nena masthead
NENA Home Staff & Editors For Readers For Authors

An Evaluation of Interstate Efforts to Re-introduce Paddlefish to the Upper Ohio River Basin
David G. Argent, William G. Kimmel, Rick Lorson, and Mike Clanc

Northeastern Naturalist, Volume 23, Issue 4 (2016): 454–465

Full-text pdf (Accessible only to subscribers. To subscribe click here.)

 

Access Journal Content

Open access browsing of table of contents and abstract pages. Full text pdfs available for download for subscribers.



Current Issue: Vol. 30 (3)
NENA 30(3)

Check out NENA's latest Monograph:

Monograph 22
NENA monograph 22

All Regular Issues

Monographs

Special Issues

 

submit

 

subscribe

 

JSTOR logoClarivate logoWeb of science logoBioOne logo EbscoHOST logoProQuest logo

Northeastern Naturalist 454 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 22001166 NORTHEASTERN NATURALIST 2V3(o4l). :2435,4 N–4o6. 54 An Evaluation of Interstate Efforts to Re-introduce Paddlefish to the Upper Ohio River Basin David G. Argent1,*, William G. Kimmel1, Rick Lorson2, and Mike Clancy3 Abstract - Historically, Polyodon spathula (American Paddlefish) occurred within the Mississippi River Basin’s large rivers, traversing hundreds of kilometers to complete their life cycle. However, populations declined in response to the installation of lock and dam (L/D) structures, declining water quality, and the loosely regulated harvest of the species. By the late 1800s, American Paddlefish were extirpated from many portions of their historic range. In response, federal and state agencies sought to restore inter-jurisdictional populations of this fish. Our objective was to assess reintroduction efforts in the northeastern-most portion of its range. Using a combination of gill nets, boat electrofishing, and larval drift nets, populations were sampled in Pennsylvania and New York over a 10-year-period, post-stocking. Although American Paddlefish were at large in navigable waters of the upper Ohio River Basin, free-flowing and tail-water areas below L/D structures appeared to hold more fish than impounded reaches. The presence of L/D structures and fixed-crest dams may inhibit upstream passage of fish and reduce the availability of forage, as reflected in reduced condition- index scores. Although gravid fishes were captured in Pennsylvania and New York, little evidence exists to suggest the presence of self-sustaining populations, as only one larval American Paddlefish was captured. The recovery of this species to its historic northeast range may hinge on continuing stocking efforts, development of fish-passage structures, conservation lockages, and improvement and protection of suitable spawning habitats. Introduction Polyodon spathula (Walbaum in Artedi) (American Paddlefish, hereafter “Paddlefish”), a potamodromous species (Wilcox et al. 2004), once swam freely within the Mississippi River Basin. This fish is known to travel long distances throughout its range and relies on precise timing of environmental cues, including water temperature, photoperiod, and river flows to successfully complete its life cycle (Jennings and Zigler 2009). The combination of declining water quality and physical impediments, such as dams, restricted populations to core areas in the mid-western United States (Bettoli et al. 2009). In response, the Mississippi Interstate Cooperative Resource Association (MICRA) was formed, pooling private, state, and federal resources to facilitate recovery of inter-jurisdictional fishes, including Paddlefish. In the northeastern United States, the Ohio River Basin represents the easternmost extent of Paddlefish (Argent et al. 2009, Bettoli et al. 2009, Cooper 1983). 1California University of Pennsylvania, 250 University Avenue, California, PA 15419. 