Occurrence of Shortnose Sturgeon in the Tidal Schuylkill River, an Urbanized and Industrialized Tributary of the Delaware River
Harold M. Brundage III1
1Environmental Research and Consulting, Inc., Lewes, DE, USA 19958. Corresponding author.
Urban Naturalist, No. 47 (2021)
Monitoring for acoustically-tagged sturgeon was conducted in the tidal Schuylkill River (Philadelphia, PA, USA), a highly urbanized and industrialized tributary of the Delaware River, during July 2018 through July 2019. Three adult Shortnose sturgeon were detected, initially during the summer and/or fall of 2018. The same fish were detected again in the spring and/or summer of 2019. Periods of continuous occupancy in the Schuylkill River ranged from 12–67 days and averaged 38.3 days. The Shortnose Sturgeon were absent from the Schuylkill River during the winter months but utilized known overwintering areas in the tidal Delaware River. This study suggests that a small percentage (~3% based on the proportion of acoustically-tagged Shortnose Sturgeon detected vs. at large) of adult Delaware River Shortnose Sturgeon seasonally utilize the tidal Schuylkill River, probably as a foraging area. The study also suggests that water quality in the Schuylkill River, particularly dissolved oxygen concentration, is generally suitable for adult Shortnose Sturgeon and provides further evidence that tributaries and smaller river systems may serve a more important role in the life history of Shortnose Sturgeon than previously thought.
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No. 47 Urban Naturalist 2021
Occurrence of Shortnose
Sturgeon in the Tidal Schuylkill
River, an Urbanized and
Industrialized Tributary of the
Harold M. Brundage III
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Cover Phograph: Adult Shortnose Sturgeon captured in the upper tidal Delaware River. Photograph ©
Harold M. Brundage III.
H.M. Brundage III
2021 No. 47
2021 Urban Naturalist 47:1–11
Occurrence of Shortnose Sturgeon in the
Tidal Schuylkill River, an Urbanized and Industrialized
Tributary of the Delaware River
Harold M. Brundage III1
Abstract - Monitoring for acoustically-tagged sturgeon was conducted in the tidal Schuylkill River
(Philadelphia, PA, USA), a highly urbanized and industrialized tributary of the Delaware River, during
July 2018 through July 2019. Three adult Shortnose sturgeon were detected, initially during the
summer and/or fall of 2018. The same fish were detected again in the spring and/or summer of 2019.
Periods of continuous occupancy in the Schuylkill River ranged from 12–67 days and averaged 38.3
days. The Shortnose Sturgeon were absent from the Schuylkill River during the winter months but
utilized known overwintering areas in the tidal Delaware River. This study suggests that a small percentage
(~3% based on the proportion of acoustically-tagged Shortnose Sturgeon detected vs. at large)
of adult Delaware River Shortnose Sturgeon seasonally utilize the tidal Schuylkill River, probably as
a foraging area. The study also suggests that water quality in the Schuylkill River, particularly dissolved
oxygen concentration, is generally suitable for adult Shortnose Sturgeon and provides further
evidence that tributaries and smaller river systems may serve a more important role in the life history
of Shortnose Sturgeon than previously thought.
Acipenser brevirostrum LeSueur (Shortnose Sturgeon) is a relatively small (<1.2 m total
length (TL)) sturgeon that inhabits large Atlantic coastal rivers and estuaries from the St. John
River, New Brunswick, Canada, to the St. Johns River, FL, USA (Vladykov and Greeley 1963).
The Shortnose Sturgeon was placed on the Endangered Species List in 1967 and is currently
listed as endangered under the federal Endangered Species Act (ESA) of 1973, as amended. The
International Union for the Conservation of Nature (IUCN) Red List of Threatened Species lists
Shortnose Sturgeon as Vulnerable (VU) (A2ce; B1ab(iii)) (IUCN 2020).
Shortnose Sturgeon occur throughout the Delaware River estuary (Brundage and Meadows
1982). Adults are abundant in the upper tidal Delaware River from Trenton, NJ to
Philadelphia, PA year-round (ERC 2006a, Hastings et al. 1987), and relatively common
in the lower tidal river from approximately Chester, PA to Wilmington, DE (ERC 2006a,
2010, 2020). The Delaware River estuary supports the third largest population of Shortnose
Sturgeon range wide; the Hudson River (NY) and the St. John River having larger
estimated populations (Kynard et al. 2016). Environmental Research and Consulting, Inc.
