Restoration of Stream Habitat for Blackside Dace,
Chrosomus cumberlandensis, in Mill Branch, Knox County,
Kentucky
Michael A. Floyd, Sherry L. Harrel, Arthur C. Parola, Chandra Hansen, J. Brent Harrel, and D. Kevin Merrill
Southeastern Naturalist, Volume 12, Special Issue 4 (2013):129–142
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2013 Southeastern Naturalist Vol. 12, Special Issue 4
Restoration of Stream Habitat for Blackside Dace,
Chrosomus cumberlandensis, in Mill Branch, Knox County,
Kentucky
Michael A. Floyd1,*, Sherry L. Harrel2, Arthur C. Parola3, Chandra Hansen3,
J. Brent Harrel1, and D. Kevin Merrill4
Abstract - The US Fish and Wildlife Service has focused the majority of its Blackside Dace
recovery efforts on preservation of extant populations, discovery of unknown populations,
and delineation of unoccupied suitable habitats. A missing component of its recovery program
has been a large-scale habitat improvement project for the species. Between 2006 and
2010, we evaluated the change in Blackside Dace abundance and distribution in response
to a 739-m restoration project on Mill Branch, a second-order tributary of Stinking Creek
in Knox County, KY. We expected Blackside Dace abundance to increase post-restoration
and predicted the species would expand its distribution within Mill Branch to include
downstream reaches. The improved habitat conditions were expected to lead to increased
diversity and abundance of other fishes. Fish surveys produced a total of 14,580 individuals,
representing 29 species. For the overall fish community, mean (± SD) species richness
in restored reaches (reach 1a; 21 ± 1, and reach 2a; 11.3 ± 0.58) was significantly greater
than mean species richness in unrestored reaches 1 (12.3 ± 3.1) and 2 (7.3 ± 1.53). Reach 2a
also had significantly greater diversity (1.7 ± 0.17) and evenness (0.69 ± 0.07) than reach
2 (1.05 ± 0.19 and 0.53 ± 0.04, respectively). Catch per unit of effort (CPUE) did not differ
significantly between restored and unrestored reaches. Blackside Dace abundance ranged
from a low of 76 in February 2006 (pre-restoration) to a high of 566 in October 2009 (postrestoration).
No significant increase in Blackside Dace CPUE or abundance was detected
within restored reaches. Our expectations with regard to Blackside Dace abundance and
CPUE were not met, but we contend that the species has benefited from the restoration. The
species’ movement within Mill Branch is no longer restricted by a perched culvert at the
Walker Road crossing, the reach downstream of Walker Road no longer has intermittent
flow, and the entire 739-m project area is protected from significant habitat disturbance.
Unfortunately, predatory centrarchids such as Redbreast Sunfish have increased post-restoration
and may be limiting Blackside Dace recovery. Nonetheless, we expect the Blackside
Dace population to increase within Mill Branch as the restoration matures and habitat conditions
continue to stabilize and improve.
Introduction
The US Fish and Wildlife Service (USFWS) has focused the majority of its
Chrosomus cumberlandensis (Blackside Dace) recovery efforts on preservation
of extant populations, discovery of unknown populations, and delineation of
unoccupied suitable habitats (USFWS 1988). Specific strategies have included
1US Fish and Wildlife Service, KY Ecological Services Field Office, Frankfort, KY
40601. 2Department of Biology, Eastern Kentucky University, Richmond, KY 40475.
3Department of Civil and Environmental Engineering, University of Louisville, Louisville,
KY 40292. 4Rosman High School, 749 Pickens Hwy, Rosman, NC 28772.
*Corresponding author - Mike_Floyd@fws.gov.
Ecology and Conservation of the Threatened Blackside Dace, Chrosomus cumberlandensis
2013 Southeastern Naturalist 12(Special Issue 4):129–142
M.A. Floyd, S.L. Harrel, A.C. Parola, C. Hansen, J. Brent Harrel, and D.K. Merrill
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(1) the use of existing legislation and regulations to protect the species and its
habitats; (2) project coordination and consultation with other federal agencies or
their state designees; (3) outreach efforts with local governments, conservation
organizations, and private landowners; (4) monitoring surveys and searches for
new populations; and (5) research studies on life history, genetics, ecology, habitat
preferences, and specific threats.