2The Pennsylvania Fish and Boat Commission Fisheries Management Area 8, 236 Lake Road, Somerset, PA 15501, 3New York State Department of Environmental Conservation, Region 9, Bureau of Fisheries, 182 East Union Street, Allegany, NY 14706. *Corresponding author - argent@calu.edu. Manuscript Editor: Tom Maier Northeastern Naturalist Vol. 23, No. 4 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 455 This Basin includes the Monongahela and Allegheny rivers, which drain portions of New York, Pennsylvania, and West Virginia, forming the headwaters of the Ohio River in Pittsburgh, PA. Lock and Dam (L/D) navigation structures, acid mine drainage, and alteration of habitat caused by dredging likely drove the decline of Paddlefish here, resulting in their designations as “extirpated, protected, or threatened” (Bettoli et al. 2009, Henley et al. 2001), depending upon location within the Ohio River Basin. The most-recent reliable historical account of Paddlefish came from a 1919 collection made at the confluence of the Kiskiminetas and Allegheny rivers in Pennsylvania (Fowler 1919). Following passage of the Federal Clean Water Act Amendments of 1972, water quality improved dramatically, such that in the 1990s natural resource agencies (e.g., Pennsylvania Fish and Boat Commission [PFBC], New York State Department of Environmental Conservation [NYSDEC], and West Virginia Department of Natural Resources [WVDNR]), with assistance from MICRA, developed programs to reintroduce Paddlefish to the upper Ohio River Basin (Clancy 2005; Henley et al. 2001; Lorson 1991, 2008). From 1991 to 2006, the PFBC released Paddlefish throughout 48 km of the lower Allegheny River and 64 km of the upper Ohio River. From 2007 through 2011, stocking locations were reduced and confined to Pool 2 (11 km in length) of the Allegheny River in odd years and to Dashields Pool (12 km in length) of the Ohio River in even years to achieve a higher stocking density of 3 Paddlefish/ha. This hatchery-derived program resulted in the stocking of over 120,000 fish of a size thought to minimize predation (250–300 mm TL; Parken and Scarnecchia 2002). Companion programs initiated by NYSDEC in 1998 and WVDNR in 2005, added 9271 and 500 fish to portions of the Allegheny and Monongahela rivers, respectively. In addition, since 2006 NYSDEC has stocked 3341 Paddlefish in Conewango Creek, which joins the Allegheny River at Warren, PA, and WVDNR has added 26,000 Paddlefish to the Ohio River immediately downstream of the Pennsylvania border (C. O’Bara, WVDNR, Parkersburg, WV, pers. comm.) providing other potential sources of colonizers. All stocked fish were tagged with binary-coded wire tags (CWT) following MICRA protocols. The PFBC committed, as part of their recovery plan, to a dedicated 10-year monitoring and assessment effort focused on the navigable reaches of the Ohio and Allegheny rivers (Lorson 2008). Post-stocking movement (Barry et al. 2007) and food resource availability (Counahan 2004) studies were conducted from 2003 to 2005. Results indicated that recently stocked Paddlefish generally crowded near L/D structures immediately following release and that zooplankton densities were considerably lower than those documented from the Mississippi River Basin which supports self-sustaining Paddlefish populations. Concurrent with these studies, survey efforts were initiated to evaluate reintroduction efforts in portions of the lower Allegheny and upper Ohio rivers in Pennsylvania. These efforts were later expanded and replicated in West Virginia and New York to permit assessment of Paddlefish in their northeastern range. Northeastern Naturalist 456 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 Vol. 23, No. 4 Our primary objective here is to summarize these assessment efforts to reintroduce Paddlefish to their historic range in the upper Ohio River Basin. In addition, we document the presence and condition of Paddlefish in the northeastern US from a region below Kinzua Dam to Allegheny L/D 9 (a free-flowing reach of the Allegheny River) and compare those to individuals captured from L/D 9 of the Allegheny River to downstream navigable reaches of the Allegheny, Ohio, and Monongahela rivers (an area bounded by a series of L/D structures). Methods From 2004 to 2010, we used gill nets (2.4-m-deep panels consisting of 2.5-, 5.0-, 7.6-, 10.1- and 12.7-cm bar mesh) to sample adult fishes every ~1.28 km in Pennsylvania’s portions of the Monongahela and Allegheny rivers’ navigable reaches (sections where water is pooled by L/D structures and has at least 2.7 m of water depth maintained for commercial boat traffic [Fig. 1]). We set nets perpendicular to shore and fished overnight, between 14–20 hours. On the Monongahela River, the study reach extended from the Morgantown L/D (located in Morgantown, WV) to the confluence with the Allegheny River in Pittsburgh, PA, a distance of nearly 142 km (Fig. 1). The navigable reach on the Allegheny River extended from Pittsburgh to the mouth of Catfish Run, a distance of nearly 115 km. At Catfish Figure 