(ERC) (2006b) estimated the population of adult Shortnose Sturgeon in the Delaware River
to be 12,047 (95% CI 10,757–13,589) using the Schnabel population estimator with markrecapture
data collected during 1999–2003. This estimate, which is the most recent available,
was very similar to an earlier Schnabel estimate of the Delaware River adult Shortnose
Sturgeon population of 12,796 (95% CI 10,228–16,367) based on mark-recapture data from
1981–1984 (Hastings et al. 1987). The similarity of the estimates suggests that the population
of adult Shortnose Sturgeon in the Delaware River was stable during the approximately
20 year period between the estimates.
1Environmental Research and Consulting, Inc., Lewes, DE, USA 19958. Corresponding author:
Associate Editor: Sonja Knapp, Helmholtz Centre for Environmental Research–UFZ.
H.M. Brundage III
2021 No. 47
Delaware River Shortnose Sturgeon overwinter in dense aggregations in the upper tidal
river between Roebling and Bordentown, NJ, and also in the lower tidal river in the vicinity
of Marcus Hook and Chester (ERC 2006a, Hastings et al. 1987). Spawning occurs primarily
in the lower non-tidal Delaware River from Trenton to Lambertville, NJ from late March
or early April into early May (Brundage 1986; ERC 2008, 2015, 2018). After spawning,
adult Shortnose Sturgeon move back to the tidal river, where they spend the summer and
fall foraging, with fish occasionally moving into Delaware Bay (O’Herron et al. 1993, ERC
2006a). Delaware River Shortnose Sturgeon generally remain in the estuary throughout
their lives, although there are a few records of their occurrence in the ocean near the mouth
of Delaware Bay (Brundage and Meadows 1982).
Juvenile Shortnose Sturgeon in the Delaware River co-occur with adults but, being sensitive
to salinity (Jarvis et al. 2001), generally remain upriver of the freshwater/saltwater
interface (Brundage and O’Herron 2009, O’Herron et al. 1993). Juvenile Shortnose Sturgeon
appear to overwinter in a dispersed fashion rather than in the aggregations typical of
adults (Brundage and O’Herron 2009).
Effects of Urbanization on Shortnose Sturgeon
Urbanization and associated industrialization have impacted Shortnose Sturgeon in a
number of ways. Construction of dams has blocked upstream spawning migrations and denied
Shortnose Sturgeon access to historic spawning sites in a number of rivers, including the Connecticut
(CT) (Kynard 1997), Hudson (NY) (Bain 1997), and Cooper (SC) rivers (Cooke and
Leach 2003), resulting in spawning and early life stage rearing in suboptimal environments
(Kynard 1997, Kynard et al. 2016). The Delaware River, however, has remained undammed,
so Shortnose Sturgeon have unimpeded access to spawning areas in the non-tidal river.
Deterioration of water quality associated with urbanization and industrialization,
especially reduction in dissolved oxygen concentration, has had a significant impact on
Shortnose Sturgeon in some rivers. Laboratory studies have shown that juvenile Shortnose
Sturgeon and other sturgeons are very sensitive to hypoxia (Campbell and Goodman 2004,
Secor and Gunderson 1998, Secor and Niklitschek 2001), with younger juveniles being
more susceptible than older juveniles (Jenkins et al. 1993). Although laboratory studies are
lacking, adult Shortnose Sturgeon are also presumed to be sensitive to low dissolved oxygen,
but perhaps less so than juveniles, since resting oxygen consumption has been shown
to decrease with body mass for other sturgeon species (Peake 2005).
Low dissolved oxygen concentrations caused by pulp mill effluent are thought to have
made portions of the Satilla and St. Marys rivers in Georgia, and the Penobscot River in
Maine unusable by Shortnose Sturgeon (Kynard et al. 2016). Low dissolved oxygen is also
believed to have historically impacted Shortnose Sturgeon in the upper tidal Hudson River,
and the large (400%) increase in the estimated Shortnose Sturgeon population in the Hudson
between the 1970s and the late 1990s has been attributed, in part, to the return of normoxic
conditions (Bain et al. 2007, Secor and Niklitschek 2001).