A missing component of the USFWS’s Blackside Dace recovery effort has
been an attempt to complete a large-scale habitat improvement project for the
species. Much of the Blackside Dace’s habitat within the upper Cumberland
River basin has been degraded by human activities, resulting in streams with
unstable substrates, sparse in-stream cover, and reduced canopy cover (O’Bara
1990, Starnes and Starnes 1981, USFWS 1988, Wood and Armitage 1997). The
specific habitat requirements of the species are not yet fully understood; however,
several characteristics are thought to be important based on field observations
(O’Bara 1990, USFWS 1988) and recent predictive models (Black et al. 2013
[this issue]). Blackside Dace tend to prefer streams with summer temperatures
below 21 ºC, conductivity values less than 240 μS/cm, and link magnitudes
between 3 and 6. These streams generally have extensive in-stream cover (i.e.,
undercut banks and woody debris), stable substrates, and continuous riparian
zones that provide bank protection and full canopy cover (> 70% ).
In this study, we evaluated the change in Blackside Dace abundance and distribution
in response to a 739-m stream habitat restoration (or reconfiguration)
on Mill Branch, a second-order tributary of Stinking Creek in Knox County,
KY. We expected Blackside Dace abundance to increase post-restoration and
predicted the species would expand its distribution within Mill Branch to include
downstream reaches. The improved habitat conditions were expected to lead to
increased diversity and abundance of other fishes.
The project location is notable because the Stinking Creek watershed is situated
at the center of the Blackside Dace’s range and is considered to be one of the
species’ last remaining strongholds (Laudermilk and Cicerello 1998, Strange and
Burr 1995). A large-scale habitat improvement project had not been attempted for
the species, so completion of such a project within the Stinking Creek watershed
represented an important recovery opportunity for Blackside Dace and had the
potential to serve as a template for future restoration efforts.
Study Area
Mill Branch (36°52'24"N, 83°43'54"W) is a second-order tributary to
Stinking Creek in eastern Knox County, KY, approximately 14.0 km east of
Barbourville (Fig. 1). The stream is roughly 3.5 km long and drains an area encompassing
4.8 km2. Elevations within the watershed range from about 300 m
to 631 m above mean sea level. Despite the high relief of the Eastern Kentucky
Coal Field physiographic region, the valley bottoms of much of the watershed
are wide and have a moderate gradient. The underlying geology of the Mill
Branch watershed is Pennsylvanian-age shale, siltstone, sandstone, and coal
(Woods et al. 2002).
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The dominant land use within the watershed is second- and third-growth
forest (97%), but the valley bottom of the lower half of the watershed, which
includes the study reach, is used for agriculture (pasture and hay production) and
contains four residences (historical land use is described in Supplemental Appendix
1, available online at https://www.eaglehill.us/SENA online/suppl-files/s12-
Sp4-1040e-Floyd-s1, and, for BioOne subscribers, at http://dx.doi.org/ 10.1656/
S1040e.s1). Forests are deciduous and are dominated by Liriodendron tulipifera
L. (Tulip Poplar), Quercus spp. (several oak species), Fagus grandifolia Ehrhart
(American Beech), and Platanus occidentalis L. (American Sycamore).
A decommissioned 0.83-km2 surface coal mine is situated along the southwest
side of Mill Branch immediately upstream of the study reach (Fig. 1). In
this area, a detention basin that collects acid mine drainage is separated from
the Mill Branch channel by a levee approximately 4 m in width. During periods
of low rainfall, conductivity increases in Mill Branch, suggesting that
contaminants from the basin are leaching into the groundwater that supplies
this reach of Mill Branch.
Site description
Within the study reach, the Mill Branch channel was divided into two morphologically
distinct reaches when the Walker Road crossing was constructed
(Fig. 1). Near the upstream end of this area, the valley bottom was forested, and a
large debris jam had formed in the channel. At Walker Road, two 1.2-m-diameter
corrugated metal culverts conveyed Mill Branch flow through the roadway embankment
that crossed the valley (Fig. 2A). Prior to restoration, sand and silt
Figure 1. Map of Mill Branch project area, Knox County, KY.
