Seasonal Distribution and Migration of Arctic Grayling in the Gulkana River, 2016–2017

Fishery Data Series No. 19-13

by Corey J. Schwanke and Matt Tyers

December 2019 Alaska Department of Fish and Game Divisions of Sport Fish and Commercial Fisheries Symbols and Abbreviations The following symbols and abbreviations, and others approved for the Système International d'Unités (SI), are used without definition in the following reports by the Divisions of Sport Fish and of Commercial Fisheries: Fishery Manuscripts, Fishery Data Series Reports, Fishery Management Reports, and Special Publications. All others, including deviations from definitions listed below, are noted in the text at first mention, as well as in the titles or footnotes of tables, and in figure or figure captions. Weights and measures (metric) General Mathematics, statistics centimeter cm Alaska Administrative all standard mathematical deciliter dL Code AAC signs, symbols and gram g all commonly accepted abbreviations hectare ha abbreviations e.g., Mr., Mrs., alternate hypothesis HA kilogram kg AM, PM, etc. base of natural logarithm e kilometer km all commonly accepted catch per unit effort CPUE liter L professional titles e.g., Dr., Ph.D., coefficient of variation CV meter m R.N., etc. common test statistics (F, t, χ2, etc.) milliliter mL at @ confidence interval CI millimeter mm compass directions: correlation coefficient east E (multiple) R Weights and measures (English) north N correlation coefficient cubic feet per second ft3/s south S (simple) r foot ft west W covariance cov gallon gal copyright  degree (angular) ° inch in corporate suffixes: degrees of freedom df mile mi Company Co. expected value E nautical mile nmi Corporation Corp. greater than > ounce oz Incorporated Inc. greater than or equal to ≥ pound lb Limited Ltd. harvest per unit effort HPUE quart qt District of Columbia D.C. less than < yard yd et alii (and others) et al. less than or equal to ≤ et cetera (and so forth) etc. logarithm (natural) ln Time and temperature exempli gratia logarithm (base 10) log day d (for example) e.g. logarithm (specify base) log2, etc. degrees Celsius °C Federal Information minute (angular) ' degrees Fahrenheit °F Code FIC not significant NS degrees kelvin K id est (that is) i.e. null hypothesis HO hour h latitude or longitude lat or long percent % minute min monetary symbols probability P second s (U.S.) $, ¢ probability of a type I error months (tables and (rejection of the null Physics and chemistry figures): first three hypothesis when true) α all atomic symbols letters Jan,...,Dec probability of a type II error alternating current AC registered trademark  (acceptance of the null ampere A trademark  hypothesis when false) β calorie cal United States second (angular) " direct current DC (adjective) U.S. standard deviation SD hertz Hz United States of standard error SE horsepower hp America (noun) USA variance hydrogen ion activity pH U.S.C. United States population Var (negative log of) Code sample var parts per million ppm U.S. state use two-letter parts per thousand ppt, abbreviations (e.g., AK, WA) ‰ volts V watts W

FISHERY DATA SERIES NO. 19-13

SEASONAL DISTRIBUTION AND MIGRATION OF ARCTIC GRAYLING IN THE GULKANA RIVER, 2016–2017

Corey J. Schwanke Alaska Department of Fish and Game, Division of Sport Fish, Glennallen

and

Matt Tyers Alaska Department of Fish and Game, Division of Sport Fish, Fairbanks

Alaska Department of Fish and Game Division of Sport Fish, Research and Technical Services 333 Raspberry Road, Anchorage, Alaska, 99518-1565 December 2019

Development and publication of this manuscript were partially financed by the Federal Aid in Sport fish Restoration Act (16 U.S.C.777-777K) under Project F-10-22 and 23, R-3-4(b).

ADF&G Fishery Data Series was established in 1987 for the publication of Division of Sport Fish technically oriented results for a single project or group of closely related projects, and in 2004 became a joint divisional series with the Division of Commercial Fisheries. Fishery Data Series reports are intended for fishery and other technical professionals and are available through the Alaska State Library and on the Internet: http://www.adfg.alaska.gov/sf/publications/. This publication has undergone editorial and peer review.

Corey J. Schwanke Alaska Department of Fish and Game, Division of Sport Fish, Mile 186.3 Glenn Highway, Glennallen, AK 99588-0047, USA

and

Matt Tyers Alaska Department of Fish and Game, Division of Sport Fish, 1300 College Road, Fairbanks, AK 99701-1599, USA

Schwanke, C. J., and M. Tyers. 2019. Seasonal distribution and migration of Arctic Grayling in the Gulkana River, 2016–2017. Alaska Department of Fish and Game, Fishery Data Series No. 19-13, Anchorage.

The Alaska Department of Fish and Game (ADF&G) administers all programs and activities free from discrimination based on race, color, national origin, age, sex, religion, marital status, pregnancy, parenthood, or disability. The department administers all programs and activities in compliance with Title VI of the Civil Rights Act of 1964, Section 504 of the Rehabilitation Act of 1973, Title II of the Americans with Disabilities Act (ADA) of 1990, the Age Discrimination Act of 1975, and Title IX of the Education Amendments of 1972. If you believe you have been discriminated against in any program, activity, or facility please write: ADF&G ADA Coordinator, P.O. Box 115526, Juneau, AK 99811-5526 U.S. Fish and Wildlife Service, 4401 N. Fairfax Drive, MS 2042, Arlington, VA 22203 Office of Equal Opportunity, U.S. Department of the Interior, 1849 C Street NW MS 5230, Washington DC 20240 The department’s ADA Coordinator can be reached via phone at the following numbers: (VOICE) 907-465-6077, (Statewide Telecommunication Device for the Deaf) 1-800-478-3648, (Juneau TDD) 907-465-3646, or (FAX) 907-465-6078 For information on alternative formats and questions on this publication, please contact: ADF&G, Division of Sport Fish, Research and Technical Services, 333 Raspberry Rd, Anchorage AK 99518 (907) 267-2375