1. Map depicting locations of sampling reaches within the Upper Ohio River Basin: (1) Allegheny Reservoir; (2) Kinzua Dam tailrace; (3) free-flowing reach of the Allegheny River, from Kinzua Dam to Lock/Dam #9; and (4) navigable reaches of the Allegheny, Monongahela, and Ohio rivers, bounded by series of L/D structur es. Northeastern Naturalist Vol. 23, No. 4 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 457 Run, the character of the river changed dramatically as the pool maintained by L/D 9 transitioned to a free-flowing/navigable river (Fig. 1). From here, we employed backpack electrofishing and gillnetting upstream to the mouth of French Creek, every 1.28 km when possible. In addition, we performed targeted gill-net sampling with multi-mesh gill nets (7.6-m-long panels of 10.1-, 12.7-, 15.2-, 17.8-, and 20.3- cm bar mesh hobbled from 6- to 4.5-m deep) on the Ohio and Allegheny rivers in areas below L/D structures. In 2011–2012, we intensively sampled with gill-nets utilizing a combination of net sizes and effort, as described above, below Emsworth and Dashields L/Ds on the Ohio River and L/D 2 and 3 on the Allegheny River, covering a reach about 65 km in length (hereafter, these areas of the Allegheny, Monongahela, and Ohio rivers will be referred to as the “naviga ble reaches”). In 2008, NYSDEC monitored the movement of Paddlefish within the Allegheny Reservoir using radio-telemetry (see Budnik 2010), observing that nearly half of the fish tracked left the reservoir during fall water releases from the epilimnion (Budnik et al. 2014). To assess the fate of these reservoir emigrants, Argent and Kimmel (2014) initiated a targeted sampling program in 2013–2014, using gillnets of varying dimensions (as described above) in areas of the upper Allegheny River, from its confluence with French Creek to the tailrace of Kinzua Dam, a distance of nearly 112 km (hereafter, designated as the “free-flowing” reach; Fig. 1). Because flow restrictions directly below Kinzua Dam prevented the use of gillnets, we employed boat electrofishing gear to sample this tailrace reach during spring 2013 and 2014, with two electrofishing runs performed each night. Electrofishing output ranged from 15 to 50 amps (peak) and 260 to 485 volts DC (peak), over an area about 120 m in width and 365 m in length. Lastly, data collected by NYSDEC from Paddlefish captured in Allegheny Reservoir (summarized in Budnik 2010 and Budnik et al. 2014) were obtained to allow for comparisons among all fish collected. All captured Paddlefish were examined for the presence of a CWT, weighed (to the nearest kg), measured (eye-to-fork length [EFL] to the nearest cm), sexed (by gamete expression), and released. We used weight and length data to compare size differences among the 4 populations sampled and to calculate Fulton’s condition index (K) for comparison with the results of Budnik (2010), using: K = (WT x 105) / EFL3, where WT is weight in kg, and EFL is eye-to-fork length measured in cm (Hoxmeier and Devries 1997). While we used Fulton’s condition index to compare fish growth among the 4 reaches surveyed, we could not determine growth rates because length or weight data at the time of stocking was not available. We used paired larval drift nets with identical dimensions (0.5-m-diameter nets, 750-μm mesh), following Braaten et al. (2009), in 15-minute sets at mid-water and benthic locations in areas where sufficient river flow permitted full deployments. This gear has been proven successful in capturing larval Paddlefish in portions of their range (Braaten et al. 2009); however, this methodology was ineffective in capturing larval fish due to low flow in navigable reaches. Therefore, in such lowNortheastern Naturalist 458 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 Vol. 23, No. 4 flow reaches we elected to perform 15-minute moving (active; ~5 km/hr) trawls in a downstream direction with the paired nets mounted from the bow of the boat to cover as much water as practicable within a given pool. One 15-minute paired-net active deployment permitted ~1 km of river to be sampled at mid-water and benthic depths. Active deployments were performed during the daytime at stations that were also sampled by gillnetting and trawling within each targeted pool. After each timed haul, the contents of each paired net were preserved on-site in 10% formalin, returned to the laboratory at California University