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Susitna-Watana Hydroelectric Project Document
ARLIS Uniform Cover Page
Title:
SuWa 270
Study of fish distribution and abundance in the upper Susitna River (Study
9.5), Evaluation of 2014 study modifications in the Black River technical
memorandum
Author(s) – Personal:
Author(s) – Corporate:
R2 Resource Consultants, Inc.
AEA-identified category, if specified:
December 17, 2014 technical memorandum filings
AEA-identified series, if specified:
Series (ARLIS-assigned report number): Existing numbers on document:
Susitna-Watana Hydroelectric Project document number 270
Published by: Date published:
[Anchorage, Alaska : Alaska Energy Authority, 2014] December 2014
Published for: Date or date range of report: Prepared for Alaska Energy Authority
Volume and/or Part numbers:
Final or Draft status, as indicated:
Attachment A
Document type: Pagination:
Technical memorandum v, 28 p.
Related work(s): Pages added/changed by ARLIS:
Cover letter to this report: Susitna-Watana Hydroelectric Project,
FERC Project no. 14241-000; Filing of additional information in
response to October 2014 Initial Study Plan Meetings. (SuWa 269)
Attachment B (SuWa 271)
Added cover letter (2 pages)
Notes:
All reports in the Susitna-Watana Hydroelectric Project Document series include an ARLIS-
produced cover page and an ARLIS-assigned number for uniformity and citability. All reports
are posted online at http://www.arlis.org/resources/susitna-watana/
December 17, 2014
Ms. Kimberly D. Bose
Secretary
Federal Energy Regulatory Commission
888 First Street, N.E.
Washington, D.C. 20426
Re: Susitna-Watana Hydroelectric Project, Project No. 14241-000
Filing of Additional Information in Response to
October 2014 Initial Study Plan Meetings
Dear Secretary Bose:
By letters dated January 28, 2014 and October 3, 2014, the Federal Energy
Regulatory Commission (Commission or FERC) modified the procedural schedule for
the preparation and review of the Initial Study Report (ISR) for the proposed Susitna-
Watana Hydroelectric Project, FERC Project No. 14241 (Project).1 As required by the
Commission’s January 28 letter, the Alaska Energy Authority (AEA) filed the ISR with
the Commission on June 3, 2014 and conducted ISR meetings on October 15, 16, 17, 21,
22, and 23, 2014. As required by the Commission’s October 3 letter, AEA will be
conducting additional ISR meetings on January 7 and 8, 2015.
In response to the October ISR meetings, AEA and licensing participants
identified two technical memoranda that AEA would file with the Commission in
December 2014, ahead of the January ISR meetings. In accordance, AEA is filing and
distributing the following technical memoranda:
• Attachment A: Study of Fish Distribution and Abundance in the Upper
Susitna River (Study 9.5) - Evaluation of 2014 Study Modifications in the
Black River Technical Memorandum. This technical memorandum describes
how the modifications to the Study of Fish Distribution and Abundance in the
Upper Susitna River (Study 9.5) outlined in the ISR were applied to the Black
River during the 2014 study year.
• Attachment B: River Productivity Study (Study 9.8) - Fish Diet Sample Size
Sufficiency Analysis Technical Memorandum. This technical memorandum
describes an analysis of stomach contents samples conducted after field
1 Letter from Jeff Wright, FERC Office of Energy Projects, to Wayne Dyok, Alaska Energy Authority,
Project No. 14241-000 (issued Jan. 28, 2014); Letter from Jeff Wright, FERC Office of Energy Projects, to
Wayne Dyok, Alaska Energy Authority, Project No. 14241-000 (issued Oct. 3, 2014).
2
sampling was completed to determine whether the sample size targets and the
actual sample sizes were sufficient to meet the Study Plan objectives.
Additionally, AEA notes that data collected during the Study Plan implementation,
to the extent they have been verified through AEA’s quality assurance and quality control
(QAQC) procedures and are publicly available, can be accessed at
http://gis.suhydro.org/isr_mtg. On December 17, 2014, AEA posted the following data to
this website:
• Baseline Water Quality Data (Study 5.5), 2014 QAQC water quality data
and DVRs per the Quality Assurance Project Plan.
Finally, AEA notes that it has posted the agenda and PowerPoint presentations for
the upcoming January ISR meetings to the Project website (http://www.susitna-
watanahydro.org/meetings/ ).
AEA appreciates the opportunity to provide this additional information to the
Commission and licensing participants, which it believes will be helpful in determining
the appropriate development of the 2015 study plan as set forth in the ISR. If you have
questions concerning this submission please contact me at wdyok@aidea.org or (907)
771-3955.
Sincerely,
Wayne Dyok
Project Manager
Alaska Energy Authority
Attachments
cc: Distribution List (w/o Attachments)
Susitna-Watana Hydroelectric Project
(FERC No. 14241)
Study of Fish Distribution and Abundance
in the Upper Susitna River (Study 9.5)
Evaluation of 2014 Study Modifications
in the Black River
Technical Memorandum
Prepared for
Alaska Energy Authority
Prepared by
R2 Resource Consultants, Inc.
December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
TABLE OF CONTENTS
1. Introduction ........................................................................................................................1
2. Sampling Decision: Increased Sampling Effort in Select Upper River Tributaries ....1
2.1. Sampling in 2013 ...............................................................................................1
2.2. Measures of Sampling Sufficiency ....................................................................1
2.3. Increased Sampling Effort .................................................................................2
2.4. Implementation of Increased Tributary Sampling Effort in 2014 .....................2
3. Results of Comparison of sampling protocols in the Black River .................................3
3.1. Fish Distribution ................................................................................................3
3.1.1. Species Richness ............................................................................................... 3
3.2. Relative Fish Abundance ...................................................................................4
3.2.1. CPUE ................................................................................................................ 4
3.3. Fish-Habitat Associations ..................................................................................6
4. Discussion............................................................................................................................6
5. Literature Cited .................................................................................................................7
6. Tables ..................................................................................................................................9
7. Figures ...............................................................................................................................21
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
LIST OF TABLES
Table 2.3-1. 2013-2014 tributary sampling summary and proposed future Upper River tributary
sampling length targets. .......................................................................................................... 9
Table 2.4-1. Black River sample unit length (meters) by tributary channel /macrohabitat and
mesohabitat type for GRTS sampling approach 2013 and 2014. ......................................... 10
Table 2.4-2. Black River mesohabitat unit count (number of replicate mesohabitat units) by
tributary macrohabitat and mesohabitat type for GRTS sampling approach 2013 and 2014.
............................................................................................................................................... 11
Table 3.1-1. Total observations of fish species in the Black River by habitat category using full
and subsampling approaches during 2014. ........................................................................... 12
Table 3.1-2. Summary of sampling sufficiency measures for the Black River in 2013 and 2014.
