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ERDC Mississippi River Studies

 

Background

The Fish Ecology Team of ERDC-EL has been conducting environmental studies for MVD since 2000.

Some members were involved in earlier studies during the Lower Mississippi River Research Program. 

Funding for pallid sturgeon studies were initiated as a result of jeopardy biological opinions (BiOp)

issued by USFWS in the Missouri and Middle Mississippi River. There was concern that a jeopardy

opinion would be issued for the Mississippi River and Tributaries Project. In 2000, virtually nothing was 

known on the status of pallid sturgeon in the Lower Mississippi River (LMR). After several years of 

developing effective sampling and evaluation techniques, ERDC began to regularly capture pallid 

sturgeon in the LMR. In 2003, the St. Louis District funded ERDC to collaborate with Missouri Dept. of 

Conservation and Southern Illinois University to evaluate pallid sturgeon populations in the Middle 

Mississippi River (MMR) in response to their jeopardy BiOp. Beginning in 2005, MVD began funding 

ERDC to evaluate benefits of dike notching and later other channel improvement projects. Studies have 

continued through FY11 and this document summarizes important findings and justification to continue 

these studies.

Application to Corps Divisions and Districts

The potential range of the pallid sturgeon, including the Ohio River and other tributaries of the 

Mississippi River, encompasses seven Corps Districts and 3 Divisions:

Mississippi Valley Division

New Orleans District

Vicksburg District

Memphis District

St. Louis District

Northwestern Division

Kansas City District

Omaha District

Southwestern Division

Little Rock District

Biological Opinions

The pallid sturgeon (Scaphirhynchus albus) was federally listed as an endangered species in 1990 and a 

recovery plan was approved in 1993. The USFWS has issued three jeopardy Biological Opinions on 

pallid sturgeon with an annual cost of addressing the reasonable and prudent measures of approximately 

$65-70 million per year (Northwest Division and St. Louis District):

• Missouri River Master Manual – Habitat restoration and population augmentation

• Upper Mississippi River/Illinois Waterway Navigation Project – Habitat restoration (Middle 

Mississippi River, MMR)

• Upper Mississippi River/Illinois Waterway Navigation Project – Towboat propeller entrainment

(MMR)
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In addition, three non-jeopardy Biological Opinions (BiOps) were issued for entrainment of pallid 

sturgeon through lower Mississippi River Diversions (Bonnet Carre, White Ditch, Covenant/Blind River), 

and others are pending (Caernarvon, Violet, Old River, and numerous proposed diversions). Nonjeopardy opinions were the result of ERDC research demonstrating that impacts to pallid populations 

were minimal. The take of pallid sturgeon allowed by the BiOps ranged from 90 to over 1,000 

individuals for the life of the projects as compared to only one individual for the Missouri and MMR 

BiOps. This disparity illustrates different policies and opinions among the different USFWS and Corps 

offices throughout the range of the species.

Significant Research Findings

The pallid sturgeon recovery plan was based principally on information available for the upper Missouri 

River and the Atchafalaya River populations. Very little data existed for pallid sturgeon in the central and 

most extensive portion of its range: the Lower Mississippi River (LMR) and the Middle Mississippi River 

(MMR). Data collected by ERDC in the Mississippi River now provide the opportunity to re-evaluate 

paradigms established in 1993 and later. 

• Prior to ERDC’s research, it was assumed that pallid sturgeon remain one of the rarest fish of the 

Missouri and Mississippi River basins and is on the ‘brink of extinction.” However, more than

500 pallid sturgeon have been collected in the LMR and MMR by ERDC and partners since 2000 

and population viability models being developed by ERDC and Applied Biomathematics indicate 

that pallid sturgeon have a self-sustaining population in the LMR and adult abundance exceed

10,000 individuals.

• The recovery plan stated that “It is unlikely that successfully reproducing populations of pallid 

sturgeon can be recovered without restoring the habitat elements (morphology, hydrology, 

temperature regime, cover, and sediment/organic matter transport) of the Missouri and 

Mississippi Rivers necessary for the species’ continued survival.” ERDC studies have 

demonstrated recruitment of pallid sturgeon, at least in the LMR. Habitat studies (dike notching, 

secondary channel restoration) continue to show that pallid sturgeon and other riverine species 

are utilizing these restored habitats. 