TABLE OF CONTENTS Page LIST OF TABLES ...... ii LIST OF FIGURES ...... ii LIST OF APPENDICES ...... ii ABSTRACT ...... 1 INTRODUCTION ...... 1 Fish Capture and Telemetry Procedures ...... 4 Data Analysis ...... 7 Seasonal and Spawning Distribution ...... 7 Distance and Direction Traveled ...... 8 Home Range ...... 8 RESULTS ...... 8 Summary of Fish Captured ...... 8 Radiotracking ...... 10 Overview ...... 10 Seasonal and Spawning Distribution ...... 10 Distance and Direction Traveled ...... 20 Home Range ...... 21 DISCUSSION ...... 22 ACKNOWLEDGEMENTS ...... 23 REFERENCES CITED ...... 24 APPENDIX A ...... 25 APPENDIX B ...... 27

i LIST OF TABLES Table Page 1. Location, dates, and number of radio tags deployed in the Gulkana River, 2016...... 5 2. Aerial tracking dates and the number of radiotagged Arctic grayling by status category in the Gulkana River, 2016–2017...... 6 3. Summary of movement information for radiotagged Arctic grayling detected during consecutive surveys in the Gulkana River, 2016–2017...... 15 4. Summary of movement direction of radiotagged Arctic grayling in the Gulkana River, 2016–2017...... 21 5. Minimum, maximum, and mean home range of radiotagged Arctic grayling in the Gulkana River from 2016 to 2017...... 21

LIST OF FIGURES Figure Page 1. Map of the Gulkana River drainage within the Upper Copper-Upper Susitna Management Area...... 2 2. Number of Arctic grayling harvested and released, and fishing effort for all species in the Gulkana River, 1995–2016...... 3 3. Map of the study area with the radiotagging locations of Arctic grayling ...... 9 4. Length frequency distribution of Arctic grayling captured and radiotagged in the Gulkana River, 2016. .... 10 5. All locations of live radiotagged Arctic grayling found during all 15 aerial surveys...... 11 6. Distribution of Arctic grayling during the overwintering period, Gulkana River...... 12 7. Distribution of Arctic grayling during the spawning period, Gulkana River...... 14 8. A summary of distance and direction of movement for Arctic grayling between consecutive surveys...... 16 9. Distribution of Arctic grayling during the summering period, Gulkana River...... 17 10. Gaussian kernel densities displaying the distribution of Arctic grayling from tagging through the 16 June 2017 survey...... 18 11. Gaussian kernel densities displaying the distribution of Arctic grayling from the 13 June 2017 survey through the final survey on 3 November 2017...... 19 12. Movements of individual fish, based on river kilometer located, during the course of the study...... 20

LIST OF APPENDICES Appendix Page A1. Summary of data archival for the Gulkana River Arctic grayling telemetry study, 2016–2017...... 26 B1. Date of capture, length, tag information, release location, final fate, date last found alive, days alive, and range of each radiotagged Arctic grayling, Gulkana River, 2016–2017...... 28

ABSTRACT Gulkana River Arctic grayling Thymallus arcticus were radiotagged in fall 2016 and tracked for the following 14 months to describe seasonal distributions, migration patterns, and to identify spawning areas. Radio tags were surgically implanted into 126 Arctic grayling ≥320 mm fork length (FL) in a 64.5 river kilometer (rkm) reach of the Gulkana River mainstem from the confluence of the Middle Fork Gulkana River down to a point approximately 5 rkm above Sourdough Creek. A total of 15 aerial tracking surveys were flown from 7 November 2016 through 3 November 2017. Arctic grayling located during tracking surveys exhibited migratory behavior. Fish that survived a full year had a mean home range of 60.9 rkm and 8 fish had home ranges >100 rkm. Migrations for spawning were generally upstream and began in early May. Most fish made post spawning movements upriver to summering locations in June and July, then downstream migrations to overwintering areas starting in August. Several new spawning areas were documented with Stump Creek and the West Fork Gulkana River being the most significant. Radiotagged fish were also present in other smaller unnamed tributaries around the West Fork Gulkana River confluence during the spawning period. Already recognized spawning tributaries such as the Middle Fork Gulkana River, Twelvemile Creek, and Sourdough Creek had radiotagged Arctic grayling in them during the spawning period, but Poplar Grove did not. Key words: Arctic grayling, Thymallus arcticus, telemetry, Gulkana River, movement, migration, home range, seasonal distribution, overwintering areas, spawning areas INTRODUCTION The Gulkana River originates in the Alaska Range and flows approximately 175 river kilometers (rkm) to the Copper River (Figure 1). The river supports one of the largest Arctic grayling Thymallus arcticus fisheries in the State of Alaska and the largest Arctic grayling fishery in the Upper Copper/Upper Susitna Management Area (Somerville 2017). Estimated catch and harvest of Arctic grayling in the Gulkana River drainage has fluctuated over the last 20 years, with catch exceeding 60,000 fish twice in the early 2000s; however, the most recent 5-year mean (2012–2016) estimated catch and harvest was 15,127 and 745 fish, respectively (Somerville 2017; Figure 2). Most fishing effort in the drainage is directed at Arctic grayling in the mainstem Gulkana River from the outlet of Paxson Lake to Sourdough Creek. Since 1989, the bag and possession limit of Arctic grayling in this area has been 5 fish with only one fish over 14 inches allowed. Numerous stock assessments have been conducted on mainstem Gulkana River Arctic grayling (Williams and Potterville 1983; Roth and Delaney 1987; Roth and Alexandersdottir 1990; Vincent-Lang and Alexandersdottir 1990; Bosch 1995; Fish and Roach 1999). Study results indicated that these graylings are migratory, live at high densities, are not long lived, and do not reach large sizes. All multi-year tagging studies showed that fish predominately migrated from overwintering areas located in deeper holes of the mainstem to tributaries such as Poplar Grove and Sourdough Creek to spawn. Once spawning was complete, fish distributed throughout the mainstem Gulkana River and into suitable habitat of the Middle Fork Gulkana River. By late fall, migrations back to overwintering areas in the mainstem began. All studies showed that Arctic grayling in the mainstem Gulkana River rarely exceed 7 years of age, and most are ages 2–4. Roth and Alexandersdottir (1990) estimated the abundance of adult Arctic grayling to be 137,500 (SE = 26,600) fish between the confluence of the Middle Fork Gulkana River and Sourdough Creek. Later, Bosch (1995) estimated the abundance of adult Arctic grayling ≥200 mm fork length (FL) to be about 90,164 (SE = 10,192) fish (the mean of annual abundance estimates from 1987–1991) in the mainstem Gulkana River using mark-recapture methods, and about 111,021 (SE = 22,031) fish using catch age analysis. Length composition has varied among studies, but all reveal the lack of trophy-sized fish (>430 mm FL) in the mainstem. Pooling all the results from the 1990, 1991, 1992, and 1998 studies, about 60% of the population was between 150–269 mm FL, 28% between 270–319 mm FL, and 12% ≥320 mm FL.