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had accumulated in this backwatered reach between the upstream debris jam and
the culverts, and the channel was multi-branched. The culverts were partially
crushed, and the upstream end of each culvert was chronically blocked by debris
and formed a barrier to fish passage. Because the culvert outlets were perched
approximately 0.3 m above the downstream channel (Fig. 2A), they also created
a significant barrier to fish migration from the downstream reach .
Downstream of the Walker Road crossing, habitat conditions were especially
poor (Fig. 2A–2C). This reach of Mill Branch had been relocated to the
base of the west valley wall and was being maintained as a channelized ditch
(Fig. 2B). Sections were periodically dredged, and all large woody debris had
been removed. Although the hillside bordering the left descending stream bank
was vegetated, canopy cover was sparse. The 2.2-ha pasture bordering the right
descending stream bank was grazed by several horses and was completely devoid
of woody vegetation (Fig. 2D).
The channel bed substrate of this reach was predominantly medium gravel
with small amounts of cobble from eroding hillside areas. Sparse in-stream
and woody lower bank cover along with frequent erosive flows created a
high-disturbance environment with little cover. All but the coarsest bed materials
were mobilized several times per year. Bank erosion created some undercut
Figure 2. Pre-restoration photographs (2006) of Mill Branch, Knox County, KY. (A)
Perched culverts at Walker Road crossing, (B) Upstream view of channel about 300 m
downstream of Walker Road, (C) Eroded bank and isolated pool downstream of Walker
Road, (D) Horse pasture on right descending bank, downstream of Walker Road.
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banks, but water levels were usually below rooting depth. Each summer and fall,
low flow generally resulted in a dry channel (Fig. 2B) or isolated pools (Fig. 2C).
Most silt and sand from eroding banks, upstream reaches, and adjacent pastures
were stored within the channel, as the infrequency of flooding limited its storage
on the valley bottom. Due to this lack of overbank storage and high rate of input
of fine material, silt and sand coated the stream-bed between bottom-scouring
events and composed the dominant substrate of most pools.
Methods
Stream restoration
Project construction was completed in three phases, during which time the entire
739-m study reach of Mill Branch was relocated and reconstructed. Phase one
involved construction of a new 556-m reach downstream of Walker Road (October
2007–January 2008), phase two involved replacement of the Walker Road
culverts and reach construction extending 61 m upstream of Walker Road (June
2008), and phase three involved construction of the final 122 m of the upstream
reach (October 2008–November 2008). A fenced, 15-m (50-ft) riparian buffer
was established along the entire restoration reach. To complete these tasks and
evaluate project success, the project area was visited on 30 separate occasions
between October 2007 (onset of construction) and March 2010 (post-restoration
phase). A detailed description of construction methods and design considerations
can be found in Supplemental Appendix 1.
Fish surveys
Fishes were surveyed within a 1.9-km section of Mill Branch using a Smith-
Root backpack electrofisher. Initially, Mill Branch was divided into three general
sampling reaches (Fig. 1). Reach 1 extended from the mouth of Mill Branch 450 m
upstream to Walker Road, reach 2 extended 820 m upstream of Walker Road to the
third road culvert, and reach 3 extended 660 m upstream from the end of reach 2.
All available habitats within each reach were searched in an upstream direction
(single-pass effort). Captured fishes were identified in the field, enumerated,
recorded, and released. Sampling time (seconds) and total length (TL; mm) of
Blackside Dace were recorded for each survey reach during all sampling events.
All surveys were completed outside of the Blackside Dace reproductive season.
We completed baseline fish surveys of reaches 1, 2, and 3 in February 2006
and March 2007. In March 2008, we expanded our survey efforts to include the
newly constructed channel below Walker Road (reach 1a). In March 2009, we
surveyed reaches 1, 1a, 2, and 3, and we expanded our survey efforts to include
the newly constructed channel upstream of Walker Road (reach 2a). Additional
surveys were completed in November 2008 (reach 1a only), August 2009 (reaches
1a and 2a only), October 2009 (all reaches), and March 2010 (all reaches).
Fish community structure for all sampling reaches and events was evaluated
through calculations of species richness (Margalef 1968), diversity (Shannon-
Wiener index; Hurlbert 1968), and evenness (Pielou 1966). Catch per unit of
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effort (CPUE) was calculated for each sampling reach and event by dividing
the number of individuals of all fish species by the sampling time (seconds).
