a dry root zone. Improving topographic diversity simulates
the ridge and swale topography of the natural floodplain by using
material dredged from the channel. This newly elevated land area is then
planted with oaks and other mast producing trees.

Measures to increase topographic diversity include the placement of
dredged material, typically in ridges, on the floodplain to raise the
root zone of flood intolerant mast trees, or the creation of isolated
floodplain potholes or scour holes. These measures are frequently
complementary to channel maintenance and other restoration measures.

Topographic diversity is similar to dike alteration in that the measure
is very localized in a relatively small area, but may have wider
benefits. The measure is important to restore terrestrial plant species
diversity that has been impacted by impoundment and inundation.

Most of the specific ecosystem restoration actions would occur in
terrestrial settings and would not affect aquatic areas, and as such are
not likely to adversely affect reproduction, numbers or distribution of
Higgins eye.

Forest Management

Most forest management would occur in terrestrial settings and would not
have an impact on aquatic areas. Furthermore, standard forestry
practices to minimize secondary erosion and impacts to the adjacent
aquatic environment will be used. As such, forestry management actions
are not likely to adversely affect reproduction, numbers, or
distribution of Higgins eye.

[4.3.1.4 Summary]{.underline}

Major changes that affected Higgins eye from operation and maintenance
of the 9-Foot Channel Project and prior navigation improvements occurred
in the years following construction and are described in the previous
biological opinion (U.S. Fish and Wildlife Service 2000). Additional
impacts to Higgins eye from the proposed navigation improvements and
associated incremental increase in tow traffic are not likely to
appreciably affect reproduction, numbers or distribution of Higgins eye
in the action area. Although some risk to individuals is possible from
implementation of specific navigation improvement projects, we believe
that the most significant risks to Higgins eye are from zebra mussels'
persistence in the UMRS. However, for reasons explained within, we
anticipate that the associated increases in commercial traffic are not
likely to increase the likelihood of zebra mussel persistence. Hence, we
do not expect any appreciable effects to reproduction, numbers, or
distribution of Higgins eye within the action area from navigation
improvements.

To date, habitat restoration/enhancement projects constructed on the
UMRS have not---in all but one instance\--adversely affected Higgins eye
due to implementation of conservation measures during project planning
to avoid impacts (see footnote on Page 17). Although the Corps and the
Service fully expect this success to continue, there may be a few
instances where adverse effects will be unavoidable. Given the large
number and variety of habitat projects proposed for construction in the
future under the Upper Mississippi River -- Illinois Waterway System
Navigation Study, it is likely that a few individual Higgins eye will be
adversely affected by one or more habitat projects. We anticipate that
the majority of these cases will be when short-term adverse effects are
necessary in order to achieve long-term benefits for Higgins eyes. As
such, we anticipate that over the term of the project, ecosystem
restorations actions will improve the reproduction, numbers or
distribution of Higgins eye within the action area.

[4.4 Cumulative Effects]{.underline}

Cumulative effects are effects of future State, tribal, local, or
private actions that are reasonably certain to occur in the action area
considered in this biological opinion. Future Federal actions that are
unrelated to the proposed action are not considered in this section
because they require separate consultation pursuant to section 7 of ESA.
The Service knows of no projects reasonably certain to occur in the
action area that will produce cumulative effects.

4.5 Conclusion

The conclusion section presents the Service's opinion regarding whether
the aggregate effects of the factors analyzed under the environmental
baseline, effects of the action, and cumulative effects in the action
area .After reviewing the current status of the Higgins eye
pearlymussel, the environmental baseline for the action area, the
effects of the proposed action and the cumulative effects, it is the
Service's opinion that implementation of the recommended plan as
proposed is not likely to jeopardize the continued existence of the
Higgins eye pearlymussel. No critical habitat has been designated for
this species; therefore, none will be affected.

The action area encompasses the range of Higgins eye. Programmatic
benefits to Higgins eye and other native mussels will occur from
implementation of the ecosystem restoration component of the Upper
Mississippi River -- Illinois Waterway System Navigation Study. While
site-specific adverse impacts to Higgins eye are likely for a small
number of actions (navigation improvements and ecosystem restoration
measures), we believe that the proposed action will not appreciably
reduce reproduction, numbers, or distribution of Higgins eye within the
action area, or appreciably reduce the likelihood of survival and
recovery of the species over 50 years.

[4.6 Incidental Take Statement]{.underline}

[4.6.1 Introduction]{.underline}

Section 9 of the Act and Federal regulation pursuant to Section 4(d) of
the Act prohibit the take of endangered and threatened species,
respectively, without special exemption. Take is defined as to harass,
harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to
attempt to engage in any such activity. Harm is further defined by the
Service to include significant habitat modification or degradation that
results in death or injury to listed species by significantly impairing
essential behavioral patterns, including breeding, feeding, or
sheltering. Harass is defined by the Service as intentional or negligent
actions that create the likelihood of injury to listed species to such
an extent as to significantly disrupt normal behavior patterns which
include, but are not limited to, breeding, feeding, and sheltering.
Incidental take is defined as take incidental to, and not the purpose
of, the carrying out of an otherwise lawful activity. Under the terms of
Section 7(b)(4) and Section 7(o)(2), take incidental to and not an
intended part of the agency action is not considered prohibited taking
under the Act, provided such take is in compliance with the terms and
conditions of this Incidental Take Statement.

The measures described below are non-discretionary, and must be
undertaken by the Corps for the exemption in Section 7(o)(2) to apply.
The Corps has a continuing duty to regulate the activity covered by this
incidental take statement. If the Corps fails to assume and implement
the terms and conditions, the protective coverage of Section 7(o)(2) may
lapse. To monitor the impact of incidental take, the Corps must report
the progress of the action and its impact on the species to the Service
as specified in the incidental take statement \[50 CFR 402.14(I)(3)\].

[4.6.2 Extent of take anticipated]{.underline}

The Service anticipates that direct incidental take of Higgins eye from
the proposed action will be in the form of harassment and harm from both
navigation and ecosystem restoration components of the Upper Mississippi
River -- Illinois Waterway system Navigation Study. However, as the
proposed action is at a programmatic scale, site- and project-specific
information is lacking. Without such detailed information, it is
difficult to quantify incidental take for specific projects with any
degree of certainty over the next 50 years. In other words, although we
are reasonably certain that adverse effects, and more specifically
incidental take, will occur during implementation of the proposed action
over the next 50 years, we do not have the information needed to
precisely quantify the amount we anticipate will occur. Nonetheless,
based on the Standards and Guidelines proposed by the Corps of
Engineers, we are able to estimate a maximum level of take that could
occur through implementation of the proposed action.

Very few (less than ten) navigation and habitat projects constructed on
the UMRS adversely affected Higgins eye since the species was listed in
1976. This is due to successful planning efforts by the Corps of
Engineers and resource agencies to avoid adverse impacts to the species.
To continue these planning efforts, the Corps of Engineers proposed
Standards and Guidelines to avoid and minimize impacts to Higgins eye
from actions proposed in the Upper Mississippi River -- Illinois
Waterway system Navigation Study. Per the proposed Standards and
Guidelines, the Corps of Engineers will coordinate with State, and
Federal resource agencies to develop site-specific project plans to
avoid and minimize impacts to Higgins eye. We anticipate that only in a
very few instances will adverse effects be unavoidable. In these
situations, it is unlikely that an entire bed or population of Higgins
will be affected. Furthermore, it is extremely unlikely that any such
project would be implemented if the viability of an EHA were to be
threatened.

Based on past experience, we believe that less than 5 percent of actions
(up to 50 projects) proposed under the Upper Mississippi River --
Illinois Waterway system Navigation Study may adversely affect Higgins
eye over 50 years. With one exception, incidental take of Higgins eye
for similar projects constructed in the past on the UMRS was less than
ten individuals per

project.[^2] Therefore, we believe the maximum incidental take that is
likely to occur over the 50

year term of the proposed action is 500 individuals.

[4.6.3 Effect of the take]{.underline}

The Corps of Engineers (2003) predicted that the population of Higgins
eye in EHAs and secondary habitats will decline from 698,000 in the
1990s to 183,000 in the 2000s due to adverse effects of zebra mussels.
Using the estimate of 183,000 as representing the current population of
Higgins eye at these locations, an incidental take of 500 individuals
represents a loss of 0.27 percent over 50 years, or 0.005 percent per
year. Other studies have shown that populations of mussels having a long
life span like Higgins eye are viable when annual total mortality is
less than 5 percent (D. Heath, Wisconsin Department of Natural
Resources, 2004, personal communication).

Regarding effects on the distribution of Higgins eye, it is unlikely
that an entire bed or population of Higgins will be affected by proposed
actions and thus incidentally taken. Furthermore, it is extremely
unlikely that any navigation or ecosystem project would be implemented
if the viability of an EHA for Higgins eye were to be threatened.
Therefore, we believe that the maximum incidental take of 500 Higgins
eye is not likely to reduce the reproduction, numbers, or distribution
of Higgins eye, result in jeopardy to the species, or destruction or
adverse modification of critical habitat (critical habitat has not been
designated for Higgins eye).

[4.6.4 Reasonable and prudent measures]{.underline}

To ensure that the anticipated level of incidental take is commensurate
with the take that occurs per the proposed action, the Corps of
Engineers (Corps) and the Service is implementing a tiered programmatic
consultation approach. This approach utilizes a tiered consultation
framework with the subject consultation resulting in this Tier I
biological opinion. All subsequent projects will be Tier II
consultations with Tier II biological opinions issued as appropriate
(i.e., whenever the proposed project will result in unavoidable adverse
effects to threatened and endangered species).

As individual projects are proposed under the recommended plan, the
Corps shall provide, for any action that may affect Indiana bats,
project-specific information to the Service that (1) describes the
proposed action and the specific area to be affected, (2) identifies the
species that may be affected, (3) describes the manner in which the
proposed action may affect listed species, and the anticipated effects,
(4) specifies whether the anticipated effects from the proposed project
are similar to those anticipated in the programmatic BO, (5) estimates a
cumulative total of take that has occurred thus far under the tier I BO,
and (6) describes any additional effects, if any, not

considered in the tier I consultation. If it is determined that the
proposed project may affect the Higgins eye pearlymussel, the Corps will
provide this information in a tier II BA to document anticipated effects
of the subject action.

The Service will review the information provided by the Corps for each
proposed project. If it is determined during this review that a proposed
project is not likely to adversely affect listed species, the Service
will complete its documentation with a standard concurrence letter and
specifies that the Service concurs that the proposed project is not
likely to adversely affect listed species or designated critical
habitat.. If it is determined that the action is likely to adversely
affect listed species or designated critical habitat and these effects
are commensurate with those contemplated in the programmatic BO, then
the Service will complete a tier II BO with a project-specific
incidental take statement within the annual allotted programmatic
incidental take, and project specific Reasonable and Prudent Measures
and Terms and Conditions, if appropriate..

The measures described below are non-discretionary, and must be
implemented by the agency for the exemption in Section 7(o)(2) to apply.
The Corps has a continuing duty to implement the activity covered by
this incidental take statement. If the Corps fails to adhere to the
terms and conditions of the incidental take statement, the protective
coverage of Section 7(o)(2) may lapse.

The Service believes the following Reasonable and Prudent Measures (RPM)
are necessary and appropriate to minimize impacts of incidental take of
Higgins eye. The RPMs are a modification of the Standards and Guidelines
found on Page 123 of the Corps of Engineers Tier I Biological
Assessment, and proposed Systemic Barge Fleeting Plan (U.S. Army Corps
of Engineers 2004a):

1\. Implement the Higgins Eye Planning Guidelines listed below for
design and implementation of navigation and ecosystem restoration
actions.

2\. Complete the Systemic Barge Fleeting Plan for the UMRS (U.S. Army
Corps of Engineers 2004a) in a timely manner.

Terms and Conditions

To be exempt from the prohibitions of Section 9 of the Act, the Corps
must comply with the following terms and conditions which implement the
reasonable and prudent measures described above and outline required
reporting/monitoring requirements. These terms and conditions are
non-discretionary. The Service's points of contact for coordination on
all terms and conditions are Mr. Dan Stinnett, Field Office Supervisor,
U.S. Fish and Wildlife Service, Twin Cities ES Field Office, 4101 East
80^th^ Street, Bloomington, Minnesota, 55425-1665 for St Paul District

projects; and Mr. Richard C. Nelson, Field Supervisor, U.S. Fish and
Wildlife Service, Rock Island Field Office, 4469-48^th^ Avenue Court,
Rock Island, Illinois 61201-9213 for Rock Island

District projects:

1\. Incorporate the following Higgins Eye Planning Guidelines as an
integral part of the planning process for actions proposed under the
Upper Mississippi River -- Illinois Waterway System Navigation Study:

> a\. Review the suitability of aquatic habitat for Higgins eye
> site-specifically for individual
>
> projects, including consideration of current range, and existing
> mussel surveys in the action area to assess the presence of and
> impacts to Higgins eye from site-specific actions.

b\. Conduct site-specific mussel surveys for Higgins eye where there is
insufficient

> information on habitat suitability and/or mussel distribution in the
> individual project area
>
> to make presence/impact determinations. If Higgins eye are not found
> in the mussel survey, use the decision criteria proposed by Wilcox et
> al. (1993) to determine the likelihood of occurrence of Higgins eye in
> the individual project area.
>
> c\. If Higgins eye are likely to be adversely affected in the
> individual project area, coordinate with the U.S. Fish and Wildlife
> Service in accomplishing the following:
>
> 1\. Develop and incorporate Conservation Measures into individual
> project plans to
>
> minimize take of Higgins eye. Conservation measures may include but
> are not limited
>
> to employing best management practices during project construction, or
> modifying
>
> project features, locations or timing of construction.
>
> For water level management projects within a pool or reach known to
> contain Higgins
>
> eye, evaluate the following Conservation Measures for implementation
> during the
>
> planning phase to minimize take of Higgins eye:
>
> a\. Limit the depth of drawdown at any of the 10 Essential Habitat
> Areas described in the revised recovery plan (U.S. Fish and Wildlife
> Service 2004), secondary habitats that are important to Higgins eye
> (U.S. Fish and Wildlife Service 2004), or locations on the UMR and
> tributaries where Higgins eye have been relocated in accordance with
> the Biological Opinion for Operation and Maintenance of the 9-Foot
> Channel Project (U.S. Fish and Wildlife Service 2000). Studies may be
> conducted to define the appropriate depth for a particular location(s)
> to minimize impacts to Higgins eye (see Item 1d below). In the absence
> of studies, a drawdown should not exceed 1.5 feet at any of the above
> habitat areas or locations.
>
> b\. Defer the drawdown if the pool elevation at the dam is greater
> than two feet above the secondary control pool elevation in excess of
> 20 days from April 1 to June 15 in the proposed drawdown year[^3]^.^
>
> c\. Lower water levels slowly (around 0.2 foot per day) during the
> drawdown to facilitate the escape of native mussels from the dewatered
> zone. The rate of drawdown should be commensurate with the proposed
> level of drawdown and the location of the drawdown.
>
> d\. Conduct studies to evaluate the distribution of Higgins eye in
> relationship to water depths in the action area, the ability of
> Higgins eye to escape the dewatered zone, and stranding of mussels
> with ongoing water level management projects. As additional
> information is obtained, the preceding Conservation Measures may be
> reviewed and revised, in coordination with the U.S. Fish and Wildlife
> Service. For example, a study for a proposed drawdown may find that
> Higgins eye are found at depths greater than 1.5 feet at a particular
> EHA or other habitat area, thereby facilitating a deeper drawdown at
> that location while minimizing impacts to Higgins eye.
>
> 2\. After conservation measures have been incorporated to minimize
> take of Higgins eye, coordination with the U.S. Fish and Wildlife
> Service, evaluate the feasibility of relocating Higgins eye from the
> impact area of navigation and ecological restoration actions that are
> likely to adversely affect Higgins eye. Factors to consider in
> determining feasibility include the size of the collection site (i.e.
> project "footprint"), substrate, water depth and flow conditions at
> the collection site, estimated number of Higgins eye and other mussels
> potentially relocated, and the availability of suitable relocation
> sites in the project area. If feasible, develop and implement a
> Higgins Eye Relocation Plan as part of the specific action and
> incorporate it into the Tier II Biological Assessment.

2\. When appropriate, incorporate Higgins eye habitat restoration into
the planning and

> implementation of ecosystem restoration projects within the range of
> the species.
>
> Implementing mussel habitat restoration as a part of the ecosystem
> restoration program will contribute to the restoration/enhancement of
> Higgins eye habitat on the UMRS in general for conservation of the
> species, and replace unavoidable habitat losses from specific
> navigation and ecosystem restoration actions, in particular.

3\. During the planning process for fish passage facilities at Lock and
Dam 19, study the risks to Higgins eye and other native mussels from
nonindigenous black carp. The study should be conducted in coordination
with the U.S. Fish and Wildlife Service and other appropriate federal
and state natural resource agencies. This information will be useful in
determining the feasibility of fish passage facilities at Lock and Dam
19 which currently limits upstream movement of fish on the UMR.

4\. In coordination with the U.S. Fish and Wildlife Service and other
appropriate federal and state natural resource agencies, initiate
development of the Systemic Barge Fleeting Plan for the UMRS in Funding
Year One of the Upper Mississippi River -- Illinois Waterway System
Navigation Capacity Improvement Project. Information from the plan will
assist in locating future actions to avoid and minimize effects to
Higgins eye. The fleeting plan should be completed within three years of
initiation and identify (1) important Higgins eye habitat areas that
should be avoided; (2) areas that are suitable for fleeting and have no
or minimal impacts on Higgins eye; and (3) other measures to
avoid/minimize the impacts of fleeting on Higgins eye.

Requirements for Monitoring and Reporting of Incidental Take of Higgins
eye pearlymussels

Federal agencies have a continuing duty to monitor the impacts of
incidental take resulting from their activities \[50 CFR 402.14(i)(3)\].
In doing so, the Federal agency must report the progress of the action
and its impact on the species to the Service as specified below.

1\. Supply the Service with an annual report, due by January 31 of each
following year, that specifies:

> a\. the progress and results of implementing the Reasonable and
> Prudent Measures and their terms and conditions,
>
> b\. the location and number of live and dead Higgins eye pearlymussels
> handled during mussel surveys or other activities identified by
> specific project, date and location including River Mile, and
>
> c\. the length, height, and if possible sex and age, of each Higgins
> eye pearlymussel handled during mussel surveys or other activities
> identified by specific project, date and location including River
> Mile.

Closing

The reasonable and prudent measures, with their implementing terms and
conditions, are designed to minimize the impact of incidental take that
might otherwise result from the proposed action. If, during the course
of the action, this level of incidental take is exceeded, such
incidental take represents new information requiring reinitiation of
consultation and review of the reasonable and prudent measures provided.
The Federal agency must immediately provide an explanation of the causes
of the taking and review with the Service the need for possible
modification of the reasonable and prudent measures.

Conservation Recommendations

Section 7(a)(1) of the Act directs Federal agencies to utilize their
authorities to further the purposes of the Act by carrying out
conservation programs for the benefit of endangered and threatened
species. Conservation recommendations are activities to be conducted at
your agency\'s discretion. They are designed to minimize or avoid
adverse effects of a proposed action on listed species or critical
habitat, to help implement recovery plans, or to develop information.

1\. Participate in the implementation of the Conservation Plan for
Freshwater Mussels of the Upper Mississippi River System (Upper
Mississippi River Conservation Committee 2004).

2\. Participate in public outreach efforts, in coordination with the
Service and other resource agencies, as a means to disseminate
information on life history and distribution of zebra mussels,
ecological importance of native mussels including Higgins eye and winged
mapleleaf (*Quadrula fragosa*), control measures to limit the spread of
zebra mussels on the UMR and tributaries, and status of mussel
propagation and relocation efforts.

In order for the Service to be kept informed of actions minimizing or
avoiding adverse effects or benefiting listed species or their habitats,
the Service requests notification of the implementation of any
conservation recommendations.

**Literature Cited**

Baker, F. C. 1928. The fresh water Mollusca of Wisconsin. Part II.
Pelecypoda. Bulletin of the Wisconsin Geological and Natural History
Survey, No. 70. 495 pp.

Cawley, E. T. 1996. A compendium of reports of mussel studies containing
*Lampsilis higginsii* from the period 1980-1996. Report for the Higgins
Eye Recovery Team - Fish and Wildlife Service. Environmental Research
Center - Loras College, Dubuque, Iowa. 84 pp.

Coker, R. E. 1919. Fresh-water mussels and mussel industries of the
United States. U.S. Dep. Int., Washington, DC, Bur. Fish., Doc. No. 805,
Appx. VIII, 28 pp.

Coker, R. E., A. F. Shira, H. W. Clark, and A. D. Howard. 1921. Natural
history and propagation of freshwater mussels. *Bulletin of the Bureau
of Fisheries* 37:77-181.

Cummings, K. S., and C. A. Mayer. 1992. Field guide to freshwater
mussels of the Midwest. Illinois Natural History Survey Manual 5. 194
pp.

Davis, M. 2001. Minnesota Department of Natural Resources, Lake City,
MN, personal communication on mussel stranding.

Gordon, R. 2001. *Lampsilis higginsii* recovery project; Genoa National
Fish Hatchery; 2001. Unpublished Report, Genoa National Fish Hatchery,
U.S. Fish and Wildlife Service, Genoa, WI. 10 pp.

Havlik, M., and L.L. Marking. 1980. A quantitative analysis of naiad
mollusks from the Prairie du Chien, Wisconsin, dredge material site on
the Mississippi River. Bulletin of the American Malacological Union,
1980: 30-34.

Havlik, M. 2001. Malacological Consultants, Inc., La Crosse, WI,
personal communication on mussel stranding.

Hay, B. 2004. Wisconsin Department of Natural Resources, Madison, WI,
personal communication on mussel booklet.

Helms, D. 2000. Mussel relocation at the proposed ramp/jetty
modification site located in Mississippi River Pool 14, Cordova, IL.
Helms & Associates, Bellevue, IA. 22 pp.

Holland-Bartels, L. E., and D. L. Waller. 1988. Fish hosts for glochidia
of the endangered freshwater mussel *Lampsilis higginsii* Lea (Bivalvia:
Unionidae). Malacological Review 21: 119-122.

Hornbach, D. J., P. Baker, and T. Deneka. 1995. Abundance and
distribution of the endangered mussel, *Lampsilis higginsii* in the
lower St. Croix River, Minnesota and Wisconsin. Final Report to the U.S.
Fish and Wildlife Service, Contract \# 14-48-000394-1009.

Maher, R. 2004. Illinois Department of Natural Resources, Brighton, IL,
personal communication on black carp.