Sl Summit an C Denali Highway G a R Lake h

a ive

i r

o o

n c

a h

i n

R a Paxson ive S r u Lake R i si Dickey v tn e

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r West Fork G ulk an a R iver Ta n a da UCUSMA Lake G Boundary Minnesota u Copper lk a Lake n Lake a Tyone Lake R i Ewan v e

Lake r

Susitna Lake C o

Crosswind Lake p p Lake Louise e Glennallen r R Moose Lake i v Tolsona Lake e r

Glenn Highway

Edgerton Klutina Highway Lake

Tazlina Lake C UCUSMA hi tina Boundary River Ton sina Summit Lake Lake

Hanagita Richardson Te b a y Lakes Highway Lake

010205Miles

Figure 1.–Map of the Gulkana River drainage within the Upper Copper-Upper Susitna Management Area.

70,000 50,000

harvested 45,000 60,000 released 40,000 effort (days fished) 50,000 35,000

30,000 40,000 25,000 30,000 20,000

15,000 Effort (days fished)

# of Arctic grayling 20,000 10,000 10,000 5,000

0 0 1995 1998 2001 2004 2007 2010 2013 2016 Year

Figure 2.–Number of Arctic grayling harvested and released (the sum is catch), and fishing effort for all species in the Gulkana River, 1995–2016.

No previous telemetry studies have been conducted on Gulkana River Arctic grayling. Refining seasonal movements and migration patterns using radiotelemetry provided updated and more accurate information than past Floy tag studies, and offered the advantage of surveying a larger area in a shorter period of time. OBJECTIVES For mature-size Arctic grayling radiotagged during the fall period in the Gulkana River, the objectives were as follows: 1) Describe the seasonal distributions and movements from fall 2016 to summer 2017. 2) Identify spawning areas. METHODS STUDY AREA The study area for fish collection included the mainstem Gulkana River from the confluence of Paxson Lake downstream approximately 75 rkm to Sourdough Creek campground. This is where the majority of sport fishing effort occurs for Arctic grayling in the drainage. The search area for aerial tracking included the mainstem Gulkana River downstream of Paxson Lake and its tributaries, the Middle Fork Gulkana River and its tributaries, and the entire West Fork Gulkana River including numerous tributaries. The search area was extended to above Paxson Lake into the East Fork Gulkana River periodically.

3 For the remainder of this report, river kilometers (rkm) will occasionally be used to describe distances along a river or tributary and, in some cases, specific point designations. These values were obtained by using a highly accurate digitized map of the Gulkana River system, which was obtained from the National Hydrography Dataset (NHD; NHD 2011). For specific point designations, confluences of rivers or tributaries were assigned rkm 0 and subsequent rkms progressed sequentially upstream. For example, designations for the Gulkana River end at the Paxson Lake outlet at rkm 137. STUDY DESIGN Overview This study described the seasonal distribution of Arctic grayling residing in the mainstem Gulkana River. A total of 126 radio tags were deployed in fall 2016 when the water temperature was cooling and during the onset of Arctic grayling overwintering migrations. A series of 15 aerial surveys were conducted over the next 14 months to document overwintering, spawning, and summering areas, as well as migration timing to and from these locations. Fish Capture and Telemetry Procedures Radio tags were deployed during 2 sampling trips. The first trip occurred 23–28 September 2016 and covered the upper mainstem Gulkana River. Two crews of 2 people used inflatable rafts to sample from Paxson Lake (rkm 137) down to the confluence of the West Fork Gulkana River (rkm 76.5), approximately 60.5 rkm. This river section was divided into quarters and 84 radio tags were apportioned evenly among the quarters, resulting in a tagging density of about 21 tags per 15 rkm (1.4 tags/rkm; Table 1). The second trip occurred 30 September–1 October 2016. A crew of 3 people used a power boat to sample between the West Fork Gulkana River and Sourdough Creek (rkm 62.5), an approximately 14 rkm section. A greater density of radio tags was deployed in this area to increase the chances of documenting new spawning areas (42 radio tags, 3 tags/rkm; Table 1). In a similar study for rainbow trout, 9 fish radiotagged at the confluence of the West Fork Gulkana River on 29 September 2010 represented all major spawning areas in the drainage the following spring, including a previously undocumented tributary of the West Fork Gulkana River (Schwanke 2015). It was theorized that Arctic grayling may exhibit similar overwintering patterns and that tagging fish at a higher density in this area would provide the best opportunity to discover new spawning areas and migration patterns. Arctic grayling were captured using standard hook and line gear and fish ≥320 mm FL were surgically implanted with tags. Tackle consisted primarily of jigs and spinners. Fish ≥320 mm FL were selected for tagging because they were large enough to accommodate the radio transmitter (tag must be <2% weight of fish, Winter 1983), expected to be mature (Bosch 1995), and their behavior was expected to be representative of all mature-sized fish. At each tagging location, the first healthy fish ≥320 mm FL captured was radiotagged and all subsequent healthy captured fish of adequate size were radiotagged until the allotted number of tags for that location were deployed.

Table 1.–Location, dates, and number of radio tags deployed in the Gulkana River, 2016. Section Dates Number of Tags Paxson Lake outlet to West Fork Gulkana River confluence 9/23–9/28 84 West Fork Gulkana River confluence to Sourdough Creek 9/30–10/1 42