............................................................................................................................................... 13
Table 3.2-1. Summary of juvenile Arctic grayling CPUE for backpack electrofishing in fish/hour
by habitat type in the Black River for three sampling periods in 2014. ............................... 13
Table 3.2-2. Summary of subadult/adult Arctic grayling CPUE for backpack electrofishing in
fish/hour by habitat type in the Black River for three sampling periods in 2014. ................ 14
Table 3.2-3. Summary of total Arctic grayling CPUE for backpack electrofishing in fish/hour by
habitat type in the Black River for three sampling periods in 2014. .................................... 15
Table 3.2-4. Summary of juvenile burbot CPUE for backpack electrofishing in fish/hour by
habitat type in the Black River for three sampling periods in 2014. .................................... 16
Table 3.2-5. Summary of subadult/adult burbot CPUE for backpack electrofishing in fish/hour by
habitat type in the Black River for three sampling periods in 2014. .................................... 17
Table 3.2-6. Summary of total burbot CPUE for backpack electrofishing in fish/hour by habitat
type in the Black River for three sampling periods in 2014. ................................................ 18
Table 3.2-7. Summary of total sculpin CPUE for backpack electrofishing in fish/hour by habitat
type in the Black River for three sampling periods in 2014. ................................................ 19
Table 3.3-1. Total observations of fish species in the Black River by season and mesohabitat type
using full and subsampling approaches during 2014. ........................................................... 20
LIST OF FIGURES
Figure 3.1-1. Species accumulation curves from the Black River GRTS sampling sites during
full and subsampling in 2014. ............................................................................................... 21
Figure 3.2-1. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River
based on CPUE for backpack electrofishing in fish/hour for juvenile Arctic grayling during
three sampling events. ........................................................................................................... 22
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-2. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River
based on CPUE for backpack electrofishing in fish/hour for subadult/adult Arctic grayling
during three sampling events. ............................................................................................... 23
Figure 3.2-3. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River
based on CPUE for backpack electrofishing in fish/hour for total Arctic grayling during
three sampling events. ........................................................................................................... 24
Figure 3.2-4. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River
based on CPUE for backpack electrofishing in fish/hour for juvenile burbot during three
sampling events. .................................................................................................................... 25
Figure 3.2-5. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River
based on CPUE for backpack electrofishing in fish/hour for subadult/adult burbot during
three sampling events. ........................................................................................................... 26
Figure 3.2-6. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River
based on CPUE for backpack electrofishing in fish/hour for total burbot during three
sampling events. .................................................................................................................... 27
Figure 3.2-7. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River
based on CPUE for backpack electrofishing in fish/hour for total sculpin during three
sampling events. .................................................................................................................... 28
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
LIST OF ACRONYMS AND SCIENTIFIC LABELS
Abbreviation Definition
ADF&G Alaska Department of Fish and Game
AEA Alaska Energy Authority
CPUE Catch per unit effort
CW Channel width
FDA UP Study of Fish Distribution and Abundance in the Upper Susitna River
FERC Federal Eneregy Regulatory Commission
GRTS Generalized random tessellation stratified sampling
IP Implementation Plan
ISR Initial Study Report
km Kilometer
km2 Square kilometers
m Meter
MC Main Channel
Mi Mile
mi2 Square miles
OC Off-Channel
OCH Off-Channel Habitat
PRM Project river mile
RSP Revised Study Plan
SE Standard Error
SPD Study Plan Determination
SR Species richness
TSR True species richness
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
1. INTRODUCTION
In 2013, AEA’s study teams conducted the first year of data collection for the Fish Distribution
and Abundance in the Upper Susitna River Study (Study 9.5). Objective 1 of the Study of Fish
Distribution and Abundance in the Upper Susitna River was to describe the seasonal distribution,
relative abundance (as determined by catch per unit effort [CPUE], fish density, and counts), and
fish-habitat associations of resident fishes, juvenile anadromous salmonids, and the freshwater
life stages of non-salmon anadromous species (RSP Section 9.5.1; AEA 2012). Sampling in
2013 was effective at documenting fish distribution (Task A). Relative abundance estimates
were effectively generated for all sampled habitats (Task B). However, analysis of habitat
associations (Task C) was limited by the low number of off-channel habitats in the mainstem
Susitna River and the low number of rare habitat types in Upper River tributaries.
Modifications to the Study Plan were presented in Part C, Section 7 of the Initial Study Report
(ISR ) filed with FERC June 3, 2014 (AEA 2014a). AEA implemented the following proposed
modifications in 2014 to gather additional information; to meet study plan objectives; and better
inform the second study year. This technical memorandum describes how the modifications to
the Study of Fish Distribution and Abundance in the Upper Susitna River (Study 9.5) outlined in
the ISR were applied to the Black River during the 2014 study year.
In response to the October 2014 ISR meetings, AEA informed the licensing participants that
AEA would be filing this TM with the Commission ahead of the January 2015 ISR meetings.
2. SAMPLING DECISION: INCREASED SAMPLING EFFORT IN
SELECT UPPER RIVER TRIBUTARIES
2.1. Sampling in 2013
The April 2013 FERC Study Plan Determination (SPD) recommended scaling sampling in
proportion to stream size (FERC 2013, p. B-124). To achieve a spatially-balanced and random
sample of fish habitats within Upper River tributaries, the length of the tributaries were divided
into sampling panels that were 200, 400, or 800 m long, depending on the tributary drainage
area, and the required percentage of stream length was sampled using a generalized random
tessellation stratified (GRTS) sampling methodology. The original sampling plan (ISR 9.5
Section 4.1.2.1) was to survey the GRTS panel for mesohabitat types, and to select one unit of
each mesohabitat type and sample 40 m (131 ft) of each selected unit. The FERC SPD
recommended all the classified mesohabitat units be sampled. However, logistical constraints in
2013 required sub-sampling 100 m (328 ft)-long units within GRTS panels. Specifically, within
a selected GRTS panel, fish sampling occurred in either a complete mesohabitat unit or up to 00
m (656328 ft) per mesohabitat for each mesohabitat type present (ISR 9.5 Section 7.1.2.4).
2.2. Measures of Sampling Sufficiency
Post-season analysis indicated that the 2013 tributary sampling program was effective at
documenting the fish species present within Upper River tributaries. The analysis consisted of
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
comparing the total number of species found in a tributary, referred as observed species richness
(SR), and an estimate of true species richness (TSR) in a tributary (Cochran 1977).
However, as indicated in Section 7.1.2.4 of Study 9.5 Initial Study Report (AEA 2014b), the
2013 sub-sampling may have been inconsistent with the intent of the April 2013 FERC SPD,
with smaller basins receiving proportionally more effort, and larger basins receiving
proportionally less. In addition, a post-2013 field season review of the remote video within each
GRTS panel indicated that there were some habitat types that were under-represented in 2013
fish sampling and the fish-habitat association analysis likely would benefit from additional
replicates.
Sampling sufficiency for characterizing fish distribution is often evaluated in relation to channel
width (Paller 1995, Patton et al. 2000, Hughes et al. 2002, Maret and Ott 2003, Reynolds et al.