Mussel Coordination Team. 2003. Saving the Higgins eye pearlymussel
(*Lampsilis higginsii*) from extinction: 2002 status report on the
accomplishments of the Mussel Coordination Team, St. Paul District Corps
of Engineers, MN. 48 pp.

Rowse, R. 2004. U.S. Fish and Wildlife Service, Bloomington, MN,
personal communication on zebra mussels in the St. Croix River.

Tucker, J. K. 1996. Post-flood strandings of unionid mussels. *Journal
of Freshwater Ecology* 11(4):433-438.

Upper Mississippi River Conservation Committee. 2004. Conservation plan
for freshwater mussels of the upper Mississippi River system. Upper
Mississippi River Conservation Committee, 4469 48^th^ Avenue Court, Rock
Island, IL. 28 pp.

U.S. Army Corps of Engineers. 2002. Final definite project report and
environmental assessment for relocation plan for the endangered Higgins
eye pearlymussel (*Lampsilis higginsii*), upper Mississippi River and
tributaries; Minnesota, Wisconsin, Iowa, and Illinois. U.S. Army Corps
of Engineers, St. Paul, Minnesota, in cooperation with the interagency
Mussel Coordination Team.

U.S. Army Corps of Engineers. 2004a. Biological assessment of the upper
Mississippi River -- Illinois waterway system navigation study. Rock
Island, St. Paul and St. Louis Districts. 193 pp.

U.S. Army Corps of Engineers. 2004b. Report to congress on the
environmental management program, Rock Island, St. Paul and St. Louis
Districts. In press.

U.S. Fish and Wildlife Service. 1983. Higgins eye mussel recovery plan.
Ft. Snelling, Minnesota. 98 pp.

U.S. Fish and Wildlife Service. 2000. Biological opinion for the
operation and maintenance of the 9-foot navigation channel on the upper
Mississippi River system, May 15, 2000, 243 pages.

U.S. Fish and Wildlife Service. 2004. Higgins Eye Pearlymussel
(*Lampsilis higginsii*) Recovery

Plan: First Revision. Ft. Snelling, Minnesota. 126 pp.

Wilcox, D.B., D.D. Anderson, and A.C. Miller. 1993. Survey procedures
and decision criteria for estimating the likelihood that *Lampsilis
higginsii* is present in areas in the upper Mississippi River system.
In: Cummings, K.S., A.C. Buchanan, and L.M. Koch, editors. Conservation
and management of freshwater mussels. Proceedings of a UMRCC symposium,
12-14 October 1992, St. Louis, MO. Upper Mississippi River Conservation
Committee, Rock Island, IL. p. 163 -- 167.

**5.0 Pallid Sturgeon (*Scaphirynchus albus*)**

[5.1 Status of the Species]{.underline}

This section presents the biological or ecological information relevant
to formulating the biological opinion. Appropriate information on the
species' life history, its habitat and distribution, and other data on
factors necessary to its survival, is included to provide background for
analysis in later sections. This analysis documents the effects of past
human and natural activities or events that have led to the current
range-wide status of the species. Portions of this information are also
presented in listing documents, the recovery plan (USFWS 1993), the
Final Biological Opinion for the Operation and Maintenance of the 9-Foot
Navigation Channel on the Upper Mississippi River System (USFWS 2000),
and the Biological Assessment of the Upper Mississippi River-Illinois
Waterway System Navigation Study (USACE 2004).

[5.1.1 Species/critical habitat description]{.underline}

The pallid sturgeon (*Scaphirynchus albus*) was listed as an endangered
species on September 6, 1990 (55 FR 36641) pursuant to the Endangered
Species Act of 1973 (16USC 1531 et seq.) as amended. No critical habitat
is designated for this species. The pallid sturgeon was originally
described as a species by Forbes and Richardson in 1905. The pallid
sturgeon is native to the Missouri and Mississippi Rivers and is adapted
to the pre-development habitat conditions that existed in these large
rivers. These conditions can generally be described as large,
free-flowing, warmwater, turbid habitats with a diverse assemblage of
physical attributes that were in a constant state of change (USFWS
1993). Floodplains, backwaters, chutes, sloughs, islands, sandbars and
main channel waters formed the large-river ecosystem that provided the
macrohabitat requirements for all life stages of pallid sturgeon and
other native large-river fish. Today, these habitats and much of the
once functioning ecosystem has been changed by human developments.

[5.1.2 Life history]{.underline}

The type specimens for identification were collected at or near Grafton,
Illinois, on the lower Illinois and Mississippi Rivers (Forbes and
Richardson 1905). The species is described as having a flattened,
shovel-shaped snout; long, slender, and completely armored caudal
peduncle; and lacks a spiracle (Smith 1979). The mouth is toothless,
protrusible, and ventrally positioned under the snout, as with other
sturgeon. Pallid sturgeon are similar in appearance to the more common
and darker shovelnose sturgeon (*S.* *platyrhynchus*). Pflieger (1975)
reported the principal features distinguishing pallid sturgeon from
shovelnose sturgeon as the paucity of dermal ossifications on the belly,
24 or more anal fin rays and 37 or more dorsal fin rays. Sexual maturity
for males is estimated to be 7 to 9 years, with 2 to 3 year intervals
lapsing between spawning events. Females are estimated to reach sexual
maturity in 15 to 20 years, with 3 to 10 year intervals between spawning
events (Keenlyne and Jenkins 1993). The length of time between spawning
events depends partially on the quality and quantity of food available
in their natural habitat (Keenlyne and Jenkins 1993). The fecundity of a
given female may vary greatly by individual, with most spawning only a
few times during a normal life span (Duffy et al. 1996). Spawning
appears to be a function of floodflows (increased discharge and
velocity) that generate spawning migrations, temperature and interaction
with other pallid sturgeon (Steve Krentz, USFWS, pers. comm. 2003). The
influence of turbidity and conductivity is unknown (Steve Krentz, USFWS,
pers. comm. 2003). Pallid sturgeon have adhesive eggs, therefore,
spawning is thought to occur over hard substrates of gravel or cobble
accompanied by moderate flow. At hatching, young pallid sturgeon begin a
migration period that may continue for up to 13 days (Kynard et al.
1998). Suitable habitat and forage food must be available after yolk-sac
absorption during the initial stages of larvae development. Larval
pallid sturgeon have been collected in the Lower Missouri River, Middle
Mississippi River and Lower Mississippi River which indicates that
limited reproduction is occurring in the wild. In April and May 2001,
the Missouri Department of Conservation (MoDOC) collected 40 larval
sturgeon utilizing the Missouri benthic trawl (Hrabik 2002). In spring
of 2003, the MoDOC collected an estimated 50 larval sturgeon in the MMR
(Dave Herzog, MoDOC, pers. comm. 2004). It is unclear at this time how
many of these larval sturgeon are pallid sturgeon or hybrids. From April
to September 2002, the CMFRO collected 11 YOY sturgeon in Lisbon Bottoms
on the Lower Missouri River. Five of these fish were identified as
shovelnose sturgeon and six still need to be identified (Grady and
Mauldin 2002). A total of eight larval sturgeon (4 in 2002 and 2 in
2003) have been collected in the Lower Missouri River as part of a
larval fish sandbar habitat study being conducted by the University of
Missouri (Kerry Reeves, Univ. of Missouri, pers. comm. 2003.). Two
individuals have been identified to species, one pallid sturgeon and one
shovelnose sturgeon, while the remainder awaits positive identification.

Pallid sturgeon feed on benthic macroinvertebrates and drifting
invertebrates during early life stages (juveniles) (Modde and Schmulbach
1977, Carlson et al. 1985). However, older juvenile and adult pallid
sturgeon are more piscivorous than the shovelnose sturgeon and switch to
a diet composed of a greater proportion of fish as they mature.

[5.1.3 Population dynamics]{.underline}

A comparison of pallid sturgeon and shovelnose sturgeon catch records
provides an indication of the relative population sizes of pallid
sturgeon compared to shovelnose sturgeon. At the time of their original
description, pallid sturgeon composed 1 in 500 (0.20%) river sturgeon
captured in the Mississippi River at Grafton, Illinois (Forbes and
Richardson 1905). However, it is not known whether this apparent rarity
of pallid sturgeon compared to other sturgeon was indicative throughout
the range or only in this part of the Mississippi River. Historical
records would indicate that pallid sturgeon were never abundant in the
Mississippi River above the mouth of the Missouri River. Carlson et al.
(1985) captured 4,355 river sturgeon on the Missouri and Mississippi
Rivers. Eleven (0.25 percent) of these were pallid sturgeon.

[Upper Missouri River]{.underline} - Duffy et al. (1996) reported that
mark and recapture data estimated 50 to 100 adult pallid sturgeon remain
in the Missouri River above Fort Peck Dam in Montana (Recovery -
priority management area #1\[RPMA #1\]) and between 200 and 300 adult
pallid sturgeon remain between Garrison Dam in North Dakota and Fort
Peck Dam, which also includes the Yellowstone River (RPMA#2). More
recently, the Upper Basin Recovery Work Group estimated that fewer than
the original estimated number of pallid sturgeon still remain, leaving
approximately 30 -- 50 adult pallid sturgeon in RPMA#1 and between 89
and 236 adult pallid sturgeon in RPMA#2 (Kapuscinski 2003).

The pallid sturgeon sub-population in this river reach is aging and
declining in status. The population is estimated at 151 individuals with
95 percent confidence intervals of 89 to 236 individuals (Kapuscinski
2003). This is down from an estimated 166 individuals in 2002 and 178
individuals in 2001. Kapuscinski (2003) estimates that this population
of wild pallid sturgeon will be extinct by 2018 based on trend data
collected for the period 1991-2003. The Service has interpreted
Kapuscinski's conclusion of extinction to mean that this sub-population
would be extirpated by 2018.

It should be noted that Kapusinski (2003) compensated for certain
assumptions that are necessary for a valid outcome from the original
method used to estimate population size (Schnable mark-recapture).
Certain assumptions for a valid outcome in the original analysis, which
were found to be incorrect, leave insufficient data to inform the
present analysis. These include the rate at which tags are shed and the
uniformity of effort expended to collect fish. These assumptions result
in an overestimation and underestimation, respectively. An additional
assumption concerning the rate of mortality during the study period was
also found to be incorrect. The original analysis assumed no mortality
during the study period. Kapusinski (2003) provided an estimate of
natural mortality (10 percent) and subtracted known marked individuals
that died during the study. Incorporating these into the analysis to
address the mortality assumption resulted in a slightly lower abundance
estimate than the estimate obtained from the original analysis.

Krentz (2000) reported capturing 23 pallid sturgeon in 2000 in RPMA#2 at
the confluence of the Yellowstone and Missouri Rivers. These fish were
primarily collected to obtain broodstock for propagation efforts. Catch
rates were calculated for the period from 1998 to 2000. The
catch-per-unit-effort (CPUE) for pallid sturgeon was 0.62/hour drifting
in 1998, 0.41/hour drifting in 1999 and 1.66/hour drifting in 2000. The
CPUE for pallid sturgeon was 1.16/hour drifting in 2001 and 0.80/hour
drifting in 2002 (Krentz et al. 2002). However, Krentz (2000) stated
that caution should be used in utilizing this information for any
analysis of relative abundance as the sampling was not random and
productive habitats were targeted.

Yerk and Baxter (2001) reported capturing 17 adult pallid sturgeon in
RPMA#2 during 2000. Eight of the adults were untagged fish. They
reported that the smallest individual captured was likely a
pallid/shovelnose sturgeon hybrid based on its character index value
(346.1). Fifteen of these adults were captured in April at the
confluence of the Missouri and Yellowstone Rivers. Yerk and Baxter
(2001) also reported recapture of three hatchery reared pallid sturgeon.

Kapuscinski and Baxter (2003) summarized the second year results of a 5
year study to investigate pallid sturgeon recovery efforts in RPMA #2.
During 2002, they captured 15 adult pallid sturgeon; however, only 3 of
these adults were untagged individuals. They noted that the recapture
rate (80 percent) was very high compared to previous years (53 percent
in 2000 and 2001). Eleven of the 15 adult pallid sturgeon were captured
during spring at the confluence of the Missouri and Yellowstone Rivers.
The CPUE for pallid sturgeon averaged 0.18 per net drifted and 1.37 per
drift hour. This compares to the CPUE of 0.50 per net drifted for 2001
(Yerk and Baxter 2000) and 1.67 per drift hour reported by Krentz
(2000). In addition, they captured a total of 6 hatchery reared pallid
sturgeon. They reported a catch rate for hatchery reared pallid sturgeon
captured in drifted trammel nets of 0.1165/hr compared to 16.19/hr for
shovelnose sturgeon (Kapuscinski and Baxter 2003).

[Middle Missouri River]{.underline} -- Sport anglers have reported up to
five pallid sturgeon catches per year on the Missouri River between the
headwaters of Oahe Reservoir in North Dakota and Garrison Dam; however,
no catches have been reported since 2002. Occasional catches were
reported from the riverine reach above Gavins Point Dam to the Fort
Randall Dam, suggesting that perhaps as many as 25 to 50 fish remain in
each of these areas. No catches of adults have been reported since 1992.
A small population also existed between Oahe Dam and the Big Bend Dam on
the Missouri River in South Dakota with perhaps 50 to 100 fish remaining
in the upper few miles of the riverine section above the headwaters of
Lake Sharpe; however, no catches have been reported since 2001 (Steve
Krentz, USFWS, pers. comm. 2003).

[Lower Missouri River]{.underline} - Recent records of the pallid
sturgeon in the Lower Missouri River from Gavins Point Dam (river mile
811.1) to the mouth of the Platte River (river mile 595.5) are rare.
According to the Service's pallid sturgeon database a total of 20 pallid
sturgeon have been reported in this reach. Eight of these fish were
reported for the unchannelized reach from Gavins Point Dam to Ponca,
Nebraska (river mile 753.0). Thirteen of these records were reported
prior to 1990. Seven pallid sturgeon have been reported since listing of
the species in 1990. The Nebraska Game and Parks Commission has been
conducting a study of the ecology of the Missouri River since 1998 by
conducting sampling in various sections of the Missouri River including
the unchannelized river below Gavins Point Dam and in the channelized
river adjacent to Nebraska. In 2000, sturgeon were sampled with a
modified benthic trawl. The CPUE averaged 1.54 shovelnose sturgeon in
the spring and 0.24 in the summer (Mestl 2001). No pallid sturgeon were
collected during this sampling effort. Additional benthic trawl sampling
was conducted as part of mitigation site monitoring. This resulted in
the collection of 16 shovelnose sturgeon at various locations and one
pallid sturgeon which was collected at Goose Island (Mestl 2001). No
data were provided concerning the pallid sturgeon in order to note
whether this was a wild origin or hatchery reared fish.

During a Mississippi Interstate Cooperative Resources Agencies (MICRA)
study from 1996 to 2000 (Grady et al. 2001), 21 pallid sturgeon were
collected in the Lower Missouri River and Middle Mississippi River. Of
the 9 pallid sturgeon collected in the Lower Missouri River, 7 were
presumed to be of wild origin, while 2 were hatchery stocked fish. Of
the 12 pallid sturgeon collected in the Middle Mississippi River, 1 was
considered a wild origin fish and 11 were considered hatchery stocked
fish (Table 6 in Grady et al. 2001). The ratio of wild pallid sturgeon
to all river sturgeon collected dropped from 1 in 398 (0.25 percent)
collected by Carlson et al. (1985) to 1 in 647 (0.15 percent) (Grady et
al. 2001). The contribution of hatchery reared fish is evident as wild
and hatchery raised pallid sturgeon accounted for 1 in 247 (0.41
percent) of all river sturgeon (Grady et al. 2001).

In 2001, the Service's Columbia Missouri Fishery Resources Office
(CMFRO) began work on the Lower Missouri River Pallid Sturgeon
Monitoring and Population Assessment Project. Sampling occurred in 6
reaches along 170 river miles and resulted in collection of 4,110 fish
from 11 families with 77 trawl hauls and 12 net nights (Doyle et al.
2002). No pallid or hybrid sturgeon were collected, however, 198
shovelnose sturgeon and 2 lake sturgeon were collected. Fourteen YOY
sturgeon were collected. While 4 of these have been identified as
shovelnose sturgeon, 10 have not yet been identified to species (Doyle
et al. 2002). In 2002, the CMFRO sampled 6 reaches along 200 river
miles. Among the 27,903 fish collected were 12 pallid sturgeon, 12
pallid/shovelnose hybrids, 3,044 shovelnose sturgeon and 28 lake
sturgeon (Doyle and Starostka 2003). Five of the pallid sturgeon were
classified as juveniles. While four of these fish were from recent
stocking of hatchery reared fish, one was presumed to be wild (Doyle and
Starostka 2003). According to Doyle and Starostka (2003) pallid sturgeon
continue to decline at a rapid rate. Within the 200 river miles they
sampled, the ratio of pallid sturgeon compared to all river sturgeon
decreased from 1:311 (0.32%) in the 1996-2000 MICRA study to 1:387
(0.26%) in 2002. It should be noted, however, that the sampling effort
in 2002 does not reflect the same sampling effort or gear utilized
during the MICRA study which was completed over a period of five years.

From January 2000 through March 2001, the CMFRO collected information on
seasonal fish abundance and species composition in the area of the
Highway 19 bridge replacement at Hermann, Missouri. They collected over
3000 fish including 3 pallid sturgeon, 14 hybrids and 1990 shovelnose
sturgeon (Milligan 2002).

[Middle Mississippi River (Upper Mississippi River miles 196.0 to
0.0)]{.underline} - In May 2002 the Corps' St. Louis District initiated
a three year Pallid Sturgeon Habitat and Population Demographics study
in the Middle Mississippi River (MMR). The study is being carried out by
staff from the Corps' Waterways Experiment Station, the Missouri
Department of Conservation (MoDOC), and SIUC. By May 2003, a total of 41
pallid sturgeon and 3,636 shovelnose sturgeon had been collected from
throughout the MMR (USACE 2003a). The ratio of pallid sturgeon compared
to shovelnose sturgeon (1:89) is much higher than in other parts of the
pallid sturgeon's range. As of March 2004, a total of 58 pallid sturgeon
have been collected in the MMR as part of this study (Jack Killgore,
USACE, pers. comm. 2004). It is conservatively estimated that
approximately 60 percent of these pallid sturgeon are MoDOC hatchery
reared fish released in 1994 and 1997 (Dave Herzog, MoDOC, pers. comm.
2003). It is also possible that the higher of pallid sturgeon to
shovelnose sturgeon may be a result of declining numbers of shovelnose
sturgeon due to commercial harvest of sturgeon flesh and roe (Dave
Herzog, MoDOC, pers. comm. 2003). In 2003, the Illinois Department of
Natural Resources (IDNR) collected 9 pallid sturgeon while sampling for
shovelnose sturgeon in the Chain of Rocks area (river miles 189.0 to
185.0) of the MMR (Rob Maher, IDNR, pers. comm. 2003), possibly
indicating this is a staging area for sturgeon spawning. This is further
substantiated by the recent collection of 7 pallid sturgeon in the Chain
of Rocks area by SIUC and IDNR. This includes one female thought to have
black eggs (Jim Garvey, SIUC, pers. comm. 2004).

[Lower Mississippi River and Atchafalaya River]{.underline} - During
sampling in 2001, Hartfield et al. (2002) collected 383 shovelnose
sturgeon (58 -- 725 mm), 11 pallid sturgeon (203-785 mm) and 3
intermediates. In 2003 trawling efforts resulted in the collection of 78
shovelnose sturgeon, 5 pallid sturgeon and one intermediate near
Vicksburg, Mississippi (Hartfield et al. 2004). In late 2000 and early
2001, biologists collected a total of 83 pallid sturgeon and 109 hybrid
sturgeon during sampling at the Old River Control Structure at the
junction of the Mississippi and Atchafalaya Rivers in Louisiana (Reed
2002). A new 4-year pallid sturgeon study was initiated in 2001 which
has thus far resulted in collection of 74 sturgeon. Of these, 11 were
pallid sturgeon and 20 were classified as hybrids (Reed 2002).

Since 1997, the Corps of Engineers, Waterways Experiment Station has
been collecting pallid sturgeon in the Lower Mississippi River, with a
formal study being initiated in 2000 (Killgore 2004). A total of 2,590
shovelnose sturgeon and 115 pallid sturgeon have been collected to date.
This yields a pallid sturgeon to shovelnose sturgeon ratio of 1:23
(Killgore 2004) which is a much higher ratio of pallid sturgeon than
what occurs in the rest of the range of the species.

[5.1.4 Status and distribution]{.underline}

The pallid sturgeon was listed because a review of the literature showed
a sharp decline in pallid sturgeon observations over the range of the
species and especially so in the Missouri River from Gavins Point Dam to
the headwaters. In the 1960's, 500 observations were made (i.e., an
average of 50 per year); in the 1970's, 209 observations (i.e. an
average of 21 per year); and in the 1980's, 65 observations (i.e., an
average of about 7 per year) over the entire 5,725 kilometers (3,550
miles) of range (50 CFR Part 17). The Final Rule went on to indicate
that the decline of the species appeared to correspond with expanded
commercial harvest while, during the same time, recruitment began to
fail. The decline, however, also followed the extensive developments of
the 1950's and 1960's of the Missouri and Mississippi rivers. Kallemeyn
(1983), and Gilbraith et al. (1988) attributed the decline, either
directly or indirectly, to habitat modification. Modification of the
pallid sturgeon's habitat by human activities has blocked fish movement,
destroyed or altered spawning areas, reduced food sources or ability to
obtain food, altered water temperatures, reduced turbidity, and changed
the hydrograph of the river system. Overfishing, pollution, and
hybridization that occur due to habitat alterations also have probably
contributed to the species population decline (USFWS 1993).

The historic distribution of pallid sturgeon as described by Bailey and
Cross (1954) primarily included the Missouri River, the Mississippi
River from the mouth of the Missouri River to the Gulf of Mexico and the
lower reaches of the Platte, Kansas and Yellowstone Rivers. Records also
indicated pallid sturgeon were present in the Mississippi River at
Grafton, Illinois, (Forbes and Richardson 1905) and as far north as
Keokuk, Iowa (Bailey and Cross 1954, Coker 1930). Today, the
distribution includes the Missouri River, Middle and Lower Mississippi
River, the Atchafalaya River and the lower reaches of the Yellowstone,
Platte, Kansas, St Francis and Big Sunflower Rivers (Constant et al.
1997). Of the total range of approximately 3,515 river miles, 28 percent
is impounded, 21 percent has been affected by upstream impoundments
(altered hydrograph, temperature and sediment budget) and 51 percent is
channelized (Keenlyne 1989). The amount of impounded river miles
fluctuates from year to year depending on the amount of inflow into
Upper Missouri River reservoirs (i.e., drought or flood conditions) and
the Corps of Engineers' operations. The channelized river miles of the
Lower Missouri River and Middle Mississippi River are also affected by
operation and maintenance of upstream impoundments, especially affecting
sediment transport. The altered hydrograph and temperature effects are
attenuated as the Missouri River progresses downstream (Robb Jacobson,
USGS, pers. comm. 2003) and enters the Mississippi River. The result is
a highly fragmented range of habitats with varying suitability for
pallid sturgeon.