Low dissolved oxygen has affected the distribution and movements of Shortnose Sturgeon
in the urbanized/industrialized central portion of the tidal Delaware River, both historically
and more recently. Brundage and Meadows (1982), reviewing incidental capture records
during 1954 through 1979, concluded that the Delaware River between Philadelphia and
Wilmington would be unavailable to Shortnose Sturgeon during summer as a result of near
zero dissolved oxygen concentrations. Although water quality in the Delaware River has
improved significantly since the 1980s, dissolved oxygen concentrations near Philadelphia
may still drop to stressful levels (~3–5 mg/l) during hot, dry summers (Moberg and DeLucia
H.M. Brundage III
2021 No. 47
2016). Acoustic tracking studies conducted during 2003–2004 (ERC 2006a) and 2009 (ERC
2010) indicated that adult Shortnose Sturgeon utilized the Philadelphia reach of the river as
a travel corridor when moving between overwintering, spawning, and foraging areas but did
not remain in that part of the river for long periods of time. Brundage and O’Herron (2009)
concluded that acoustically-tagged juvenile Shortnose Sturgeon were unlikely to use the
Philadelphia area in summer because of low dissolved oxygen concentrations.
Chemical contaminants released from urban areas and industrial sites may also impact
Shortnose Sturgeon. Shortnose Sturgeon early life stages appear to be particularly vulnerable
to contaminants, with effects ranging from sublethal deformities to mortality (Chambers
et al. 2012, Kocan et al. 1996, McConnell and Chambers 2018). Shortnose Sturgeon
are known to bioaccumulate various inorganic and organic chemicals, but studies linking
contaminant body burdens to effects in sturgeon are lacking. ERC (2002) reported that adult
Shortnose Sturgeon collected from the Delaware River had concentrations of polychlorinated
dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated
biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), aluminum, cadmium,
and copper in gonad and liver tissue above adverse effect concentrations reported for other
fish species. PCDDs, PCDFs, PCBs, DDE, and cadmium have been ide ntified as endocrine
disrupting compounds (EDCs), and there is evidence that the adverse effects of these chemicals
may be exacerbated when they occur in combination (Monosson 1997). Matsche et al.
(2012) identified a relatively high incidence of intersex (11.6%), as well as altered hormone
levels, in adult Shortnose Sturgeon collected in the upper tidal Delaware River, which could
have been caused by exposure to EDCs, perhaps in combination with hypoxia, but cautioned
that additional study would be needed to determine if reproduction was being affected.
While Shortnose Sturgeon have been relatively well studied in the mainstem Delaware
River, information on their use of tributaries is lacking. In this paper, I discuss the occurrence
of Shortnose Sturgeon in the Schuylkill River, a highly urbanized and industrialized
tributary of the Delaware River.
The Schuylkill River flows approximately 198 km from its headwaters in Schuylkill County,
PA to its confluence with the tidal Delaware River at Philadelphia (the confluence of the
Schuylkill River with the Delaware River is located at Delaware River kilometer (rkm) 148.8
based on DRBC (1969)). Tidal influence in the Schuylkill River is limited by Fairmount Dam,
located 13.6 km from the confluence. The tidal Schuylkill River is fresh water year round.
The tidal segment of the Schuylkill River is located entirely within the City of Philadelphia,
and adjacent land areas are heavily industrialized and densely populated. Much of the
shoreline of the tidal Schuylkill River has been bulkheaded, and there is little shallow water
habitat. The lower 10 km of the Schuylkill River has been dredged for navigation. The river
bottom consists of course sand and gravel overlain by mud and contains a large percentage
of anthracite coal from historical coal mining upriver (Ettinger 1982). Water quality in the
tidal Schuylkill River has historically been degraded by sewage, industrial effluents, and
urban runoff (Kaufman et al. 2011).
Capture, Handling, and Acoustic Tagging of Sturgeon
Shortnose Sturgeon and Acipenser oxyrinchus oxyrinchus Mitchell (Atlantic Sturgeon)
were captured for acoustic tagging by bottom-set gill net (5.1–15.2 cm stretched mesh)
H.M. Brundage III
2021 No. 47
or semi-balloon trawls (4.9 or 16.2 m mouth widths) in the upper tidal (~ rkm 210) or
lower tidal Delaware River (between approximately rkm 123–140) during November 2011
through February 2019 in studies funded by the National Marine Fisheries Service (NMFS)
and the US Army Corps of Engineers (USACE).
Sturgeons were carefully removed from the nets and placed in an out-board live car
or an on-board tank containing river water at ambient temperature and dissolved oxygen
levels. Sturgeon were identified to species, measured for fork length (FL) and total length
(TL), weighed, and tagged with a numbered T-bar tag (Floy Tag and Manufacturing, Inc.,
Seattle, WA), and/or a passive integrated transponder (PIT) (Biomark, Inc., Boise, ID).