of Pennsylvania to be identified to the lowest practicable taxonomic level, and pooled to form a station composite from both stationary and active sampling events. We determined Paddlefish length–weight relationships for each sampling locality and compared the log-transformed data using analysis of covariance (Zar 2010) to determine if differences existed in the slopes of these relationships. In addit ion, we used analysis of variance to determine if differences in Fulton’s condition index existed among the 4 defined sampling localities. To determine where differences occurred, we conducted Fisher’s LSD post-hoc. All tests were considered significant if P < 0.05. Results Varying amounts of gillnet effort were used to capture Paddlefish from 2004 to 2014 in New York and Pennsylvania (Table 1), with differing levels of success (Table 2). New York State DEC captured 78 Paddlefish with gill-nets in Allegheny Reservoir, while efforts in Pennsylvania yielded 13 fish from navigable reaches and 11 fish from free-flowing reaches with similar gear. No Paddlefish were collected with backpack electrofishing gear. As fish crowded below Kinzua Dam in spring 2013 and 2014, the ability to capture Paddlefish with boat electrofishing gear greatly increased, yielding 24 fish after nearly 4 hours of effort, compared to the 24 fish collected from 28,143 gillnet-hours expended elsewhere. Boat electrofishing within the environment below the dam produced catch per unit effort (CPUE) orders of magnitude higher than gillnetting (Table 2). Of the 126 Paddlefish collected, 2 were not weighed or measured; the remaining 124 fish ranged in size from 41 to 112 cm EFL and in weight from 1.2 to 24.9 kg (Fig. 2). Length–weight relationships, although similar in shape, revealed patterns Table 1. Summary of location, year sampled, period sampled, gear, and effort expended to capture Paddlefish. Reservoir = Kinzua Reservoir; Tailrace = tailrace of Kinzua Dam; Free-Flowing = region of river from tailrace of Kinza Dam to LD#9 on the Allegheny River; and Navigable = navigable waterways bounded by L/D structures on the Allegheny, Monongahela, and Ohio rivers within Pennsylvania. EF = electrofishing. Location Year sampled Period sampled Gear Effort (hr) Reservoir 2008–2011 May–June Gillnet 6939.0 Tailrace 2013–2014 May Boat EF 3.8 Free-flowing 2013–2014 May–July Gillnet 6083.0 Navigable 2004–2012 April–July Gillnet 15,121.0 Northeastern Naturalist Vol. 23, No. 4 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 459 with significantly different slopes (ANCOVA: P < 0.05; Fig. 2). Fulton’s condition index (K) ranged from 0.65 to 4.15, with differences apparent among the 4 sampling localities; it peaked in the reservoir and slowly declined downstream to the navigable reaches (Fig. 3). The average condition (as measured by Fulton’s K) of reservoir Paddlefish was significantly higher than that of all other sampling localities (Fisher’s LSD: P < 0.05). We could not determine sex for most fish as they were in either immature or in pre-spawn condition; however, 4 were externally identified as gravid females by gamete expression. Table 2. Summary of Paddlefish captures location on reaches (reservoir, tailrace, free-flowing, or navigable; see Table 1 for definitions) of the Ohio, Allegheny, and Monongahela rivers from 2004 to 2014. Number of fish capture, CPUE, mean eye-to-fork length, and mean weight are presented. Location No. caught CPUE (fish/100 hr) Mean EFL (cm) Mean weight (kg) Reservoir 76 1.12 80.38 13.71 Tailrace 24 632.00 79.27 9.21 Free-flowing 11 0.18 76.82 8.04 Navigable 13 0.09 84.08 10.20 Figure 2. Length–weight relationships (exponential) among 4 Paddlefish populations of the Upper Ohio River Basin. Line designations are as follows, dotted = reservoir (n = 76, R2=0.79), dashed = tailrace (n = 24, R2 = 0.87), dot-dash = free-flowing (n = 11, R2 = 0.71), and solid line = navigable (n = 13, R2 = 0.95). Figure represents a grand total (N) of 124 Paddlefish. Northeastern Naturalist 460 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 Vol. 23, No. 4 Among Paddlefish collected from the reservoir, tailrace, and free-flowing reaches (i.e., fishes from New York’s stocking efforts), CWTs were detected in most fish. We did not detect a CWT in 1 Paddlefish collected in the navigable reaches of Pennsylvania or from 4 fish captured in the tailrace reach. Although 2 stocking locations (Conewango