Due to intensive study effort in recent years, catch records have
increased indicating pallid sturgeon remain scarce but are widely
distributed throughout their range (Figure 5-1).

![](media/image7.png){width="5.996527777777778in"
height="3.6243055555555554in"}

**Figure 5-1. Rangewide Distribution of Pallid Sturgeon Catch Records**

As noted with the above information, pallid sturgeon are widely
distributed throughout their range and occur in small numbers relative
to the closely related shovelnose sturgeon **(**see Table 5-1).
Increasingly, the total numbers of pallid sturgeon collected during
sampling reflect higher numbers of released hatchery reared fish and
hybrids than wild fish. The collection of larval and juvenile pallid
sturgeon is becoming more common due to increased effort and gear
efficiency. However, the low numbers of these age classes suggests to
most sturgeon researchers that pallid sturgeon reproduction is a rare
event and recruitment from reproduction has not been documented. It
should be noted that the numbers of larval and juvenile pallid sturgeon
collected may also be an artifact of sampling gear bias and/or a
variable level of effort aimed at these size classes.

As is shown in Table 5-1, data that are collected and reported
throughout the range of the pallid sturgeon is inconsistent and
difficult to compare between reaches. The Service concludes from the
data represented in Table 5-1 and discussed in the text above that there
is a continuous and ongoing decline in the population of adult pallid
sturgeon in the Upper Missouri River reaches. Additionally, for both the
Lower Missouri River alone, as well as the Lower Missouri River and the
Middle Mississippi River combined, there appears to be a shift in the
relative abundance of pallid sturgeon to shovelnose and other river
sturgeon. Data from Grady et al. (2001) and MoDOC indicate that
shovelnose sturgeon populations are either stable or declining,
respectively. This indicates to the Service that there is a true
reduction in the abundance of pallid sturgeon to reflect a lower ratio
of pallid sturgeon compared to other sturgeon species.

**Table 5-1. Estimates of adult pallid sturgeon and ratio of pallid
sturgeon to other sturgeon from the literature and reports.**

+-----------+-----------+---------+----------+----------+------------+
| **Upper   | **Middle  | **Lower | **Middle | **Lower  | **Lower    |
| Missouri  | Missouri  | M       | Mis      | Missouri | M          |
| River**   | River**   | issouri | sissippi | Rive     | ississippi |
|           |           | River** | River**  | r/Middle | River**    |
|           |           |         |          | Mis      |            |
|           |           |         |          | sissippi |            |
|           |           |         |          | River    |            |
|           |           |         |          | Co       |            |
|           |           |         |          | mbined** |            |
+-----------+-----------+---------+----------+----------+------------+
| 200-300   | 25-50     | 1:311   | 1:89     | 1:398    | 1:23       |
|           |           | (0.32%) | (        | (0       | (4.3%)     |
| Duffy et  | (GPD to   |         | 1.1%)^1^ | .25%)^2^ |            |
| al. 1996  | FRD)      | Grady   |          |          | Killgore   |
|           |           | et al.  | USACE    | Carlson  | 2004       |
|           |           | 2001    | 2003     | et al.   |            |
|           |           |         |          | 1985     |            |
+-----------+-----------+---------+----------+----------+------------+
| 178       |           | 1:387   |          | 1:647    |            |
|           |           | (0.26%) |          | (0.15%)  |            |
| Year 2001 |           |         |          |          |            |
|           |           | Doyle   |          | Grady et |            |
| K         |           | and     |          | al. 2001 |            |
| apusinski |           | St      |          |          |            |
| 2003      |           | arostka |          | 1        |            |
|           |           | 2003    |          | 996-2000 |            |
|           |           |         |          | Cu       |            |
|           |           |         |          | mulative |            |
+-----------+-----------+---------+----------+----------+------------+
| 166       |           |         |          |          |            |
|           |           |         |          |          |            |
| Year 2002 |           |         |          |          |            |
|           |           |         |          |          |            |
| K         |           |         |          |          |            |
| apusinski |           |         |          |          |            |
| 2003      |           |         |          |          |            |
+-----------+-----------+---------+----------+----------+------------+
| 151       |           |         |          |          |            |
|           |           |         |          |          |            |
| (89-236)  |           |         |          |          |            |
| (95%      |           |         |          |          |            |
| Co        |           |         |          |          |            |
| nfidence) |           |         |          |          |            |
|           |           |         |          |          |            |
| Year 2003 |           |         |          |          |            |
|           |           |         |          |          |            |
| K         |           |         |          |          |            |
| apusinski |           |         |          |          |            |
| 2003      |           |         |          |          |            |
+-----------+-----------+---------+----------+----------+------------+

^1^ Ratio on Middle Mississippi River is to shovelnose sturgeon only

^2^ Ratio is to all river sturgeon (shovelnose, lake, pallid, hybrid)

# 

To summarize, since issuance of the 2000 Biological Opinion (USFWS
2000a), additional pallid sturgeon research and survey work has been
initiated. This includes additional collection of small numbers of
pallid sturgeon larvae and juveniles. However, evidence of recruitment
of wild origin pallid sturgeon is lacking. The species is largely being
maintained through artificial propagation programs, particularly in the
Upper Missouri River where the sub-population below Fort Peck Dam is
predicted to be extirpated by 2018. An exception to this is the Lower
Mississippi River, where the species status is largely unknown with the
exception of recent collections in several locations. Hybridization with
the closely related shovelnose sturgeon in the Lower Missouri River and
Mississippi remains a concern (Keenlyne et al, 1994).

Pallid sturgeon are threatened by many factors, including habitat loss
and degradation, hybridization, commercial fishing, and
contaminants/pollutants. These threats to the species appear to be
increasing rather than decreasing and continue to adversely affect the
pallid sturgeon.

New threats

Additional threats to the species further compound the species status.
Entrainment due to dredging operations and commercial navigation traffic
represents an unknown, but perhaps significant, threat to the species
through direct mortality. The presence of exotic Asian carp has
increased dramatically in the Missouri and Mississippi Rivers. These
species compete with native river fish for food and habitat and may
present a significant long-term threat to the pallid sturgeon.

[5.2 Environmental Baseline]{.underline}

This section is an analysis of the effects of past and ongoing human and
natural factors leading to the current status of the species, its
habitat, and ecosystem within the action area. Factors affecting the
species include those described previously under *Status and
Distribution*, *Reasons* *for Decline*, and *New Threats.* In accordance
with 50 CFR §402.02, the action area includes all areas to be affected
directly or indirectly by the Federal action and not merely the
immediate area involved in the action. The Corps' Biological Assessment
defined the project area as the Upper Mississippi River and Illinois
Waterway. The Upper Mississippi River extends from the confluence of the
Ohio River to Upper St. Anthony Falls in Minneapolis-St. Paul,
Minnesota. The Illinois Waterway extends from its confluence with the
Mississippi River at Grafton, Illinois to T.J. O'Brien Lock in Chicago,
Illinois. However, beyond this project area, portions of the Lower
Missouri River and the Lower Mississippi River will experience indirect
effects as a result of the proposed action. These indirect effects will
occur in the form of increased navigation traffic as a result of
navigation improvements and improved habitat quality and biological
productivity as a result of ecosystem restoration (e.g., improved water
quality, improved habitat quality). Therefore, the action area for
purposes of this analysis includes the Upper Mississippi River, Illinois
Waterway, Lower Missouri River and Lower Mississippi River.

The past and present impacts of construction, operation and maintenance
of the 9-Foot Channel Project were analyzed in the 2000 Biological
Opinion (USFWS 2000a). The 2000 Biological Opinion highlighted the
importance of the Middle Mississippi River to the pallid sturgeon and
provides baseline information for this biological opinion for the
Navigation Study. Therefore, the environmental baseline in the 2000
Biological Opinion is incorporated by reference. Environmental baseline
information from the 2000 Biological Opinion is included to the extent
that it will add clarity and context to this biological opinion.
Otherwise the environmental baseline is based on surveys, studies, and
other information obtained since 2000. In addition, the following
information is also updated in the environmental baseline: 1) State,
local and private actions already affecting the species or that will
occur contemporaneously with this consultation; 2) unrelated Federal
actions affecting pallid sturgeon that have completed formal or informal
consultations; and 3) Federal and other actions within the action area
that may benefit pallid sturgeon.

[5.2.1 Status of the pallid sturgeon within the action area]{.underline}

The current status of pallid sturgeon in the action area remains largely
unknown, but available information suggests to the Service that there
may be a reduction in the abundance of wild pallid sturgeon, as
reflected in generally lower ratios of pallid sturgeon to other sturgeon
species. As reported in the rangewide status section on pallid sturgeon,
during a MICRA study from 1996 to 2000 (Grady et al. 2001), 21 pallid
sturgeon were collected in the Lower Missouri River and Middle
Mississippi River. Of the 9 pallid sturgeon collected in the Lower
Missouri River, 7 were presumed to be of wild origin, while 2 were
hatchery stocked fish. Of the 12 pallid sturgeon collected in the Middle
Mississippi River, 1 was considered a wild origin fish and 11 were
considered hatchery stocked fish. The ratio of wild pallid sturgeon to
all river sturgeon collected dropped from 1 in 398 (0.24 percent)
collected by Carlson et al. (1985) to 1 in 647 (0.15 percent) (Grady et
al. 2001). The contribution of hatchery reared fish is evident as wild
and hatchery raised pallid sturgeon accounted for 1 in 247 (0.41
percent) of all river sturgeon (Grady et al. 2001). Doyle and Starostka
(2003) reported the ratio of wild pallid sturgeon to all river sturgeon
collected in combined 2002 samples was 1:387 (0.26 percent). Data
collected from 1996-2000 within the same reaches showed a ratio of 1:311
(0.32 percent) (Grady et al. 2001). On the other hand, within the Middle
Mississippi River and the Lower Mississippi River, the ratio of pallid
sturgeon to shovelnose sturgeon is reported at 1:89 (1.12 percent) and
1:23 (4.34 percent), respectively (USACE 2003a, Killgore 2004).

There are a number of factors that could influence wild pallid sturgeon
abundance and the different ratios of pallid sturgeon compared to other
sturgeon in the catch: 1) increased harvest pressure on shovelnose
sturgeon, 2) a prevalence of stocked pallid sturgeon in the catch,
and/or 3) a greater rate of decline in pallid sturgeon populations. Data
on declining shovelnose sturgeon populations in the Middle Mississippi
River supports increased harvest pressure as being a factor. The MoDOC
(Hrabik 2002) reports that catch per unit effort of shovelnose sturgeon
during winter sampling using gill nets showed a dramatic decline from
1997 to 2002. From other studies, however, shovelnose sturgeon
populations in the Lower Missouri River and Middle Mississippi River
show no apparent excessive exploitation as would be evidenced by reduced
numbers of large reproductive fish (Grady et al. 2001, Doyle and
Starostka 2003). Commercial sturgeon harvest has been closed in
Louisiana and Mississippi for a number of years. In the last few years
the state of Arkansas closed commercial sturgeon fishing in the
Mississippi River, while it is still allowed in Illinois, Missouri,
Kentucky, and Tennessee.

It is also believed that capture of hatchery released pallid sturgeon is
playing a major role in influencing the overall ratio of pallid sturgeon
to other sturgeon. Based on the presence of coded wire tags, it is
conservatively estimated that approximately 60 percent of the pallid
sturgeon recently collected in the Middle Mississippi River are hatchery
reared fish released in 1994 and 1997 by the MoDOC (Dave Herzog, MoDOC,
pers. comm. 2003). It is unclear what factors may be influencing the
relatively higher percentage of pallid sturgeon compared to shovelnose
sturgeon in the Lower Mississippi River.

Within the action area there is some evidence of reproduction with the
occasional capture of larval stages and juveniles. However, the
population structure remains unknown. Opportunities for collection of
larval and juvenile pallid sturgeon are increasing with gear
improvements and targeted sampling, but the low numbers of these age
classes suggest to most sturgeon researchers that pallid sturgeon
reproduction is a rare event and that recruitment to reproductive age
classes is not occurring. However, it should be noted that the numbers
of larval and juvenile pallid sturgeon collected may also be an artifact
of sampling gear bias and/or a variable level of effort aimed at these
size classes.

As noted above, relative abundance estimates of pallid to other sturgeon
have ranged from 0.24 to 4.34 percent. Recent data from Grady et al.
(2001) and Herzog (2002) in the action area indicate that shovelnose
sturgeon populations are either stable or declining, respectively. This,
along with increased capture of hatchery-raised fish implies that wild
pallid sturgeon numbers may also be stable to declining.

[5.2.2 Factors affecting the pallid sturgeon environment in the action
area]{.underline}

Habitat loss

[Lower Missouri River]{.underline} - In the Lower Missouri River from
Gavins Pt. Dam downstream approximately 76.1 miles to Sioux City, Iowa,
suitable physical habitat conditions exist; however, dam operations
affect current/velocity, turbidity, water depth, substrate, temperature
and the hydrograph. From Sioux City downstream approximately 139.5 miles
to the mouth of the Platte River, the physical habitat conditions are
substantially reduced and the hydrograph is significantly altered. From
the mouth of the Platte River, downstream approximately 595.5 miles to
the Mississippi River, the physical habitat conditions improve and the
alterations to the hydrograph are attenuated due to the influences of
tributary inflow. The transport and suspension of sediment for turbidity
and habitat development and sustainability is also significantly
impaired.

Since 2000, bank stabilization and maintenance continues through out
this river reach. The Corps has been implementing certain habitat
development aspects of the 2000 Biological Opinion for Missouri River
Operations (USFWS 2000b). These include land acquisition (1,100 acres)
from Gavins Point Dam to Sioux City, Iowa, to benefit piping plovers,
least terns, and pallid sturgeon. During 2001 through 2003, the Corps
made modifications to the navigation project that resulted in the
creation of 1,365 acres of shallow water habitat. Projects included:
excavation of over 400 notches in dikes; construction of reverse
dikes/notches at Marion and Plowboy Bends; side channel construction at
Overton Bottoms, Tobacco Island and California Bend; buried dike
excavation and notching at Overton Bottoms; chevron construction and
dike lowering near Nebraska City; and modification of dike maintenance
at selected locations from Sioux City to the mouth to encourage aquatic
habitat development.

According to the 2000 Biological Opinion for Missouri River Operations,
approximately 77,000 acres (105 acres/mile) of shallow water, slow
velocity habitat occurred in the predevelopment river below Sioux City,
Iowa. It was estimated that approximately 2-5 percent or 2.1-5.25
acres/mile of the historical acreage remains between Sioux City and the
Grand River confluence in the developed river. Since issuance of the
2000 Biological Opinion for Missouri River Operations, the Corps
conducted new modeling studies which estimate that approximately 18.0
acres/mile of shallow water habitat currently occurs below the Grand
River in the Lower Missouri River (6,017 total acres). The 2000
Biological Opinion for Missouri River Operations RPA specified that
20-30 acres of shallow water habitat should be created in the Lower
Missouri River. As such, an estimated 8,000 to 14,000 additional acres
of shallow water habitat must be established.

[Middle Mississippi River]{.underline} - The MMR historically had a
meandering pattern and shifted its course over the years, leaving oxbows
lakes and backwaters (Theiling 1999). The undeveloped river was shallow
and characterized by a series of runs, pools and channel crossings that
provided a diversity of depth (Theiling 1999). In 1824, the MMR surface
area totaled 109 mi^2^ (87.2% riverbed, 12.8% islands) (Simons et al.
1974). In 1796, Collot (1826) surveyed the river and mapped 55 side
channels. His historical account describes a very dynamic system with
the capability to create and maintain a diversity of habitat types. In
describing the great potential for change in the system, Collot (1826)
wrote:

> *"The Mississippi River has not only the inconvenience of being of an
> immense extent, of winding in a thousand different directions, and of
> being intercepted by numberless islands; its current is likewise
> extremely unequal, sometimes gentle, sometimes rapid; at other times
> motionless; which circumstances will prevent, as long as both sides
> remain uninhabited, the possibility of obtaining just data with
> respect to distances. But an insurmountable obstacle will always be
> found in the instability of the bed of this river, which changes every
> year; here a sharp point becomes a bay; there an island disappears
> altogether. Further on, new islands are formed, sandbanks change their
> spots and directions, and are replaced by channels; the sinuosities of
> the river are no longer the same; here where it once made a bend it
> now takes a right direction, and there the straight line becomes a
> curve; here ravages and disorders cannot be arrested or mastered by
> the hand of man, and it would be extreme folly to undertake to
> describe them, or to pretend to give a faithful chart of this vast
> extent of waters, as we have done for the course of the Ohio, since it
> would not only be useless but dangerous."*

Today, the natural meandering processes of the MMR have been altered
through channelization. Wingdams, revetments, closing structures and
bendway weirs have fixed the channel in place, disrupting the dynamic
processes that create and maintain pallid sturgeon habitat. Physical
habitat in the MMR is becoming homogeneous. With construction of the
nine-foot channel navigation project, the river bank top width has been
reduced, side channels, islands and ephemeral sand bars have been lost,
and the physical process of channel meandering has been arrested.
Stabilization of the river has led to extensive levee development
isolating most of the floodplain. Sediment transport and availability
for habitat development have been significantly impaired as a result of
Corps' actions on both the Upper Mississippi River and the Missouri
River. The result has been the loss of aquatic habitat diversity over
time. This process is on-going.

[Lower Mississippi River]{.underline} -- The 954.0 river miles of the
Lower Mississippi River represents approximately 25 percent of the
historic range of the pallid sturgeon. This area represents perhaps the
best remaining habitat available for pallid sturgeon. Although the Lower
Mississippi River has been altered with channel regulating works (e.g.,
dikes, revetments) to promote river navigation, aquatic habitat
diversity remains. This includes side channel/island complexes and
backwaters. The river is much wider than the Lower Missouri River and
the Middle Mississippi River. Unlike the Middle Mississippi River,
levees tend to be set back, allowing more access to floodplain habitats
which improves foraging conditions for pallid sturgeon through
production of small fish and aquatic invertebrates.

However, the amount of aquatic habitat lost as a result of channel
regulation in the Lower Mississippi River has not been assessed. The
Lower Mississippi River Conservation Committee has developed a Lower
Mississippi River Aquatic Resource Management Plan. One objective of
this plan is to identify, define, describe and delineate habitats in the
Lower Mississippi River. To that end, the Lower Mississippi River
Resource Assessment was authorized in the Water Resources Development
Act of 2000. To date, funding has not been appropriated to complete the
assessment.

As of 2000 approximately 80% of the floodplain of the Middle Mississippi
River had been isolated from the main channel due to levee construction.
This number continues to increase as additional levee projects are
constructed. Since 2000, the Ste. Genevieve 500 year levee project has
been completed. Although this levee was constructed to protect the
historic town, it was largely constructed along the bank of the Middle
Mississippi River and provides additional flood protection for large
amounts of agricultural land. The Festus/Crystal City Small Flood
Control Project is currently under construction. This 100 year flood
protection project is designed to protect the cities, including a
wastewater treatment facility, from backwater flooding from the
Mississippi River. In addition, the Corps has recently approved the
Design Deficiency Study for the Bois Brule Levee and Drainage District
in Missouri. This project will correct design deficiencies to ensure a
50 year level of flood project for this largely agricultural area.
However, given recent adjustments in flow frequencies, the level of
protection will actually be much greater than the 50 year level.

Throughout the action area, isolated backwaters, side channels and
wetlands have been degraded due to incompatible agricultural practices,
poor stormwater management and sedimentation. Destruction and isolation
of these important floodplain features has reduced riverine productivity
(Theiling et al. 2000) by decreasing energy inputs (organic matter,
carbon) into the main channel and precluding seasonal flood pulses (Junk
et al. 1989, Ward and Stanford 1995, Ward et al. 1999), thus reducing
habitat quality for main channel fisheries. Isolation of wetlands
reduces their habitat value to riverine fish, which make seasonal
movements to backwaters and floodplains (USACE 1999b). Levees also
contribute to increased flood heights and increased water level
variability because floodwaters are confined in a smaller
cross-sectional area (Belt 1975, Chen and Simons 1986, Bellrose et al.
1983). As a result, flood control projects in the action area have
affected the production of forage food organisms for pallid sturgeon
(macroinvertebrates and fish) and may have isolated pallid sturgeon from
important rearing/feeding areas and/or seasonal refugia.

Hybridization

The rate of hybridization between pallid sturgeon and shovelnose
sturgeon may be increasing in the action area. Studies in the Middle
Mississippi River suggest a relatively high incidence of hybridization
between shovelnose sturgeon and pallid sturgeon (Sheehan 1997a, 1997b,
1998). Sheehan et al. (1997b) and Carlson and Pflieger (1981) noted a
3:2 ratio of hybrid sturgeon to pallid sturgeon. Sheehan et al. (1997b)
speculated that if this is representative of the sturgeon populations in
the Middle Mississippi River, hybridization may pose a significant
threat to pallid sturgeon as the species continues to cross with
shovelnose sturgeon. Keenlyne et al. (1994) reported that hybridization
may be occurring in half of the river reaches within the range of pallid
sturgeon and that hybrids may represent a high proportion of remaining
sturgeon stocks.

During the MICRA study from 1996 to 2000, seven pallid/shovelnose
sturgeon hybrids were collected in the Middle Mississippi River and 15
were collected in the Lower Missouri River. The rate of hybridization
increased from 1 in 365 (0.27 percent) river sturgeons in the late
1970's (Carlson et al. 1985) to 1 in 235 (0.42 percent) in the 1990's
(Grady et al. 2001).

Surveys conducted as part of the Highway 19 bridge replacement project
near Hermann, Missouri, resulted in collection of 3 pallid sturgeon, 14
hybrids and 1,990 shovelnose sturgeon (0.70 percent hybrids) (Milligan
2002). In addition, as part of the Lower Missouri River Pallid Sturgeon
Monitoring and Population Assessment Project, CMFRO collected 12 pallid
sturgeon, 12 hybrids and 3022 shovelnose sturgeon (0.39 percent hybrids)
(Doyle and Starostka 2003).

In the Lower Mississippi River, Hartfield, et al. (2002) collected 11
pallid sturgeon, 3 intermediates and 383 shovelnose sturgeon (0.76
percent intermediate). Hartfield (2002) later reported collection of 9
pallid sturgeon, 615 shovelnose sturgeon and 6 intermediates that were
more similar to shovelnose sturgeon (2.0 percent intermediate).