• It was assumed that hybridization with shovelnose sturgeon is occurring in the Mississippi River 

and that hybrids may represent a high proportion of remaining sturgeon stocks. It was further 

assumed that hybridization results from Corps projects degrading habitat and reducing 

reproductive isolation between the two species. ERDC analyzed taxonomic characters of LMR 

pallid sturgeon and concluded that most misidentifications were the result of allometric growth of 

key characters used to separate the two species. ERDC concluded that a “hybrid swarm” was not 

occurring in the Mississippi River. However, field identification of pallid sturgeon is still 

problematic for many groups, which has resulted in a USFWS study comparing taxonomic 

identification to genetics; ERDC is providing specimens for this study.

• There were numerous unsubstantiated accounts of elevated mortality of pallid sturgeon for 

various reasons, but especially related to both sport and commercial fishing activities. ERDC 

quantified mortality rates showing that annual mortality in the MMR, where commercial and 

recreational sturgeon fishing was taking place, is substantially higher (> 37 %) than in the LMR, 

where fishing is negligible (13%). In 2010, a Similarity of Appearance (SOA) ruling was issued 

by USFWS banning all commercial fishing where the two species co-occur. ERDC was 

instrumental in justifying the SOA based on mortality data collected over the past 10 years. In 

addition, the low mortality rate in the LMR further substantiated stable or expanding populations 

of pallid sturgeon. 

ERDC has also conducted studies on swimming performance of pallid sturgeon used to evaluate 

entrainment risk through water diversions and dredges, quantified before and after utilization of restored 
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secondary channels by pallid sturgeon and other species, continued to measure environmental benefits of 

certain types of channel improvements (hard points, chevrons, notching), collaborated with other 

researchers to document gravel bar habitat in the LMR, which is where pallid sturgeon spawn, and 

develop sturgeon distribution maps that can be used by District personnel for planning purposes. 

Numerous papers have been completed as a result of funded studies by MVD and Districts (see below), 

and more articles are being prepared. 

Benefits of Corps’ Research to Protection and Conservation of Pallid Sturgeon

• The Corps will have adequate information to either support or refute statements made concerning 

the status of pallid sturgeon relative to potential threats (e.g., habitat degradation, entrainment).

• The Corps will have quantified benefits of creating habitat diversity as part of the Channel 

Improvement Program of the MR&T

• Collaboration with other groups and agencies (e.g., Lower Mississippi River Conservation 

Program, Audubon, The Nature Conservancy) is facilitated by Corps participation in data 

collection and presentations

• Research information will be used to prepare or support documentation related to the Endangered 

Species Act including Conservation Plans and Biological Opinions

• Information sharing at the annual Channel Improvement Interagency meetings conducted by 

Memphis and Vicksburg Districts legitimizes MVD’s environmental stewardship goals in the 

Mississippi River.

• Development of a long-term data base results in a better understand of demographic trends of 

pallid sturgeon and other riverine species related to habitat changes and hydroperiod (e.g., affects 

of 2011 flood).

• The database developed over the last 12 years was used in the Lower Mississippi River Resource 

Assessment (LMRA) to describe baseline conditions and will be used to address future goals

related to implementation of the LMRA 

• The Corps environmental database (fish and habitat data combined) in the Mississippi River 

extends from the mouth of the Missouri River to the mouth of the Mississippi River. Information 

has been obtained from the database to update GIS maps where sturgeon were collected, analyze 

effects of water diversions in the southern portion of the LMR on pallid sturgeon entrainment, 

assess potential impacts of dredging, and used by outside agencies under Data User Agreements

to evaluate environmental assessment of proposed hydrokinetics.

• Corps research includes pallid sturgeon assessment in MMR to support St. Louis District’s 

obligations to meet the requirements of jeopardy Biological Opinions and will ensure that studies 

are compatible between the four Districts in the free-flowing Mississippi River.

• Tagging studies have demonstrated that sturgeon can move more than 1,000 miles between the 

LMR and Missouri Rivers, indicating the need for a range-wide assessment.

• Collections of pallid sturgeon continues to provide tissue samples to USFWS in their efforts to 

better understand genetic integrity of pallid sturgeon. 

• Most importantly, continued sturgeon studies in the Mississippi River will ensure that the Corps 

complies with the Endangered Species Act using scientifically defensible information.