2003, Kirsch et al. 2014). Fish sampling and habitat surveys completed in 2013 provided
channel width information that was not available to incorporate into the Implementation Plan
(AEA 2013). The AEA study team reviewed the 2013 sampling effort in the context of field
measurements of channel width to prioritize additional sampling. Kirsch et al. (2014)
recommended sampling lengths of 40 wetted channel widths for wadeable streams, 120 channel
widths for nonwadeable streams in basins with a watershed area of 100-300 km2 (38.6 – 115.8
mi2), and more than 140 channel widths in nonwadeable streams in larger drainage basins.
2.3. Increased Sampling Effort
AEA proposed to apply the recommendation from Kirsch et al. 2014 for determining the length
of Upper River tributaries to sample during the next year of sampling as described in Upper
River technical memorandum filed September 17, 2014 (R2 Resource Consultants 2014). The
stream-specific sample length changes for all Upper River tributary waters were presented in the
September 2014 technical memorandum and are included in Table 2.3-1 for ease of access.
AEA proposed to maintain the spatial configuration of the original GRTS panel sampling and
apportioned the additional sampling length within the existing panels by selecting the number of
fully-sampled panels necessary to achieve the sampling length target as described in ISR Section
9.5.7.1.2.4. However, in the Black River the total length of main channel habitat within GRTS
panels selected for sampling in 2013 was short target sampling lengths, so two more panels were
added to the 2014 fish surveys.
2.4. Implementation of Increased Tributary Sampling Effort in 2014
As described in ISR Section 9.5.7.1.2.4, AEA implemented the recommended increase in
sampling in the Black River in 2014. The proposed increase in sampling length for the Black
River was more than triple the effort expended in 2013 (Table 2.4-1). In 2013, the 100 m (328
ft) sub-sampling approach occurred in six GRTS panels (Panels 1, 2, 4, 6, 7, 9) and resulted in
sampling of 11 mesohabitat units within 1,050 m (0.65 mi) of sample unit length (Table 2.4-2).
In 2014, sampling the full length of all available main channel mesohabitats and 20x wetted-
widths of off-channel habitats present within in the same six panels resulted in 19 mesohabitat
units for a total length of 2,724 m (1.69 mi) sampled (Table 2.4-2). In order to achieve the target
length of 3,178 m (1.97 mi) of recommended sampling (Table 2.3-1), two additional 400 m
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
panels were added using the GRTS methodology (Panels 3 and 5). These eight panels also
included 402 m of off-channel habitats so the total effort in 2014 completed surveys in 28
mesohabitat units for a total of 3,619 m (2.25 mi).
3. RESULTS OF COMPARISON OF SAMPLING PROTOCOLS IN
THE BLACK RIVER
The 2014 sampling was conducted so as to first replicate the 2013 survey length and then extend
the sampling to the full targeted sample length. Breaking the data in this way facilitated
comparison between the subsample and full sample approaches and avoided concerns about
interannual variability of data that could result from comparing 2013 and 2014 data sets. For the
remainder of the memorandum, the replicated data set is referred to as the 2014 subsample while
the data collected from the fully expanded effort is referred to as the ‘full sample’. The purpose
of such a comparison was to determine if completing the full sampling approach improved
AEA’s ability to meet study objectives. The evaluation that follows is based on various species
metrics including fish distribution, species richness, relative abundance, and fish-habitat
associations.
3.1. Fish Distribution
Five fish species were identified in the Black River system during the full 2014 sampling effort:
Arctic grayling (Thymallus arcticus), burbot (Lota lota), longnose sucker (Catostomus
catostomus), sculpin (Cottid sp.), and round whitefish (Prosopium cylindraceum) (Table 3.1-1).
These species represent resident salmonid or non-salmonid functional groups and all were
observed previously in the Black River. Notably absent in 2014, were anadromous juvenile
Chinook salmon (Oncorhynchus tshawytscha), observed in Black River during subsampling in
2013.
In replicating the 2013 survey effort, the 2014 subsample resulted in the collection of three of the
five species documented: Arctic grayling, burbot, and sculpin. Longnose sucker and round
whitefish were found in the extended survey length in low numbers; only1 longnose sucker and 5
whitefish were observed out of 3,193 total fish observations (Table 3.1-1). Due to their relative
rarity in the Black River habitats, the subsampling approach was insufficient to reliably detect
these species.
3.1.1. Species Richness
The observed species richness (SR), or the total number of species found in the Black River in
2014, and an estimate of true species richness (TSR) following the concepts of Cochran (1977)
were used as measures of sampling sufficiency, indicative of the success of the full and
subsampling approaches in detecting species’ presence. The SR and TSR values, and when these
metrics were first achieved within the GRTS panel matrix, are shown in Table 3.1-2 and depicted
in Figure 3.1-1. As discussed above, the observed SR from the full sample was five species
collected from eight GRTS panels. The five species were detected within the first two GRTS
panels. The estimated TSR for the Black River was 5.6 species. The subsample returned only
three species from six GRTS panels and all three were detected in the first site. The SR and TSR
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
were both calculated at 3.0 fish for the subsampling effort. These calculations highlight the
limitations of this analysis when all species are either very common (observed at all six sites) or
very rare (never observed).
3.2. Relative Fish Abundance
Fish counts across all sites, mesohabitats, sampling methods, and seasons are shown in Table
3.1-1 for the full and subsamples. Sculpin dominated the catches followed by Arctic grayling,
and burbot using both the full and sub-sampling methods. Since the full sample effort totaled 3.4
times the stream distance of the subsampling (3,619/1,050m = 3.4x), it was expected that the
numeric factor between fish counts of fish from the two approaches should be in the range of
3.4x (or conversely, the subsample ran slightly less than 30 percent of the full sample). As
expected, the count expansion factors for Arctic grayling, burbot, and sculpin ranged between
2.7 and 3.9x (Table 3.1-1). This finding suggests the subsampling approach provided consistent
information compared to the full sampling regarding the most abundant species.
3.2.1. CPUE
Fish abundance information can be somewhat biased as a function of sampling gear type and the
level of effort expended during the surveys. For this reason fish counts are often reported in
terms of relative fish abundance and the counts are normalized with respect to effort. For
comparative purposes, catch per unit of effort (CPUE) was calculated for the most frequently
used sampling technique performed during the 2014 surveys, backpack electrofishing.
Analyses were conducted for the three species most often observed, with several lifestage
groupings:
• Arctic grayling juveniles, subadult/adults, and total of all lifestages,
• Burbot juveniles, subadults/adults, and total of all lifestages, and
• Sculpin total of all lifestages.
CPUE was estimated as catch per hour of shocking time for each species/lifestage combination
within each mesohabitat unit sampled using backpack electrofishing. Mesohabitats were the
primary mesohabitat sampling units and were sampled as clusters defined by GRTS panels.
Average CPUE and the associated standard error (SE) for each mesohabitat type was estimated
using a combined ratio estimate (Cocharn 1977). Calculations were performed with package
survey (Lumley 2004, Lumley 2014) in the statistical software R (version 3.1.1; R Core Team
2014).