Commercial Fishing

It has previously been reported that mortality of pallid sturgeon occurs
as a result of illegal and incidental harvest from both sport and
commercial fishing activities. Herzog (2002) reports that the commercial
fishers observed over the years are non-discriminate in their take of
sturgeon (including pallid sturgeon). Recently, the MoDOC has documented
incidental/illegal harvest of pallid sturgeon as a result of commercial
sturgeon fishing (Craig Gemming, MoDOC, pers. comm. 2003). The value of
native sturgeon roe has increased dramatically in recent years due to
the collapse of the Russian caviar industry. As the commercial harvest
of shovelnose sturgeon roe increases, there will be an increased
by-catch of pallid sturgeon incidental to this harvest. This has the
potential to further depress pallid sturgeon populations. For example,
Williamson (2002) recently summarized reports from various states for
the harvest of shovelnose sturgeon (flesh and eggs). In Illinois, the
harvest of shovelnose sturgeon roe has increased from 47 pounds reported
in 1990 to 8,197 pounds in 2001. The commercial shovelnose sturgeon
catch (flesh and roe) in Missouri increased from 12,183 pounds in 1999
to 65,128 pounds in 2001 for the Mississippi River and from 7,472 pounds
in 1999 to 12,370 pounds in 2001 for the Missouri River. The increase
harvest pressure of shovelnose sturgeon has also created concern for the
population status of this species. Herzog (2002) reports that the catch
per unit effort for Middle Mississippi River shovelnose sturgeon
collections declined from 527 fish (25 net nights) in 1997 to 30 fish
(20 net nights) in 2002. The high was 1,052 fish (54 net nights) in
1998. As a result, the MoDOC has proposed regulation changes to further
protect sturgeon populations and the Iowa Department of Natural
Resources has closed commercial sturgeon fishing in the Missouri River
(Steve Krentz, USFWS, pers. comm. 2003). Commercial sturgeon harvest has
been closed in Louisiana and Mississippi for a number of years. In the
last few years the state of Arkansas closed commercial sturgeon fishing
in the Mississippi River, while it is still allowed in Illinois,
Tennessee, Kentucky, and Missouri.

Contaminants

Environmental contaminants may play a role in the decline of pallid
sturgeon, citing fish consumption health advisories from Kansas City to
the mouth of the Mississippi, representing 45 percent of the pallid
sturgeon's total range (USFWS 2000b). In addition, PCBs, cadmium (Cd),
mercury (Hg), and selenium (Se) were detected at elevated but below
lethal levels in tissues of three pallid sturgeon tissues from the
Missouri River in North Dakota and Nebraska. Detectable levels of
chlordane, DDE, DDT and dieldrin were also reported (Ruelle and Keenlyne
1994). The 2000 Biological Opinion for Missouri River Operations also
hypothesized that the "prolonged egg maturation cycle of pallid
sturgeon, combined with a bioaccumulation of certain contaminants in
eggs, could make contaminants a likely agent adversely affecting eggs
and embryo, development or survival of fry, thereby reducing
reproductive success." Environmental contaminants, although suspected to
have a role in sturgeon dynamics, have only recently begun to be more
fully examined in relation to sturgeon reproduction and health in both
the MMR and Missouri River and more information is needed.

Coffey et al. (2000) conducted a preliminary contaminant investigation
on fish collected from a chlordane consumption advisory site
(contaminants known to be present) in the MMR and from a reference site
without advisories (contaminants not known to be present). Results
indicate that wild shovelnose collected from the consumption advisory
site exhibited enlarged livers, often an indicator of contaminant
exposure. These affected fish were also determined to have among the
highest tissue concentrations of organochlorine compounds and
metabolites. Some results were a bit contradictory, with one fish having
high residue levels and no health anomalies, and some results were
observed in fish from both contaminated and reference areas. However,
sample sizes in this study were small. These preliminary data suggest
that the role of environmental contaminants on sturgeon dynamics needs
to be further evaluated.

Coffey et al. (2001) also conducted a risk assessment for MMR pallid
sturgeon. Using conservative assumptions in most parts of the
assessment, they determined that water and sediment may carry
biologically important concentrations of contaminants, at levels
reducing the food base and increasing exposure and bioaccumulation in
pallid tissues. Most notable were the eight heavy metals found in
sediments that have been detected in fish tissue, including in sturgeon,
above adverse effect thresholds (As, Cd, Cu, Pb, Hg and Se). This is
also the case for DDD, DDE, chlordane and dieldrin.

Papoulias et al. (draft preliminary results, 2003) sampled adult
shovelnose sturgeon monthly in the Lower Missouri River between May 2001
and June 2002. Investigations noted an unusually high incidence of
sturgeon with characteristic gonadal anomalies consistent with abnormal
hermaphroditism (AH). AH in an animal is characterized by possessing
both male and female gonads or abnormal gonads exhibiting both male and
female characteristics within the same organ (ovo-testes). Papoulias and
Tillitt (2004) noted observing the incidence of intersex as high as 13%
among male shovelnose sturgeon. It is unknown whether this condition
occurs in pallid sturgeon. Papoulias and Tillitt (2004) state that
factors that may cause hermaphroditism in sturgeon and the consequences
on reproduction are unknown. Senescence, genetic abnormalities,
hybridization, radiation, chemicals, diet, temperature and environmental
disturbance have all been implicated in the literature. Papoulias et al.
(2003) found that "gonadal abnormalities may indicate the potential for
reproductive impairment in this species and others and should be
investigated."

Commercial Navigation Traffic

Previously mentioned under new threats, commercial navigation traffic
within the action area is a private enterprise, however, it is also a
direct effect of the Corps' operation and maintenance of the navigation
system. The effect of towboat propellers on fish populations is a
concern associated with commercial navigation traffic. As part of the
Restructured Mississippi and Illinois River Navigation Feasibility
Study, the Corps has conducted several studies to determine the impacts
of navigation traffic on fisheries resources. Of particular concern has
been the entrainment of fish larvae; however, the Corps has also
conducted studies to evaluate entrainment of juvenile and adult fish.
Although some of these studies were initiated prior to the 2000
Biological Opinion (USFWS 2000a), much of the data/information regarding
entrainment and baseline traffic effects has only recently become
available. Therefore, the following information will serve to update the
baseline analysis contained within the 2000 Biological Opinion.

[Larval Sturgeon]{.underline} - Cada (1990) reported that fish eggs and
larvae that pass through water currents induced by a propeller may come
in contact with the blade and can experience stresses from pressure
changes and shear forces. Killgore et al. (2001) evaluated mortality of
icthyoplankton entrained through a scale model of a towboat propeller.
Fish species tested included larval shovelnose sturgeon, larval lake
sturgeon, the larvae and eggs of paddlefish, larval blue sucker and
juvenile common carp. Fish were subjected to treatments at various shear
stress levels ranging from 634 to 4,743 dynes/cm^2^ (1 dyne = the force
that would give a free mass of 1 g an acceleration of 1 cm/s^2^)
(Killgore et al. 2001). They found mortality to be a linear function of
shear stress for all species and life stages. Larger larvae (e.g.,
shovelnose sturgeon) experienced lower mortality, while smaller larvae
(e.g., lake sturgeon, blue suckers) experienced higher mortality (\>75
percent). All larval species experienced delayed mortality, particularly
at higher stress levels; however, common carp juveniles and paddlefish
eggs did not experience delayed mortality (Killgore et al. 2001).

Shear stress from propeller jet velocities can exceed 5,000 dynes/cm^2^.
Killgore et al. (2001) concluded that shear stress due to towboat
traffic is probably a primary force contributing to the mortality of
icthyoplankton entrained during vessel passage, but the magnitude of
mortality is dependent on individual size of icthyoplankton. The extent
of mortality would be a function of the amount of tow traffic in a given
river system, towboat speed and traffic levels during the time of year
when larvae are most susceptible to shear stress (e.g., early
developmental phase) (Killgore et al. 2001).

In order to estimate the impacts of commercial navigation traffic on
fish populations due to larval fish entrainment, the Corps conducted
complex modeling studies utilizing a model called NavLEM. The following
briefly explains this process:

The year 2000 traffic was utilized as the baseline condition (e.g.,
without project) for this analysis. The results indicate that 4.8
million sturgeon larvae were entrained and killed by commercial
navigation traffic in the open river for the Year 2000 (Bartell and Nair
2003). These estimated numbers of entrained and killed larvae are
difficult to evaluate directly given that natural rates of larval fish
mortality are high (Bartell and Nair 2003) and fish typically produce
large numbers of eggs and larvae (USACE 2004b). To put this in
perspective, the 4.8 million sturgeon larvae are estimated to represent
approximately 0.81 percent of the sturgeon larvae produced in the open
river during the year 2000 spawning season (Bartell and Nair 2003).
However, this percentage is only an approximation and assumes larvae are
evenly distributed across the river (Bartell and Nair 2003).

The model estimates that in the baseline condition for the Middle
Mississippi River, 2,962 sturgeon equivalent adult fish were lost due to
commercial navigation traffic (USACE 2004b, Bartell and Nair 2003).
Utilizing the ratio of pallid sturgeon to shovelnose sturgeon of 1:84,
this would equate to approximately 35 pallid sturgeon being lost in the
Middle Mississippi River in the baseline condition. Further, the model
estimates that 59 sturgeon recruits were lost due to commercial
navigation in the Middle Mississippi River (Bartell and Nair 2003). This
equates to approximately 2 pallid sturgeon recruits being lost every 3
years in the baseline condition.

It should be noted that there is a great deal of uncertainty associated
with modeling and estimating larval fish mortality. These uncertainties
are explained in detail in Appendix ENV-E of the Navigation Feasibility
Report. The actual numbers of pallid sturgeon lost in any given year
would be a function of many factors, including: overall sturgeon larvae
abundance, distribution of larvae in the navigation channel (vertically
and horizontally), navigation traffic levels during the larval drift
period and navigation channel depth.

[Juvenile/Adult Sturgeon]{.underline} - Guetreter et al. (2003)
developed a method to estimate mortality rates of adult fish caused by
entrainment through the propellers of commercial towboats operating in
river channels. They estimated entrainment mortality rates of adult
fishes in Pool 26 of the Upper Mississippi River and Alton Pool of the
Illinois River where fish kills attributed to entrainment were observed.
Their estimates of entrainment mortality rates were 0.53 fish/km of
towboat travel (80 percent confidence interval, 0.00 -- 1.33 fish/km)
for shovelnose sturgeon. They concluded that their approach applies more
broadly to commercial vessels operating in confined channels, including
other large rivers and intracoastal waterways.

During discussions with the Corps as they developed their Biological
Assessment, the Corps expressed concerns that the entrainment mortality
rates reported by Guetreter et al. (2003) overestimate mortality to
shovelnose sturgeon due to towboats. Their main concerns were associated
with the sampling design that resulted in filtering only a small
fraction of the propwash from towboats and which was not designed to
account for rare events. In addition, the Corps expressed concern that
the mortality rate was based on collection of one dead shovelnose
sturgeon during ambient sampling and not during trawling behind a moving
towboat.

Despite a wide disparity in estimating the mortality of shovelnose
sturgeon, and subsequently pallid sturgeon, attributed to commercial
navigation traffic. However, the best information available indicates
sturgeon are entrained by towboats. This results not only in
instantaneous mortality, but delayed mortality and injuries resulting in
harm. In addition, although data for other species may indicate the
capability to move away from towboats, this may not be the case with
sturgeon. Informal and unpublished observations by USGS indicate that
shovelnose sturgeon exhibit a 3-dimensional flight response, scattering
in all directions, including straight upward (Steve Gutreuter, USGS,
pers. comm. 2004). Such behavior may make them more susceptible to
towboat entrainment than other species of fish.

Despite the difficulties, some analysis of baseline traffic mortality is
warranted in order to better understand the impacts of commercial
navigation traffic on pallid sturgeon. To determine the extent of
shovelnose sturgeon mortality attributed to towboats, two data points
are required. The first data point is the mortality rate expressed a
fish/km of towboat travel. For this analysis, we have utilized the
mortality rate for skipjack herring reported by Killgore et al. (2003)
of 0.01 fish/km. It is recognized that this mortality rate may either
underestimate or overestimate the mortality rate of shovelnose sturgeon.
The mortality rate likely underestimates the mortality of all fish
caused by towboat entrainment since some of the mortality attributed as
being net induced by Killgore et al. (2003) likely occurred as a result
of entrainment. On the other hand, the mortality rate likely
overestimates the mortality rate for shovelnose sturgeon since skipjack
herring are pelagic and likely more susceptible to entrainment than
sturgeon or benthic fish.

To further refine the mortality estimate, consideration was given to the
number of shovelnose sturgeon collected as a percentage of the overall
number of fish collected in the study by Killgore et al. (2003) which is
0.02%. Therefore, the mortality rate estimate for shovelnose sturgeon is
calculated as: 0.01 mortality of fish/km X 0.0002 shovelnose sturgeon/km
= 0.000002 shovelnose sturgeon/km of towboat travel. It should be noted
that Dettmers et al. (2001) found that shovelnose sturgeon comprised
approximately 5% of the fish population in the navigation channel of
Pool 26. However, they did not collect any shovelnose sturgeon in the
navigation channel of the Alton Pool of the Illinois River. The
disparity in the numbers of shovelnose sturgeon collected in the two
studies adds further uncertainty to calculating sturgeon entrainment due
to towboats.

The second data point required for this analysis is the km of towboat
travel for the MMR. This information can be obtained by multiplying the
baseline navigation traffic information for the MMR by the length (km)
of river traveled. Table 5-2 provides baseline traffic information as
provided by the Corps for the Open River and Pool 27. The baseline or
future without project condition is based on the "Future Without Project
-- TCM Least Favorable Scenario" (USFWS 2004b). This allows a more
conservative (for the species) estimate of the effects of the proposed
action.

**Table 5-2: Baseline Traffic -- Annual (Future Without Project)**

  ----------------------- ----------------------- -----------------------
  YEAR                    OPEN RIVER              POOL 27

  2000                    10,185                  8,075

  2010                    9,778                   7,699

  2020                    9,796                   7,654

  2030                    9,957                   7,680

  2040                    10,259                  7,842

  2050                    9,818                   7,309
  ----------------------- ----------------------- -----------------------

Table 5-3 provides the baseline km of towboat travel based on
multiplying the number of towboats by the length of river (e.g., 296.06
km for the Open River and 27.35 km for Pool 27) (per Tom Keevin, USACE,
St. Louis District and Steve Bartell, Cadmus Group, Inc., Maryville,
TN).

**Table 5-3: Baseline KM of Tow Travel (Annual)**

  ----------------- ----------------- ----------------- -----------------
  YEAR              OPEN RIVER        POOL 27           TOTAL KM

  2000              3,015,371         220,851           3,236,222

  2010              2,894,875         219,568           3,105,442

  2020              2,900,204         209,337           3,109,541

  2030              2,947,869         210,048           3,157,917

  2040              3,037,280         214,479           3,251,758

  2050              2,906,717         199,901           3,106,618
  ----------------- ----------------- ----------------- -----------------

An estimate of the number of shovelnose sturgeon killed by towboat
entrainment can be calculated by multiplying the mortality rate estimate
(0.000002 fish/km) and the km of towboat travel estimates. From this
information, an estimate of the number of pallid sturgeon killed can be
determined based on the ratio of pallid sturgeon to shovelnose sturgeon
in the Middle Mississippi River. This ratio varies depending on the
number of sturgeon collected during ongoing sampling. For purposes of
this analysis and consistency with the Corps' Biological Assessment
(USACE 2004a), the ratio utilized is 1:84 (e.g., 1 pallid sturgeon for
every 84 shovelnose sturgeon. This ratio is based on the results of
ongoing sampling in the Middle Mississippi River. Table 5-4 represents
the baseline traffic mortality estimates for shovelnose sturgeon and
pallid sturgeon. Overall, under existing conditions, it is estimated
that 1 pallid sturgeon is killed every 10 years.

**Table 5-4: Baseline and Incremental Increase in Traffic Mortality
Estimates (Annual)**

  ----------------------- ----------------------- -----------------------
                          BASELINE                BASELINE

  YEAR                    SHOVELNOSE STURGEON     PALLID STURGEON

  2000                    6.5                     0.1

  2010                    6.2                     0.1

  2020                    6.2                     0.1

  2030                    6.3                     0.1

  2040                    6.5                     0.1

  2050                    6.2                     0.1
  ----------------------- ----------------------- -----------------------

Of necessity, certain assumptions are utilized in these calculations.
These include: 1) Sturgeon abundance in the Middle Mississippi River is
the same as in Pool 26 and the Alton Pool of the Illinois River; 2)
Sturgeon entrainment by towboats is a relatively rare event, but does
occur; 3) In the Middle Mississippi River, sturgeon are equally
susceptible to entrainment as pelagic fish, such as skipjack herring or
gizzard shad; and 4) Although pallid sturgeon are rare compared to
shovelnose sturgeon, they are equally susceptible to towboat
entrainment. Similar to larval fish, the actual numbers of
juvenile/adult pallid sturgeon entrained in any given year would be a
function of many factors, including: overall sturgeon abundance,
distribution of sturgeon within the navigation channel (both vertically
and horizontally), navigation traffic levels, sturgeon abundance in the
navigation channel during different seasons and navigation channel
depth. In addition, although the rate is not measurable, many sturgeon
likely suffer delayed mortality as a result injuries sustained during
entrainment. Also many fish sustain non-fatal injuries, however, these
may affect overall fish health and reproductive capability, resulting in
harm.

[]{.mark}

In addition to the effects of point-to-point tow traffic, fleeting and
terminal facilities are necessary at specific points on the river system
to transfer commodities, and to provide fuel and service to towboats.
Numerous fleeting and terminal facilities are located in the action
area. Within the species range, these facilities are most numerous in
the St. Louis Harbor, but are also widely distributed along the river
system to take advantage of rail and highway transportation modes.
Fleeting areas are typically constructed within main channel border
habitats. Towboats maneuvering within fleeting areas cause resuspension
of sediments. In addition, fleeting areas and terminals often require
periodic dredging, which disturbs bottom sediments. Most often, these
sediments are disposed in the open water downstream. As a result of
these activities, fleeting operations likely affect macroinvertebrate
production on a local scale. In addition, contaminated sediments may be
resuspended and transferred downstream.

Towboats maneuver and reconfigure barges in both authorized fleeting
areas and unregulated areas. The use of unregulated areas is referred to
as casual mooring and has involved tying of to

larger bankline trees with braided steel cable, resulting in girdling
and eventual toppling. Harbor boats and towboats maneuvering in
near-shore areas contribute to bankline erosion as well as bottom
sediment resuspension noted previously. Since pallid sturgeon exhibit a
preference for main channel border habitats (Sheehan et al. 1998, 2002),
this may result in entrainment of juvenile and adult sturgeon, thus
resulting in some degree of mortality.

Commercial Sand and Gravel Dredging

In 1998, the Corps' Waterways Experiment Station published a Technical
Note that summarizes existing literature regarding potential impacts to
aquatic organisms caused by entrainment during dredging and dredged
material disposal operations (Reine and Clarke 1998). Entrainment in
this case is defined as the direct uptake of aquatic organisms by the
suction field generated at the draghead or cutterhead (Reine and Clarke
1998). Armstrong et al. (1982) reported entrainment rates that ranged
from 0.001 to 0.135 fish/cy for both pipeline and hopper dredging
activities. They found that both small and large fish were entrained in
similar proportions, and, therefore, concluded that large fish did not
actively avoid the dredge any more than small fish. Armstrong et al.
(1982) reported an initial mortality rate of 37.6 percent. Larson and
Moehl (1990) reported entrainment rates ranging from \<0.001 to 0.341
fish/cy during a 4-year study at the mouth of the Columbia River in
Oregon. The majority of fish entrained were demersal with a few pelagic
species also being collected (Larson and Moehl 1990).

Buell (1992) monitored entrainment by the hydraulic dredge *R.W.
Lofgren* during dredging operations in the Columbia River. Buell
reported an entrainment rate of 0.015 fish/cy for white sturgeon
(*Acipenser transmontanus*). Substantial numbers of juvenile white
sturgeon (300 to 500 mm) were entrained, which was largely attributed to
dredging in an area referred to as the local "sturgeon hole". However,
the overall entrainment rate reported by Buell (1992) is comparable to
rates reported for other species of fish. To date, no studies have been
completed in the Missouri or Mississippi Rivers to evaluate possible
fish entrainment due to commercial sand and gravel dredging or
navigation channel maintenance. The Corps has previously stated that
entrainment of pallid sturgeon due to navigation channel maintenance
dredging could not be ruled out (USACE 1999a).

Invasive Species

Since issuance of the 2000 Biological Opinion, Asian carp populations
have greatly increased in the Missouri River and Mississippi River
systems. Bighead carp and silver carp have become the most abundant
large fish in portions of the Lower Missouri River (Duane Chapman, USGS,
pers. comm. 2003). The abundance of these fish, coupled with their
ability to consume massive quantities of phytoplankton and zooplankton,
presents a great risk to the productivity of the Missouri River and
Mississippi River aquatic food web. Bighead and silver carp have the
potential to consume and retain large quantities of energy from lower
trophic levels of the river's food web. This could occur to such a
degree that pallid sturgeon and most other native fishes will be
negatively impacted. In addition, pallid sturgeon larvae may be preyed
upon by bighead and silver carp while they are part of the
ichthyoplankton.

[Bighead carp]{.underline} *-* Bighead carp are known to school and
occupy the upper to middle layers of the water column. They prefer large
rivers and depend on velocity, a spring rise in the hydrograph and
temperature regimes to spawn (Lin 1991). Five ontogenic shifts in
feeding ecology of bighead carp were summarized by Lazareva et al.
(1977) in fish less than 1 year of age. These included feeding on
phytoplankton, then shifting to protococcaeceans, diatoms, bluegreen
algae and *Rotaria* eggs, and finally to feeding on zooplankton
exclusively. Bighead carp have a large suction volume, fast growth rates
and voracious appetites enabling them to decimate concentrations of
zooplankton quickly. Preliminary data from the Missouri River indicates
that bighead carp can also feed on detritus, which gives them an
alternate food source in periods when zooplankton concentrations are low
(Duane Chapman, USGS, pers. comm. 2003).

Laird and Page (1996) state that bighead carp have the potential to
deplete zooplankton populations that could negatively impact the food
availability for many larval fish, adult filter feeding fish and native
mussels to a significant degree. Most species of fish in the Missouri
and Mississippi Rivers have a larval stage in which the fish are part of
the plankton, and thus can be vulnerable to Asian carp predation.
Bighead carp host a number of disease causing agents, including 2
bacteria, 1 fungus, 22 protozoa, 6 trematoda, 3 cestoda and 3 copepoda
species (Jennings 1988). The impact of these agents on native fish has
not been assessed.