Selected sturgeon were internally tagged with Vemco (now Innovasea Systems, Inc., Shad
Bay, Nova Scotia, Canada) 69 kHz coded acoustic transmitters (model V8, V9, V13, or V16)
matched to the weight of the fish. Sturgeon for acoustic tag implantation were anesthetized
using tricaine methanesulfonate (MS-222) at a dose of 50–100 mg/l and then held upside
down in a cradle while the gills were perfused with aerated flowing water. The transmitter
was inserted into the body through a longitudinal incision in the abdomen. The incision
was closed with interrupted sutures of 3-0 polydioxanone (PDS), and treated with povidone
iodine (10% solution) and petrolatum to prevent infection. Post surgery, fish were held in
an aerated holding tank and released upon recovery from anesthesia. Shortnose and Atlantic
sturgeons are tolerant of handling and tag implantation surgery, and, based on subsequent
acoustic tag detections, it is unlikely that any mortality resulted from the procedures.
All sampling and handling of sturgeon followed established protocols (Kahn and Mohead
2010) and was performed in accordance with NMFS Permits to Take Endangered Species
for Scientific Purposes Nos. 14604, 16438, or 19331 or requirements of NMFS Biological
Opinions issued for the USACE Delaware River Main Channel D eepening Project.
Monitoring for Acoustically-tagged Sturgeon in the Tidal Schuylkill River
Monitoring for acoustically-tagged sturgeon in the tidal Schuylkill River was conducted
during July 17, 2018 through July 17, 2019 using Vemco VR2W omnidirectional receivers
deployed at two locations, 1.2 and 5.9 km upriver of the confluence with the Delaware River
(Fig. 1). Based on calculated tag life, 89 Shortnose Sturgeon (6 juveniles and 83 adults)
and 81 juvenile Atlantic Sturgeon were at large in the Delaware River with active acoustic
tags when the Schuylkill River receivers were deployed in July 2018, and an additional 23
Shortnose Sturgeon (6 juveniles and 17 adults) and 107 juvenile Atlantic Sturgeon were
tagged in January–February 2019 and, thus, available for detection during approximately
the second half of the receiver deployment period.
Three adult Shortnose Sturgeon (tag codes 16490, 20767, and 55377), but no juvenile
Shortnose Sturgeon or juvenile Atlantic Sturgeon, were detected by the Schuylkill
River receivers (Table 1). The Shortnose Sturgeon occurred during two periods, initially
in the summer and/or fall of 2018 and again in the spring and/or summer of 2019 (Fig.
2). Collectively, the Shortnose Sturgeon were present in the Schuylkill River during
mid-April through mid-November but were absent during the winter months. The Shortnose
Sturgeon moved back and forth between receivers and were sometimes detected
by both receivers on the same day. Periods of continuous occupancy in the Schuylkill
River ranged from 12–67 days (Table 1) and averaged 38.3 days. The mean lengths and
weight of the Shortnose Sturgeon detected in the Schuylkill River (865 mm TL, 766 mm
H.M. Brundage III
2021 No. 47
FL, and 4.36 kg) (Table 1) were considerably greater than the mean lengths and weight
of acoustically-tagged adults at large in the Delaware River (781 mm TL, 675 mm FL,
and 2.93 kg).
The three Shortnose Sturgeon were detected at receivers throughout the tidal Delaware
River during the periods they were not in the Schuylkill River. Shortnose Sturgeon tag code
16490 overwintered in the lower tidal Delaware River between Wilmington (rkm 112) and
Marcus Hook (rkm 129), and tag codes 20767 and 55377 overwintered in the upper tidal
Delaware River between Roebling (rkm 199) and Bordentown (rkm 207). Tag code 55377
Figure 1. Locations of acoustic receivers on the tidal Schuylkill River, City of Philadlephia, PA.
Table 1. Detections of acoustically-tagged Shortnose Sturgeon in the tidal Schuylkill River during July
17, 2018 through July 17, 2019.
Measurements at Tagging
16490 11/16/16 928 812 4.62 9/30-10/26/18 14 283
5/3-6/14/19 36 1556
Total 50 1839
20767 12/27/15 863 777 5.04 7/23-11/10/18 60 2780
4/12-7/17/19 41 5802
Total 101 8582
55377 11/15/11 803 708 3.42 7/20-28/18 12 61
4/30-7/17/19 67 668
Mean 865 766 4.36 Total 79 729
H.M. Brundage III
2021 No. 47
was detected on the spawning grounds in the non-tidal Delaware River near Yardley, PA
(rkm 221) during March 26–April 26, 2019, just before it moved back to the Schuylkill
River, swimming over 73 km in five days.