CPUE for backpack electrofishing results by mesohabitat type and sampling events (seasons) are
shown in Tables 3.2-1 through 3.2-7. The mean, standard error, and number of replicate
mesohabitat units sampled for the full and subsampling approaches are shown in each of the
tables. Boxplots comparing the subsample and the full sample CPUE results for the three species
and three sampling events, early summer, late summer, and fall are presented by habitat type and
life history stage in Figures 3.2-1 to 3.2-7.
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3.2.1.1. Arctic Grayling
The CPUE for juvenile Arctic grayling ranged between 0 and 10 fish/hr during the full sample
survey depending on habitat type. The same metric for the subsample ranged from 0 to 11
fish/hr. The CPUE results were nearly identical for all habitat types and all seasons during the
full and subsample surveys (Table 3.2-1, Figure 3.2-1). The standard errors were generally
lower for the full sample, as expected due to increased sampling. This finding suggests that the
main benefit for an expanded sampling effort for juvenile Arctic grayling in terms of relative
abundance was an increase in precision.
Given the lower abundances of subadult and adult life stages, it appears the grayling capture rate
was slightly greater in the full sample compared to the subsample for boulder riffle, rapid, and
upland slough habitats (Table 3.2-2, Figure 3.2-2). A small improvement in accuracy of relative
abundance for the full sample was apparent for subadult/adult Arctic grayling.
The total CPUE for all Arctic grayling, regardless of life history stage, indicated similar findings
as for the juvenile grayling. Since juveniles comprise at least 63 percent of this total, and since
the added benefit ascribed to the subadult/adult class was small, the full sampling effort did not
provide considerable improvement in CPUE accuracy for this species compared to what could be
determined from the subsample (Table 3.2-3, Figure 3.2-3). However, there were improvements
in precision of the estimates, which can be helpful in comparing abundance among habitats.
3.2.1.2. Burbot
The CPUE for juvenile burbot ranged between 0 and 4 fish/hr during the full sample survey and
from 0 to 8 fish/hr for the subsample. The mean CPUE results differed between the full and
subsampling surveys (Table 3.2-4, Figure 3.2-4). This finding suggests there may have been
added benefit in accuracy as well as precision (reduced SE estimates) for the full sample effort
for juvenile burbot.
There were no adult and very few subadult burbot captured during 2014 by any of the sampling
approaches. Given the rare occurrences of this life history stage, it appears the burbot capture
rate was slightly greater during the full sample compared to the subsample for boulder riffle, and
rapid habitats (Table 3.2-5; Figure 3.2-5). A small added benefit for the full sample effort was
apparent for subadult burbot.
The total CPUE for all burbot, regardless of life history stage, indicated similar findings as the
juvenile burbot. Small gains in accuracy and precision during the full sample were observed,
particularly in riffle habitats and in the rapid habitat that was not sampled in the subsample
approach (Table 3.2-6, Figure 3.2-6).
3.2.1.3. Sculpin
Sculpin were the most abundant species observed during the surveys. Given the small overall
size of the sculpin, the total of all life histories was evaluated for this species.
The mean CPUE for sculpin ranged between 23 and 82 fish/hr during the full sample survey and
from 37 to 91 fish/hr for the subsample. In some habitats, the CPUE data show large differences
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
in mean estimates between the full and subsample methods, but the mean estimates using the full
sample methodology were not always higher or lower (Table 3.2-7, Figure 3.2-7). Thus, the
subsample did not result in consistently biased estimates of average CPUE. Precision, however,
was substantially better (lower SE) with the full compared to the subsampling approach, with a
few exceptions. In these few cases when the subsampling method offered lower standard errors
than the full survey, the sample size was very small and likely resulted in an underestimate in the
overall variability in CPUE. The full sample resulted in more realistic variability measurements
and better precision in estimating CPUE for sculping. This finding suggests that the only added
benefit for an expanded sampling effort for sculpin is in small increases in estimating error.
3.3. Fish-Habitat Associations
For consistency with the ISR (AEA 2014), this section documents the total observations (counts)
of fish species and life history types among mesohabitats during the 2014 sub- and full sampling.
The total observations of fish species in the Black River system by season and macrohabitat type
are presented in Table 3.3-1. When these count data are reviewed simultaneously with the
increased sampling of mesohabitats depicted in Tables 3.2-1 and 3.2-2 (taken from R2 Resource
Consulants 2014), it is clear that the 2014 sampling effort resulted in increased replicates of fish
counts across habitats, including rarer habitats. This increased replication will better support a
full evaluation of fish-habitat association for the USR once the study modification is
implemented in Upper River tributaries during the next year of study.
In addition, some general observations based on fish counts by habitat, including seasonal shifts
in habitat associations as fish grew and matured and as water temperature declined are presented
below.
• Highest counts of Arctic grayling, sculpin, and burbot were in boulder riffle habitat,
followed closely by counts in run/glide habitat
• Arctic grayling counts lowest in upland slough habitat
• Overall trend for Arctic grayling, sculpin, and burbot was for reduced counts from
summer to fall
• Patterns in habitat associations were similar across life stages for Arctic grayling
• Sculpin found in all habitat types sampled
• Round whitefish and longnose sucker were rare in all Black River mesohabitats
4. DISCUSSION
This technical memorandum was prepared to assess whether additional sampling effort improved
AEA’s ability to meet study objectives including fish distribution, relative abundance, or habitat
associations in the Black River. The subsampling approach performed adequately where species
and habitats were abundant. The expanded, full sampling approach provided the greatest return
with respect to rare habitats and rare species and, thus, confirms the adequacy of the ISR
proposed modification. Thus, AEA recommends continuing future surveys using the full
sampling approach. After successfully implementing the full sampling approach in the Black
River, AEA recommends adopting the tributary sampling modifications and targets from the
Initial Study Report 7.1.2.4, as summarized in Section 2.3 above.
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
In applying this modified approach, the sampling length in all but one tributary would be
maintained or increased beyond that accomplished in 2013 (R2 Resource Consultants 2014).
The sample length for each tributary will be developed for the length of main-channel to be
sampled and will be accomplished by sampling the fewest number of GRTS panels possible to
accommodate the target length. The use of the GRTS panel process for selection will ensure that
survey sites are spatially balanced throughout the mainstem. In addition, because the target
lengths are based on main channel panels, the length of off-channel habitat surveyed will be in
addition to the length of sample targets, as was evident for the Black River in 2014. As the
application of this modification in the Black River has shown, this modified approach will allow
for inclusion of additional mesohabitat replicates and will improve AEA’s ability to discuss fish
use of habitats for rare species and habitats in Upper River tributaries.
5. LITERATURE CITED
Alaska Energy Authority (AEA). 2012. Revised Study Plan: Susitna-Watana Hydroelectric
Project FERC Project No. 14241. December 2012. Prepared for the Federal Energy
Regulatory Commission by the Alaska Energy Authority, Anchorage,
Alaska. http://www.susitna-watanahydro.org/study-plan.