[Silver carp]{.underline} *-* Silver carp are known to school and occupy
the upper to middle layers of the water column. Similar to bighead carp,
silver carp feeding ecology shifts as the fish ages. As adults, they
feed primarily on phytoplankton with zooplankton as a secondary food
source. Due to a modified gill structure, the fish filters food items at
a ratio of 248:1. Silver carp also feed on organic detritus and
associated bacteria, indicating opportunistic feeding behavior. In large
numbers, the silver carp has the potential to cause enormous damage to
native species because it feeds on plankton required by larval fish and
native mussels (Laird and Page 1996) and has the potential to compete
with adult native fish that rely on plankton for food (Pflieger 1997).
Intraspecific feeding competition between silver carp and endemic fishes
in backwater habitats, lakes, pools, etc., appears to be the greatest
threat. Silver carp may also displace native river fish from spawning
habitats.

[Grass carp]{.underline} *-* Grass carp are herbivorous and depend on
floodplain habitats for successful recruitment. In most rivers where
grass carp reproduce successfully, floodplains provide a large volume of
still, shallow, warm water containing vegetative cover. There are few
macrophytes in the Missouri or Mississippi Rivers. However, ongoing
efforts to reconnect the floodplain in these river systems, while
essential to native species, will also likely benefit grass carp.

[Other invasive aquatic species]{.underline} - There are other aquatic
invasive species in the Great Lakes and Illinois River that may
eventually move into the Mississippi and Missouri Rivers and which may
prove to be detrimental to pallid sturgeon. These include the ruffe and
round goby.

Additional Federal Project/Programs, State, Local and Private Actions

Implementation of the O&M Biological Opinion Reasonable and Prudent
Alternative

In April 2000, the Service issued a jeopardy Biological Opinion (USFWS
2000a) for pallid sturgeon to the Corps of Engineers for continued
operation and maintenance of the nine-foot channel navigation project on
the Upper Mississippi River. The impacts of continued operation and
maintenance of the nine-foot channel project on the pallid sturgeon are
described in detail in the 2000 Biological Opinion are incorporated here
by reference. The Corps accepted the Reasonable and Prudent Alternative
(RPA) and is in the process of implementing it. The RPA called for: 1)
conducting a pallid sturgeon habitat study in the Middle Mississippi
River; 2) development of a pallid sturgeon conservation and restoration
plan, which would include monitoring of both pallid sturgeon populations
and habitat; 3) implementation of a long-term aquatic habitat
restoration program to restore habitat quantity, quality and diversity;
and 4) implementation of short-term aquatic habitat restoration measures
(e.g., pilot projects). Although the pallid sturgeon conservation and
restoration plan is still under development, to date the Corps has
completed a number of pilot projects that have improved habitat
conditions on a local scale. These projects include rehabilitation of
Santa Fe Chute side channel, placement of woody debris piles in various
locations, incorporation of woody debris into dikes during maintenance,
dike notching, and construction of a chevron dike to facilitate
development of a sand bar island and associated aquatic habitat. The
Corps has indicated a commitment to continue to implement the RPA as
described, including the long-term aquatic habitat restoration program.
Thus, overall habitat conditions on the MMR should stabilize and improve
over time.

Emergency Wetland Reserve Program and Wetland Reserve Program

The Service and states are working with the Natural Resources
Conservation Service and the Farm Services Agency to protect and restore
flood-created habitats and floodplain wetlands through the Emergency
Wetland Reserve Program and the Wetland Reserve Program. These programs
provide incentive payments to landowners for conservation easements
(perpetual and 30-year). As of 2002, approximately 25,462 acres of
floodplain lands along the Lower Missouri River have been enrolled in
the program. Along the Middle Mississippi River, approximately 21,000
acres of floodplain lands in Illinois have been enrolled. The majority
of the floodplain lands enrolled in these programs continues to be
isolated from the river system due to levees. However, those lands that
are connected to the river system, provide habitat for fish spawning and
invertebrate production and also provide nutrients for the river system.

National Wildlife Refuge Projects

[Big Muddy National Fish and Wildlife Refuge]{.underline} - The Big
Muddy National Fish and Wildlife Refuge is authorized to acquire up to
60,000 acres (24,300 ha) of the Missouri River floodplain between Kansas
City and St. Louis. To date, the Service has acquired 8,139 in 10 units
and manages an additional 1,301 acres (527 ha) of Corps' mitigation
lands. Acquisition of additional refuge lands is contingent on adequate
funding and willing sellers, and may take 20 to 50 years to complete.
The Corps has already initiated habitat restoration (reforestation
through plant succession and planting, chutes, wet prairies, etc.).
Adjacent to Jameson Island in central Missouri, the Service and the
Corps have modified channel training structures to increase
shallow-water and sandbar habitat. The Corps and the Service are also
working to maintain a navigation grade control structure at a chute
created at Lisbon Bottoms during the 1993 and 1995 floods. The Corps has
modified repairs to a revetment to allow continued flow through the
chute. Habitat improvements have already shown positive biological
results as documented in the fish use of those areas. A wide variety of
fish species, including several of special concern and the pallid
sturgeon, have been documented in and around those habitats. Taking full
advantage of the restoration opportunities of the Refuge is expected to
take many years. The long-term benefits of those areas should be
evaluated to better refine potential restoration work.

[Desoto National Wildlife Refuge]{.underline} - Desoto National Wildlife
Refuge (NWR) also manages the nearby Boyer Chute NWR near Blair,
Nebraska. The refuge is a joint Federal and local conservation
partnership to restore a portion of Missouri River habitat that flows
through the 2.5-mi (4 km) chute paralleling the river. Currently, the
refuge covers approximately 2,000 ac (810 ha). The Refuge is currently
working with the Corps to construct new aquatic habitats on the refuge.

[Middle Mississippi River National Wildlife Refuge]{.underline} - The
Middle Mississippi River NWR was established following the flood of 1993
and is managed as part of the Mark Twain NWR Complex. To date
approximately 4,200 acres of floodprone lands have been acquired. This
includes the recent acceptance of Beaver Island as a result of a
donation from a partnership with Ducks Unlimited and the American Land
Conservancy. The primary management goal of the refuge is to restore
habitats that have been lost or degraded as a result of modifications to
the floodplain and river. The Service is currently working with the
Corps to implement habitat restoration projects, including sidechannel
and off-channel aquatic habitat restoration for the benefit of pallid
sturgeon.

[Restoration stocking]{.underline} **-** In response to obvious declines
in pallid sturgeon numbers and the notable lack of recruitment, MoDOC
began an augmentation effort by releasing fingerlings raised at Blind
Pony State Fish Hatchery. Through this effort, approximately 7,000
fingerlings were released in the Missouri and Mississippi Rivers in 1994
and an additional 3,000 fingerlings were released in 1997 (Graham 1997,
1999). Since 2000, approximately 16,600 hatchery raised pallid sturgeon
have been released in the Lower Missouri River. No additional hatchery
reared pallid sturgeon have been released in the Middle Mississippi
River or Lower Mississippi River since 1997. However, this year pallid
sturgeon were collected in the Lower Mississippi River and several of
these fish have been spawned at Natchitoches National Fish Hatchery
(Steve Krentz, USFWS, pers. comm. 2004).

The outcome of stocking as a tool to avoid extinction and to recover
pallid sturgeon will not be known for some time. To be successful,
stocked pallid sturgeon must mature to spawn in suitable habitat,
recruit to the population, then spawn again.

[5.2.3. Summary]{.underline}

As noted previously, the current status of pallid sturgeon in the action
area remains largely unknown. Within the action area there is some
evidence of reproduction with the occasional capture of larval stages
and juveniles, but an accurate estimate of age structure in the action
area is not possible at this time. As noted above, relative abundance
estimates of pallid to other sturgeon have ranged from 0.24 to 4.34
percent. Recent data from Grady et al. (2001) and Herzog (2002) in the
action area indicate that shovelnose sturgeon populations are either
stable or declining, respectively. This, along with increased capture of
hatchery-raised fish implies that wild pallid sturgeon numbers may also
be stable to declining.

[5.3 Effects of the Action]{.underline}

This section includes an analysis of the direct and indirect effects of
the proposed action on the species and/or its critical habitat and its
interrelated and interdependent activities.

The Upper Mississippi River-Illinois Waterway System Navigation Study
proposes to implement both navigation improvement and ecosystem
restoration actions. The navigation improvement program also contains a
mitigation component for unavoidable adverse impacts to natural
resources of the UMRS.

This Tier I biological opinion for the pallid sturgeon evaluates the
effects of these actions from a programmatic scale. Site-specific
impacts will be evaluated during the Tier II planning process for
specific projects and Tier II biological opinions provided to the U.S.
Army Corps of Engineers for those projects that are likely to adversely
affect pallid sturgeon.

The proposed action (project) is the implementation of the recommended
plan contained in the Draft Integrated Feasibility Report and
Programmatic EIS for the Upper Mississippi River-Illinois Waterway
System Navigation Feasibility Study (USACE 2004). If enacted as
recommended, the project will include Federal policy changes,
interagency coordinating mechanism or institutional arrangement
modifications, changes in operation of existing facilities, manipulation
of landcover types to change habitat features, and a suite of
construction activities for navigation feature improvement, navigation
structure modification, and ecosystem restoration.

Conservation measures to minimize harm to listed species which are
proposed by the action agency are also considered part of the proposed
project and their implementation is required under the terms of the
consultation. The Corps did not include Conservation Measures in their
March 2004 Biological Assessment:

Short term impacts to pallid sturgeon at all life stages in the action
area during construction activity are expected to be outweighed by the
long term benefits of proposed ecosystem restoration measures. Improved
aquatic habitat diversity and structural diversity would be expected to
benefit the species. The long-term effects of the program on pallid
sturgeon will be positive, although it is difficult at this point to
determine the full extent of positive impacts. This uncertainty occurs
for several reasons. Firstly, the full scope of the program and its
implementation has yet to be determined. Although the types of projects
to be constructed in the Middle Mississippi River are generally known,
the full scope or scale of these projects remains uncertain and will be
dependent upon funding levels, prioritization and the results of
implementation of the adaptive management framework. Secondly, one of
the major ecosystem needs for the Middle Mississippi River is floodplain
restoration, including restored floodplain connectivity. However, much
of the floodplain in the MMR is in private ownership, therefore,
restoration in these areas will largely require cost-share partners and
will require willing sellers. Even in the best situations, restoration
of connectivity will be challenging. Given these limitations, it is not
certain that large scale floodplain restoration will be achievable, at
least not in the near term.

[5.3.1 Direct effects]{.underline}

[5.3.1.1 Navigation improvements]{.underline}

The range of the pallid sturgeon does not overlap with any of the
proposed site-specific construction measures proposed. Therefore, this
construction is not likely to adversely affect pallid sturgeon.

Commercial Navigation Traffic

Commercial navigation traffic within the action area is a private
enterprise, however, it is also a direct effect of the Corps' operation
and maintenance of the navigation system. With implementation of the
proposed action, navigation traffic is expected to increase in the
action area. The effect of towboat propellers on fish populations is a
concern associated with commercial navigation traffic. As part of the
Navigation Feasibility Study, the Corps has conducted several studies to
determine the impacts of navigation traffic on fisheries resources. Of
particular concern has been the entrainment of fish larvae, however, the
Corps has also conducted studies to evaluate entrainment of juvenile and
adult fish.

[Larval sturgeon]{.underline} - Cada (1990) reported that fish eggs and
larvae that pass through water currents induced by a propeller may come
in contact with the blade and can experience stresses from pressure
changes and shear forces. Killgore et al. (2001) evaluated mortality of
icthyoplankton entrained through a scale model of a towboat propeller.
Fish species tested included larval shovelnose sturgeon, larval lake
sturgeon, the larvae and eggs of paddlefish, larval blue sucker and
juvenile common carp. Fish were subjected to treatments at various shear
stress levels ranging from 634 to 4,743 dynes/cm^2^ (1 dyne = the force
that would give a free mass of 1 g an acceleration of 1 cm/s^2^)
(Killgore et al. 2001). They found mortality to be a linear function of
shear stress for all species and life stages. Larger larvae (e.g.,
shovelnose sturgeon) experienced lower mortality, while smaller larvae
(e.g., lake sturgeon and blue suckers) experienced higher mortality
(\>75 percent). All larval species experienced delayed mortality,
particularly at higher stress levels, however, common carp juveniles and
paddlefish eggs did not experience delayed mortality (Killgore et al.
2001).

Shear stress from propeller jet velocities can exceed 5,000 dynes/cm^2^.
Killgore et al. (2001) concluded that shear stress due to towboat
traffic is probably a primary force contributing to the mortality of
icthyoplankton entrained during vessel passage, but the magnitude of
mortality is dependent on individual size of icthyoplankton. The extent
of mortality would be a function of the amount of tow traffic in a given
river system, towboat speed and traffic levels during the time of year
when larvae are most susceptible to shear stress (e.g., early
developmental phase) (Killgore et al. 2001).

In order to estimate the impacts of commercial navigation traffic on
fish populations due to larval fish entrainment, the Corps conducted
complex modeling studies utilizing a model called NavLEM. The Service
requested the Corps to determine if the results of this modeling effort
could be utilized to determine the annual mortality of adult shovelnose
sturgeon that could be attributed to increased navigation traffic. This
information could then be used to estimate the number of equivalent
pallid sturgeon adults lost as a result of increased navigation traffic.
The BA (USACE 2004a), pages 73-76, explains the methodology and results
of this analysis.

A summary of the Corps' modeling results for annualized adults lost for
the open river reach (excluding Pool 27) for shovelnose sturgeon and
pallid sturgeon are as follows: The pallid sturgeon equivalent adults
lost is based on the ratio of pallid sturgeon to shovelnose sturgeon of
1 to 84 for the Middle Mississippi River and are presented in
parentheses. The numbers reflect the equal allocation of the total
number of lost adults across the 50 year planning period. Equivalent
adults lost do not occur until the year 2026 as traffic increases are
not expected until 2020 in this

analysis. The 2020 entrainment impacts show up initially in 2026
following 5 years to reach adulthood. The results of this analysis show
that for the years 2026-2035, 2036-2045, and 2046-

2050 there are separate, temporally overlapping projections with
associated minimum, average and maximum values.

Utilizing the ratio of pallid sturgeon to shovelnose sturgeon for the
Middle Mississippi River of 1 to 84, the data from this analysis
indicates a conservative estimate of 3 to 4 equivalent adult pallid
sturgeon may be lost due to increased navigation traffic during the 50
year planning period. The data for Pools 16-27 was excluded from this
estimation as pallid sturgeon are not known to occur in Pools 16-26.
Pool 27 is a relatively short reach of the Middle Mississippi River
(27.35 km) and the number of pallid sturgeon lost in this reach is
expected to be a relatively minor increment that should be captured in
the estimate of 3 to 4 fish for the Middle Mississippi River. The
additional mortality of pallid sturgeon larvae is not expected to occur
until 2020 and beyond when navigation traffic is predicted to increase.

It should be noted that there is a great deal of uncertainty associated
with modeling and estimating larval fish mortality. These uncertainties
are explained in detail in Appendix ENV-E of the Navigation Feasibility
Report (USACE 2004b). The actual numbers of pallid sturgeon lost in any
given year would be a function of many factors, including: overall
sturgeon larvae abundance, distribution of larvae in the navigation
channel (vertically and horizontally), navigation traffic levels during
the larval drift period and navigation channel depth.

[Juvenile/Adult sturgeon]{.underline} - Guetreter et al. (2003)
developed a method to estimate mortality rates of adult fish caused by
entrainment through the propellers of commercial towboats operating in
river channels. They estimated entrainment mortality rates of adult
fishes in Pool 26 of the Upper Mississippi River and Alton Pool of the
Illinois River where fish kills attributed to entrainment were observed.
Their estimates of entrainment mortality rates were 0.53 fish/km of
towboat travel (80 percent confidence interval, 0.00 -- 1.33 fish/km)
for shovelnose sturgeon. They concluded that their approach applies more
broadly to commercial vessels operating in confined channels, including
other large rivers and intracoastal waterways.

During discussions with the Corps as they developed their Biological
Assessment, the Corps expressed concerns that the entrainment mortality
rates reported by Guetreter et al. (2003) overestimate mortality to
shovelnose sturgeon due to towboats. Their main concerns were associated
with the sampling design that resulted in filtering only a small
fraction of the propwash from towboats and which was not designed to
account for rare events. In addition, the Corps expressed concern that
the mortality rate was based on collection of one dead shovelnose
sturgeon during ambient sampling and not during trawling behind a moving
towboat.

Based on the several studies referenced above, there could be a wide
disparity in estimating the mortality of juvenile/adult shovelnose
sturgeon, and subsequently pallid sturgeon, attributed to commercial
navigation traffic. However, the best information available indicates
sturgeon are entrained by towboats. This results not only in
instantaneous mortality, but delayed mortality and injuries resulting in
harm. In addition, although data for other species may indicate the
capability to move away from towboats, this may not be the case with
sturgeon. Informal and unpublished observations by USGS indicate that
shovelnose sturgeon exhibit a 3-dimensional flight response, scattering
in all directions, including straight upward (Steve Gutreuter, USGS,

pers. comm. 2004). Such behavior may make them more susceptible to
towboat entrainment than other species of fish.

Despite the difficulties, some analysis of incremental increases in
traffic mortality is warranted in order to better understand the impacts
of commercial navigation traffic on pallid sturgeon. To determine the
extent of shovelnose sturgeon, and subsequently pallid sturgeon,
mortality attributed to towboats, two data points are required. The
first data point is the mortality rate expressed as fish/km of towboat
travel. For this analysis, we have utilized the mortality rate for
skipjack herring reported by Killgore et al. (2003) of 0.01 fish/km. It
is recognized that this mortality rate may either underestimate or
overestimate the mortality rate of shovelnose sturgeon. The mortality
rate likely underestimates the mortality of all fish caused by towboat
entrainment since some of the mortality attributed as being net induced
by Killgore et al. (2003) likely occurred as a result of entrainment. On
the other hand, the mortality rate likely overestimates the mortality
rate for shovelnose sturgeon since skipjack herring are pelagic and are
likely more susceptible to entrainment than sturgeon or benthic fish.

To further refine the mortality estimate, consideration was given to the
number of shovelnose sturgeon collected as a percentage of the overall
number of fish collected in the study by Killgore et al. (2003) which is
0.02% (includes both Mississippi River and Illinois River samples).
Therefore, the mortality rate estimate for shovelnose sturgeon is
calculated as: 0.01 mortality of fish/km X 0.0002 shovelnose sturgeon/km
= 0.000002 shovelnose sturgeon/km of towboat travel. It should be noted
that Dettmers et al. (2001) found that shovelnose sturgeon comprised
approximately 5% of the fish population in the navigation channel of
Pool 26. However, they did not collect any shovelnose sturgeon in the
navigation channel of the Alton Pool of the Illinois River. The
disparity in the numbers of shovelnose sturgeon collected in the two
studies adds further uncertainty to calculating sturgeon entrainment due
to towboats.

The second data point required for this analysis is the incremental
increase in km of towboat travel for the MMR. This information can be
obtained by multiplying the incremental increase in navigation traffic
information for the MMR by the length (km) of river traveled. Table 5-5
provides incremental increase in traffic information as provided by the
Corps for the Open River and Pool 27. The future with project condition
is based on the "Future With Project -- TCM Most Favorable Scenario"
(USACE 2004b). This allows a more conservative estimate (for the
species) of the effects of the proposed action.

**Table 5-5: Incremental Traffic Increases -- Annual (Future With
Project -- Future Without Project)**

  ----------------------- ----------------------- -----------------------
  YEAR                    OPEN RIVER              POOL 27

  2000                    0                       0

  2010                    1,652                   1,503

  2020                    2,949                   2,675

  2030                    4,762                   4,381

  2040                    6,502                   6,006

  2050                    6,927                   6,427
  ----------------------- ----------------------- -----------------------

Table 5-6 - provides the incremental increase in km of towboat travel
based on multiplying the number of towboats by the length of river
(e.g., 296.06 km for the Open River and 27.35 km for Pool 27) (per Tom
Keevin, USACE, St. Louis District and Steve Bartell, Cadmus Group, Inc.,
Maryville, TN).

**Table 5-6: Incremental Increase KM of Tow Travel (Annual)**

  ----------------- ----------------- ----------------- -----------------
  YEAR              OPEN RIVER        POOL 27           TOTAL KM

  2000              0                 0                 0

  2010              489,091           41,107            530,198

  2020              873,081           73,161            946,242

  2030              1,409,837         119,820           1,529,658

  2040              1,924,982         164,264           2,089,246

  2050              2,050,808         175,778           2,226,586
  ----------------- ----------------- ----------------- -----------------

An estimate of the number of shovelnose sturgeon killed by towboat
entrainment can be calculated by multiplying the mortality rate estimate
(0.000002 fish/km) and the km of towboat travel estimates. From this
information, an estimate of the number of pallid sturgeon killed can be
determined based on the ratio of pallid sturgeon to shovelnose sturgeon
in the Middle Mississippi River. This ratio varies depending on the
number of sturgeon collected during ongoing sampling. For purposes of
this analysis and consistency with the Corps' Biological Assessment
(USACE 2004a), the ratio utilized is 1:84 (e.g., 1 pallid sturgeon for
every 84 shovelnose sturgeon. This ratio is based on the results of
ongoing sampling in the Middle Mississippi River. Table 5-7 represents
the incremental traffic increase mortality estimates for shovelnose
sturgeon and pallid sturgeon. Overall, under future with project
conditions, it is estimated that an additional 1-2 pallid sturgeon will
be killed over the 50 year project life.