Additionally, CPUE for Blackside Dace only was calculated for each sampling
reach and event by dividing the number of dace individuals by the sampling time
(minutes). A Mann Whitney U test (SAS 2011) was used to detect differences in
CPUE, species richness, diversity, and evenness between pre- and post-restoration
sampling events for all three reaches (α = 0.05). A Mann Whitney U test was
also used to compare differences in CPUE of Blackside Dace between pre- and
post-restoration sampling events for all three reaches (α = 0.05). Recruitment,
age structure, and abundance of Blackside Dace were examined by constructing
TL-frequency histograms for each sampling event.
Results
Stream restoration
A detailed analysis of the physical restoration will be presented in a separate
publication, but herein we provide some general observations. Continuous flow
was observed in the restored channel during all 30 site-visits, even during drier
periods in late summer and fall. The new Walker Road culvert posed no observable
barriers to fish passage during low-flow and base-flow periods (Fig. 3A). No evidence
of channel incision or lateral migration was observed in the restored channel.
Figure 3. Post-restoration photographs of Mill Branch. (A) Upstream view of new culvert
at Walker Road crossing (March 2008), (B) Upstream view of new channel downstream
of Walker Road (September 2008), (C) Upstream view of new channel approximately 300
m downstream of Walker Road (September 2009), (D) Downstream view of riparian zone
and fenced pasture (downstream of Walker Road, June 2012).
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Woody debris and root wads installed during project construction were still in
place. Vegetative cover increased within the fenced riparian zone (Figs. 3B–3D).
Fish surveys
Fish surveys produced a total of 14,580 individuals, representing 29 species
(Table 1). Nine species—Lampetra aepyptera (Least Brook Lamprey),
Campostoma anomalum (Central Stoneroller), Blackside Dace, Chrosomus
erythrogaster (Southern Redbelly Dace), Pimephales notatus (Bluntnose Minnow),
Semotilus atromaculatus (Creek Chub), Lepomis auritus (Redbreast
Sunfish), Etheostoma caeruleum (Rainbow Darter), and Etheostoma kennicotti
(Stripetail Darter)—were observed in all reaches. Twenty-eight of 29 species
were observed downstream of Walker Road (reaches 1 and 1a), and 8 species—
Lythrurus fasciolaris (Scarlet Shiner), Notemigonus crysoleucas (Golden
Shiner), Rhinichthys obtusus (Western Blacknose Dace), Hypentelium nigricans
(Northern Hog Sucker), Ameiurus nebulosus (Brown Bullhead), Lepomis gulosus
(Warmouth), Ambloplites rupestris (Rock Bass), and Ethostoma sagitta
(Cumberland Arrow Darter)—were limited to these reaches. One species, Etheostoma
blennioides (Greenside Darter), was observed only above Walker Road
in reaches 2 and 2a. The most species (26) were observed in reach 1a, while the
fewest species (9) were observed in reach 3. Creek Chub was the most abundant
species, followed by Blackside Dace, Bluntnose Minnow, White Sucker, and
Central Stoneroller. One notable community response was an observed increase
in Redbreast Sunfish abundance downstream of Walker Road (reaches 1 and 1a).
Prior to the restoration, Redbreast Sunfish abundance in reach 1 ranged from 14
(2006) to 42 (2007). After the restoration, we observed an increase in Redbreast
Sunfish abundance in reach 1a, including the following totals: November 2008 =
95, August 2009 = 178, October 2009 = 125, and March 2010 = 156.
Mean species richness in reaches 1a and 2a increased significantly compared
to unrestored reaches (reaches 1 and 2, respectively; Table 2). Mean species richness
increased from 12.3 (±3.1) at reach 1 (pre-restoration) to 21 (±1) at reach
1a after the restoration (z = -1.70, P = 0.04). Similarly, mean species richness
increased from 7.3 (±1.53) at reach 2 (pre-restoration) to 11.3 (±0.58) at reach 2a
after the restoration (z = -1.77, P = 0.04). Although not statistically significant
(z = 1.52, P = 0.06), mean species richness at reach 3 increased from 2.3 (±1.5)
before the restoration to 8 (±0) after the restoration. Mean diversity and evenness
at reach 2a increased significantly compared to reach 2 (z = -1.75, P = 0.04 and
z = -1.74, P = 0.04, respectively). Evenness did not differ significantly between
pre- and post-restoration sampling events in reach 3. Mean CPUE for all fishes
and for all reaches before and after the restoration did not differ significantly
(Table 3).