Alaska Energy Authority (AEA). 2013. Final Susitna River Fish Distribution and Abundance
Implementation Plan: Susitna-Watana Hydroelectric Project FERC Project No.
14241. March 2013. Prepared for the Federal Energy Regulatory Commission by the
Alaska Energy Authority, Anchorage, Alaska. http://www.susitna-watanahydro.org/wp-
content/uploads/2013/03/Attachment-A.pdf.
Alaska Energy Authority. 2014a. Initial Study Report, Salmon Escapement Study, Study Plan
Section 9.5, Part C Susitna-Watana Hydroelectric Project, FERC Project No. 14241.
June 2014. Anchorage, Alaska. http://www.susitna watanahydro.org/type/documents.
Alaska Energy Authority (AEA). 2014b. Initial Study Report: Susitna-Watana Hydroelectric
Project FERC Project No. 14241. June 2014. Prepared for the Federal Energy
Regulatory Commission by the Alaska Energy Authority, Anchorage,
Alaska. http://www.susitna-watanahydro.org/type/documents.
Cochran, W.G. 1977. Sampling Techniques. Third Edition. John Wiley & Sons, New York.
Federal Energy Regulatory Commission (FERC), Office of Energy Projects. 2013. Study Plan
Determination for the Susitna-Watana Hydroelectric Project. Federal Energy Regulatory
Commission, Washington, D.C. Issuance: 20130201-3041.
Hughes, R.M., P.R. Kaufmann, A.T. Herlihy, S.S. Intelmann, S.C. Corbett, M.C. Arbogast and
R.C. Hjort. 2002. Electrofishing Distance Needed to Estimate Fish Species Richness in
Raftable Oregon Rivers. North American Journal of Fisheries Management. 22(4).
Kirsch, J.M., J.D. Buckwalter, and D.J. Reed. 2014. Fish inventory and anadromous cataloging
in the Susitna River, Matanuska River, and Knik River basins, 2003 and 2011. Alaska
Department of Fish and Game, Fishery Data Series No. 14-04, Anchorage.
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 7 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Lumley, T. (2004). Analysis of complex survey samples. Journal of Statistical Software 9(1): 1-
19.
Lumley, T. (2014). “survey: analysis of complex survey samples”. R package version 3.30.
Maret, T.R. and D.S. Ott. 2003. Assessment of fish assemblages and minimum sampling effort
required to determine biotic integrity of large river in southern Idaho, 2002: U.S.
Geological Survey Water-Resources Investigations Report 2003-4274, 16 p.
Paller, M.H. 1995. Relationships among number of fish species sampled, reach length surveyed,
and sampling effort in South Carolina Coastal Plain streams. North American Journal of
Fisheries Management. 15: 110–120.
Patton, T.M., Hubert, W.A., Rahel, F.J., and Gerow, K.G. 2000. Effort needed to estimate
species richness in small streams on the Great Plains in Wyoming. North American
Journal of Fisheries Management 20: 394–398.
R Core Team (2014). R: A language and environment for statistical computing. R Foundation
for Statistical Computing, Vienna, Austria. URL http://www.R-project.org/.
R2 Resource Consultants, Inc. 2014. Proposed 2015 Modifications to Fish Distribution and
Abundance Study Plan Implementation Technical Memorandum. Susitna-Watana
Hydroelectric Project. September 2014.
Reynolds, L., A.T. Herlihy, P.R. Kaufmann, S.V. Gregory, and R.M. Hughes. 2003.
Electrofishing effort requirements for assessing species richness and biotic integrity in
western Oregon streams. North American Journal of Fisheries Management 23(2): 450-
461.
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 8 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
6. TABLES
Table 2.3-1. 2013-2014 tributary sampling summary and proposed future Upper River tributary sampling length targets.
GRTS Sampled Tributaries
Drainage
Basin
Area (km2)
Chinook
salmon
presence
GRTS
Sampling
Unit Size
(m)
Number of
GRTS
Population
Sample Units
Number
of 2013
Sample
Sites
Number of
mesohabitats
sampled 2013
Meters
Sampled
2013
% Sampled
2013
Number of
mesohabitats
sampled 2014
Meters
sampled
2014
Average
Wetted
width (m)
Channel
Widths
Sampled
2013
Kirsch et
al. 2014
target (CW)
Kirsch et
al. 2014
target (m)
Kirsch et
al. 2014
target (%)
Proposed
Change (m)
Oshetna River (PRM 235.1)1424.5 yes 800 52 13 28 2,604 6%----36 73 140 5,026 12%2,422
Black River NA no 400 24 6 11 1,050 11%28 3619 23 46 140 3,178 33%2,128
Goose Creek (PRM 232.8)269.1 no 200 81 20 38 3,107 19%----14 219 120 1,704 11%-1,403
Kosina Creek (PRM 209.1)1036.5 yes 800 24 6 10 1,000 5%----32 31 120 4,522 24%3,522
Tsisi Creek NA no 400 23 6 10 980 11%----14 69 140 1,988 22%1,008
Watana Creek (PRM 196.9)452.7 yes 400 60 15 30 2,561 11%----11 231 140 1,554 6%--
Watana Creek Tributary NA no 200 67 13 18 1,459 11%----10 154 140 1,330 10%--
Unnamed Tributary (PRM 194.8)321.2 no 400 32 2 4 300 2%----3 88 140 476 4%176
GRTS Total ------454 81 149 13,061 8%--------19,778 12%7,853
Jay Creek (PRM 211)160.1 no NA --NA 8 324 --14 ----------
Unnamed Tributary (PRM 206.3)<80.3 no NA --NA ------3 263 6.9 --------Direct
Unnamed Tributary (PRM 204.5)<80.3 no NA --NA ------2 330 4.5 --------Direct
Unnamed Tributary (PRM 197.7)<80.3 no NA --NA ------5 358 7.1 --------Direct
Deadman Creek (PRM 189.4)453.5 no NA --NA ------5 357 28.4 ----------
Direct Sample Total ----------8 324 --15 1,308 ------------
Direct sample Tributaries
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 9 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 2.4-1. Black River sample unit length (meters) by tributary channel /macrohabitat and mesohabitat type for GRTS sampling approach 2013 and 2014.