River and Allegheny Reservoir) were used by NYSDEC, recovered CWTs indicated that all fish originated from the Allegheny Reservoir stocking. Despite performing over 500 hauls with drift nets, we captured only 1 larval paddlefish from the navigable reach of the Allegheny River. Discussion Natural resource agencies in Pennsylvania, New York, and West Virginia have made concerted efforts to reintroduce Paddlefish populations to the northeast fringe of their range in the upper Ohio River Basin with limited success. Monitoring efforts, in addition to angler reports compiled by the PFBC, provide ample evidence of the movement of Paddlefish stocked from bordering states into reaches of the Monongahela and the upper Allegheny rivers not stocked by the PFBC. Yet, evidence of self-sustaining Paddlefish populations in the upper Ohio River Basin is scant, consisting solely of the capture of a single larval paddlefish and 5 adult fish Figure 3. Fulton’s K mean-condition factor values of Paddlefish from reaches (n: reservoir = 76, tailrace = 24, free-flowing = 11, and navigable = 13) of the Allegheny, Monongahela, and Ohio rivers. Vertical whiskers denote standard deviation. Overall, data ranged from 0.65 to 4.15, with significantly higher values for the reservoir (Fisher’s LSD: P < 0.05). Northeastern Naturalist Vol. 23, No. 4 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 461 lacking identifiable tags (Argent and Kimmel 2006), suggesting that spawning habitat may be limited or non-accessible within the upper Ohio Rive r Basin. One of the most significant challenges to the reintroduction of self-sustaining Paddlefish populations to the northeastern portion of their range is presented by the Kinzua Dam, which blocks upstream fish movement in the upper Allegheny River. While Budnik et al. (2014) documented a 50% dispersal of Paddlefish from Allegheny Reservoir to downstream reaches, upstream passage of fishes is impossible given the design of the structure. With respect to the establishment of Paddlefish populations in the free-flowing upper Allegheny River and navigable downriver reaches below Kinzua Dam, however, fish from the Allegheny Reservoir, along with periodic stockings in Conewango River since 2006, have provided potential colonizers, enhancing restoration efforts in Pennsylvania. The success of those efforts is supported by gillnet-captured fish as far as 24 km below Kinzua Dam and a 2014 angler report, documenting movement to the tailrace of Tionesta Reservoir, located 74 km downstream of Kinzua Dam. In the navigable reaches, fish can move freely within pools, but have likely been restricted in traveling from one pool to an upstream contiguous pool by the rate at which lockages occur. Downstream movement is less dependent on lockage frequency, as fish may actively or passively traverse dam crests. Anecdotally, 2 Paddlefish monitored by Barry et al. (2007) were captured by anglers in Kentucky, 675 km downriver and 6 years after these fish were stocked in the Montgomery Pool of the Ohio River. Recent changes by the US Army Corps of Engineers (USACE) may further hamper fish movement both up and down-stream on the Allegheny and Monongahela rivers. In 2013, L/D structures 6 through 9 were closed on the Allegheny River, given insufficient-to-nonexistent barge traffic to warrant lockages, thereby restricting movement across 42 km of river for all fishes. Federal funding was secured to permit a lockage on each weekend day and holiday between late May and June 2015 for recreational boat traffic in this area (USACE 2015). Likewise, given reduced barge traffic, the Hildebrand and Opekiska L/D structures in West Virginia remain closed indefinitely on the Monongahela River (USACE 2013), thereby restricting access to the upper reaches of the Monongahela River . The CWT program launched by resource agencies and MICRA is anticipated to provide further evidence of movement by Paddlefish, given that spools used by MICRA are sequentially numbered and retention is relatively high. The PFBC and NYSDEC reported approximately 99% and 90% CWT retention, respectively, among hatchery-reared fishes. Recovered CWTs suggest that some Paddlefish had been at large for up to 15 years. No fish stocked by WVDNR were recovered in Pennsylvania by gillnetting, suggesting that downriver movements in the Monongahela River and upstream movements within the Ohio River are rare or non-existent. The