Radio tags were manufactured by Lotek Wireless Incorporated1 (Model MCFT2-3EM). The tags measured 12 × 53 mm and weighed 10 g in air. They were digitally encoded, equipped with a motion sensor, and programmed to operate daily for 12 hours between 0800 and 2000 hours. The 126 unique tags emitted signals every 2.5 s and were divided evenly between 3 radio frequencies (148.340, 148.410, and 148.430 MHz). The motion sensor emitted a unique code when a tagged fish was inactive. Inactivity was triggered after satisfying a preprogrammed time (24 h) and sensitivity level (1) criterion. Tags that emitted the inactive code over multiple surveys were interpreted as a dead fish. Radio tags were surgically implanted following well-established procedures (Winter 1983; Summerfelt and Smith 1990). Fish selected for radiotagging were anesthetized with AQUI-S using procedures outlined by Brown et al. (2002). Anesthetized fish were measured to the nearest millimeter fork length (FL), placed ventral side up in a padded cradle, and the gills were irrigated with a water/anesthesia solution throughout the surgery. Surgical utensils were disinfected in a Nolvasan solution and rinsed with saline solution prior to each surgery. A 15 mm incision was made anterior to the pelvic girdle, along the left ventral side, about 5–10 mm from the midventral axis. A grooved director was placed into the coelomic cavity through the incision to direct a 16-gauge 25.4 cm hypodermic needle inserted from posterior of the pelvic girdle toward the incision (Brown et al. 2002). The tag antenna wire was routed from the incision past the pelvic girdle by threading the wire through the needle. Upon exit, the needle and grooved director were removed and the radio tag was fully inserted into the coelomic cavity. The incision was sutured with 3 to 4 simple interrupted stitches of monofilament suture material (Wagner et al. 2000) and treated with a surgical adhesive (Vetbond). After surgery, fish were immediately placed into a large recovery tote filled with fresh river water to regain equilibrium before they were released in a slow-flowing portion of the river. Radiotagged Arctic grayling were relocated using radio receivers manufactured by Lotek Wireless Incorporated (Model SRX 600) and aerial tracking techniques. A total of 15 tracking flights were performed during 7 November 2016–3 November 2017 (Table 2). The frequency of surveys was highest during the spawning period (May and June) to better assess spring movements to probable spawning locations. Aerial surveys were flown 100 to 300 m above ground elevation with a Piper Super Cub fixed-wing aircraft wired for telemetry. Two H-antennas (148–152 MHz), 1 mounted on each wing, were connected to a splitter and controlled by a selecting switch. Antennas were connected to an SRX 600 radio receiver that scanned each frequency for 5 s intervals. The receiver had an internal global positioning system (GPS) and an external magnetic antenna to automatically record the time and location of detected fish.

1 Product names are used for completeness but do not constitute endorsement.

5 Table 2.–Aerial tracking dates and the number of radiotagged Arctic grayling by status category in the Gulkana River, 2016–2017.

Number of Fish Survey number Survey date Alive Dead Missing 1 11/7/2016 99 16 11 2 3/22/2017 83 25 18 3 5/8/2017 76 31 19 4 5/16/2017 71 36 19 5 5/23/2017 74 36 16 6 a 5/30/2017 66 42 18 7 6/6/2017 66 46 14 8 6/13/2017 61 47 18 9 6/20/2017 56 53 17 10 6/27/2017 51 54 21 11 a 7/19/2017 45 58 23 12 a 8/7/2017 38 64 24 13 a 9/1/2017 33 68 25 14 a 9/28/2017 28 78 20 15 11/3/2017 22 80 24 a Surveyed above Paxson Lake.

Multiple locations, times, and signal strengths of detected fish were logged with the radio receivers during each survey. All data were downloaded from the aerial tracking receiver using Lotek Wireless Incorporated WinHost proprietary software and converted to a Microsoft Excel spreadsheet (Lotek 2005). Specific locations of tagged fish were determined for every survey by selecting the highest signal strength from a series of logged locations for each identified fish. For the data analyses, GPS locations for each fish were adjusted to the nearest river location (shapefile vertex) on a digitized map of the Gulkana River system obtained from NHD (2011). To minimize overlapping fish locations for visual presentations, unsnapped locations of fish (i.e., where the airplane was when the highest signal strength was recorded) were used when making the figures for this report.

DATA COLLECTION For each fish implanted with a radio tag, length (nearest mm FL), GPS waypoint of capture/release location (decimal degree WGS84 Datum), and radio tag frequency and code were recorded. Recorded aerial survey data included date and time of the survey, radio tag frequency and code for all located tags, and a latitude and longitude (WGS84 Datum) reading from the receiver’s internal GPS. DATA ANALYSIS After the location of each fish was plotted on a map, fish locations were labeled by survey, and individual fish were assigned a fate of active or alive (A), inactive or dead (I), or at-large or missing (AL). The fate of each fish was determined by examining the movement history and data provided by the motion sensors. Reviewing the movement history of each radiotagged fish was required because the motion sensor sometimes did not accurately reflect the fate of a tagged fish during a given survey. The history of sensor recordings for each fish was examined to determine when and if the fish had died, and its fate was corrected for subsequent surveys. For example, a fish with an inactive signal for one or more surveys that later made significant movements and emitted an active signal was considered alive for the inactive period. Conversely, a fish with an intermittent active signal while exhibiting no detectable movement throughout the tracking history was considered dead at the time of consecutive inactive signals. At the conclusion of aerial tracking flights, all fish were classified as alive, dead, or missing. All edited biological and telemetric data were entered and archived in an Excel spreadsheet (Appendix A1). At-large fish were excluded from the data analyses for flights during which they were considered at-large. These fish may have left the study area, experienced tag failure, or been overlooked during a particular survey. If the fish was relocated on subsequent surveys, its movement history was included in the final analysis. Seasonal and Spawning Distribution Single surveys were used to illustrate important seasonal distributions of radiotagged Arctic grayling. Overwintering locations were defined as fish locations during late winter when fish were confined and concentrated due to factors such as reduced water flow, thickening ice, and dissolved oxygen. These late winter locations probably represent the presence of critical overwintering habitat. Spawning locations were defined after scrutinizing each fish’s movements during the presumed spawning period of mid-May through late May. Time and duration fish spent on previously known and obvious spawning locations during this study were used to determine general spawning timing. A single survey was chosen to represent peak spawning based on mean movements of fish between surveys. More specifically, when mean movements decreased between surveys during the spawning period, it was implied that many fish were stationary on the spawning grounds and that date was chosen as the peak spawning date. Summer locations were displayed as locations of fish during late summer. As with spawning, the exact aerial survey date chosen to represent summering locations was when mean movements between surveys was the shortest, indicating most Arctic grayling were in their preferred summering locations.