Trib Hab Type
Trib MC/OC HabType Secondary Secondary Tertiary
Mesohabitat
Boulder riffleRapidRun/GlideBoulder riffleRiffleRun/GlideRun/GlideBoulder riffleRun/GlideRiffleRun/GlideBoulder RifflePool Run/GlideBlack River: Panel 01 100 100 100 100 200
Black River: Panel 02 100 100 200 100 100 300
Black River: Panel 04 100 100 100
Black River: Panel 06 100 100 50 250 250
Black River: Panel 07 100 100 100
Black River: Panel 09 100 100 100
300 - 100 400 100 - 100 50 250 - 100 100 - 200 - - 100 100 200 1,050
Black River: Panel 01 104 296 400 127 127 527
Black River: Panel 02 100 245 345 55 55 140 140 540
Black River: Panel 03 43 282 75 400 51 44 95 495
Black River: Panel 04 90 90 310 310 40 40 440
Black River: Panel 05 400 400 400
Black River: Panel 06 150 100 250 100 100 50 50 400
Black River: Panel 07 210 190 400 17 17 417
Black River: Panel 09 280 280 120 120 400
787 562 471 1,820 100 100 555 17 772 520 50 55 - 625 51 44 127 180 402 3,619
Grand
Total
Primary Primary Tributary Upland Slough
Split Channel
Split
Total
Complex
Total
Complex Channel
Year
Off-Channel Habitat
OCH
Total
Single
Total
Main Channel
Single Channel
20132013 Total 20142014 Total
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 2.4-2. Black River mesohabitat unit count (number of replicate mesohabitat units) by tributary macrohabitat and mesohabitat type for GRTS sampling approach 2013 and 2014.
Tributary Habitat Type
Trib MC/OC HabType Secondary Secondary Tertiary
Mesohabitat
Boulder riffleRapidRun/GlideBoulder riffleRiffleRun/GlideRun/GlideBoulder riffleRun/GlideRiffleRun/GlideBoulder RifflePool Run/GlideBlack River: Panel 01 1 1 1 1 2
Black River: Panel 02 1 1 2 1 1 3
Black River: Panel 04 1 1 1
Black River: Panel 06 1 1 1 3 3
Black River: Panel 07 1 1 1
Black River: Panel 09 1 1 1
3 - 1 4 1 - 1 1 3 - 1 1 - 2 - - 1 1 2 11
Black River: Panel 01 1 1 2 1 1 3
Black River: Panel 02 1 1 2 1 1 1 1 4
Black River: Panel 03 1 2 2 5 2 1 3 8
Black River: Panel 04 1 1 1 1 1 1 3
Black River: Panel 05 1 1 1
Black River: Panel 06 1 1 2 1 1 1 1 4
Black River: Panel 07 1 1 2 1 1 3
Black River: Panel 09 1 1 1 1 2
5 4 4 13 1 1 2 1 5 2 1 1 - 4 2 1 1 2 6 28 201320142013 Total
2014 Total
Complex
Total
Off-Channel Habitat
OCH
Total
Grand
Total
Main Channel Primary Primary Tributary Upland Slough
Year
Single Channel
Single
Total
Split Channel
Split
Total
Complex Channel
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 11 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.1-1. Total observations of fish species in the Black River by habitat category using full and subsampling approaches during 2014.
Habitat
Category
2014 Full Samplea
2014 Subsamplea
Burbot Arctic
Grayling
Longnose
Sucker
Sculpin
Sp.
Round
Whitefish
b
Burbot Arctic
Grayling
Longnose
Sucker
Sculpin
Sp.
Round
Whitefishb
Black River
Mainstem 101 422 0 2,147 5 37 122 0 736 0
Unnamed
Tributary 3 52 0 206 0 NS NS NS NS NS
Upland
Slough 9 10 1 237 0 5 2 0 207 0
Total
Observations 113 484 1 2,590 5 42 124 0 943 0
Factor (Full/
subsample) 2.7 3.9 - 2.7 - 0.37 0.26 - 0.36 -
a Counts from all sampling methods
b Whitefish total includes unidentified species
NS = Not surveyed during 2014 under the subsampling approach
0 = Surveyed in 2014 without any recorded fish observations by any of the collection
methods
Susitna-Watana Hydroelectric Project Alaska Energy Authority
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.1-2. Summary of sampling sufficiency measures for the Black River in 2013 and 2014.
Upper River Tributary
Number
of
Sample
Sites
SRa
Site when
SR first
observed
TSR H-Tb
Site when
TSRH-T -1
first
observed
TSRH-T
minus SR
Percent of
TSR
observed
Black River Subsample 2013 6 6 3 6.6 3 0.6 91%
Black River Subsample 2014 6 3 1 3.0 1 0.0 100%
Black River Full Sample 2014 8 5 2 5.6 2 0.6 89%
a Observed species richness - the total number of species found in a tributary
b Horvitz-Thompson estimate (Cochran 1977) of the true species richness in a tributary
Table 3.2-1. Summary of juvenile Arctic grayling CPUE for backpack electrofishing in fish/hour by habitat type in the Black River for three sampling periods in 2014.
Arctic Grayling Juveniles
2014 Full Sample 2014 Subsample
Number of Units1 Mean SE Number of Units1 Mean SE
Boulder Riffle
Early Summer 12 5.9 1.3 4 5.0 2.9
Late Summer 11 9.9 1.9 4 11.0 0.4
Fall 14 5.2 1.2 4 3.8 1.2
Run/Glide
Early Summer 9 9.1 3.0 4 7.6 3.2
Late Summer 11 4.9 1.1 6 5.9 2.9
Fall 9 3.4 1.1 4 5.1 1.7
Rapids
Early Summer 4 6.6 2.9 0 n/a n/a
Late Summer 4 1.4 1.7 0 n/a n/a
Fall 2 7.8 1.1 0 n/a n/a
Riffles
Early Summer 2 2.3 n/a 1 4.6 n/a
Late Summer 1 0.0 n/a 0 n/a n/a
Fall 2 9.3 n/a 1 7.0 n/a
Upland Sloughs
(Pools + Run/Glide)
Early Summer 5 0.7 0.5 2 0.0 n/a
Late Summer 4 0.0 0.0 2 0.0 n/a
Fall 4 1.4 0.9 2 2.9 2.5
1Replicate mesohabitat units
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 13 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.2-2. Summary of subadult/adult Arctic grayling CPUE for backpack electrofishing in fish/hour by habitat type in the Black River for three sampling periods in 2014.
Arctic Grayling Subadults/Adults
2014 Full Sample 2014 Subsample
Number of Units1 Mean SE Number of Units1 Mean SE
Boulder Riffle
Early Summer 12 1.6 0.84 4 0.4 0.36
Late Summer 11 1.0 0.38 4 0.0 n/a
Fall 14 0.6 0.23 4 0.6 0.50
Run/Glide
Early Summer 9 1.1 0.51 4 1.8 0.63
Late Summer 11 0.0 n/a 6 0.0 n/a
Fall 9 0.4 0.30 4 0.0 n/a
Rapids
Early Summer 4 5.2 2.00 0 n/a n/a
Late Summer 4 0.0 n/a 0 n/a n/a
Fall 2 0.0 n/a 0 n/a n/a
Riffles
Early Summer 2 0.7 n/a 1 0.0 n/a
Late Summer 1 0.0 n/a 0 n/a n/a
Fall 2 0.0 n/a 1 0.0 n/a
Upland Sloughs
(Pools + Run/Glide)
Early Summer 5 0.7 0.54 2 0.0 n/a
Late Summer 4 0.0 n/a 2 0.0 n/a
Fall 4 0.0 n/a 2 0.0 n/a
1Replicate mesohabitat units
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 14 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.2-3. Summary of total Arctic grayling CPUE for backpack electrofishing in fish/hour by habitat type in the Black River for three sampling periods in 2014.