Only 76 Blackside Dace were collected throughout Mill Branch in February
2006 prior to the restoration (Table 4), and most of these individuals were
adults ranging in size between 40 mm and 72 mm TL (Fig. 4). In March 2007,
surveys produced a large number of recruited individuals, with 89% of the 525
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Table 1. Summary of fishes collected in Mill Branch, Knox County , KY 2006−2010.
Sampling Reach
Species Common Name 1 1a 2 2a 3 Abundance
Lampetra aepyptera (Abbott) Least Brook Lamprey X X X X X 124
Campostoma anomalum (Rafinesque) Central Stoneroller X X X X X 804
Chrosomus cumberlandensis (Starnes & Starnes) Blackside Dace X X X X X 2366
Chrosomus erythrogaster Rafinesque Southern Redbelly Dace X X X X X 147
Cyprinella spiloptera (Cope) Spotfin Shiner X X X X 163
Luxilus chrysocephalus Rafinesque Striped Shiner X X X X 338
Lythrurus fasciolaris (Gilbert) Scarlet Shiner X X 4
Notemigonus crysoleucas (Mitchill) Golden Shiner X 19
Notropis buccatus (Cope) Silverjaw Minnow X X X 151
Notropis rubellus (Agassiz) Rosyface Shiner X 16
Pimephales notatus (Rafinesque) Bluntnose Minnow X X X X X 1763
Semotilus atromaculatus (Mitchill) Creek Chub X X X X X 5757
Rhinichthys obtusus Agassiz Western Blacknose Dace X 3
Catostomus commersonii (Lacapede) White Sucker X X X X 912
Hypentelium nigricans (Lesueur) Northern Hog Sucker X X 6
Ameiurus natalis (Lesueur) Yellow Bullhead X 14
Ameiurus nebulosus (Lesueur) Brown Bullhead X 1
Lepomis auritus (L.) Redbreast Sunfish X X X X X 756
Lepomis cyanellus Rafinesque Green Sunfish X X X X 31
Lepomis gulosus (Cuvier) Warmouth X 19
Lepomis macrochirus Rafinesque Bluegill X X X 140
Lepomis megalotis (Rafinesque) Longear Sunfish X X 38
Ambloplites rupestris (Rafinesque) Rock Bass X 15
Micropterus salmoides (Lacapede) Largemouth Bass X X 14
Micropterus punctulatus (Rafinesque) Spotted Bass X X 48
Etheostoma blennioides Rafinesque Greenside Darter X X 2
Etheostoma caeruleum Storer Rainbow Darter X X X X X 316
Etheostoma kennicotti (Putnam) Stripetail Darter X X X X X 612
Ethostoma sagitta (Jordan & Swain) Cumberland Arrow Darter X 1
Number of Species 19 26 16 17 9 14,580
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Table 2. Summary of fish community metrics for Mill Branch, Knox County, KY.
Feb 06 Mar 07 Mar 08 Nov 08 Mar 09 Aug 09 Oct 09 Mar 10
CPUE
Reach 1 0.04 0.21 0.02 - - - - -
Reach 2 0.04 0.15 0.10 - 0.18 - 0.18 0.08
Reach 3 0.02 0.08 0.004 - 0.22 - 0.11 0.08
Reach 1a - - 0.03 0.20 0.11 - 0.19 0.12
Reach 2a - - - - 0.13 - 0.22 0.10
Richness
Reach 1 13 15 9 - - - - 0
Reach 2 9 6 7 - 7 - 10 9
Reach 3 3 3 1 - 4 - 8 8
Reach 1a - - 11 13 14 20 22 21
Reach 2a - - - - 8 11 12 11
Diversity
Reach 1 1.74 1.93 1.63 - - - -
Reach 2 1.27 0.93 0.96 - 0.99 - 1.31 1.38
Reach 3 0.27 0.57 - - 0.46 - 0.57 0.92
Reach 1a - - 1.96 1.81 1.97 1.84 2.14 2.18
Reach 2a - - - - 1.47 1.86 1.67 1.52
Evenness
Reach 1 0.68 0.71 0.74 - - - - -
Reach 2 0.58 0.52 0.49 - 0.51 - 0.51 0.60
Reach 3 0.25 0.52 - - 0.33 - 0.28 0.44
Reach 1a - - 0.82 0.71 0.75 0.62 0.69 0.72
Reach 2a - - - - 0.71 0.78 0.67 0.63
Table 3. Mann Whitney U-test comparisons of fish metrics within sample reaches before
and after restoration activities. Numbers in bold are significant at α = 0.05. BSD =
Blackside Dace.