**Table 5-7: Incremental Increase in Traffic Mortality Estimates
(Annual)**

+-----------------------+-----------------------+-----------------------+
| YEAR                  | SHOVELNOSE STURGEON   | PALLID                |
|                       |                       |                       |
|                       |                       | STURGEON              |
+-----------------------+-----------------------+-----------------------+
| 2000                  | 6.5                   | 0.1                   |
+-----------------------+-----------------------+-----------------------+
| 2010                  | 6.2                   | 0.1                   |
+-----------------------+-----------------------+-----------------------+
| 2020                  | 6.2                   | 0.1                   |
+-----------------------+-----------------------+-----------------------+
| 2030                  | 6.3                   | 0.1                   |
+-----------------------+-----------------------+-----------------------+
| 2040                  | 6.5                   | 0.1                   |
+-----------------------+-----------------------+-----------------------+
| 2050                  | 6.2                   | 0.1                   |
+-----------------------+-----------------------+-----------------------+

Of necessity, certain assumptions are utilized in these calculations.
These include: 1) sturgeon abundance in the Middle Mississippi River is
the same as in Pool 26 and the Alton Pool of the Illinois River, 2)
sturgeon entrainment by towboats is a relatively rare event, but does
occur, 3) in the Middle Mississippi River, sturgeon are equally
susceptible to entrainment as pelagic fish, such as skipjack herring or
gizzard shad, and 4) although pallid sturgeon are rare compared to
shovelnose sturgeon, they are equally susceptible to towboat
entrainment. Similar to larval fish, the actual numbers of
juvenile/adult pallid sturgeon entrained in any given year would be a
function of many factors, including: overall sturgeon abundance,
distribution of sturgeon within the navigation channel (both vertically
and horizontally), navigation traffic levels, sturgeon abundance in the
navigation channel during different seasons and navigation channel
depth. In addition, although the rate is not measurable, many sturgeon
likely suffer delayed mortality as a result injuries sustained during
entrainment. Also many fish sustain non-fatal injuries, however, these
may affect overall fish health and reproductive capability, resulting in
harm.

During informal consultation, velocity changes resulting from passing
towboats was identified as possibly adversely affecting pallid sturgeon.
Increased commercial navigation traffic might cause fish displacement
from low velocity habitats during cold water periods. If displacement
occurs and fish continue to drift for long periods of time, survival is
unlikely (USACE 2004b). Physical model studies conducted by the Corps
indicate that velocities under ambient conditions in the vicinity of
wingdams exceed displacement velocities for fish. With the exception of
an area immediately behind the wingdam and close to the shoreline, all
ambient velocities exceeded 0.10 m/sec and ranged from 0.10 to .50 m/sec
(USACE 2004b). The results also indicate that under existing conditions,
barge traffic increases velocities in the vicinity of wingdams beyond
pallid sturgeon critical swimming speeds at low temperatures (e.g., 0.15
m/s at 10 ^○^C, Adams et al. 2003). The magnitude of this change in
velocity is dependent upon the distance of the towboat from the wingdam
and whether the towboat is upbound or downbound.

During cold temperatures, pallid sturgeon are likely seeking low
velocity refugia that occur in association with wingdams. As navigation
induced velocity changes are persistent in the Middle Mississippi River
under baseline conditions and ambient velocities often exceed
displacement velocities, it is likely that pallid sturgeon actively
avoid areas subject to extreme velocity changes due to navigation
traffic. Therefore based on the best information available at this time,
we concur with the Corps' assessment that incremental increases in
navigation traffic would have little additional effect.

[5.3.1.2 Mitigation]{.underline}

Mitigation planning for the impacts associated with incremental
increases in navigation traffic falls into four major biological areas
-- fisheries, submersed aquatic plants, bank erosion, and backwater-side
channel sedimentation (USACE 2004a). Despite discussion in the Corps'
Biological Assessment, only fisheries and bank erosion mitigation is
being applied to the Middle Mississippi River (USACE 2004b). The
activities being proposed for mitigation has the potential to both
adversely and beneficially affect pallid sturgeon. However, the proposed
mitigation strategy is based on staged implementation depending upon
staged implementation of navigation study alternatives. In addition, the
proposed mitigation will be implemented within the adaptive management
framework. As a result, there is a high degree of uncertainty as to
whether the effects of the proposed mitigation on pallid sturgeon will
be realized.

According to the Corps' Biological Assessment (USACE 2004a), fishery
mitigation measures include large woody debris anchors, backwater
improvements, dike alterations and fish passage. All of the mitigation
measures are designed to improve the fishery of the Mississippi River
(USACE 2004b). Short-term adverse impacts to pallid sturgeon could occur
depending upon location and timing of construction. This could include
physical displacement and short-term decreases in forage food abundance
due to construction.

However, in the long-term the effects of these measures on pallid
sturgeon would be beneficial. Large woody debris anchors provide
important structure for the attachment of invertebrates (Nilsen and
Larimore 1973) and provide habitat for fish (Lehtinen 1997, Ward and
Stanford 1995, Benke et al. 1985), both of which are important food
resources for pallid sturgeon. Backwaters provide both important winter
and nursery habitat for fish (Scaeffer and Nickum 1986, Bodensteiner and
Lewis 1992) and are important for invertebrate production (Neuswagner et
al. 1982). Large introductions of woody debris can have a major impact
on channel morphology by creating local scour and deposition patterns,
including initiating formation of islands and mid-channel bars (Ward and
Stanford 1995). Improving side channels and backwaters would increase
zooplankton, macroinvertebrate and fish production, thus improving the
forage base for pallid sturgeon. Modification of wing dams/dikes would
increase habitat diversity that may provide improved foraging habitat,
larval/juvenile rearing habitat and seasonal refugia for pallid
sturgeon.

Bank erosion mitigation measures include such structural measures as
offshore revetments, bank protection and vegetative/bioengineered
protection. Bank erosion measures could have further long-term adverse
impacts to pallid sturgeon by further reducing channel meandering and
the input of sediment and nutrients into the main channel. However,
these effects would be difficult to quantify given that much of the MMR
is already revetted and channel meandering has been arrested by existing
channel regulating works structures.

Use of off-bankline revetments or incorporating woody debris into
protection measures would be beneficial to pallid sturgeon by providing
important riverine habitat for fish species and macroinvertebrates that
serve as prey for pallid sturgeon. Bankline revetments are known to
provide habitat for a rich abundance of invertebrates (Beckett et al.
1983, Payne et al. 1989) and fish (Farabee 1986). In addition,
commercial fisherman capture shovelnose sturgeon on rock revetments
during the spawning season, suggesting the possibility that these areas
could potentially be used by pallid sturgeon for spawning (USACE 2004a,
Jack Killgore, USACE, pers. comm. 2004).

[5.3.1.3 Ecosystem restoration]{.underline}

Descriptions of proposed ecosystem restoration measures are summarized
in *Project Description* preceding, and the Biological Assessment (USACE
2004)

Island Building

The recommended plan includes 91 island building projects throughout the
UMRS. These projects have an estimated footprint impact of 30 acres
each, with a total estimated area of influence of about 91,000 acres, or
about 1,000 acres per project (USACE 2004a).

Depending upon the location and timing of island building and the
methods utilized for construction, short term adverse effects are likely
for pallid sturgeon. For example, larval pallid sturgeon have been
collected at the downstream tips of islands. Building islands near these
locations during life stages when pallid sturgeon utilize this habitat
type may result in either mortality or displacement of larval/juvenile
fish. Obtaining material for island creation from these areas may also
result in mortality as young fish may be entrained or physical
displacement may occur. Dredging and disposal to build islands will
result in short term changes to local zooplankton, macroinvertebrate and
small fish populations which may also be detrimental by reducing young
pallid sturgeon prey. While pallid sturgeon evolved in highly turbid
river environments, large local increases in turbidity may also impact
young pallid sturgeon foraging capability and success.

However, long-term positive benefits to pallid sturgeon are anticipated
as a result of island building. Island habitats provide bathymetric
diversity and create rearing habitats for larval and juvenile pallid
sturgeon. In addition, with island establishment, side channels are also
created which provide additional aquatic habitat diversity that may also
provide larval/juvenile rearing habitat and provide seasonal refugia and
forage food production areas.

Fish passage

Fish passage structures that may impact pallid sturgeon have been
proposed at Melvin Price Locks and Dam and at Kaskaskia Lock and Dam. As
discussed in the Corps' Biological Assessment, short-term adverse
impacts may occur due to construction impacts (e.g., localized increases
in turbidity) and potential elimination of habitat utilized by pallid
sturgeon. These adverse effects are anticipated to be insignificant.

The long-term effects of these fish passage structures may be more
significant, but are potentially beneficial. Historic records indicate
pallid sturgeon were collected in the Mississippi River as far north as
Keokuk, Iowa (Bailey and Cross 1954, Coker 1930). While pallid sturgeon
have been collected in the tailwaters of Melvin Price Locks and Dam, it
is extremely uncertain as to whether this species would move into Pool
26 if fish passage was provided.

There are no historic records of pallid sturgeon in the Kaskaskia River.
However, pallid sturgeon commonly occur at the mouth of the Kaskaskia
River and recently, have also been located in the tailwaters of
Kaskaskia Lock and Dam. Providing fish passage at this location may
provide the opportunity for pallid sturgeon to migrate into the
Kaskaskia River for spawning. Alternatively, Kaskaskia Lock and Dam may
be preventing spawning runs for the shovelnose sturgeon, thus possibly
contributing to hybridization between the two species due to spawning
habitat overlap. Fish passage at Kaskaskia Lock and Dam may provide
increased spawning habitat for shovelnose sturgeon, reducing the amount
of overlap between the species in the main channel of the Mississippi
River.

Floodplain Restoration

The recommended plan calls for 16 projects below Pool 13, each with a
footprint of about 5,000 acres, totaling about 80,000 acres. Short-term
adverse effects to pallid sturgeon may occur depending upon techniques
utilized for floodplain restoration. For example, if material is dredged
from the river and disposed in floodplain areas to create ridge habitat
for reforestation, such activities could have short-term adverse
effects. Dredging material may result in mortality through entrainment
or physical displacement of pallid sturgeon. Dredging results in
short-term changes to local zooplankton, macroinvertebrate and small
fish populations which may be detrimental by reducing young pallid
sturgeon prey. While pallid sturgeon evolved in highly turbid river
environments, large local increases in turbidity may also impact young
pallid sturgeon foraging capability and success.

The long-term beneficial effects of the floodplain restoration measure
on pallid sturgeon is unknown. While the importance of the seasonal
flood pulse and river connection is mentioned in the Corps' BA, there is
no discussion of floodplain connectivity as part of restoration in the
southern reaches. Without connectivity, flow of nutrients to the river
produced by the above referenced activities will be greatly inhibited.
Fish will have limited access to floodplain habitats, thus floodplain
spawners which produce forage fish will not benefit from the restored
habitats.

Water Level Management and Dam Point Control

The recommended plan includes implementing water level management in 12
pools. The area of influence for a 2-foot drawdown is approximately
2,350 acres in each pool. The recommended plan also includes changing
control points in Pools 25 and 16. The direct area of influence would
total approximately 6,000 acres. The indirect area of influence is much
larger and not easily defined. For example, fish may come from great
distances to exploit flooded terrestrial areas, or energy transported
from the floodplain to the river may be processed many miles away. The
change in flood regimes can also directly and indirectly affect
floodplain plant communities (USACE 2004a).

Water level management of backwater projects varies greatly in scope
from large-scale projects using permanent management levees and fixed
pumps affecting thousands of acres, to small backwaters isolated with
temporary berms and drawn down with portable pumps affecting less than
100 acres. Under The recommended plan, seven backwater water level
management projects, totaling 7,000 acres of influence are proposed
(USACE 2004a).

The effects of water level management in the Pools and Dam Point Control
on pallid sturgeon will be beneficial but are difficult to quantify.
Improved aquatic plant production throughout the UMR-IWW should improve
water quality in the river system. In addition, increased aquatic plant,
macroinvertebrate and fish production should facilitate the transfer of
energy throughout the system. Pallid sturgeon should realize some of
these benefits even though the species occurs outside the area of direct
impact.

Similarly, the impacts of water level management in backwaters are
difficult to quantify, but overall would be generally beneficial by
improving nutrient input/cycling and improving forage food production
for pallid sturgeon. Some short term adverse effects could occur as a
result of construction. This could result in large localized increases
in turbidity and locally reduced prey items. Restricting flow into
contiguous backwaters for long periods could have long term adverse
impacts by preventing the flow of nutrients and prey items into the main
channel for utilization by pallid sturgeon.

Backwater Restoration

The recommended plan includes 208 backwater restoration projects with a
20 acre footprint each. The result would be 124,800 acres of influence,
or approximately 600 aces per project (USACE 2004a).

Backwater restoration projects may have short term adverse effects to
pallid sturgeon. However, depending upon the location of the project,
these effects should be minimal as pallid sturgeon are not known to
directly utilize backwater habitats, particularly disconnected
backwaters located in the floodplain. Large localized increases in
turbidity may impact pallid sturgeon ability to successfully forage. In
addition, there may be localized decreases in zooplankton,
macroinvertebrates and small forage fish during and immediately after
construction. Construction of closing dams or restricting flow into
currently connected backwaters would have a long-term adverse impact to
pallids sturgeon by precluding the use of this habitat.

Over the long-term, pallid sturgeon are expected to benefit from
backwater restoration projects. Improved productivity in these habitats
will increase pallid sturgeon forage base and improve nutrient inputs
into the main channel. In addition, projects that connect backwaters to
the main channel and provide deep water habitat may provide seasonal
refugia depending upon the degree of connectivity.

Side Channel Restoration

Side channels serve as important nursery areas and as refugia from the
swift currents and harsh environments of the thalweg (Environmental Sci.
and Eng. 1982, Fremling et al. 1989). Recent evidence suggests that side
channels may be important rearing areas for larval pallid sturgeon. In
1999, one confirmed and two probable larval pallid sturgeon were
collected from a large sandbar complex at the lower end of Lisbon Chute,
a reconnected side channel of the Missouri River (Jim Milligan and
Joanne Grady, USFWS, pers. comm. 2000). More recently, MoDOC have
collected larval pallid sturgeon in the Middle Mississippi River at
downstream island tips (Hrabik 2002). This habitat type is associated
with side channel/island complexes. In addition, adult pallid sturgeon
have been captured in MMR side channels (Mike Peterson, MoDOC, pers.
comm. 1999, Dave Herzog, MoDOC, pers. comm. 2003). Furthermore, side
channels are an integral component of the habitat complexity of the UMR
ecosystem, particularly the MMR. These areas not only provide nursery
areas and refugia for fish, but serve an important role in the cycling
of nutrients and in the production of food organisms for many species.

In its natural state, an alluvial river divides itself into two or more
channels by the processes of either erosion or deposition. Side channels
which are obliterated by deposition are replaced by new side channels
caused by floods and/or river migrations. In the MMR, the river is no
longer free to migrate and produce new side channels (Simons et al.
1974) due to channel training structures (e.g., wingdams, revetments,
closing structures). Side channels in the MMR have been closed off and
others have sedimented in (Simons et al. 1975, Theiling 1999). The loss
of side channels is well documented. In 1797 there were 55 side channels
(Collot 1826), 35 in 1860 (Simons et al. 1974), 27 in 1968 (Simons et
al. 1974), and only 25 today (USACE 1999a). Many of the remaining side
channels are not natural but were created as a result of wingdam/dike
field construction. Many of those that remain are degraded and much
smaller than in the past (Theiling et al. 2000) and function more as
backwater habitat since they are disconnected from the main channel
during large portions of the year. For example, within six study reaches
analyzed, Theiling et al. (2000) noted that approximately 918 acres of
secondary channel habitat was lost during the period 1950 to 1994 due to
closing structures and resulting sediment accumulation and terrestrial
encroachment. Of this amount, approximately 275 acres were lost from
1975 to 1994. In the absence of further human-induced changes in
hydrology or geomorphology of the MMR, most of the remaining side
channels may disappear (Theiling 1999). Side channels provide seasonal
refugia, larval and juvenile rearing habitat and forage food production
for pallid sturgeon. For this reason, the 2000 Biological Opinion RPA
identified restoration of side channels as a high priority measure to
preclude jeopardy to the species.

The recommended plan includes 147 side channel restoration projects with
a footprint impact of approximately 100 acres per project. The total
area of influence is estimated to be approximately 14,700 acres (USACE
2004a).

Side channel restoration may have short-term adverse effects to pallid
sturgeon depending upon the location and timing of construction and the
methods utilized. As larval pallid sturgeon utilize the downstream tips
of islands, construction activities that impact these areas may displace
larval/juvenile fish or result in direct mortality. Similarly,
construction activities that impact deep water habitat in side channels
during winter may displace adult pallid sturgeon. Large local increases
in turbidity may also impact young pallid sturgeon foraging capability
and success.

However, the long-term positive benefits of side channel restoration for
pallid sturgeon should be extremely significant. Restoration of these
habitats should create additional downstream island tip habitat and
bathymetric diversity that will provide larval/juvenile rearing habitat.
Improving depth and accessibility in sidechannels will provide
additional seasonal refugia for pallid sturgeon. In addition, side
channel restoration will increase zooplankton, macroinvertebrate and
fish production, thus increasing pallid sturgeon prey base and providing
for nutrient inputs into the main channel.

Wing Dam and Dike Alteration

The effect of channel training structures in reducing channel width and
surface area, and thereby habitat diversity, was most apparent within a
few years of construction. However, although occurring at a slower rate,
the effects are ongoing. For example, in evaluating side channel
sedimentation and land cover change in the MMR, Theiling et al. (1999)
found that main channel habitat decreased by 1667 acres in the six study
reaches during the period 1950 to 1994. Of this amount, approximately
412 acres were lost from 1975 to 1994. In addition, dikes and revetments
have not only narrowed the river channel, but deepened it as well (Chen
and Simons 1986, Nielson et al. 1984). Simons et al. (1974) gave the
following example of riverbed degradation in a 14-mile reach of the MMR
due to channel constriction:

> *By 1966 the river had been contracted to an average width of 1800
> feet. The riverbed had lowered about 8 feet between 1889 and 1966. In
> July 1967, the Corps of Engineers selected this 14-mile reach as a
> test reach to develop design criteria on obtaining and maintaining a
> dependable 9-foot deep navigation channel \[Degenhardt 1973\]. Between
> 1967 and 1969, this test reach narrowed from 1800 feet to 1200 feet in
> width. In 1971, the riverbed was resurveyed. The contraction from 1800
> feet to 1200 feet had resulted in a 3-foot lowering of the riverbed
> \[Degenhardt 1973\]. In 1971 the low water riverbed in the 14-mile
> reach between mile 140 and 154 was on the average 11 feet lower than
> in 1889."\
> *

Channel training structures have also altered the natural hydrograph of
the MMR by contributing to higher water surface elevations at lower
discharges than in the past and to a downward trend in annual minimum
stages (Simons et al. 1974, Wlosinski 1999). Wlosinski (1999) found
water-surface elevations have decreased at the same low discharge of
60,000 cfs during the period from 1880 to present. The downward shift of
annual minimum stages can be partially attributed to the degradation of
the low-water channel by wingdams (Simons et al. 1974). River stages
fluctuate as much as 15 m annually, effectively dewatering some
secondary channels during low stages (Fremling et al. 1989).

*Notching dikes, lowering their profile, or altering their angle to the
channel are some actions that can be used to increase habitat diversity
through the creation of new scour holes, sandbars, and flow refugia.
When wing dike alteration is done on the dike field level, or in
association with new structure placements, new side channels, islands
and off-channel areas can be created. The recommended plan includes 64
wing dam/dike alteration projects (five structures per project) for a
total of approximately 640 acres of influence*. \[excerpt from USACE
2004a\]

Wing dam and dike fields are utilized by pallid sturgeon. Deep scour
holes that develop in association with wing dams provide seasonal
refugia, particularly during winter. Pallid sturgeon also utilize the
sand bar habitat that accretes between wingdams. Although their
preference for this habitat is poorly understood, at a minimum it is
believed these areas provide important foraging habitat. Although the
2000 Biological Opinion RPA identified modification of channel training
structures as a medium priority for pallid sturgeon, wing dam/dike
alterations is critical to improving habitat diversity in the MMR for a
wide range of species.

Depending upon the time of year and location of construction, these
projects may have short-term adverse effects for pallid sturgeon.
Activities that impact existing deepwater habitat may result in
displacement of pallid sturgeon. Projects that impact existing sand bar
habitat may disrupt foraging habitat. However, these adverse effects are
expected to occur at a local, individual dike scale. By completing
restoration/enhancement projects at the scale of the dike field,
long-term beneficial effects for pallid sturgeon should result by the
creation of additional side channels, sand bars and scour holes. Such
activities are likely to create additional larval/juvenile rearing
habitat and seasonal refugia and improve forage food production.
Construction of closing dams, additional revetment construction and
restricting flow into contiguous backwaters may have long-term adverse
effects to pallid sturgeon by reducing accessibility to important
habitats like side channels and reducing forage food and nutrient inputs
into the main channel.

Island Protection and Shoreline Protection

The effects of island/shoreline protection projects on pallid sturgeon
are mixed. The use of revetments (in conjunction with wing dams) has
largely arrested the natural meandering capability of the river, thus
reducing habitat diversity. Many islands in the Middle Mississippi River
have been lost, mostly due to sediment accretion in side channels.
Therefore, the protection of the remaining islands will provide
long-term benefits to pallid sturgeon to the extent the project protects
the sidechannel and downstream island tip habitat that is important for
pallid sturgeon. Long-term adverse impacts could occur as a result of
constructing closing dams or additional levees. These projects could
restrict access of pallid sturgeon to important habitat for
larval/juvenile rearing and seasonal refugia and also impact the input
of pallid sturgeon forage food and nutrients into the main channel.

Shoreline protection measures could have further long-term adverse
impacts to pallid sturgeon by further reducing channel meandering and
the input of sediment and nutrients into the main channel. However,
these effects would be difficult to quantify given that much of the
Middle Mississippi River is already revetted and channel meandering
arrested.

Use of off-bankline revetments or incorporating woody debris into
protection measures would be beneficial to pallid sturgeon by providing
important riverine habitat for fish species and macroinvertebrates that
serve as prey for pallid sturgeon. Bankline revetments are known to
provide habitat for a rich abundance of invertebrates (Beckett et al.
1983, Payne et al. 1989) and fish (Farabee 1986). In addition,
commercial fisherman capture shovelnose sturgeon on rock revetments
during the spawning season, suggesting the possibility that these areas
could potentially be used by pallid sturgeon for spawning (USACE 2004a,
Jack Killgore, USACE, pers. comm. 2004).

Topographic diversity

Topographic diversity projects may have both short-term adverse effects
and long-term beneficial effects to pallid sturgeon depending on
location and timing of construction. Obtaining dredge material from the
main channel or other areas may result in entrainment of pallid
sturgeon, possibly leading to mortality. However, obtaining dredge
material from either main channel border or side channel habitats could
create additional bathymetric diversity, including deep holes, which
would be beneficial to pallid sturgeon.

Forest Management

Although a terrestrial activity, some management actions proposed to
implement this ecosystem measure could impact the aquatic environment
(e.g., shore pipe, boosters to reach dredged material placement sites,
use small dredges to expand placement options) and could adversely
affect pallid sturgeon depending upon timing and location of dredging
and depending upon where dredge material is obtained. Dredging for
material could result in entrainment and mortality of pallid sturgeon or
displacement from larval/juvenile rearing habitats. However, additional
bathymetric diversity could be created which would be a beneficial
effect.