capture of 5 Paddlefish lacking identifiable tags provides a measure of support for the possibility that natural reproduction may have occurred (Argent and Kimmel Northeastern Naturalist 462 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 Vol. 23, No. 4 2006). The size of fish we collected included individuals that should be sexually mature (following Jennings and Zigler 2009). These results lend support to the possibility that these fish are the result of natural reproduction and that self-sustaining populations may eventually exist. Our attempts to collect larval Paddlefish with drift nets (gear described by Braaten et al. 2009), however, were largely unsuccessful, as only one larval individual was captured after more than 1000 hours of sampling. This result suggests that spawning habitat may be limited in the upper Ohio River Basin. While Paddlefish may have access to nearly 200 km of free- flowing river and a few hundred km of navigable tributary waters, a lack of suitable spawning habitat may impede the establishment of self-sustaining populations. Most fish collected as part of this evaluation were documented from upstream free-flowing reaches where riverine habitats changed from slow-moving pools to swift-flowing reaches. The presence of L/D structures in the navigable reaches provided only isolated locations where scoured gravels remained. Bathymetry work summarized by Nieman et al. (1999) and Long and Chapman (2008) identified a complexity of habitat types along many reaches of the Allegheny and Ohio rivers; however, when compared with preferred Paddlefish habitat descriptions (Hubert et al. 1984), these may have been too widely scattered in the northeastern river sections considered here to provide sufficient habitat to sustain a Paddlefish population. Budnik et al. (2014) reported condition factors for Paddlefish collected inside Allegheny Reservoir comparable to those from populations in the mid-western US, suggesting that fish were able to find a suitable forage base. However, while zooplankton are present in and around Allegheny Reservoir, populations of the invasive Bythotrephes longimanus (Leydig) (Spiny Water Flea), which periodically dominate the tailrace, may hamper Paddlefish growth in the river (Argent et al. 2014). The Spiny Water Flea has been implicated as a predator of zooplankton (Yan et al. 2011), and the presence of the large spine inhibits its consumption by some fish species (Compton and Kerfoot 2004). The spine may also render these organisms difficult for Paddlefish fry to consume as they become obligate filter feeders. The tailrace below Kinzua Dam harbors a high density of zooplankton, which declines progressively downstream (Argent et al. 2014). Unlike Allegheny Reservoir and its tailrace, however, navigable reaches of the Ohio and Allegheny rivers do not support high densities of zooplankton (Counahan 2004). The lack of zooplankton may be responsible for the lower condition-index values exhibited by fish captured there and the shift in length–weight relationships from Allegheny Reservoir downriver to the navigable reaches. The protection afforded to Paddlefish by Pennsylvania and New York as a “species of conservation concern” and the effort both agencies have put forth to restore this species may not be enough to guarantee robust self-sustaining populations throughout the northeast fringe of their range, given the threats and challenges identified above. Of greatest attainable need is determining what contribution fishes stocked in Conewango Creek and Allegheny Reservoir have on the establishment of Paddlefish in free-flowing reaches downstream from Kinzua Northeastern Naturalist Vol. 23, No. 4 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 463 Dam to L/D 9, and if natural reproduction is occurring to the degree necessary to support self-sustaining populations. Sampling reaches below Kinzua Dam confirmed movement of Paddlefish stocked by NYSDEC through Kinzua Dam. While stocked fish were at large, however, our collection of few Paddlefish in either pre- or post-spawn condition or larvae provided little evidence of natural reproduction. Unlike portions of the impounded lower Allegheny and upper Ohio rivers, which appear habitat-limited, the reaches sampled in the free-flowing sections provide a diversity of habitat types. Therefore, while we were unable to document evidence of self-sustaining