CPUE
Reach Stats # fish/sec # BSD/min Richness Diversity Evenness
1 Mean (SD) 0.09 (0.1) 0.30 (0.48) 12.3 (3.1) 1.77 (0.15) 0.71 (0.03)
1a Mean (SD) 0.16 (0.05) 0.06 (0.02) 21.0(1) 2.06 (0.18) 0.67 (0.05)
z 0.29 0.1 -1.70 -1.31 0.44
P-value 0.39 0.5 0.04 0.09 0.33
2 Mean (SD) 0.09 (0.06) 2.39 (1.54) 7.3 (1.53) 1.05 (0.19) 0.53 (0.04)
2a Mean (SD) 0.18 (0.08) 2.79 (1.68) 11.3 (0.58) 1.7 (0.17) 0.69 (0.07)
z 0.59 0.28 -1.77 -1.75 -1.74
P-value 0.28 0.39 0.04 0.04 0.04
3 Mean (SD) 0.035 (0.04) 0.80 (0.35) 2.3 (1.5) 0.42 (0.21) 0.38 (0.19)
3 Mean (SD) 0.1 (0.02) 0.35 (0.54) 8.0(0) 0.75 (0.25) 0.36 (0.12)
z 1.18 0.87 1.52 0.82 0.10
P-value 0.11 0.19 0.06 0.20 0.50
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individuals collected ranging from 24–49 mm TL. In subsequent years, when
surveys were completed in all available reaches (reaches 1a, 2, 2a, and 3), Blackside
Dace abundance ranged from a low of 256 in March 2010 to a high of 566
in October 2009 (Table 4).
We observed a gradual increase in post-restoration Blackside Dace numbers
downstream of Walker Road (reach 1a); however, these totals were lower than the
maximum pre-restoration abundance observed in March 2007 (reach 1). Reach
2 had the highest observed Blackside Dace abundance throughout the study
(Table 4). Differences in mean CPUE for Blackside Dace between restored and
unrestored reaches were not significant (Table 3).
Discussion
The fish fauna of Mill Branch was similar to that of other second-order
streams in the upper Cumberland River basin (Laudermilk and Cicerello 1998).
As expected, the highest species richness was observed near the stream’s
mouth, with upstream reaches (reach 3) supporting fewer species. Cumberland
Arrow Darter, a Federal Candidate species, was not known from Mill Branch
prior to this study, but a single individual was observed in reach 1 during the
March 2007 sampling event. The single specimen’s origin is unknown, but it
may have moved into the area from adjacent Stinking Creek tributaries (e.g.,
Moore Creek) where the species is known to occur. The increased abundance
of Redbreast Sunfish in reach 1a is a concern because this species represents a
non-native, potential predator of small fishes, including Blackside Dace (Davis
1972, Sandow et al. 1975). The increased Redbreast Sunfish abundance in
reach 1a could limit Blackside Dace abundance.
Our data suggest that the stream restoration is having a positive effect on
the overall fish community. Compared to unrestored reaches, species richness
was higher in both restored reaches (reaches 1a and 2a), and diversity
and evenness improved upstream of Walker Road (reach 2a). Trends in CPUE
of restored reaches also suggested improvement, but these results were not
significant. Based on our observations of habitat conditions within the restored
reaches, we speculate that the fish community has benefited from increases in
flow duration, substrate stability, and available cover, as well as a continuous,
unobstructed channel.
Table 4. Summary of Blackside Dace abundance, Mill Branch, Knox County, KY.