Distance and Direction Traveled Movements of radiotagged fish were analyzed and summarized by plotting coordinates of all located fish deemed to be alive at the time of each survey onto a digitized map of the drainage using both ArcGIS and the riverdist package (Tyers 2016) for R (R Core Team 2018). The net movement (distance) between tracking events was determined by subtracting the river locations (i.e., 0.1 rkm assignments) of individual fish that were detected during consecutive surveys. These distances were summarized and reported as absolute values using the riverdist package. Fish that were not found alive during consecutive surveys were not used in this portion of the analysis. As with movement, direction (upstream or downstream) was calculated for fish found alive during consecutive surveys. When a fish either entered or left a tributary and traveled both upstream and downstream between surveys, the direction that fish traveled the furthest was designated for that fish. For example, if a fish traveled down a tributary 3 rkm then up the mainstem 15 rkm, that fish was categorized as having traveled upstream for that time period. Home Range Home ranges were determined for fish that survived year one (tagging to 28 September 2017). To boost sample sizes for this analysis, fish that lived 10+ months were included in the home range analysis because most annual movements had occurred by the survey on 19 July 2017 (e.g., this period encompassed summertime distribution, wintertime distribution, and spawning distribution). Home ranges were defined as the total spatial extent of each radiotagged fish located between described time periods. They were calculated as the sum of the mainstem Gulkana River extent (the distance between the highest and lowest location observed in the drainage), plus the distance traveled one way to the most extreme location in all tributaries. Home ranges were calculated using the home-range function in the riverdist package (Tyers 2016). Extent of spawning migrations were also calculated by tracking the distance fish swam from their overwintering locations to their presumed spawning locations. Specifically, this range analysis was done by measuring the distance between fish locations in late March (overwintering) and their location during the aerial survey chosen to represent peak spawning. RESULTS SUMMARY OF FISH CAPTURED A total of 126 Arctic grayling were captured and tagged in September and October 2016; 84 radio tags were deployed between Paxson Lake and the West Fork Gulkana River confluence, and 42 tags were deployed from the West Fork Gulkana River confluence to a point approximately 5 rkm above Sourdough Creek (Table 1; Figure 3). Radiotagged fish ranged in size from 320 to 380 mm FL and averaged 339 mm FL (SD = 15.3; Figure 4). Approximately 60% of all radiotagged Arctic grayling were <340 mm FL. GPS coordinates of tagging locations, lengths of individual fish, tag frequencies and codes, ultimate fates, and ranges (maximum rkm traveled) are recorded in Appendix B1. Water temperatures were low during the tagging period, ranging from 3–7°C.

East Fork Gulkana River

Swede Hungry Lake Hollow Dickey Creek Lake Paxson Lake M idd le F or k G ulk 9 ana G Riv u er l k 4 a n 8 a Twelvemile Creek R iv 6 er 9

3 6 4

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i Grove v iv e

Tagging Locations e Creek r r 23 September-1 October 2016 Ewan n=126 Lake

Crosswind Lake

r e v i R r

e ± p

010205Kilometers p o C Figure 3.–Map of the study area with the radiotagging locations of Arctic grayling. Numbers associated with dots represent the number of Arctic grayling radiotagged at that location.

0.40 n = 126 0.35

0.30

0.25

0.20

Frequency 0.15

0.10

0.05

0.00 320-329 330-339 340-349 350-359 360-369 370-379 380-389

Length (mm FL)

Figure 4.–Length frequency distribution of Arctic grayling captured and radiotagged in the Gulkana River, 2016.

RADIOTRACKING Overview Fifteen aerial surveys were conducted from 7 November 2016 to 3 November 2017 (Table 2). Aerial surveys were flown every 1–3 months and weekly when Arctic grayling were suspected to move the most for spawning (8 May through 27 June). Fish were relocated over a cumulative range of 272 rkm throughout this study (Figure 5). Previously undocumented spawning areas were identified, and most were in boggy habitat. Areas important to summering and overwintering were also documented. Seasonal and Spawning Distribution A late winter aerial survey on 22 March 2017 revealed several significant overwintering areas (Figure 6). It is important to note, however, that these locations were probably the most influenced by tagging distribution because tags were deployed late in the fall after overwintering migrations had started. The biggest overwintering concentration (38 fish) was located in a 7 rkm reach between the West Fork Gulkana River and Sourdough Creek (Figure 6). The next largest concentration (16 fish) was in an 11 rkm reach beginning immediately below Sourdough Creek. Overwintering aggregations of tagged fish were also found in the Lower West Fork Gulkana River, mainstem Gulkana River below Stump Creek, and in the mainstem below the Middle Fork Gulkana River confluence.

East Fork Gulkana River

Swede Hungry Lake Hollow Creek Dickey Lake Paxson Lake M idd le F ork Gu lka na G Ri ver u l k a n a Twelvemile Creek R iv er

Stump Creek

W est Fo rk Gu lkana River

Sourdough Fish Creek Lake

G u

l G k a

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R R i

i Grove v

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e Creek r Overall distribution of r radiotagged Arctic grayling Ewan considered alive during Lake this study Crosswind Lake

r e v i R r

± p

010205Kilometers p o C Figure 5.–All locations of live radiotagged Arctic grayling found during all 15 aerial surveys.

East Fork Gulkana River

Swede Hungry Lake Hollow Dickey Creek Lake Paxson Lake M idd le F ork Gu lka na G Ri ver u l k a n a Twelvemile Creek R iv er

Stump Creek

W est Fo rk Gu lkana River

Sourdough Fish Creek Lake

G u

l G k a

a k

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n a a Poplar

R R i

i Grove v

v e

e Creek r Overwintering Locations r 22 March 2017 Ewan n=83 Lake

Crosswind Lake

r e v i R r

± p

09.5194.75 Kilometers p o C Figure 6–Distribution of Arctic grayling during the overwintering period (22 March 2017), Gulkana River.