Arctic Grayling Total
2014 Full Sample 2014 Subsample
Number of Units1 Mean SE Number of Units1 Mean SE
Boulder Riffle
Early Summer 12 7.5 1.7 4 5.4 3.0
Late Summer 11 11.0 1.8 4 11.0 0.4
Fall 14 5.8 1.3 4 4.4 1.4
Run/Glide
Early Summer 9 10.0 2.9 4 9.4 3.1
Late Summer 11 4.9 1.1 6 5.9 2.9
Fall 9 3.8 1.3 4 5.1 1.7
Rapids
Early Summer 4 12.0 3.7 0 n/a n/a
Late Summer 4 1.4 1.7 0 n/a n/a
Fall 2 7.8 1.1 0 n/a n/a
Riffles
Early Summer 2 3.0 n/a 1 4.6 n/a
Late Summer 1 0.0 n/a 0 n/a n/a
Fall 2 9.3 n/a 1 7.0 n/a
Upland Sloughs
(Pools + Run/Glide)
Early Summer 5 1.5 1.1 2 0.0 n/a
Late Summer 4 0.0 n/a 2 0.0 n/a
Fall 4 1.4 0.9 2 2.9 2.5
1Replicate mesohabitat units
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 15 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.2-4. Summary of juvenile burbot CPUE for backpack electrofishing in fish/hour by habitat type in the Black River for three sampling periods in 2014.
Burbot Juveniles
2014 Full Sample 2014 Subsample
Number of Units1 Mean SE Number of Units1 Mean SE
Boulder Riffle
Early Summer 12 2.1 0.52 4 2.9 1.0
Late Summer 11 4.3 1.20 4 8.3 2.7
Fall 14 1.2 0.29 4 2.4 0.7
Run/Glide
Early Summer 9 2.4 0.92 4 3.0 2.0
Late Summer 11 0.7 0.35 6 0.4 0.2
Fall 9 0.0 n/a 4 0.0 n/a
Rapids
Early Summer 4 4.4 3.30 0 n/a n/a
Late Summer 4 1.4 1.70 0 n/a n/a
Fall 2 0.0 n/a 0 n/a n/a
Riffles
Early Summer 2 0.7 n/a 1 0.0 n/a
Late Summer 1 3.3 n/a 0 n/a n/a
Fall 2 0.0 n/a 1 0.0 n/a
Upland Sloughs
(Pools + Run/Glide)
Early Summer 5 0.9 0.69 2 2.3 2.0
Late Summer 4 0.0 n/a 2 0.0 n/a
Fall 4 1.1 0.99 2 2.1 1.9
1Replicate mesohabitat units
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 16 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.2-5. Summary of subadult/adult burbot CPUE for backpack electrofishing in fish/hour by habitat type in the Black River for three sampling periods in 2014.
Burbot Subadults/adults1
2014 Full Sample 2014 Subsample
Number of Units1 Mean SE Number of Units2 Mean SE
Boulder Riffle
Early Summer 12 0.4 0.32 4 0.0 n/a
Late Summer 11 0.1 0.08 4 0.0 n/a
Fall 14 0.0 n/a 4 0.0 n/a
Run/Glide
Early Summer 9 0.0 n/a 4 0.0 n/a
Late Summer 11 0.0 n/a 6 0.0 n/a
Fall 9 0.0 n/a 4 0.0 n/a
Rapids
Early Summer 4 1.1 0.66 0 n/a n/a
Late Summer 4 0.0 n/a 0 n/a n/a
Fall 2 0.0 n/a 0 n/a n/a
Riffles
Early Summer 2 0.0 n/a 1 0.0 n/a
Late Summer 1 0.0 n/a 0 n/a n/a
Fall 2 0.0 n/a 1 0.0 n/a
Upland Sloughs
(Pools + Run/Glide)
Early Summer 5 0.0 n/a 2 0.0 n/a
Late Summer 4 0.0 n/a 2 0.0 n/a
Fall 4 0.0 n/a 2 0.0 n/a
1 No adult burbot were collected. 2Replicate mesohabitat units
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 17 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.2-6. Summary of total burbot CPUE for backpack electrofishing in fish/hour by habitat type in the Black River for three sampling periods in 2014.
Burbot Total
2014 Full Sample 2014 Subsample
Number of Units1 Mean SE Number of Units1 Mean SE
Boulder Riffle
Early Summer 12 3.0 0.96 4 2.9 1.0
Late Summer 11 4.5 1.10 4 8.3 2.7
Fall 14 1.2 0.29 4 2.4 0.8
Run/Glide
Early Summer 9 2.4 0.92 4 3.0 2.0
Late Summer 11 0.7 0.35 6 0.4 0.2
Fall 9 0.0 n/a 4 0,0 n/a
Rapids
Early Summer 4 6.6 2.70 0 n/a n/a
Late Summer 4 1.4 1.70 0 n/a n/a
Fall 2 0.0 n/a 0 n/a n/a
Riffles
Early Summer 2 0.7 n/a 1 0.0 n/a
Late Summer 1 3.3 n/a 0 n/a n/a
Fall 2 0.0 n/a 1 0.0 n/a
Upland Sloughs
(Pools + Run/Glide)
Early Summer 5 0.9 0.69 2 2.3 2.0
Late Summer 4 0.0 n/a 2 0.0 0.0
Fall 4 1.1 0.99 2 2.1 1.9
1Replicate mesohabitat units
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 18 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.2-7. Summary of total sculpin CPUE for backpack electrofishing in fish/hour by habitat type in the Black River for three sampling periods in 2014.
Sculpin Total
2014 Full Sample 2014 Subsample
Number
of Units1 Mean SE
Number
of Units1 Mean SE
Boulder Riffle
Early Summer 12 68 11 4 39 5.3
Late Summer 11 53 9.9 4 77 12
Fall 14 30 5.3 4 37 6.8
Run/Glide
Early Summer 9 69 9.1 4 91 11
Late Summer 11 82 15 6 75 15
Fall 9 51 9.0 4 68 20
Rapids
Early Summer 4 46 12 0 n/a n/a
Late Summer 4 77 1.9 0 n/a n/a
Fall 2 43 15 0 n/a n/a
Riffles
Early Summer 2 52 n/a 1 54 n/a
Late Summer 1 23 n/a 0 n/a n/a
Fall 2 47 n/a 1 52 n/a
Upland Sloughs
(Pools + Run/Glide)
Early Summer 5 35 11 2 63 26
Late Summer 4 35 19 2 70 24
Fall 4 45 15 2 91 5.5
1Replicate mesohabitat units
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 19 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Table 3.3-1. Total observations of fish species in the Black River by season and mesohabitat type using full and subsampling approaches during 2014.