Feb 06 Mar 07 Mar 08 Nov 08 Mar 09 Aug 09 Oct 09 Mar 10
Reach 1 6 75 0 - - - - -
Reach 2 63 386 406 - 316 - 322 119
Reach 3 7 64 0 - 44 - 75 55
Reach 1a - - 0 0 0 2 4 13
Reach 2a - - - - 43 132 165 69
Total 76 525 406 0 403 134 566 256
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Our length-frequency estimates for Blackside Dace indicated a life span of
>3 years and revealed age class patterns similar to those reported by Starnes and
Starnes (1981). In most years, we could distinguish three Blackside Dace age
classes, with the highest recruitment between 2006 (76 individuals) and 2007
Figure 4. Size-frequency histograms for Blackside Dace in Mill Branch, 2006−2010.
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(525 individuals, with 450 age-0 individuals). Blackside Dace total abundance
(all reaches) declined sharply in 2010 with little evidence of recruitment. The actual
cause of the decline is unknown, but we suspect it may be related to increased
stream flow (elevated rainfall totals) during the 2009 reproductive season, which
may have disrupted spawning behavior or swept away eggs and fry (NWS 2013).
Because the decline in Blackside Dace abundance was observed across all sampling
reaches, we do not suspect the decline was related to the restoration. Our
initial assumption was that the improved habitat conditions and permanent flow
within restored reaches would benefit the Blackside Dace population, resulting
in increased abundance, especially within habitats downstream of Walker Road
(reach 1a). However, we observed no significant change in the Blackside Dace
population as a result of the restoration. Blackside Dace CPUE within reach 2a
appeared to increase, but the change was not significant.
Why did we not see a positive response by the Blackside Dace population?
Our evaluation of the restoration suggests that (1) inputs of fine sediment from
upstream reaches may be limiting spawning and foraging sites within the restored
channel, (2) increased abundance of the predatory, non-native Redbreast Sunfish
in reaches 1a and 2a may be contributing to reduced dace abundance, (3) food
availability (periphyton, macroinvertebrates) may be inadequate within the restored
channel, and (4) insufficient time has passed for the restoration to mature
and stabilize.
Measurable improvements (greater abundance, higher CPUE) in the Blackside
Dace population have not been observed to date, but we contend that the
restoration effort has created more favorable habitat conditions for the species.
Most notably, Blackside Dace movement within Mill Branch is no longer
restricted by a perched culvert at the Walker Road crossing, the reach downstream
of Walker Road no longer has intermittent flow, and the entire 739-m
project area is protected from significant habitat disturbance. Under current
conditions, individuals can freely pass between upstream and downstream
reaches, and individuals that move downstream of Walker Road will no longer
be trapped in a reach that typically dries each year. As the restoration matures
and habitat conditions continue to stabilize and improve, we expect the Blackside
Dace population to increase within Mill Branch and we will conduct annual
surveys to track its response.
Acknowledgments
This project was made possible through the cooperation and assistance of four
Mill Branch landowners. Field assistance was provided by Carrie Allison, Mike Armstrong,
Seth Bishop, Dirk Bradley, Stephanie Brandt, Sue Bruenderman, Sunni Carr,
Mike Compton, Ryan Evans, Jason Fisher, Mason Howell, Gabriel Jenkins, Mindi
Lawson, Clayton Mastin, Ben Mater, Aric Payne, Joe Settles, Doug Stephens, Jacob
Stewart, David Thaemert, Matt Thomas, Tony Velasco, Bill Vesely, and John Williams.
Greg Abernathy and Shauna Dunham (Kentucky State Nature Preserves Commission)
kindly prepared Fig. 1. Brian Jones, of the Natural Resources Conservation Service
141
M.A. Floyd, S.L. Harrel, A.C. Parola, C. Hansen, J. Brent Harrel, and D.K. Merrill
2013 Southeastern Naturalist Vol. 12, Special Issue 4
(NRCS) and Brian Hacker (Knox County Conservation District) assisted in landowner
participation, project development, and project coordination. The Knox County Fiscal
Court provided fill material during placement of the new culvert at Walker Road. Construction
was directed by Eric Dawalt, currently of Ridgewater, LLC, and Jonathan
Charles, of Bluegrass Streams, LLC. Project funding was provided by NRCS (through
the Wildlife Habitat Incentive Program), the USFWS’s Partners for Fish and Wildlife
program, the Kentucky Department of Fish and Wildlife Resources (through the Landowner
Incentive Program), Cumberland Valley RC&D (a Service Private Stewardship
Grant), and the Kentucky Division of Conservation (State Cost Share Program). Mr.