The survey on 23 May 2017 was chosen to represent spawning locations because movements of Arctic grayling between weekly surveys was the least during this time, indicating fish were somewhat stationary for spawning (Table 3; Figures 7 and 8). The mainstem Gulkana River and its tributaries located in the vicinity of the West Fork Gulkana River confluence were important during the spawning period (Figure 7). Stump Creek was not previously documented as a spawning tributary for Arctic grayling, but 11 radiotagged fish were located there during the peak spawning survey. Additionally, a 4.5 rkm reach above Stump Creek had 7 radiotagged fish in it, and another 5.5 rkm reach of the mainstem below Stump Creek contained 14 radiotagged fish. The reach of the mainstem Gulkana River from the West Fork Gulkana River confluence downstream approximately 5.5 rkm had 14 grayling in it during the peak spawning survey. Other reaches appearing important for spawning were the West Fork Gulkana River (7 tags), Sourdough Creek (4 tags), the Paxson Lake outlet (3 tags), and two unnamed east bank tributaries (1 tag each; Figure 7). Two radiotagged fish were also found in popular rainbow trout spawning areas: 1 in the Middle Fork Gulkana River and 1 in Twelvelmile Creek. The date of 19 July 2017 was chosen to display summertime locations (Figure 9). This is when movement between surveys was reduced indicating summering locations were reached (Table 3; Figure 8). Summering distribution was very different from overwintering and spawning distribution, with most of the fish residing above Stump Creek. Of substantial importance was an 8 rkm stretch that included the lower 4 rkm stretch of Hungry Hollow Creek extending downstream 4 rkm into the Middle Fork Gulkana River. This section had 11 radiotagged fish in it during the 19 July 2017 survey. The confluence of the Middle Fork Gulkana River, the confluence of Twelvemile Creek, and a lake up Stump Creek each had 4 radiotagged fish in them (Figure 9). Locations of fish for all surveys are shown in Figures 10 and 11. Seasonal habitat preferences can be inferred from this timeline of maps. Many fish migrated to a short 3 rkm reach of river between the Paxson Lake outlet and the Middle Fork Gulkana River confluence. Tagged fish started utilizing this reach on 23 May 2017 and the number of fish in this area steadily increased until densities peaked (9 radiotagged fish) during the 27 June 2017 survey. During the subsequent survey on 19 July, all fish left the area, with many heading up the Middle Fork Gulkana River or back down the mainstem. Despite the Middle Fork Gulkana River being important for summering, only a single fish overwintered in the lower reach near the confluence with the mainstem Gulkana River (Figures 9 and 10). Another notable observation was the West Fork Gulkana River appeared important for spawning and overwintering, but not for summering. Lastly, various tributaries between Stump Creek and Sourdough Creek were important for spawning and summering, but not overwintering. Throughout the duration of this study, only a single live fish was detected north of Paxson Lake in the East Fork Gulkana River (Figures 9 and 11). Although not detailed in the tables or figures, 3 fish migrated up above Paxson Lake into the East Fork Gulkana River. This area was only flown during 5 of the 14 surveys (Table 2) due to fiscal constraints. When all 3 fish were first detected on 19 July, 2 were already determined to be mortalities. Of the 3 fish located in the East Fork Gulkana River, one was tracked in the mainstem Gulkana River during the previous survey (27 June 2017), one was not found during the previous survey (27 June 2017), and the last one was not detected during both the previous surveys (20 and 27 June 2017). Two of these fish provided evidence that they were probably on their way north and were either in Paxson Lake or already in the East Fork Gulkana River, weeks before being first detected there on 19 July.

East Fork Gulkana River

Swede Hungry Lake Hollow Dickey Creek Lake Paxson Lake M idd le F ork Gu lka na G Ri ver u l k a n a Twelvemile Creek R iv er

Stump Creek

W est Fo rk Gu lkana River

Sourdough Fish Creek Lake

G u

l G k a

a k

n o

n a a Poplar

R R i

i Grove v

v e

e Creek r Spawning Locations r 23 May 2017 Ewan n=74 Lake

Crosswind Lake

r e iv R r

e ± p

010205 Kilometers p o C Figure 7.–Distribution of Arctic grayling during the spawning period (23 May 2017), Gulkana River.

Table 3.–Summary of movement information for radiotagged Arctic grayling detected during consecutive surveys in the Gulkana River, 2016–2017.

Days Absolute Upstream Downstream Between Sample Movement (rkm) Movement (rkm) Movement (rkm) Dates of Surveys Surveys Size Mean SD Max. Min. Max. Min. Tagging–11/07/2016 37–46 99 14.0 16.2 13.3 0.1 75.2 0.1 11/07/2016–3/22/2017 135 77 6.6 8.0 19.8 0.3 52.4 <0.1 3/22/2017–5/08/2017 47 67 8.4 8.5 33.6 0.7 36.8 0.4 5/08/2017–5/16/2017 8 62 6.1 10.5 25.0 0.1 71.1 0.1 5/16/2017–5/23/2017 7 66 7.7 11.3 67.6 0.1 23.6 0.1 5/23/2017–5/30/2017 7 63 5.3 8.0 37.3 0.1 21.0 0.1 5/30/2017–6/06/2017 7 60 7.9 11.4 50.3 <0.1 33.7 <0.1 6/06/2017–6/13/2017 7 59 8.3 10.5 53.1 0.1 18.6 <0.1 6/13/2017–6/20/2017 7 54 6.8 10.1 33.9 <0.1 42.8 <0.1 6/20/2017–6/27/2017 7 49 5.0 9.1 44.4 0.2 12.8 0.1 6/17/2017–7/19/2017 22 40 10.3 13.9 60.3 0.1 7.3 0.1 7/19/2017–8/07/2017 19 37 3.3 9.6 3.3 <0.1 53.8 0.1 8/07/2017–9/01/2017 25 30 9.3 21.2 6.1 0.2 80.8 <0.1 9/01/2017–9/28/2017 27 27 9.7 18.4 4.6 0.1 67.5 0.1 9/28/2017–11/03/2017 36 22 15.0 25.0 4.0 0.3 101.9 0.2

Figure 8.–A summary of distance and direction of movement for Arctic grayling between consecutive surveys. The boxes represent the 25th–75th percentiles, the black lines are the medians, the whiskers represent the range within 1.5 times the inner quartile range of the median (IQR), and the dots represent individual movements that were >IQR. Negative movements were downstream; positive movements were upstream.

East Fork Gulkana River

Swede Hungry Lake Hollow Dickey Creek Lake Paxson Lake M idd le F ork Gu lka na G Ri ver u l k a n a Twelvemile Creek R iv er

Stump Creek

W est Fo rk Gu lkana River

Sourdough Fish Creek Lake

G u

l G k a

a k

n o

n a a Poplar

R R i

i Grove v

v e

e Creek r Summering Locations r 19 July 2017 Ewan n=45 Lake

Crosswind Lake

r e v i R r

± p

010205 Kilometers p o C Figure 9.–Distribution of Arctic grayling during the summering period (19 July 2017), Gulkana River.

Figure 10.–Gaussian kernel densities displaying the distribution of Arctic grayling from tagging through the 16 June 2017 survey. Darker shading represents higher densities of radiotagged fish. The midpoint of the 23 September to 1 October 2016 tagging duration is 27 September 2016.

Figure 11.–Gaussian kernel densities displaying the distribution of Arctic grayling from the 13 June 2017 survey through the final survey on 3 November 2017. Darker shading represents higher densities of radiotagged fish.