Basin-wide Perspective 

The Corps does not currently have an organized, basin-wide perspective on pallid sturgeon research and 

recovery goals. A range-wide assessment is being considered and some major benefits of a coordinated

program are as follows:

• Research has shown that pallid sturgeon move between Corps Divisions (i.e., between the lower 

Missouri and MMR), so the stocking questions related to hybridization and genetic integrity of 

sub-populations have become more controversial. Documented examples of long-range
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movement of pallid sturgeon clearly indicate that a basin-wide research and recovery program is 

warranted. 

• Pallid sturgeon in the LMR represent a stable and possibly expanding population that could be 

used a reference to population recovery goals in the MMR and Missouri River. 

• In some Missouri River studies, the more abundant shovelnose sturgeon is being used as a 

surrogate due to the difficulty in collecting pallid sturgeon. Therefore, information on pallid 

sturgeon spawning, rearing, and habitat use derived in the MMR and LMR will support 

interpretation of data obtained for shovelnose sturgeon in the lower Missouri River.

• Telemetry is being used in the Missouri and Mississippi Rivers to track movements of fish. 

Additional coordination is necessary to establish compatibility of all telemetry gear used by the 

Corps and create a series of remote receivers that provide continuous monitoring of pallid 

sturgeon moving between the Missouri River, MMR, and LMR.

• The Corps continues to plan and construct habitat restoration features in the Missouri and 

Mississippi rivers despite the uncertainty in benefits and population recovery goals. Habitat 

restoration guidelines for pallid sturgeon need to be developed for all Corps Districts.

 

ERDC Mississippi River Publications 

Sponsored (either entirely or in part) by MVD and Districts

Baker, J.A., K.J. Killgore, and R.L. Kasul. 1991. Aquatic habitats and fish communities

in the lower Mississippi River. Rev. Aquat. Sci. 3: 313-356. 

Morrow, J.V., J.P. Kirk, K.J. Killgore, and S.G. George. 1998. Age, growth, and 

mortality of shovelnose sturgeon in the lower Mississippi River. North American

Journal of Fisheries Management 18:725-730.

Adams, R., J.J. Hoover, and K.J. Killgore. 1998. Observations of swimming ability in 

shovelnose sturgeon (Scaphirhynchus platorynchus). Journal of Freshwater Ecology 12: 631-

633. 

Hoover, J. J., Killgore, K. J., and Walker, G. 1998. "Fish habitat restoration of an oxbow lake in 

the Mississippi delta." Proceedings of the 23rd Annual Conference on Ecosystems Restoration 

and Creation, P. J. Cannizzaro, ed., Hillsborough Community College Institute of Florida 

Studies, Tampa, FL, 259-276

Adams, S.R., J.J. Hoover, and K.J. Killgore. 1999a. Swimming endurance of juvenile

pallid sturgeon, Scaphirhynchus albus. Copeia 1999: 802-807. 

Adams, S.R., T.M. Keevin, K.J. Killgore, and J.J. Hoover. 1999b. Stranding potential of

young fishes subjected to simulated vessel-induced drawdown. Trans. Am. Fish. Soc. 

128: 1230-1234. 

Hoover, J.J. and K. J. Killgore. 1999. Juvenile pallid sturgeon in laboratory aquaria. American 

Currents 25 (4): 1-7.

Keevin, T. M., S. R. Adams, and K. J. Killgore. 2000. Effects of pressure changes induced by 

commercial navigation traffic on mortality of early life stages of fish. ENV Report 34, Upper 
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Mississippi River-Illinois Waterway System Navigation Study, ERDC-Waterways Experiment 

Station, Vicksburg, MS, 11 pp.

Hoover, J. J., K. J. Killgore, and S. G. George. 2000. Horned serpents, leaf dogs, and spoonbill 

cats: 500 years of paddlefish ponderings in North America. American Currents 26 (2): 1-10. 

Killgore, K.J., S.T. Maynord, M.D. Chan, and R.P. Morgan, II. 2001. Evaluation of

propeller-induced mortality on early life history stages of selected fish species. N. Am.

J. Fish. Management 21: 947-955. 

Keevin, T.M., S. T. Maynord, S.R. Adams, and K. J. Killgore. 2002 Mortality of fish early life 

stages resulting from hull shear stress associated with passage of commercial navigation traffic. 