Virgil Lee Andrews, Jr. (Field Supervisor, Kentucky Ecological Services Field Office)
provided valuable project oversight and financial support in the form of equipment,
and travel expenses. The Kentucky Aquatic Resource Fund provided financial support
for publication costs.
Disclaimer
The findings and conclusions in this article are those of the authors and do not necessarily
represent the views of the US Fish and Wildlife Service.
Literature Cited
Black, T.R., B.K. Jones, and H.T. Mattingly. 2013. Development and validation of habitat
models for the threatened Blackside Dace, Chrosomus cumberlandensis, at two spatial
scales. Southeastern Naturalist 12(Special Issue 4):6–26.
Davis, J.R. 1972. Spawning behavior, fecundity rates, and food habits of the Redbreast
Sunfish in southeastern North Carolina. Proceedings of the Southeastern Association
of Game and Fish Commissioners 25:556–560.
Hurlbert, S.H. 1978. The measurement of niche overlap and some relatives. Ecology
59:67−77.
Laudermilk, E.L., and R.R. Cicerello. 1998. Upper Cumberland River drainage, Kentucky
fish collection catalog (1982–1994). Unpublished report prepared for Kentucky
State Nature Preserves Commission. Frankfort, KY.
Margalef, R. 1968. Perspectives in Ecological Theory. University of Chicago Press,
Chicago, IL. 111 pp.
National Weather Service (NWS). 2013. Climate information for London-Corbin Airport
(KLOZ), Jackson, Kentucky Weather Forecast Office. Available on line at http://www.
crh.noaa.gov/jkl/?n =loz_climate. Accessed 24 June 2013.
O’Bara, C.J. 1990. Distribution and ecology of the Blackside Dace, Phoxinus cumberlandensis
(Osteichthyes: Cyprinidae). Brimleyana 16:9–15.
Pielou, E.C. 1966. The measurement of diversity in different types of biological collections.
Journal of Theoretical Biology 13:131−144.
Sandow, J.T., D.R. Holder, and L.W. McSwain. 1975. Ecological aspects of the Redbreast
Sunfish in Satilla River, Georgia. Proceedings of Southeastern Association of Game
and Fish Commissioners 28:296–396.
SAS Institute, Inc (SAS). 2011. SAS 9.3. Cary, NC.
Starnes, L.B., and W.C. Starnes. 1981. Biology of the Blackside Dace, Phoxinus cumberlandensis.
American Midland Naturalist 106:360–372.
Strange, R.M., and B.M. Burr. 1995. Genetic variability and metapopulation dynamics
in the federally threatened Blackside Dace, Phoxinus cumberlandensis (Pisces: Cyprinidae).
Unpublished report prepared for Kentucky Department of Fish and Wildlife
Resources. Frankfort, KY.
M.A. Floyd, S.L. Harrel, A.C. Parola, C. Hansen, J. Brent Harrel, and D.K. Merrill
2013 Southeastern Naturalist
142
Vol. 12, Special Issue 4
US Fish and Wildlife Service (USFWS). 1988. Blackside Dace recovery plan. Southeast
Region, Atlanta, GA. 23 pp.
Wood, P.J., and P.D. Armitage. 1997. Biological effects of fine sediment in the lotic environment.
Environmental Management 21:203–217.
Woods, A.J., J.M. Omernik, W.H. Martin, G.J. Pond, W.M. Andrews, S.M. Call, J.A.
Comstock, and D.D. Taylor. 2002. Ecoregions of Kentucky (color poster with map
[scale = 1:1,000,000], descriptive text summary tables, and photographs). US Geological
Survey, Reston, VA.
Supplemental Appendix 1. Historical land use and restoration methods and design
considerations. (Available online at https://www.eaglehill.us/SENA online/suppl-files/
s12-Sp4-1040e-Floyd-s1, and, for BioOne subscribers, at http://dx.doi.org/ 10.1656/
S1040e.s1).