19 Distance and Direction Traveled Movement of fish between consecutive surveys revealed trends regarding seasonal distribution and habitat preferences. Generally, fish moved downstream to overwinter and were relatively stationary until spring time (Tables 3 and 4; Figures 8 and 12). During both years, 77% of the fish moved downstream between late September and early November (Table 4). These time periods were also when the greatest movement occurred between surveys with mean distances traveled being 14.0 rkm in 2016 and 15.0 rkm in 2017 (Table 3). Movements were minimal during the 4.5-month period between 7 November 2016 and 22 March 2017, with 82% of the fish moving downstream and a mean distance traveled of 6.6 rkm. Aerial surveys became more frequent after the 8 May 2017 survey, and fish tended to move upstream throughout spring and into the summer. As stated earlier, the survey on 23 May 2017 was chosen to represent spawning because movement between surveys slowed, indicating that most radiotagged fish were relatively stationary and presumably spawning (Table 3; Figure 8). The next notable observation occurred between the 19 July and 7 August 2017 surveys when mean distance traveled was 3.3 rkm (Table 3). This implies that final summering locations were reached by mid-July. Subsequent surveys showed downstream movements back to overwintering areas (Table 4).

Figure 12.–Movements of individual fish which survived an entire year, based on river kilometer (rkm) located, during the course of the study. Dotted lines are from fish that were not located on consecutive surveys.

Table 4.–Summary of movement direction of radiotagged Arctic grayling in the Gulkana River, 2016–2017. Days between Number Proportion Number Proportion Dates of surveys surveys upstream upstream downstream downstream Tagging-11/07/2016 37–46 23 0.23 76 0.77 11/07/2016–3/22/2017 135 14 0.18 63 0.82 3/22/2017–5/08/2017 47 40 0.60 27 0.40 5/08/2017–5/16/2017 8 41 0.66 21 0.34 5/16/2017–5/23/2017 7 42 0.64 24 0.36 5/23/2017–5/30/2017 7 37 0.59 26 0.41 5/30/2017–6/06/2017 7 38 0.63 22 0.37 6/06/2017–6/13/2017 7 41 0.69 18 0.31 6/13/2017–6/20/2017 7 33 0.61 21 0.39 6/20/2017–6/27/2017 7 27 0.55 22 0.45 6/27/2017–7/19/2017 22 27 0.68 13 0.32 7/19/2017–8/07/2017 19 15 0.41 22 0.59 8/07/2017–9/01/2017 25 9 0.30 21 0.70 9/1/2017–9/27/2017 27 7 0.26 20 0.74 9/27/2017–11/3/2017 36 5 0.23 17 0.77

Home Range Gulkana River Arctic grayling exhibited relatively large ranges during this study. A total of 28 fish survived a full year, and their mean annual home range was 60.9 rkm (SD = 35.0; Table 5). The largest home range of these fish was 111.9 rkm and the smallest was 7.1 rkm. Movement data suggest that very little movement occurred in July and August (Table 3; Figure 8); therefore, to boost sample sizes of this analysis, the mean home range of 45 fish that lived from the time of tagging to 19 July 2017 was also examined (Table 5). These fish had a mean home range of 58.0 rkm (SD = 33.6), and the maximum home range was 115.3 rkm. Lastly, we examined the mean movements from overwintering locations (22 March 2017) to presumed spawning locations (23 May 2017). A total of 67 fish were located and deemed alive during both these surveys and the mean distance traveled was 21.6 rkm (SD = 19.0; Table 5).

Table 5.–Minimum, maximum, and mean home range of radiotagged Arctic grayling in the Gulkana River from 2016 to 2017.

a Active Home range (rkm) Time period fish (n) Mean SD Max. Min. Tagging (9/23–10/1/2016) to next fall (9/28/2017) 28 60.9 35.0 111.9 7.1 Tagging (9/23–10/1/2016) to next summer (7/19/17) b 45 58.0 33.6 115.3 4.3 Overwintering (3/22/2017) to spawning period (5/23/2017) 67 21.6 19.0 90.6 0.4 a Home range was calculated using the distance traveled from the uppermost extent to the lowermost extent for individual Arctic grayling, plus distance to the most extreme locations in any tributaries, over the course of a designated time period b To bolster sample sizes, home range was also examined from the time of tagging to the 7/19/2017 survey. This time period of 10+ months captures almost all the seasonal migrations over the course of a year.

21 DISCUSSION The annual movements of Arctic grayling in the Gulkana River seemed to follow the general trend of upstream migrations during spring and summer, then downstream movements for overwintering in the fall. Typically, radiotagged Arctic grayling made short upstream migrations starting in early May for spawning, then migrated further upriver for summering. Some fish made an additional midsummer migration upstream as shown between the surveys on 20 June 2017 and 19 July 2017 (Figure 8). It is believed that this is when the waters of the mainstem Gulkana River started to warm and fish sought out the cooler waters of Hungry Hollow Creek and the Middle Fork Gulkana River (Figure 11). This 8 rkm reach of Hungry Hollow/Middle Fork Gulkana River seems very important to this population. It is recommended that a stock assessment occur in this area during late July because it could serve as an index area that may represent the general health of the mainstem Gulkana River stock. It would also be important to record summertime water temperatures at this site and in the mainstem Gulkana River below Paxson Lake to see if these fish are truly seeking cooler waters. Several of the fish residing in this reach and other fish in the mainstem Gulkana River started making downstream movements by the 7 August 2017 survey when 59% of the radiotagged fish moved downstream (Table 4). This trend increased through the end of the study when 77% of the fish migrated downstream during the last survey on 3 November 2017 (Table 4; Figure 8). The most significant finding during this study was the documentation of Stump Creek as a substantial spawning tributary. A total of 11 different tagged fish (14.9% of the live radiotagged fish) were found in this tributary during the peak spawning survey on 23 May 2017. Additionally, 13 different fish (18.3% of all live radiotagged fish) were present in Stump Creek during the previous survey on 16 May. This small discrepancy exists because the selection of “peak” spawning date was chosen based on the cessation of movement as a whole population (Tables 3 and 4; Figure 8), and not specific to spawning tributaries. Tributaries probably warm faster, and spawning occurs sooner, than in the mainstem waters that are fed by frozen Paxson Lake during the spawning period. Regardless of the true proportion of fish spawning in this tributary, no prior reports mentioned this creek as important to Arctic grayling. A second unexpected observation was that no radiotagged Arctic grayling went to Poplar Grove Creek to spawn. Past Floy-tagging studies have focused on this creek because it was believed to be an important spawning area. During studies from 1986–1992, a total of 10,042 mature Arctic grayling were tagged from this creek using weir methods (Williams and Potterville 1983; Roth and Delaney 1987; Roth and Alexandersdottir 1990; Vincent-Lang and Alexandersdottir 1990; Bosch 1995). Poplar Grove Creek was sampled in 1986, and from 1988–1991. It was not sampled in 1987 because the water was too low for Arctic grayling to enter the tributary. Beaver dams have also been known to impede spawning migrations in Poplar Grove Creek. During this study, except for a single fish located near the mouth of Poplar Grove Creek, no radiotagged Arctic grayling were close to Poplar Grove Creek at the time of spawning. This likely means one of two things. The first is that Poplar Grove Creek represents a small portion of the spawning population, and it was sampled in the past due to easy access. The second possibility is that the timing and distribution of our tag deployment missed the component of the population that spawns in Poplar Grove Creek. However, this is unlikely because fish tagged from Poplar Grove Creek in the late 1980s and early 1990s distributed themselves throughout the mainstem Gulkana River for summering (Bosh 1995).