a Counts from all sampling methods
b Whitefish total includes unidentified species
NS = Not surveyed during 2014 under the subsampling approach
0 = Surveyed in 2014 without any recorded fish observations by any of the collection methods
Longnose Sucker Sculpin Sp. Round Whitefishb Longnose Sucker Sculpin Sp. Round Whitefishb
Juvenile All Life Stages Juvenile All Life Stages All Life Stages All Life Stages All Life Stages Juvenile All Life Stages Juvenile All Life Stages All Life Stages All Life Stages All Life Stages
Early Summer 15 27 66 112 0 504 4 6 11 16 21 0 116 0
Late Summer 19 22 62 92 0 331 0 9 9 17 22 0 120 0
Fall 11 14 40 58 0 273 0 4 5 7 11 0 67 0
Early Summer 5 9 10 26 0 65 0 NS NS NS NS NS NS NS
Late Summer 4 4 3 6 0 101 0 NS NS NS NS NS NS NS
Fall 0 0 6 7 0 35 0 NS NS NS NS NS NS NS
Early Summer 2 3 3 5 0 96 1 1 2 3 3 0 48 0
Late Summer 2 2 0 0 0 11 0 NS NS NS NS NS NS NS
Fall 0 0 4 8 0 29 0 0 0 2 6 0 20 0
Early Summer 12 13 26 39 0 239 0 6 7 18 23 0 141 0
Late Summer 6 6 40 50 0 305 0 3 3 19 28 0 142 0
Fall 1 1 14 19 0 158 0 0 0 8 8 0 82 0
Early Summer 2 2 4 5 0 7 0 NS NS NS NS NS NS NS
Fall 0 0 3 5 0 2 0 NS NS NS NS NS NS NS
Late Summer 0 0 3 3 0 8 0 NS NS NS NS NS NS NS
Fall 0 0 0 0 0 4 0 NS NS NS NS NS NS NS
Early Summer 1 1 11 32 0 2 0 NS NS NS NS NS NS NS
Late Summer 0 0 0 0 0 24 0 NS NS NS NS NS NS NS
Fall 0 0 6 7 0 159 0 NS NS NS NS NS NS NS
Early Summer 3 4 1 3 1 62 0 2 2 0 0 0 44 0
Late Summer 0 0 3 4 0 3 0 NS NS NS NS NS NS NS
Fall 1 2 0 1 0 1 0 NS NS NS NS NS NS NS
Early Summer 1 1 0 1 0 45 0 1 1 0 1 0 39 0
Late Summer 1 1 0 0 0 68 0 1 1 0 0 0 68 0
Fall 1 1 1 1 0 58 0 1 1 1 1 0 56 0
Run/Glide
Run/Glide
Riffle
Boulder Riffle
Black River Mainstem
Unnamed Tributary
Upland Slough
StudyPeriodMesohabitat Type
Run/Glide
Pool
Full 2014 Sampling Approacha Subsampling Approacha
Boulder Riffle
Rapid
Riffle
Burbot Arctic Grayling Burbot Arctic Grayling
2014
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 20 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
7. FIGURES
Figure 3.1-1. Species accumulation curves from the Black River GRTS sampling sites during full and subsampling in
2014. Note: The species accumulation curve generated during subsampling in 2013 is provided for reference.
0
1
2
3
4
5
6
7
1 2 3 4 5 6 7 8Cumulative Species Count Site Number
Black River Subsample 2013 Black River Subsample 2014 Black River Full Sample 2014
Susitna-Watana Hydroelectric Project Alaska Energy Authority
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TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-1. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River based on CPUE for backpack
electrofishing in fish/hour for juvenile Arctic grayling during three sampling events. The boxes represent the
interquartile range (i.e., 1st to 3rd quartile of data), the black line in the box is the median. The whiskers extend to the full range of the data unless one or more data points are extreme, in which case these points are plotted separately as
small circles. Box width is proportional to sample size.
Run/Glide
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Boulder Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Rapid
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Upland Slough Pool and Run/G
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 22 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-2. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River based on CPUE for backpack electrofishing in fish/hour for subadult/adult Arctic grayling during three sampling events. The boxes represent the
interquartile range (i.e., 1st to 3rd quartile of data), the black line in the box is the median. The whiskers extend to the full range of the data unless one or more data points are extreme, in which case these points are plotted separately as small circles. Box width is proportional to sample size.
Run/Glide
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
10
12
Boulder Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
10
12
Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
10
12
Rapid
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
10
12
Upland Slough Pool and Run/G
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
10
12
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 23 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-3. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River based on CPUE for backpack electrofishing in fish/hour for total Arctic grayling during three sampling events. The boxes represent the interquartile
range (i.e., 1st to 3rd quartile of data), the black line in the box is the median. The whiskers extend to the full range of the data unless one or more data points are extreme, in which case these points are plotted separately as small circles. Box width is proportional to sample size.
Run/Glide
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Boulder Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Rapid
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Upland Slough Pool and Run/G
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
25
30
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 24 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-4. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River based on CPUE for backpack electrofishing in fish/hour for juvenile burbot during three sampling events. The boxes represent the interquartile range
(i.e., 1st to 3rd quartile of data), the black line in the box is the median. The whiskers extend to the full range of the data unless one or more data points are extreme, in which case these points are plotted separately as small circles. Box width is proportional to sample size.
Run/Glide
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Boulder Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Rapid
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Upland Slough Pool and Run/G
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 25 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-5. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River based on CPUE for backpack electrofishing in fish/hour for subadult/adult burbot during three sampling events. The boxes represent the interquartile
range (i.e., 1st to 3rd quartile of data), the black line in the box is the median. The whiskers extend to the full range of
the data unless one or more data points are extreme, in which case these points are plotted separately as small circles. Box width is proportional to sample size.
Run/Glide
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
Boulder Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
Rapid
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
Upland Slough Pool and Run/G
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
2
4
6
8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 26 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-6. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River based on CPUE for backpack electrofishing in fish/hour for total burbot during three sampling events. The boxes represent the interquartile range
(i.e., 1st to 3rd quartile of data), the black line in the box is the median. The whiskers extend to the full range of the data
unless one or more data points are extreme, in which case these points are plotted separately as small circles. Box width is proportional to sample size.
Run/Glide
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Boulder Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Rapid
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Upland Slough Pool and Run/G
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
5
10
15
20
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 27 December 2014
TECHNICAL MEMORANDUM EVALUATION OF STUDY MODIFICATIONS IN THE BLACK RIVER
Figure 3.2-7. Boxplots comparing 2014 subsampling to 2014 full sample in the Black River based on CPUE for backpack electrofishing in fish/hour for total sculpin during three sampling events. The boxes represent the interquartile range
(i.e., 1st to 3rd quartile of data), the black line in the box is the median. The whiskers extend to the full range of the data
unless one or more data points are extreme, in which case these points are plotted separately as small circles. Box width is proportional to sample size.
Run/Glide
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
50
100
150
200
Boulder Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
50
100
150
200
Riffle
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
50
100
150
200
Rapid
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
50
100
150
200
Upland Slough Pool and Run/G
PEF CPUESub Full Sub Full Sub Full
Early Summer Late Summer Fall
0
50
100
150
200
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 28 December 2014