There is only one previously published record of a sturgeon in the Schuylkill River.
This record, which appeared in the Philadelphia Inquirer (Bauers 2014), was of an adult
Shortnose Sturgeon caught by a fisherman near the base of Fairmount Dam in summer 2014.
Results of the present study suggest that a small percentage (~3% based on the proportion
of acoustically-tagged Shortnose Sturgeon detected vs. at large) of adult Delaware River
Shortnose Sturgeon may seasonally utilize the Schuylkill River. The return of the same three
fish detected in summer/fall 2018 to the Schuylkill River in spring/summer 2019 suggests a
regularity to their occurrence, at least for those individuals. The results of this study, combined
with the incidental capture at Fairmount Dam, suggest that the entire tidal Schuylkill
River may be utilized by Shortnose Sturgeon.
Although there appears to be ample invertebrate food resources in the Delaware River
(Kreeger et al. 2010), it is likely that Shortnose Sturgeon use the tidal Schuylkill River as
Figure 2. Occurrence of Shortnose
Sturgeon tag codes 16490 (top), 20767
(middle), and 55377 (bottom) in the tidal
Schuylkill River during July 17, 2018
through July 17, 2019.
H.M. Brundage III
2021 No. 47
foraging habitat considering the times of year and long durations they spent there. Shortnose
Sturgeon are benthic feeders with a broad diet, feeding opportunistically on insect larvae,
crustaceans, mollusks, and polychaetes (Dadswell et al. 1984, Kynard et al. 2016). Ettinger
(1982) reported 22 genera of benthic invertebrates in the tidal Schuylkill River, many of
which are known prey items of Shortnose Sturgeon.
The occurrence of the three Shortnose Sturgeon in the Schuylkill River may be related to
an innate tendency of some individuals to roam. Acoustically-tagged adult Shortnose Sturgeon
in the Delaware River typically evidence one of two generalized movement patterns,
either making long excursions throughout the tidal river or remaining locally in the upper
tidal river (ERC 2006a, 2010). Such dichotomy in movement behavior has been documented
in other fish species (Secor 2015), and fish making more wide-ranging movements can be
referred to as “roamers” or “explorers”. Secor (2015) proffers that the tendency to roam is a
personality trait that is part of an individual fish’s “behavioral syndrome”, and Sih and Bell
(2008) suggest that this trait may be heritable. Roamers have a tendency to explore novel
situations regardless of risk (Secor 2015). Exploratory behavior allows fish to discover and
utilize new areas and, thereby, extend their range if environmental conditions allow. The occurrence
of the three Shortnose Sturgeon in the tidal Schuylkill River over multiple seasons
indicates that environmental conditions in the system were suitable for those individuals.
The Schuylkill River has a long history of pollution by municipal and industrial discharges,
and urban runoff, and in the early 1900’s, it was described as “grossly polluted” and
“almost exhausted of dissolved oxygen” (Stevenson 1914). Water quality in the Schuylkill
River has improved through implementation of pollution control programs pursuant to the
1961 Delaware River Basin Compact, the 1972 Clean Water Act and subsequent amendments,
and other initiatives. Based on analysis of 1980–2005 data, Kaufman et al. (2011)
reported significant improvements in dissolved oxygen, total suspended sediment (TSS),
and phosphorus concentrations in the Schuylkill River, although nitrogen concentrations
remained high, probably because of the ongoing input of organic matter to the river.
There are no dissolved oxygen data for the tidal Schuylkill River for the period of sturgeon
monitoring. The most recent data was collected by the Philadelphia Water Department
(PWD 2015) using continuously recording sondes located 0.8 and 7.8 km upriver of the Delaware
River confluence during the summers (July–September) of 2012 and 2013. PWD’s
data showed that individual dissolved oxygen concentrations at the 0.8 km station (usable
data were obtained only in 2013 at this station) ranged from ~3.8–9.6 mg/l (daily average
~4.9–7.9 mg/l), with most individual readings above 5 mg/l. Dissolved oxygen concentrations
at the 7.8 km station ranged from ~4.0–10.0 mg/l (daily average ~4.8–8.9 mg/l), with
most readings above 5.5 mg/l in 2012; and ~5.9–9.0 mg/l (daily average ~6.9–9.0 mg/l,),
with most readings above 7 mg/l, in 2013 (PWD 2015).