ENV Report 35 - Upper Mississippi River-Illinois Waterway. U.S. Army Engineer Research and 

Development Center, Vicksburg, MS.

Killgore, K.J., J.J. Hoover, R.A. Hrabik. 2002. Pallid sturgeon captured four years after its 

release. American Currents 28[2]: 30. 

Adams, S. R., G.L. Adams, G. L., and G.R. Parsons. 2003. Critical swimming speed and

behavior of juvenile shovelnose sturgeon and pallid sturgeon. Trans. Am. Fish. Soc.132: 392-

397. 

Parsons, G. R., J. J. Hoover, and K. J. Killgore. 2003. Effect of pectoral fin ray removal on 

station-holding ability of shovelnose sturgeon. North American Journal of Fisheries 

Management 23: 742-747.

Hoover, J.J. 2004. Rare treasure from river bottom: juvenile goldeye (Hiodon alosoides) for 

medium-sized aquaria. American Currents 30[3]: 1-6. 

Hoover, J. J., K. J. Killgore, D. G. Clarke, H. Smith, A. Turnage, and J. Beard. 2005. Paddlefish 

and Sturgeon Entrainment by Dredges: Swimming Performance as an Indicator of Risk. ERDC 

TN-DOER-E22, Engineer Research and Development Center, Vicksburg, MS 

Hoover, J. J., S. G. George, and K. J. Killgore. 2007. Diet of shovelnose sturgeon and pallid 

sturgeon in the free-flowing Mississippi River. Journal of Applied Ichthyology 23, 494-499.

Killgore, K. J., J. J. Hoover, S. G. George, B. R. Lewis, C. E. Murphy, and W. E. Lancaster. 

2007a. Distribution, Relative Abundance, and Movements of Pallid Sturgeon in the FreeFlowing Mississippi River. Journal of Applied Ichthyology 23, 476-483.

Killgore, K. J., , J. J. Hoover, J.P. Kirk, S. G. George, B. R. Lewis, and C. E. Murphy. 2007b. 

Age and growth of Pallid Sturgeon in the Free-Flowing Mississippi River. Journal of Applied 

Ichthyology 23, 452-456.

 
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Murphy, C.E., J.J. Hoover, S.G. George, and K.J. Killgore. 2007a. Morphometric variation 

among river sturgeons (Scaphirhynchus spp.) of the middle and lower Mississippi River. Journal 

of Applied Ichthyology 23: 313-323. .

Murphy, C., J. Hoover, S. George. B. Lewis, and J. Killgore. 2007b. Types and occurrence of 

morphological anomalies in the Scaphirhynchus spp. of the Middle and Lower Mississippi River. 

Journal of Applied Ichthyology 23: 354-358

Hoover, J. J., A. Turnage, and K. J. Killgore. 2009. Swimming performance of juvenile 

paddlefish: quantifying risk of entrainment. Pages 141-155 in C.P. Paukert and G. D. Scholten 

(eds.), Paddlefish Management, Propagation, and Conservation in the 21st Century. American 

Fisheries Symposium 66. 

Hoover, J.J., K.A. Boysen, C.E. Murphy, and S.G. George. 2009. Morphological variation in 

juvenile paddlefish. Pages 157-171 in Paukert, C. P., and G. Scholten (eds). Paddlefish 

Management, Propagation, and Conservation in the 21st Century: Building from 20 years of 

Research and Management. American Fisheries Society, Bethesda, Maryland. 

Divers, S.J, S. S. Boone, J.J. Hoover, K.A.Boysen, K.J. Killgore, C.E. Murphy, and S.G. George. 

2009. Field endoscopy for identifying gender, reproductive stage and gonadal anomalies in freeranging sturgeon (Scaphirhynchus) from the lower Mississippi River. Journal of Applied 

Ichthyology 25: 68-74.

George, S. G.. and W. T. Slack. 2010. Evidence of a contact zone for mudpuppies (Necturus sp.) 

in the lower Mississippi River. IRCF Reptiles and Amphibians 17(3): 156-157.

George, S. G. 2010. Timber rattlesnake (Crotalus horridus) swims the Mississippi River. IRCF 

Reptiles and Amphibians 17 (1): 40-41.