populations, the presence of adult Paddlefish, the availability of suitable habitat (though widely scattered), and riverine connectivity portend well for the future of this species in the free-flowing upper Allegheny River, below Kinzua Dam. The continued recovery of Paddlefish to the upper Allegheny River may also hinge on future stocking efforts by NYSDEC, as this reach was never targeted for restoration by the PFBC during the 20-year period in which Pennsylvania waters were stocked. Future population assessments should include: 1. Continued radio-telemetry studies focusing on pre- and post-spawning movement of adult Paddlefish to reveal the effect of dams on migratory patterns and to identify potential spawning habitat; 2. Further dialogue among the Seneca Nation, NYDEC, PFBC, WVDNR, and the USACE, as each party exercises some level of fishery or water resources management that affects Paddlefish and other aquatic species in the upper Ohio River Basin; 3. Expanded efforts using appropriate methods (e.g., consider increasing boat electrofishing surveys during spring) to document natural reproduction via larval drift- netting, as well as sampling to capture adult free-ranging Paddlefish; 4. Increased stockings in the reach between Allegheny L/D 9 and Kinzua Dam; and 5. Evaluating the zooplankton resources available to Paddlefish in Allegheny Reservoir and the Allegheny, Ohio, and Monongahela rivers. Acknowledgments We thank the US Fish and Wildlife Service/PA Fish and Boat Commission for funding this work through state wildlife grant SWG T2-10-R-1. We gratefully acknowledge assistance from US Army Corps of Engineers, the PA Fish and Boat Commission (Brian Ensign, Diana Day, Robert Ventorini [former], and Kelly Wiley), and numerous private boat dock/launch owners/operators for helping with field-sampling logistics. We thank the following individuals for their help with field sampling: Jeffrey Ambrose, Nick Bobich, Dan Dascani, Brian Deleonibus, Devin Demario, David Drescher, Levi Kaczka, Matthew Kinsey, Justin Peel, Colton Riley, Benjamin Trask, and Chris Warden. Lastly, 2 anonymous reviewers and Manuscript Editor, Tom Maier, provided helpful comments on earlier drafts of this manuscript. Northeastern Naturalist 464 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 Vol. 23, No. 4 Literature Cited Argent, D.G., and W.G. Kimmel. 2006. Current status of Paddlefish in Pennsylvania. Pennsylvania State Wildlife Grant Project: T-13. Final Report. The Pennsylvania Fish and Boat Commission, Somerset, PA. Argent, D.G., and W.G. Kimmel. 2014. Update on the status of Paddlefish in Pennsylvania. Pennsylvania State Wildlife Grant Project: T2-10-R-1. Phase III. Final Report. The Pennsylvania Fish and Boat Commission, Somerset, PA. Argent, D.G., W.G. Kimmel, R. Lorson, P. McKeown, D.M. Carlson, and M. Clancy. 2009. Paddlefish restoration to the upper Ohio and Allegheny river systems. Pp. 397–410, In C.P. Paukert and G.D. Scholten (Eds.). Paddlefish Management, Propagation, and Conservation in the 21st Century: Building From 20 Years of Research and Management. American Fisheries Society Special Symposium 66, Bethesda, MD. 443 pp. Argent, D.G., W.G. Kimmel, D. Gray, B. Deleonibus, and D. Drescher. 2014. Longitudinal distribution of the Spiny Water Flea (Bythotrephes cederstroemi) in a major Pennsylvania river. BioInvasions Records 3:89–95. Barry, P.M., R.F. Carline, D.G. Argent, and W.G. Kimmel. 2007. Movement and habitat use of stocked juvenile Paddlefish in the Ohio River system, Pennsylvania. North American Journal of Fisheries Management 27:1316–1325. Bettoli, P.W., J.A. Kerns, and G.D. Scholten. 2009. Status of Paddlefish in the United States. Pp. 23–38, In C.P. Paukert, and G.D. Scholten (Eds.). Paddlefish Management, Propagation, and Conservation in the 21st Century: Building From 20 Years of Research and Management. American Fisheries Society Special Symposium 66, Bethesda, MD.443 pp. Braaten, P.J., D.B. Fuller, and R.D. Lott. 2009. Spawning migrations and reproductive dynamics of Paddlefish in the upper Missouri River Basin, Montana and North Dakota. Pp. 103–122, In C.P. Paukert and G.D. Scholten (Eds.). Paddlefish Management, Propagation, and Conservation in the 21st Century: Building From 20 Years of Research and Management. American Fisheries Society Special Symposium 66, Bethesda, MD. 443 pp. Budnik, R.R. 2010. Seasonal movements of Paddlefish in the Allegheny Reservoir. M.Sc. Thesis. State University of New York, Fredonia, NY. Budnik, R.R., M. Clancy, J.G. Miner, and W.D. Brown. 