Secor and Niklitschek (2001) concluded that young-of-year Shortnose Sturgeon will
experience lost production in habitats with <60% dissolved oxygen saturation, which corresponds
to 4.3–4.7 mg/l at summertime temperatures (22–27C°), and observed lethal effects
at dissolved oxygen concentrations ≤ 3.3 mg/l. Assuming that the dissolved oxygen
concentrations observed by PWD (2015) in 2012 and 2013 are representative of prevailing
conditions, dissolved oxygen levels in the tidal Schuylkill River appear to be generally
suitable for Shortnose Sturgeon, particularly adults, which likely have a greater tolerance
for low dissolved oxygen conditions than juveniles, although oxygen levels may transiently
drop to stressful levels during periods of high water temperature and low fresh water inflow.
The three Shortnose Sturgeon detected in the Schuylkill River may have been better adapted
to transient low dissolved oxygen conditions since they were large fish and, based on Peake
H.M. Brundage III
2021 No. 47
(2005), would have lower resting oxygen consumption rates than smaller individuals.
The absence of detection of juvenile Shortnose or Atlantic sturgeons suggests that the
Schuylkill River is not currently utilized by this life stage, although juveniles of both species
occur in the adjacent Delaware River, particularly during the non-summer months
(Brundage and O’Herron 2009; Hale et al. 2016; H. Brundage, ERC, Lewes, DE, unpubl.
data). This may be the result of the juvenile sturgeon’s requirement for higher dissolved
Shortnose Sturgeon are generally thought to inhabit deep, mainstem reaches of large
coastal rivers (Bain 1997, Dadswell et al. 1984, Kynard et al. 2016), although Kieffer and
Kynard (2012a, b), reported that some Shortnose Sturgeon may forage in the lower reaches
of large tributaries of the Connecticut River. More recently, Hodgdon et al. (2019) identified
the Saco River estuary, a proportionally small river flowing into the Gulf of Maine, as
a seasonal foraging area for Shortnose Sturgeon. The pattern of occurrence of Saco River
Shortnose Sturgeon, where the same individuals returned to the same river reaches over
multiple years, is similar to what I observed in the Schuylkill River. Together, these studies
suggest that tributaries and smaller river systems may serve a more important role in the life
history of Shortnose Sturgeon than previously thought.
Water quality improvement has allowed the return of a number of formerly extirpated
fish species to the tidal Schuylkill River. Perillo and Butler (2009) identified 29 fish species
in the tidal Schuylkill River, including the anadromous Alosa aestivalis Mitchill (Blueback
Herring), Alosa mediocris Mitchill (Hickory Shad), Alosa pseudoharengus Wilson
(Alewife), Alosa sapidissima Wilson (American Shad), and Morone saxatilis Walbaum
(Striped Bass), which can now pass into the non-tidal river through a fishway constructed
at Fairmount Dam. Other species that are now common in the tidal river include Carpiodes
cyprinus LeSueur (Quillback), Catostomus commersonii Lacepède (White Sucker), Cyprinus
carpio Linnaeus (Common Carp), Dorosoma cepedianum LeSueur (Gizzard Shad),
Ictalurus punctatus Rafinesque (Channel Catfish), Micropterus dolomieu Lacepède (Smallmouth
Bass), Morone americana Gmelin (White Perch), and the invasive Pylodictis olivaris
Rafinesque (Flathead Catfish) (Perillo and Butler 2009).
This study provides further evidence of the unique capabilities of acoustic telemetry for
studying the occurrence and movements of aquatic animals (see reviews by Cooke et al. 2004,
Crossin et al. 2017, and Hussey et al. 2015) and is an example of how acoustic tagging for
specific projects can be leveraged to study other areas and address other topics. Longer-term
investigation of the use of the tidal Schuylkill River, as well as other tributaries and small rivers,
by sturgeons, combined with the collection of relevant water quality data, is encouraged.
Sturgeon monitoring in Schuylkill River was funded by Evergreen Resources Group, LLC. I
thank Tiffani Doerr, of Evergreen, and Jenny Kachel and Jennifer Menges, of Stantec Consulting
Services, Inc., for their interest and support. I also thank Tim Delk of Stantec and Sean Gorby of
ERC for their assistance deploying and retrieving the acoustic receivers, and Glenn Curry of Stantec
for preparing the receiver location figure. Finally, I thank two anonymous reviewers for their
constructive comments on the manuscript.
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