In addition, several management actions are proposed that could have
long-term positive effects for pallid sturgeon. These actions generally
involve floodplain reconnection and include: notching levees, setback
levees, and removal of levees. Such actions would improve production of
zooplankton, macroinvertebrates and fish that provide forage for pallid
sturgeon. Nutrient inputs into the main channel would also be improved.

[5.3.1.4. Summary]{.underline}

Many of the ecosystem measures proposed in the recommend plan were
included in the 2000 Biological Opinion (USFWS 2000a) Reasonable and
Prudent Alternative as actions necessary for the pallid sturgeon. This
includes island building (e.g., restore gravel bars, restore sand bars),
side channel restoration, floodplain restoration (e.g., restore
floodplain connectivity, restore the riparian corridor, restore woody
debris) and wing dam/dike alteration (e.g., modify training structures).
The benefits of such ecosystem measures are described in recent
literature on river/floodplain ecology. (Beamesderfer and Farr 1997,
Benke et al. 1985, Petts et al. 1989, Ward and Stanford 1995).

[5.4 Cumulative Effects]{.underline}

Cumulative effects include the effects of future state, tribal, local or
private actions that are reasonably certain to occur in the action area
considered in this biological opinion. Future Federal actions that are
unrelated to the proposed action are not considered in this section
because they require separate consultation under section 7 of the Act.
The Service is unaware of any additional state, tribal, local or private
actions that are reasonably certain to occur in the action area
producing cumulative effects beyond those ongoing effects already
considered in the Environmental Baseline.

[5.5 Conclusion]{.underline}

After reviewing the current status of pallid sturgeon, the environmental
baseline for the action area, the effects of the proposed action and the
cumulative effects, it is the Service's biological opinion that the
Corps' proposed implementation of the alternatives for navigation
improvements and ecosystem restoration is not likely to jeopardize the
continued existence of the pallid sturgeon. No critical habitat has been
designated for this species, therefore, none will be affected.

As discussed in the 2000 BO (USFWS 2000), and section 5.2 preceding, the
MMR is important to the survival and recovery of the pallid sturgeon.
The range of the pallid sturgeon does not overlap with any of the
proposed site-specific construction measures proposed. Therefore, this
construction is not likely to adversely affect pallid sturgeon, and
projected traffic increases associated with the recommended plan are
estimated to increase pallid sturgeon mortality by only 1-2 fish over
the entire project life. Ecosystem restoration measures will only affect
a few individuals on a temporary localized basis during project
construction, and will, over the project life, contribute to restoration
of features beneficial to pallid sturgeon. Therefore, we do not
anticipate any negative effects to the MMR population, and consequently,
no reductions in reproduction, numbers or distribution of the rangewide
population of pallid sturgeon.

[5.6 Incidental Take Statement]{.underline}

[5.6.1 Introduction]{.underline}

Section 7 of the Act and Federal regulation under Section 4(d) of the
Act prohibit the take of endangered and threatened species,
respectively, without special exemption. Take is defined as to harass,
harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to
attempt to engage in any such conduct. Harm is further defined by the
Service to include significant habitat modification or degradation that
results in death or injury to listed species by significantly impairing
essential behavioral patterns, including breeding, feeding, or
sheltering. Harass is defined by the Service as intentional or negligent
actions that create the likelihood of injury to listed species to such
an extent as to significantly disrupt normal behavior patterns which
include, but are not limited to, breeding, feeding or sheltering.
Incidental take is defined as take that is incidental to, and not the
purpose of, the carrying out of an otherwise lawful activity. Under the
terms of section 7(b)(4) and section 7(o)(2), taking that is incidental
to and not intended as part of the agency action is not considered
prohibited taking under the Act provided that such taking is in
compliance with the terms and conditions of this Incidental Take
Statement.

The measures described below are non-discretionary, and must be
undertaken by the Corps so that they become binding conditions of any
action directly implemented by the Corps or any contract, grant, or
permit issued, as appropriate, for the exemption in section 7(o)(2) to
apply. The Corps has a continuing duty to regulate the activity covered
by this incidental take statement. If the Corps (1) fails to assume and
implement the terms and conditions or (2) fails to require the
contractor, grantee or permit applicant to adhere to the terms and
conditions of the incidental take statement through enforceable terms
that are added to the contract, grant document or permit, the protective
coverage of section 7(o)(2) may lapse. In order to monitor the impact of
incidental take, the Corps must report the progress of the action and
its impact on the species to the Service as specified in the incidental
take statement. \[50 CFR §402.14(I)(3)\]

[5.6.2 Extent of take anticipated]{.underline}

The amount or extent of incidental take for pallid sturgeon can be
quantified for certain aspects of the proposed action and cannot be
quantified for other aspects. Based on the assumptions and estimates
provided in the preceding *Effects of the Action* section, the Service
anticipates that 4 juvenile/adult and 2 equivalent adult pallid sturgeon
will be incidentally taken as a result of increased navigation traffic
associated with navigation improvements during the 50 year planning
period. This incidental take is expected to be in the form of killing.

The Corps proposed ecosystem restoration program will involve dredging
and disposal of material in habitat utilized by pallid sturgeon. As
such, pallid sturgeon may be killed by entrainment due to dredging or by
disposal of material in occupied habitat. The Service anticipates that
no more than 1 juvenile/adult and 20 larval pallid sturgeon per year
will be killed as a result of these actions.

Incidental take of pallid sturgeon as a result of other aspects of the
proposed action will be difficult to detect for the following reasons:
pallid sturgeon are widely distributed in the action area; pallid
sturgeon are rare and occupy habitats where detection is difficult;
finding dead or impaired specimens is unlikely; and losses may be masked
by seasonal fluctuations in numbers or other causes that makes detection
difficult. Non-quantifiable incidental take is expected to be in the
form of killing, harm and harassment. This incidental take is explained
further below for each component of the proposed action.

[Commercial Navigation Traffic]{.underline} **-** Not all pallid
sturgeon entrained by towboat propellers are killed instantaneously.
Some individuals will suffer delayed mortality. Others will suffer
non-fatal injuries that may affect reproductive fitness/capability
and/or long-term survival, thus causing harm.

[Project Mitigation]{.underline} **-** Implementation of project
mitigation measures will result in physical displacement of individual
pallid sturgeon and short-term decreases in forage food abundance which
is harassment.

[Fleeting]{.underline} **-** Towboats are utilized to maneuver barges
into and out of fleeting areas. Increased towboat activity will result
in additional pallid sturgeon being killed or injured through towboat
propeller entrainment. In addition, habitat modification associated with
constructing fleeting areas, movement of barges into/out of fleeting
areas and maintenance dredging will result in physical displacement of
pallid sturgeon or decreases in forage food abundance which is
harassment.

[Ecosystem Restoration Program]{.underline} **-** Habitat restoration
will result in habitat modification that will physically displace pallid
sturgeon. Short-term decreases in forage food abundance will occur.
These effects result in harm and harassment of pallid sturgeon.

Since the level of incidental take of pallid sturgeon for these aspects
of the proposed action cannot be adequately determined, incidental take
will be anticipated by: (1) loss or modification of larval/juvenile
pallid sturgeon rearing habitat (downstream island tips and/or sandbars
with current disrupting features); and (2) loss or adverse modification
of connected side channel/backwater habitats which provide seasonal
refugia and serve as forage food production areas.

Loss of larval/juvenile rearing habitat

The individual components of the Corps proposed action that are most
likely to result in incidental take of larval/juvenile pallid sturgeon
rearing habitat are island building and wing dam/dike alteration.
According to the Corps' Biological Assessment (USACE 2004a), 91 island
building projects are proposed with a total of 91,000 acres of
influence. Conservatively, it is estimated that approximately 1/3 (30)
of these projects would be constructed in the Middle Mississippi River
with an estimated area of influence of 30,000 acres. It is anticipated
that no more than 10% of these projects would adversely impact pallid
sturgeon larval/juvenile rearing habitat for a total of 3,000 acres of
impact. Similarly, the Corps' has proposed 64 wing dam/dike alteration
projects with a 640 acres area of influence. It is estimated that
approximately ¾ of these projects would be implemented in the Middle
Mississippi River with an estimated area of influence of 480 acres. It
is estimated that no more that 10% of these projects would adversely
impact pallid sturgeon larval/juvenile rearing habitat for a total of 48
acres of impact. These calculations are based on the assumption that the
entire area of influence would be adversely impacted. This assumption is
made in order to provide the most conservative estimate (for the
species) of anticipated impacts.

Loss or adverse modification of connected side channel/backwater habitat

The individual components of the Corps proposed action that are most
likely to result in incidental take of pallid sturgeon seasonal refugia
and forage food production areas are side channel and backwater
restoration. According to the Corps' Biological Assessment, 147 side
channel restoration projects are proposed with a total of 14,700 aces of
influence. Conservatively, it is estimated that approximately ½ of these
projects would be constructed in the Middle Mississippi River with an
estimated area of influence of 7,400 acres of influence. It is
anticipated that no more than 25% of these projects would adversely
affect pallid sturgeon seasonal refugia and forage food production by
isolating these habitats from the main channel, for a total of 1,850
acres of impact. Similarly, the Corps' has proposed 208 backwater
restoration projects with a total of 124,800 acres of influence. It is
estimated that approximately ¼ of these projects would be constructed in
the Middle Mississippi River with an estimated 31,200 acres of
influence. It is anticipated that no more 10% of these projects would
aversely affect pallid sturgeon seasonal refugia and forage food
production by isolating these habitats from the main channel, for a
total of 3,120 acres of impact. These calculations are based on the
assumption that the entire area of influence would be adversely
impacted. This assumption is made in order to provide the most
conservative estimate (for the species) of anticipated impacts.

[5.6.3 Effect of the take]{.underline}

In the accompanying biological opinion, the Service determined that this
level of expected take is not likely to result in jeopardy to the
species, or destruction or adverse modification of critical habitat.

[5.6.4 Reasonable and prudent measures]{.underline}

To ensure that the anticipated level of incidental take is commensurate
with the take that occurs per the proposed action, the Corps of
Engineers (Corps) and the Service is implementing a tiered programmatic
consultation approach. This approach utilizes a tiered consultation
framework with the subject consultation resulting in this Tier I
biological opinion. All subsequent projects will be Tier II
consultations with Tier II biological opinions issued as appropriate
(i.e., whenever the proposed project will result in unavoidable adverse
effects to threatened and endangered species).

As individual projects are proposed under the recommended plan, the
Corps shall provide, for any action that may affect Indiana bats,
project-specific information to the Service that (1) describes the
proposed action and the specific area to be affected, (2) identifies the
species that may be affected, (3) describes the manner in which the
proposed action may affect listed species, and the anticipated effects,
(4) specifies whether the anticipated effects from the proposed project
are similar to those anticipated in the programmatic BO, (5) estimates a
cumulative total of take that has occurred thus far under the tier I BO,
and (6) describes any additional effects, if any, not considered in the
tier I consultation. If it is determined that the proposed project may
affect the pallid sturgeon, the Corps will provide this information in a
tier II BA to document anticipated effects of the subject action.

The Service will review the information provided by the Corps for each
proposed project. If it is determined during this review that a proposed
project is not likely to adversely affect listed species, the Service
will complete its documentation with a standard concurrence letter and
specifies that the Service concurs that the proposed project is not
likely to adversely affect listed species or designated critical
habitat.. If it is determined that the action is likely to adversely
affect listed species or designated critical habitat and these effects
are commensurate with those contemplated in the programmatic BO, then
the Service will complete a tier II BO with a project-specific
incidental take statement within the annual allotted programmatic
incidental take, and project specific Reasonable and Prudent Measures
and Terms and Conditions, if appropriate..

The Service believes the following reasonable and prudent measures are
necessary and minimize impacts of incidental take of pallid sturgeon:

1\. As referenced in the Corps' Biological Assessment (USACE 2004a), the
Corps shall implement additional towboat propeller entrainment studies
to further evaluate the scope of impacts additional tow traffic will
have on juvenile/adult pallid sturgeon. These studies will utilize the
methodology developed by Killgore et al. (2003) or other methods as
deemed appropriate. This RPM addresses incidental take associated with
incremental increases in navigation traffic.

2\. The Corps shall implement studies to more fully determine larval
sturgeon densities in the Middle Mississippi River. The information
obtained in these studies can then be used to further refine estimated
larval pallid sturgeon mortality and measurement of equivalent adults
lost. This RPM addresses incidental take associated with incremental
increases in navigation traffic.

3\. The Corps shall develop a fleeting plan for the Middle Mississippi
River. This fleeting plan shall identify important pallid sturgeon
habitat areas that should be placed "off-limits" to fleeting, identify
areas that are suitable for fleeting and having no or minimal impacts on
pallid sturgeon and identify other measures that should be taken to
minimize the impacts of fleeting on pallid sturgeon.

4\. Pre-project fisheries surveys and physical habitat surveys will be
completed for each project, as appropriate, to assess the sites current
value for pallid sturgeon. The need for pre-project monitoring may be
determined on a site specific basis, in consultation with the Service,
as not all projects will impact pallid sturgeon. This RPM addresses
incidental take associated with navigation project mitigation and the
ecosystem restoration program.

Terms and Conditions

In order to be exempt from the prohibitions of section 9 of the Act, the
Corps must comply with the following terms and conditions, which carry
out the reasonable and prudent measures described above and outline
required reporting/monitoring requirements. These terms and conditions
are non-discretionary.

1\. The Corps shall develop a study plan for additional towboat
entrainment studies in the Middle Mississippi River. This plan of study
shall be developed in coordination with the Service and other fisheries
sampling experts from the states, universities and/or the USGS, as
appropriate. The plan of study shall be completed no later than the end
of fiscal year 2010.

2\. Additional towboat entrainment studies as described in the plan of
study developed in Term and Condition #1 shall be completed by no later
than the end of fiscal year 2015. Annual monitoring reports and a final
report on towboat entrainment studies shall be provided to the Service.

3\. The Corps shall develop a study plan for collecting larval sturgeon
densities in the Middle Mississippi River. This plan of study shall be
developed in coordination with the Service and other fisheries sampling
experts from the states, universities and/or USGS, as appropriate. The
plan of study shall be completed no later than the end of fiscal year
2010.

4\. The Corps will revise larval sturgeon entrainment estimates for the
Middle Mississippi River based on the data collected in the larval
sturgeon density study. These revised estimates will be completed no
later than fiscal year 2017.

5\. In coordination with the U.S. Fish and Wildlife Service and other
appropriate federal and state natural resource agencies, initiate
development of the Systemic Barge Fleeting Plan for the Upper
Mississippi River System in Funding Year One of the Upper Mississippi
River - Illinois Waterway System Navigation Capacity Improvement
Project. Information from the plan will assist in locating future
actions to avoid and minimize effects to pallid sturgeon. The fleeting
plan should be completed within three years of initiation and identify
(1) important pallid sturgeon habitat areas that should be avoided; (2)
areas that are suitable for fleeting and have no or minimal impacts on
pallid sturgeon; and (3) other measures to avoid/minimize the impacts on
pallid sturgeon.

######## Requirements for Monitoring and Reporting of Incidental Take of Pallid Sturgeon

Federal agencies have a continuing duty to monitor the impacts of
incidental take resulting from their activities \[50 CFR 402.14(i)(3)\].
In doing so, the Federal agency must report the progress of the action
and its impact on the species to the Service as specified below.

1\. Supply the Service with an annual report, due by January 31 of each
following year, that summarizes the progress of studies, surveys, and
plans prepared in support of the preceding reasonable and prudent
measures.

2\. The larval sturgeon densities plan of study developed in Term and
Condition #3 shall be completed by no later than the end of fiscal year
2015. Annual monitoring reports and a final report shall be provided to
the Service.

3\. Site specific monitoring plans will be developed and implemented
during and following construction of project mitigation features and
ecosystem restoration projects in order to further evaluate incidental
take of pallid sturgeon. This RPM addresses incidental take associated
with navigation project mitigation and the ecosystem restoration
program.

4\. All dead pallid sturgeon encountered during sampling and monitoring
activities will be preserved on ice and provided to the University of
Alabama per the Service's cooperative agreement. Blood and tissue
samples will be provided to Southern Illinois University at Carbondale
for genetics analysis. The Fish and Wildlife Service Ecological Services
Field Offices in Rock Island and Marion, Illinois will be notified of
any dead pallid sturgeon.

Closing

The reasonable and prudent measures, with their implementing terms and
conditions, are designed to minimize the impact of incidental take that
might otherwise result from the proposed action. The anticipated amount
of incidental take for pallid sturgeon is described above. If, during
the course of the action, this level of incidental take is exceeded,
such incidental take represents new information requiring reinitiation
of consultation and review of the reasonable and prudent measures
provided. The Corps must immediately provide an explanation of the
causes of the taking and review with the Service the need for possible
modification of the reasonable and prudent measures.

Conservation Recommendations

Section 7(a)(1) of the Act directs Federal agencies to use their
authorities to further the purposes of the Act by carrying out
conservation programs for the benefit of endangered and threatened
species. Conservation recommendations are discretionary agency
activities to minimize or avoid adverse effects of a proposed action on
listed species or critical habitat, to help carry out recovery plans, or
to develop information.

1\. Since sturgeon show a preference for other habitats besides the main
channel, providing more diverse habitats in the Middle Mississippi River
should redistribute those fish out of the main channel, making them less
susceptible to towboat entrainment. Therefore, we recommend accelerated
habitat restoration in the MMR in order to minimize effects to pallid
sturgeon.

2\. In order for the Service to be kept informed of actions minimizing
or avoiding adverse effects or benefiting listed species or their
habitats, the Service requests notification of the implementation of any
conservation recommendations.

**Literature Cited**

Armstrong, D., B. Stevens, and J. Hoeman. 1982. Distribution and
abundance of Dungeness crab and *Crangon* shrimp, and dredged-related
mortality of invertebrates and fish in Grays Harbor, Washington.
Technical Report. School of Fisheries, Univ. of Washington, Washington
Dept. of Fisheries, and U.S. Army Corps of Engineers, Seattle District.

Bailey, R.M., and F.B. Cross. 1954. River sturgeons of the American
genus *Scaphirhynchus*: Characters, distribution, and synonymy. Papers
of the Michigan Academy of Science, Arts and Letters. 39:169-208.

Bartell, S.M., and S.K. Nair. 2003. Upper Mississippi and Illinois River
Navigation Feasibility Study: Ecological Assessment of Tow Cost Model
Alternatives 2, 4, 5, and 6: Part 2. Larval Fish Entrainment and Fish
Population Extrapolations. Draft Report prepared by The Cadmus Group,
Inc., Maryville, Tennessee, for the U.S. Army Corps of Engineers, Rock
Island District, Rock Island, Illinois. 110pp + Appendices.

Beamesderfer, R.C.P., and R.A. Farr. 1997. Alternatives for the
protection and restoration of sturgeon and their habitat. Environmental
Biology of Fishes. 48:407-417.

Beckett, D.C., C.R. Bingham, and L.R. Sanders. 1983. Benthic
macroinvertebrates of selected habitats of the lower Mississippi River.
J. of Freshwater Ecology. 2:247-261.

Bellrose, F.C., S.P. Havera, F.L. Paveglio, Jr., and D.W. Steffeck.
1983. The fate of lakes in the Illinois River Valley. Biological Notes
119. Illinois Natural History Survey, Champaign, Illinois. 27pp.

Belt, C.B. 1975. The 1973 flood and man's constriction of the
Mississippi River. Science. 89:681-684.

Benke, A.C., R.L. Henry, III, D.M. Gillespie, and R.J. Hunter. 1985.
Importance of snag habitat for animal production in southeastern
streams. Fisheries. 10(5):8-13.

Bodensteiner, L.R., and W.M. Lewis. 1994. Downstream drift of fishes in
the Upper Mississippi River during winter. J. of Freshwater Ecology.
9:45-46.

Buell, J. 1992. Fish entrainment monitoring of the Western-Pacific
Dredge *R.W. Lofgren* during operations outside the preferred work
period. Prepared for the Western-Pacific Dredging Company by Buell and
Associates, Inc., Portland, OR.

Cada, G.F. 1990. A review of studies relating to the effects of
propeller-type turbine passage on fish early life stages. North American
J. of Fisheries Management. 10:418-426.

Carlson, D.M., and W.L. Pflieger. 1981. Abundance and life history of
the lake, pallid, and shovelnose sturgeons in Missouri. Missouri Dept.
of Conservation, Endangered Species Project SE-1-6. Jefferson City,
Missouri.

Carlson, D.M., W.L. Pflieger, L. Trial, and P.S. Haverland. 1985.
Distribution, biology, and hybridization of *Scaphirhynchus albus* and
*S. platorynchus* in the Missouri and Mississippi Rivers. Environmental
Biology of Fishes. 14(1):51-59.

Chen, Y.H., and D.B. Simons. 1986. Hydrology, hydraulics and
geomorphology of the Upper Mississippi River System. Hydrobiologia.
136:5-20.

Coffey, M., J. Harshbarger, K. Phillips, C. Berg., and T. Gross. 2000.
Middle Mississippi River Sturgeon Preliminary Contaminants
Investigation. Final Report. U.S. Fish and Wildlife Service, Rock
Island, Illinois.

Coker, R.E. 1930. Studies of common fishes of the Mississippi River at
Keokuk. U.S. Department of Commerce, Bureau of Fisheries Document.
1072:141-225.

Collot, V. 1826. A journey in North America. Arthur Bertrand,
Bookseller, Paris. 2 Volumes and 1 map atlas.

Dettmers, J.M., S. Gutreuter, D.H. Wahl, and D.A. Soluk. 2001. Patterns
in abundance of fishes in main channels of the upper Mississippi River
System. Can. J. Fish. Aquat. Sci. 58:933-942.

Doyle, W., and A. Starostka. 2003. 2002 Annual Report for the Lower
Missouri River Monitoring and Population Assessment Project. Report
prepared for the U.S. Army Corps of Engineers, Northwest Division. U.S.
Fish and Wildlife Service, Columbia Missouri Fisheries Resources Office.
January 2003. 38pp.

Doyle, W., L. Mauldin, J. Grady and J. Milligan. 2002. Lower Missouri
River Pallid Sturgeon Monitoring and Population Assessment Project.
Annual Report prepared for the U.S. Army Corps of Engineers, Northwest
Division. U.S. Fish and Wildlife Service, Columbia Missouri Fisheries
Resources Office. January 2002. 18pp.

Duffy, W.G., C.R. Berry and K.D. Keenlyne. 1996. Biology of the pallid
sturgeon with an annotated bibliography through 1994. Cooperative Fish
and Wildlife Research Unit, Technical Bulletin 5. South Dakota State
University, Brookings.