2014. Assessment of Paddlefish reintroduction into Allegheny Reservoir. North American Journal of Fisheries Management 34:1055–1062. Clancy, M. 2005. Assessment of Paddlefish (Polyodon spathula) restoration in the Allegheny River system. Region 9 Fisheries, New York State Department of Environmental Conservation, New York State Wildlife Grants Program Federal Fiscal Year 2005, Allegheny, NY. Compton, J.A., and W.C. Kerfoot. 2004. Colonizing inland lakes: Consequences of YOY fish ingesting the spiny cladoceran (Bythotrephes cederstroemi). Journal of Great Lakes Research 30 (Suppl 1):315–326. Cooper, E.L. 1983. Fishes of Pennsylvania and the Northeastern United States. The Pennsylvania University Press, University Park, PA. Counahan, D. 2004. An assessment of zooplankton as a food resource for Paddlefish (Polyodon spathula) in the Ohio River. M.Sc. Thesis. The Pennsylvania State University, University Park, PA. Fowler, H.W. 1919. A list of the fishes of Pennsylvania. Proceedings of the Biological Society of Washington 32:49–74. Northeastern Naturalist Vol. 23, No. 4 D.G. Argent, W.G. Kimmel, R. Lorson, and M. Clancy 2016 465 Henley, D., L. Frankland, S. Hale, C. O’Bara, and T. Stefanavage. 2001. Paddlefish in the Ohio River sub-Basin: Current status on strategic plan for management. Ohio River Fisheries Management Team Technical Committee Team, Final Report 2001.1, Columbus, OH. Hoxmeier, R.J.H., and D.R. DeVries. 1997. Habitat use, diet, and population structure of adult and juvenile Paddlefish in the lower Alabama River. Transactions of the American Fisheries Society 126:288–301. Hubert, W.A., S.H. Anderson, P.D. Southall, and J.H. Crance. 1984. Habitat suitability index models and instream flow suitability curves: Paddlefish. US Fish and Wildlife Service, Washington, DC. Jennings, C.A., and S.J. Zigler. 2009. Biology and life history of Paddlefish in North America: An update. Pp. 1–22, In C.P. Paukert and G.D. Scholten, (Eds.). Paddlefish Management, Propagation, and Conservation in the 21st Century: Building From 20 Years of Research and Management. American Fisheries Society Special Symposium 66, Bethesda, MD. 443 pp. Long, E., and E.J. Chapman. 2008. A unique approach to bathymetry mapping in a large river system using GIS tools to evaluate hidden habitat. ArcUser. Available online at http://www.esri.com/news/arcuser/0708/eli-river.html. Lorson, R. 1991. Paddlefish restoration plan for the Ohio and Allegheny Rivers in Pennsylvania 1991–2000. The Pennsylvania Fish and Boat Commission, Somerset, PA. Lorson, R. 2008. Paddlefish restoration and management plan for Pennsylvania. The Pennsylvania Fish and Boat Commission, Somerset, PA. Nieman, D., G. Sermarini, W. Ettinger, T. Proch, J. Arway, and J. Schulte. 1999. Habitat Filters, GIS, and Riverine Fish Assemblages: Sifting Through the Relationships Between Fishes and Their Habitat. US EPA, Cincinnati, OH. Parken, C.K., and D.L. Scarnecchia. 2002. Predation on age-0 Paddlefish by Walleye and Sauger in Great Plains Reservoir. North American Journal of Fisheries Management 22:730–739. US Army Corps of Engineers (USACE). 2013. Schedule of operations for 2013 Allegheny river locks. Notice 13-09 Revised. Available online at https://www.lrp.usace.army.mil/ Portals/ 72/docs/navigation/notices/Nav%20Notice%2013-09_Revised.pdf. Accessed 15 May 2015. USACE. 2015. Upper Allegheny locks to open weekends and holidays. Release No. NR15- 142. Available online at https://www.lrp.usace.army.mil/Media/ NewsReleases/tabid/ 11552/Article/589443/upper-allegheny-locks-to-open-on-weekends-and-holidays. aspx. Accessed 15 May 2015. Wilcox D.B., E.L. Stefanik, D.E. Kelner, M.A. Cornish, D.J. Johnson, I.J. Hodgins, S.J. Zigler, and B.L. Johnson. 2004. Improving fish passage through navigation dams on the upper Mississippi River system. Environmental Report 54. Upper Mississippi River— Illinois Waterway System Navigation Study. Interim Report. US Army Corps of Engineers, Vicksburg, MS . Yan N.D., B. Leung, M.A. Lewis, and S.D. Peacor. 2011. The spread, establishment, and impacts of the Spiny Water Flea, Bythotrephes longimauns, in temperate North America: A synopsis of the special issue. Biological Invasions 13:2423–24 32. Zar, J. H. 2010. Biostatistical Analysis. 5th Edition. Prentice-Hall, Englewood Cliffs, NJ.