| Effects
of Continued Operation and Maintenance Considered in the Biological Opinion |
Direct Effects
1) Water level regulation
2) Impoundment
3) Dredging and Disposal
4) Channel Training Structures/Revetment
Indirect Effects
1) Tow traffic
2) Fleeting
3) Contaminants
Interrelated Effects
1) Open River Enhancement Project
Interdependent Effects
1) Missouri River Bank Stabilization and Navigation Project
Cumulative Effects
1) Commercial harvest of shovelnose sturgeon
| Project impact to Species |
Continued alteration and disruption of dynamic,
natural river processes that create and maintain habitat
Continued loss of habitat quality, quantity and
diversity resulting in:
Reduced spawning
habitat, thus, reduced reproductive success and/or increased incidence of hybridization
Reduced availability of larval and
juvenile rearing habitat
Reduced availability of seasonal
refugia for all life stages
Reduced availability and quantity of
forage food
Potential mortality of juvenile
sturgeon
Continued reduced sediment transport:
Reduced habitat and substrate
diversity
Increased predation
Increased competition
Decreased foraging capability
Continued blocked migration routes:
Reduced availability
of pallid sturgeon and shovelnose sturgeon spawning habitat
Increased incidence of hybridization
Continued nutrient
cycling disruption:
Reduction in natural
forage base
Continued
transference and homogenization of contaminants:
Impaired reproductive
success
Reduced fish health
MMR
represents an important genetic conduit between the Lower Missouri River
and the Lower Mississippi River. Impacts to the MMR influence pallid
sturgeon populations in both of these river sections, (i.e., the area
of impact if much greater than just the MMR). Changes in the MMR affect
the population viability of pallid sturgeon in the Lower Missouri and
Lower Mississippi Rivers, and thus, influence survival and recovery
of the entire Lower Missouri River-MMR-Lower Mississippi population
unit.
MMR
represents a significant portion of 1 of 6 designated recovery priority
management areas. These areas provide the greatest opportunities for
successful recovery. Thus, loss or further degradation of any such areas
will substantially compromise recovery efforts and likely the survival
of the species.
MMR
represents an area that is currently known to be utilized by larval/young-of-the-year
pallid sturgeon and is one of only a few areas in which some natural
reproduction may be occurring.
MMR
represents approximately 10% of the species' range that is believed
to have suitable habitat (e.g., somewhat unaffected by impoundments).
Habitat
loss is the primary factor threatening the survival and recovery of
the species. Continued O&M will result in further habitat degradation
and loss to the extent that the suitability of the MMR for pallids will
be lost.
Although
the effects will have the greatest influence on the MMR, the proposed
project will substantially impact pallid populations in the Lower Missouri
and Lower Mississippi Rivers (as explained above). That is, the proposed
project will adversely affect the core of pallid range; hence, appreciably
reduce the likelihood of both the survival and recovery of the species.
| Reasonable
and Prudent Alternatives |
Habitat loss and alteration due to the continued
operation and maintenance of the Nine-Foot Channel Project are likely to jeopardize the
continued existence of the pallid sturgeon.
Destruction and
alteration of habitats due to modification of the river system is the primary cause of the
pallid sturgeon decline (i.e., due to declines in reproduction, growth and survival).! The recovery plan
calls for restoring the functions of the large-river ecosystem. The broad habitat needs of
pallid sturgeon suggest that only large-scale, system-wide habitat protection and
improvement programs can be expected to provide significant benefits for species
threatened by habitat alteration.! Therefore, to avoid
jeopardizing the continued existence of the pallid sturgeon, while continuing operation
and maintenance of the 9-foot channel, further net loss or degradation of habitat during
the 50 year project life must be prevented. This will require:
A comprehensive pallid
sturgeon habitat study to better characterize spawning habitat and seasonal and various
life stage use in the MMR$Development of a
pallid sturgeon conservation and restoration plan$Implementation of a
long-term aquatic habitat restoration program to mitigate the future adverse effects of
O&M
Implementation of
short-term aquatic habitat restoration measures and studies
| Reasonable
and Prudent Measures |
New construction projects will
require individual Section 7 consultation
Dredged material will be disposed of in the
thalweg of the channel, unless otherwise utilized for habitat restoration or other
beneficial use
Dredging will occur outside the
presumed window of pallid sturgeon reproduction (12 April - June 30)!Live pallid sturgeon caught in
sampling gear will be released
Data collected with
implementation and monitoring of the RPA will be utilized to further develop measures to
minimize incidental take
| Current status of Section 7 Consultation |
Biological Opinion provided to the Corps of
Engineers in May 2000
Corps of Engineers= implementation letter provided to the Service in
August 2000
The St. Louis District, Corps
of Engineers has assembled a pallid sturgeon expert team which developed a draft Plan of
Study for pallid sturgeon research and monitoring in the MMR. The draft Plan of Study is
titled AHabitat Preference and Demographics of
Pallid Sturgeon Populations in the Middle Mississippi River@ and includes the following components:
**Pallid sturgeon are the focus of this study, however, shovelnose
sturgeon will be included in field measurements and data analysis
Measure habitat utilization by
life stage and season
Evaluate habitat preference based on
macrohabitat availability
Quantify demographic parameters including
mortality, density, age and growth
Evaluate diet and food preferences
The draft Plan of Study was
provided to the Service and state resource agencies for comment in March 2000.! The Service solicited comments
on the draft Plan of Study from members of the Middle Basin States Pallid Sturgeon
Recovery Workgroup and then submitted comments to the Corps in April 2000.! The Corps of Engineers is
developing a biological assessment to address the effects of emergency dredging (i.e.,
dredging during the 12 April - 30 June time frame)! Several side channel
rehabilitation and enhancement projects are in various stages of planning for construction
under several Corps= authorities. It is likely
that planning for the Schenimann Chute Habitat Rehabilitation and Enhancement Project will
be completed this year. The Corps has completed a micro-model for a side-channel creation
project near the Jefferson Barricks bridge.! A dike alteration project is
being planned for implementation as a Habitat Rehabilitation and Enhancement Project under
the Environmental Management Program! The Corps of Engineers has
planned a woody debris experimental project under the Avoid and Minimize Program. This
project is slated for construction in fiscal year 2001.! The Corps of Engineers is
continuing to fund a pallid sturgeon telemetry study as part of the Avoid and Minimize
Program. Information collected from this on-going research will likely supplement
information collected in the habitat preference study.
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