Environmental Science and Engineering, Inc. 1982. Final Report, Great
III Ecological Health Characterization. Report DACW43-81-C-00065
prepared for the U.S. Army Corps of Engineers, St. Louis District, St.
Louis, Missouri.

Farabee, G.F. 1986. Fish species associated with revetted and natural
main channel border habitats in Pool 24 of the Upper Mississippi River.
N. Amer. J. Fisheries Management. 6:504-508.

Forbes, S.A., and R.E. Richardson. 1905. On a new shovelnose sturgeon
from the Mississippi River. Bulletin of the Illinois State Laboratory of
Natural History. 7:37-44.

Fremling, C.R., J.L. Rasmussen, R.E. Sparks, S.P. Cobb, C.F. Bryan, and
T.O. Claflin. 1989. Mississippi River fisheries: A case history. Pages
309-351 [in]{.underline} D.P. Dodge, ed., Proceedings of the
International Large River Symposium. Canadian Special Publication of
Fisheries and Aquatic Sciences 106. Dept. of Fisheries and Oceans,
Ottawa, Ontario, Canada.

Grady, J.M., and L. Mauldin. 2002. Columbia Fishery Resources Office
Pallid Sturgeon Activities. [In.]{.underline} R. Wilson, ed., Pallid
Sturgeon Recovery Update, Issue No. 12.

Grady, J.M., J. Milligan, C. Gemming, D. Herzog, G. Mestl and R.J.
Sheehan. 2001. Pallid and Shovelnose Sturgeons in the Lower Missouri and
Middle Mississippi Rivers. Final Report for MICRA.

Graham, K., 1997. Missouri Department of Conservation successfully
spawns pallid sturgeon *in* M. Dryer, editor, Pallid Sturgeon Recovery
Update, Issue No. 9.

Graham, K., 1999. Pallid Sturgeon Reintroduction in Missouri, *in* S.
Krentz, editor, Pallid Sturgeon Recovery Update, Issue No. 10.

Gutreuter, S., J.M. Dettmers, and D.H. Wahl. 2003. Estimating Mortality
Rates of Adult Fish From Entrainment Through the Propellers of River
Towboats. Trans. American Fisheries Society. 132:646-661.

Hartfield, P., D. Drennen, T. Slack, and R. Nassar. 2002. Sturgeon
Survey in the Lower Mississippi River. [In.]{.underline} R. Wilson, ed.,
Pallid Sturgeon Recovery Update, Issue No. 12.

Hartfield, P. 2002. Minutes of the Pallid Sturgeon Lower Basin Work
Group Meeting. November 19-21, 2002. Vicksburg, MS.

Hartfield, P., D. Drennen, and T. Slack. 2004. Trawl Collections from
the Mississippi River in the Vicinity of Vicksburg, MS.
[In.]{.underline} R. Wilson. ed., Pallid Sturgeon Recovery Update, Issue
No. 14.

Herzog, D. 2002. Open River Field Station Report for January 2002.
Missouri Department of Conservation, Fisheries Research, Assessment and
Monitoring Section, Open River Field Station, Cape Girardeau, Missouri.

Hrabik, R.A., 2002. Missouri Dept. of Conservation Fisheries Research,
Assessment, and Monitoring Section. [In.]{.underline} R. Wilson, ed.,
Pallid Sturgeon Recovery Update, Issue No. 12.

Jacobson, R.B., and M.S. Laustrup. 2000. Habitat Assessment for Pallid
Sturgeon Overwintering Surveys, Lower Missouri River. Report by the U.S.
Geological Survey, Columbia Environmental Research Center, Columbia,
Missouri.

Jennings, D.P. 1988. Bighead carp (*Hypophthalmicthys nobilis*): a
biological synopsis. U.S. Fish and Wildlife Service, Biological Report.
88(29). 35pp.

Junk, W.J., P.B. Bayley, and R.E. Sparks. 1989. The flood pulse concept
in river-floodplain systems, p. 110-127. [In]{.underline} D.P. Dodge,
ed., Proceedings of the International Large River Symposium. Can. Spec.
Publ. Fish. Aquat. Sci. 106.

Kapuscinski, K. 2003. Population Abundance Estimation of Wild Pallid
Sturgeon in Recovery-priority Management Area #2 of the Missouri and
Yellowstone Rivers, 1991-2003. Draft Report. Montana Fish, Wildlife &
Parks. November 6, 2003.

Kapuscinski, K.L., and M.W. Baxter. 2003. Lower Missouri and Yellowstone
Rivers Pallid Sturgeon Study, 2002 Report. Submitted to Western Area
Power Administration. Montana Fish, Wildlife and Parks, Fort Peck,
Montana.

Keenlyne, K.D. 1989. A report on the pallid sturgeon. U.S. Fish and
Wildlife Service, Pierre, South Dakota. 20 pp.

Keenlyne, K.D., and L.G. Jenkins. 1993. Age at sexual maturity of the
pallid sturgeon. Transactions of the American Fisheries Society.
122:393-396.

Keenlyne, K.D., L.K. Graham, and B.C. Reed. 1994. Hybridization between
the pallid and shovelnose sturgeons. Proc. South Dakota Academy of
Science. 73:59-66.

Killgore, J., C. Murphy, D. Wolff, and T. Keevin. 2003. Evaluation of
Towboat Propeller-Induced Morality of Juvenile and Adult Fishes in the
Upper Mississippi River System. Draft Report. 18pp.

Killgore, K.J., S.T. Maynord, M.D. Chan, and R.P. Morgan II. 2001.
Evaluation of Propeller-Induced Mortality on Early Life Stages of
Selected Fish Species. North American J. of Fisheries Management.
21:947-955.

Killgore, K.J. 2004. U.S. Army Corps of Engineers Research and
Development Center, Waterways Experiment Station. [In]{.underline}. R.
Wilson, ed., Pallid Sturgeon Recovery Update, Issue No. 14.

Krentz, S. 2000. 2000 Summary Report of work conducted by the Missouri
River FWMAO on Missouri-Yellowstone River's Pallid Sturgeon. U.S. Fish
and Wildlife Service, Missouri River FWMAO, Bismarck, North Dakota.

Kynard, B., E. Henyey, and M. Horgan. 1998. Studies on early life
behavior of shovelnose sturgeon. Turner Falls, Massachusetts: U.S.
Geological Survey, Biological Resources Division, Conte Anadromous Fish
Research Center.

Laird, C.A., and L.M. Page. 1996. Non-native fishes inhabiting the
streams and lakes of Illinois. Illinois Natural History Survey Bulletin.
35(1):1-51.

Lazareva, L.P., M.O. Omarov, and A.N. Lezina. 1977. Feeding and growth
of the bighead, *Aristichthys noblis*, in the waters of Dagestan. J. of
Ichthyology. 17(1):65-71.

Lehtinen, R.M., N.D. Mundahl, and J.C. Madejczyk. 1997. Autumn use of
woody snags by fishes in backwater and channel border habitats of a
large river. Environmental Biology of Fishes. 49:7-19.

Liebelt, J.E. 2000. Lower Missouri River and Yellowstone River pallid
sturgeon study, 1999 report. Submitted to the Western Area Power
Administration, Grant Agreement No. 94-BAO-709. Montana Fish, Wildlife
and Parks, Helena.

Lin, Z. 1991. Pond fisheries in China. Pearl River Fisheries Institute
of the Chinese Academy of Sciences. Pergamon Press. Elmsford, New York.
10-14pp.

Mestl, G.E. 2001. 2000 Missouri River Ecology.
Dingell-Johnson/Wallop-Breaux Project Report by the Nebraska Game and
Parks Commission. F-75-R-18. September 2001.

Milligan, J. 2002. Hermann Bridge Replacement Study Report. Report by
the U.S. Fish and Wildlife Service, Columbia Missouri Fisheries
Resources Office to the Missouri River Natural Resources Committee,
16^th^ Annual Proceedings.

Neuswagner, D.J., W.W. Taylor, and J.B. Reynolds. 1982. Comparison of
macroinvertebrate herpobenthos and haptobenthos in side channel and
slough in the Upper Mississippi River. Freshwater Invertebrate Biology.
1:13-24.

Nielson, D.N., R.G. Rada, and M.M. Smart. 1984. Sediments of the Upper
Mississippi River: Their sources, distribution, and characteristics.
Pages 67-98 [in]{.underline} J.G. Wiener, R.V. Anderson, and D.R.
McConville, eds., Contaminants in the Upper Mississippi River.
Butterworth Publishers, Stoneham, Massachusetts.

Papoulias, D.M., M.L. Wildhaber, and A.J. DeLonay. 2003. Fact Sheet
Preliminary Data Summary: Abnormal Hermaphroditism in Shovelnose
Sturgeon from the Missouri River. USGS, Columbia Environmental Research
Center, Columbia, Missouri.

Papoulias, D.M., and D. Tillitt. 2004. USGS Columbia Environmental
Research Center Research Activities -- Contaminants. [In.]{.underline}
R. Wilson, ed., Pallid Sturgeon Recovery Update, Issue No. 14.

Payne, B.S., C.R. Bingham, and A.C. Miller. 1989. Life history and
production of dominant larval insects on stone dikes in the Lower
Mississippi River. Lower Mississippi River Environmental Program Report
18. U.S. Army Corps of Engineers, Mississippi River Commission,
Vicksburg, Mississippi.

Petts, G.F., J.G. Imhof, B.A. Manny, J.F.B. Maher, and S.B. Weisberg.
1989. Management of fish populations in large rivers: a review of tools
and approaches. p. 578-588. [in]{.underline} D.P. Dodge, ed.,
Proceedings of the International Large River Symposium, Can. Spec. Publ.
Fish. Aquat. Sci. 106.

Pflieger, W.L. 1975. The fishes of Missouri. Missouri Dept. of
Conservation, Jefferson City, Missouri. 372pp.

Reed, B., 2002. Louisiana Pallid Sturgeon Activities 2001.
[In.]{.underline} R. Wilson, ed., Pallid Sturgeon Recovery Update, Issue
No. 12.

Reine, K., and D. Clarke. 1998. Entrainment by hydraulic dredges -- A
review of potential impacts. Technical Note DOER-E1. U.S. Army Engineer
Research and Development Center, Vicksburg, MS.

Ruelle, R., and K.D. Keenlyne. 1994. The suitability of shovelnose
sturgeon as a pallid sturgeon surrogate. Contaminant Information
Bulletin. SD-ES-94-03. U.S. Fish and Wildlife Service, Pierre, South
Dakota.

Schaeffer, W. A., and J. G. Nickum. 1986. Backwater areas as nursery
habitats for fishes in Pool 13 of the upper Mississippi River.
Hydrobiologia. 136:131-140.

Sheehan, R.J., R.C. Heidinger, P.S. Wills, M.A. Schmidt, G.A. Conover,
and K. Hurley. 1997a. Middle Mississippi River Pallid Sturgeon Habitat
Use Project. Fisheries Research Laboratory and Department of Zoology,
Southern Illinois University at Carbondale, Carbondale, Illinois.

Sheehan, R.J. R.C. Heidinger, K.L. Hurley, P.S. Wills, and M.A. Schmidt.
1997b. Middle Mississippi River Pallid Sturgeon Habitat Use Project:
Year 2 Annual Progress Report, December 1997. Fisheries Research
Laboratory and Department of Zoology, Southern Illinois University at
Carbondale, Carbondale, Illinois.

Sheehan, R.J., R.C. Heidinger, K.L. Hurley, P.S. Wills, and M.S.
Schmidt. 1998. Middle Mississippi River Pallid Sturgeon Habitat Use
Project: Year 3 Annual Progress Report, December 1998. Fisheries
Research Laboratory and Department of Zoology, Southern Illinois
University at Carbondale, Carbondale, Illinois.

Smith, P. W. 1979. The fishes of Illinois. University of Illinois Press,
Urbana.

Stanford, J.A., J.V. Ward, W.L. Liss, C.A. Frissell, R.N. Williams, J.A.
Lichatowich, and C.C. Coutant. 1996. A general protocol for restoration
of regulated rivers. Regulated Rivers: Research and Management.
12:391-413.

Theiling, C.H. 1999. River geomorphology and floodplain features. Pages
4-1 to 4-21 [in]{.underline} USGS Ecological status and trends of the
Upper Mississippi River system: A report of the Long Term Resource
Monitoring Program. USGS Upper Midwest Environmental Sciences Center,
LaCrosse, Wisconsin. LTRMP 99-T001. 236pp.

Theiling, C., M. Craig, and K. Lubinski. 2000. Side Channel
Sedimentation and Land Cover Change in the Middle Mississippi River
Reach of the Upper Mississippi River System. USGS Upper Midwest
Environmental Sciences Center, LaCrosse, Wisconsin. 82pp.

U.S. Army Corps of Engineers. 1999a. Tier I Biological Assessment for
Operation and Maintenance of the Upper Mississippi River Navigation
Project within the St. Paul, Rock Island, and St. Louis Districts.

U.S. Army Corps of Engineers. 1999b. Draft Upper Mississippi River and
Illinois Waterway Cumulative Effects Study. U.S. Army Corps of
Engineers, Rock Island District, Rock Island, Illinois.

U.S. Army Corps of Engineers. 2003a. Implementation of the Biological
Opinion, Annual Progress Report. September 2003. U.S. Army Corps of
Engineers, St. Louis District.

U.S. Army Corps of Engineers. 2004a. Biological Assessment of the Upper
Mississippi River -- Illinois Waterway System Navigation Study. U.S.
Army Corps of Engineers, Rock Island, St. Paul, and St. Louis. 193pp.

U.S. Army Corps of Engineers. 2004b. Draft Upper Mississippi River --
Illinois Waterway Navigation Feasibility Study with Draft Environmental
Impact Statement. Rock Island, St. Louis, St. Paul and New Orleans
Districts. 613pp + Appendices.

U.S. Fish and Wildlife Service. 1993. Pallid sturgeon recovery plan.
U.S. Fish and Wildlife Service, Bismarck, North Dakota. 55 pp.

U.S. Fish and Wildlife Service. 2000a. Final Biological Opinion for the
Operation and Maintenance of the 9-Foot Navigation Channel on the Upper
Mississippi River System. Prepared by Region 3, U.S. Fish and Wildlife
Service, Fort Snelling, Minnesota. 240 pp.

U.S. Fish and Wildlife Service. 2000b. Biological Opinion on the
Operation of the Missouri River Main Stem Reservoir System, Operation
and Maintenance of the Missouri River Bank Stabilization and Navigation
Project, and Operation of the Kansas River Reservoir System.

Ward, J.V., and J.A. Stanford. 1995. Ecological Connectivity in Alluvial
River Ecosystems and Its Disruption by Flow Regulation. Regulated
Rivers: Research and Management. 11:105-119.

Ward, J.V., K. Tockner, and F. Schiemer. 1999. Biodiversity of
Floodplain River Ecosystems: Ecotones and Connectivity. Regulated
Rivers: Research and Management. 15:125-139.

Williamson, D.F. 2003. Caviar and Conservation: Status, Management and
Trade of North American Sturgeon and Paddlefish. TRAFFIC North America.
Washington, D.C. World Wildlife Fund.

Wirgin, I.I., J.E. Stabile, and J.R. Waldman. 1997. Molecular analysis
in the conservation of sturgeons and paddlefish. Environmental Biology
of Fishes. 48:385-398.

Wlosinski, J. 1999. Hydrology. Pages 6-1 to 6-10 [in]{.underline} USGS
Ecological status and trends of the Upper Mississippi River system: A
report of the Long Term Resource Monitoring Program. USGS Upper Midwest
Environmental Sciences Center, LaCrosse, Wisconsin. LTRMP 99-T001.
236pp.

Yerk, D.B., and M.W. Baxter. 2001. Lower Missouri and Yellowstone Rivers
Pallid Sturgeon Study, 2000 Report. Report submitted to Western Area
Power Administration. Montana Fish, Wildlife and Parks, Fort Peck,
Montana.

**Personal Communication**

Chapman, Duane, pers. comm. 2003. U.S. Geological Survey, Columbia
Environmental Research Center, Columbia, Missouri.

Garvey, Jim, pers. comm. 2004. Fisheries and Illinois Aquaculture
Center, Southern Illinois University, Carbondale, Illinois.

Gemming, Craig, pers. comm. 2003. Missouri Department of Conservation,
Jefferson City, Missouri.

Grady, Joanne, pers. comm. 2000. U.S. Fish and Wildlife Service,
Columbia FRO, Columbia, Missouri.

Gutreuter, Steve, pers. comm. 2004. U.S. Geological Survey, Upper
Midwest Environmental Sciences Center, LaCrosse, Wisconsin.

Herzog, David, pers. comm. 2004. Missouri Department of Conservation,
Cape Girardeau, Missouri.

Herzog, David, pers. comm. 2003. Missouri Department of Conservation,
Cape Girardeau, Missouri.

Jacobson, Robb, pers. comm.. 2003. U.S. Geological Survey, Columbia
Environmental Research Center, Columbia, Missouri.

Killgore, Jack, pers. comm. 2004. U.S. Army Corps of Engineers,
Waterways Experiment Station, Vicksburg, Mississippi.

Krentz, Steve, pers. comm. 2003. U.S. Fish and Wildlife Service,
Missouri River FWMAO, Bismarck, North Dakota.

Maher, Rob, pers. comm.. 2003. Illinois Department of Natural Resources.

Milligan, Jim, pers. comm. 2000. U.S. Fish and Wildlife Service,
Columbia FRO, Columbia, Missouri (retired).

Reeves, Kerry, pers. comm. 2003. University of Missouri, Columbia,
Missouri.

**REINITIATION NOTICE -- CLOSING STATEMENT**

This concludes formal consultation on the actions outlined in the
recommended plan provided in the Draft Integrated Feasibility Report and
Programmatic EIS for the Upper Mississippi River-Illinois Waterway
System Navigation Feasibility Study, 29 April 2004, and contained in the
Corps' Biological Assessment, dated April 2004. As provided in 50 CFR
§402.16, reinitiation of formal consultation is required where
discretionary Federal agency involvement or control over the action has
been retained (or is authorized by law) and if: (1) the amount or extent
of incidental take is exceeded; (2) new information reveals effects of
the agency action that may affect listed species or critical habitat in
a manner or to an extent not considered in this opinion; (3) the agency
action is subsequently modified in a manner that causes an effect to
listed species or critical habitat not considered in this opinion; or
(4) a new species is listed or critical habitat designated that may be
affected by the action. In instances where the amount or extent of
incidental take is exceeded, any operations causing such take must cease
pending reinitiation.

[^1]:
    ####  Until recently, Higgins eye was considered a deep water species, not occurring in water depths less than 3 feet (U.S. Fish and Wildlife Service 2004). However, numerous Higgins eye have been collected by the MCT in water depths of 1.5 to 3 feet at the Cassville mussel bed (Pool 11) and the Cordova EHA (Pool 14) (Mussel Coordination Team 2003). However, the chance of Higgins eye inhabiting very shallow water (\< 1.5 feet) during normal pool elevations is highly unlikely due to the extreme environmental conditions associated with these areas (i.e., freezing, ice damage, wave action, extreme heat). In 2001, a 1.5-foot drawdown at the dam was conducted in Pool 8, and some mussels were found stranded or in very shallow water, including two Higgins eye (M. Havlik, Malacological Consultants, La Crosse, Wisconsin, 2001, personal communication). In 2001, river discharges and water levels were high most of the spring and early summer, and mussel tracks and stranded mussels were observed in floodplain forest areas after the water receded in other UMR pools as well (M. Davis, Minnesota Department of Natural Resources, 2001, personal communication). During approximately a 30-day period from April 13 to May 13, 2001, Pool 8 water elevation was more than 2 feet above the secondary control pool elevation, and exceeded 6 feet for a few days. These conditions probably contributed to the number of stranded mussels observed during the 2001 Pool 8 drawdown. It is not known if mussels actively moved to these areas or were carried there by the excessive flows, but it is often the case that mussels will be displaced outside their normal distribution during high water events by either mode (Tucker 1996, Coker *et al.* 1921). For future pool level drawdowns, Conservation Measures were developed by the Corps of Engineers in their Tier I BA to avoid impacts to Higgins eye from stranding (U.S. Army Corps of Engineers 2004a).

[^2]: That exception was past dredging activities in the East Channel of
    the UMR at Prairie du Chien, Wisconsin. Havlik and Marking (1980)
    examined dredged material deposited on an upland site after
    maintenance dredging by the Corps of Engineers in 1976. They
    documented the presence of an extremely rich mussel assemblage in
    the East Channel including 175 Higgins eye that were killed by
    dredging activities (they did not estimate total mortality). The
    East Channel was subsequently included within the larger Prairie du
    Chien EHA for Higgins eye (U.S. Fish and Wildlife Service 1983). In
    a 1993 biological opinion to the Corps of Engineers, the Service
    concluded that future channel maintenance and commercial navigation
    activities in the East Channel would jeopardize the continued
    existence of Higgins eye (U.S. Fish and Wildlife Service 1993). The
    Service provided protective measures to avoid the likelihood of
    jeopardy to Higgins eye including suspending navigation channel
    maintenance dredging in the East Channel between the Highway 18
    Bridge and the turning basin, hazardous material spill prevention
    and response measures, and reinitiation of formal section 7
    consultation if commercial transportation exceeded established
    limits. These measures reduced the likelihood that a significant
    number of Higgins eye would be killed from future dredging and
    navigation activities. Also, the invasion of zebra mussels decimated
    the Higgins eye population at the Prairie du Chien EHA since 1993
    (U.S. Army Corps of Engineers 2004a).

[^3]: In April and May 2001, the maximum elevation above normal water
    levels in Pool 8 was approximately 6 feet. Water levels remained 2
    feet above normal pool for greater than 30 days during April through
    June 15, 2001. During this period, mussels moved into shallower
    habitats. The high waters occurring for an extended period of time
    prior to the Pool 8 drawdown, combined with an unusual period of
    drought immediately after the drawdown was initiated, greatly
    contributed to observed stranding of mussels during the 2001
    drawdown. Stranded mussels were observed in Pool 5 and other
    navigation pools that did not experience a drawdown, suggesting a
    strong correlation between mussel stranding and the severe
    flooding/drought conditions of 2001 (M. Davis, Minnesota Department
    of Natural Resources, 2001, personal communication). This flooding
    scenario is rare. From 1970 to 2003, there were only 4 years (1975,
    1986, 1997 and 2001) where water levels remained high (greater than
    2 feet) in Pool 8 for an extended period of time (greater than 20
    days) during the period April 1 through June 15. The above
    restriction, because of the rarity of these events, should provide
    an opportunity for drawdowns to occur in navigation pools while
    avoiding/minimizing impacts to Higgins eye.