Hoover, J.J., J.A. Collins, K.A. Boysen, A.W. Katzenmeyer, and K.J. Killgore. 2011. 

Critical swim speeds of adult shovelnose sturgeon in rectilinear and boundary layer flow. 

Journal of Applied Ichthyology 27: 226-230. 

Hoover, J.J., K.A. Boysen, J.A. Beard, and H. Smith. 2011. Assessing the risk of entrainment 

by cutterhead dredges to juvenile lake sturgeon (Acipenser fulvescens) and juvenile pallid 

sturgeon (Scaphirhynchus albus). Journal of Applied Ichthyology 27: 369-379. 

Killgore, K.J., L.E. Miranda, C.E. Murphy, D. M. Wolff, J. J. Hoover, T. M. Keevin, S.

T. Maynord, and M. A. Cornish. 2011. Fish entrainment rate through towboat propellers in the

upper Mississippi and Illinois Rivers. Transactions of the American Fisheries Society 140: 570-

581.

Miranda, L.E. and K. J. Killgore. 2011. Catfish spatial distribution in the free-flowing
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Mississippi River. Pages 521-534 in P. H. Michaketz and V. H. Travnichek, editors. 

Conservation, ecology, and management of catfish: the second international symposium. 

American Fisheries Society Symposium 77, Bethesda, Maryland.

Harrison, A. B., S. G. George, W. T. Slack. 2011. Nymphal cicadas (Hemiptera: Cicadidae) as a 

prey item of shovelnose sturgeon (Scaphirhynchus platorynchus) in the lower Mississippi River. 

Southeastern Naturalist 10 (2): 371-373. 

Killgore, K.J., B. Bruchman, R. Hunt, L. Yu Lin, J.J. Hoover, Don Johnson, Dave Johnson, G. 

Young, K. Parrish, R. Goldman, and A. Casper. 2012. EnviroFish, Version 1.0: User’s Manual. 

ERDC/EL TR-12-19, Vicksburg, MS: Engineer Research and Development Center.

Killgore, K. J., J. J. Hoover, and B. R. Lewis. 2012. Ranking secondary channels

for restoration using an index approach. EMRRP Technical Notes Collection.

ERDC TN-EMRRP-ER-?. Vicksburg, MS: U.S. Army Engineer Research and

Development Center. http://el.erdc.usace.army.mil/emrrp/techran.html.

K. A. Boysen, K. J. Killgore, J. J. Hoover. 2012. Ranking Restoration Alternatives for the Lower 

Mississippi River: Application of Multi-Criteria Decision Analysis. EMRRP Technical Notes 

Collection. EMRRP-SR-?. Vicksburg, MS: U.S. Army Engineer Research and Development 

Center. http://el.erdc.usace.army.mil/emrrp/techran.html.

George, S. G., W. T. Slack, and J. J. Hoover. 2012. A note on the fecundity of pallid sturgeon. 

Journal of Applied Ichthyology 28:512-515.

Miranda, L.E., K.J. Killgore, and J.J. Hoover. 2013. Fish Assemblages in Borrow-pit Lakes of 

the Lower Mississippi River. Transactions of the American Fisheries Society 142 (3): 596-605. 

Divers. S.J., S.S. Boone, A. Berliner, E.A. Kurimo, K.A. Boysen, D. Johnson, K. J. Killgore, 

S.G. George, J. J. Hoover. 2013. Non-lethal acquisition of large liver samples from free-ranging 

river sturgeon (Scaphirhynchus) using single-entry endoscopic biopsy forceps. Journal of 

Wildlife Diseases 49 (2): 321-331.

Miranda, L. E. and K. J. Killgore. 2013. Entrainment of shovelnose sturgeon by towboat 

navigation in the upper Mississippi River. Journal of Applied Ichthyology (2013): 1-7.

Miranda, L. E. and K. J. Killgore. 2013. Fish depth distributions in the lower Mississippi River. 

River Research and Applications. Wiley Online Library (wileyonlinelibrary.com) DOI: 

10.1002/rra.2652.

George, S.G., W.T. Slack, and K.J. Killgore. 2013. First recorded occurrence of Oncorhynchus 

mykiss (Rainbow trout) in Louisiana. The Southeastern Naturalist, Issue 12.