22 Another outcome that was unexpected was having 3 radiotagged fish travel upstream through Paxson Lake and into the East Fork Gulkana River. Extensive Floy tagging studies in the past documented this movement, but at a much lower rate. Bosh (1995) reported the tagging of >38,000 Arctic grayling in the mainstem Gulkana River, Poplar Grove, and in Sourdough Creek from 1986–1992. Of these, >2,500 were recaptured, only 12 of which were recaptured above Paxson Lake. This represented a south to north mixing rate of about 0.5%. Of the 66 radiotagged fish that survived past the spawning period during this study, 4.5% made post-spawn migrations above Paxson Lake. This disparity probably exists because we only tagged large mature sized fish in this study, and this trait might be more common in large fish. The last significant distribution outcome of this study was the importance of the West Fork Gulkana River for overwintering and spawning. No fish spent the summer in this major tributary, but 10 fish were found in it during the 7 November 2016 survey, 6 during the 22 March 2017 survey, and 7 during the peak spawning survey on 23 March 2017 (Figure 10). Post-radiotagging survival was acceptable during this study. A total of 99 (79%) fish were still alive on the 7 November 2016 survey. Tagging efforts strategically did not start until late September when water temperatures were cool prior to freeze-up. Water temperatures were 3–7°C during tagging and the river was flowing with slush just a few days after tagging was completed. It is believed that tagging fish during this late-fall coldwater window was paramount to the success of this study. Two previous telemetry studies in the region had much poorer survival with tagging taking place earlier in the year. Gryska (2015) radiotagged 100 Arctic grayling in the Delta River from 22–29 July 2008 and 46% had died within 2.5 months. Schwanke (2015) radiotagged 100 rainbow trout in the Gulkana River during August and September of 2010. Of the 91 fish tagged in August, 50% did not survive to the first survey on 7 October 2010. Conversely, of the 9 rainbow trout radiotagged in late September (same time frame as this study), 8 survived to the winter (Schwanke 2015). The poor initial survival of fish tagged in August was probably associated with warmer water conditions. A total of 28 (22%) of the 126 Arctic grayling radiotagged in this study survived a full year during this study. Bosh (1995) estimated that annual survival of Arctic grayling in the mainstem Gulkana River was 42% (SE = 2.4%) from 1986–1990. It was expected that survival after a year during this study would be much lower because the largest, and presumably oldest, Arctic grayling in the population were radiotagged.

ACKNOWLEDGEMENTS This was a joint project between the Alaska Department of Fish and Game, Division of Sport Fish and the Bureau of Land Management, Glennallen Field Office. A small but effective group of people deserve thanks for helping deploy radio tags: Mark Somerville, Loren St. Amand, and Mike Willard. Harley McMahan piloted the plane for all the surveys, and his skills and knowledge of the area were huge assets. April Behr and James Savereide provided editorial assistance, and Rachael Kvapil prepared the report for publication.

23 REFERENCES CITED Bosch, D. E. 1995. Population dynamics and stock assessment of Arctic grayling (Thymallus arcticus) in the Gulkana River drainage, Alaska. M. S. Thesis, University of Alaska, Fairbanks. Brown, R. J., C. Lundestadt, and B. Schulz. 2002. Movement patterns of radio-tagged adult humpback whitefish in the upper Tanana River drainage. U. S. Fish and Wildlife Service, Alaska Fisheries Data Series Number 2002-1. Fish, J. T., and S. M. Roach. 1999. Evaluation of the Arctic grayling stock in the Gulkana River, 1998. Alaska Department of Fish and Game, Fishery Data Series No. 99-28, Anchorage. Gryska, A. D. 2015. Seasonal distribution of Arctic grayling in the Upper Delta River. Alaska Department of Fish and Game, Fishery Data Series No. 15-21, Anchorage. Lotek. 2005. Guide to the SRX 600 receiver. Manual Revision A, #10112. March 16th, 2005. Lotek Fish and Wildlife Monitoring Systems. Newmarket, Ontario, Canada. NHD (National Hyrdrography Dataset). 2011. U.S. Department of the Interior, U.S. Geological Survey. http://nhd.usgs.gov/data.html (Accessed December 2011). R Core Team. 2018. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/ Roth, K. J., and M. Alexandersdottir. 1990. Assessment of the Arctic grayling sport fishery resources in the Gulkana River during 1986, 1987, and 1988. Alaska Department of Fish and Game, Fishery Data Series No. 90-49, Anchorage. Roth, K. J., and K. Delaney. 1987. Assessment of sport fishery resources in the Gulkana River with emphasis on Arctic grayling Thymallus arcticus, 1986. Alaska Department of Fish and Game, Fishery Data Series No. 17, Anchorage. Schwanke, C. J. 2015. Seasonal distribution and migration of rainbow trout in the Gulkana River, 2010-2012. Alaska Department of Fish and Game, Fishery Data Series No. 15-01, Anchorage. Somerville, M. A. 2017. Fishery management report for the recreational fisheries of the Upper Copper/Upper Susitna River management area, 2016. Alaska Department of Fish and Game, Fishery Management Report No. 17-45, Anchorage. Summerfelt, R. C., and L. S. Smith. 1990. Anesthesia, surgery, and related techniques. Pages 213-272 [In] C. B. Schreck and P. B. Moyle, editors. Methods for fish biology. American Fisheries Society, Bethesda, Maryland. Tyers, M. 2016. riverdist: River Network Distance Computation and Applications. R package version 0.12.0 https://cran.r-project.org/web/packages/riverdist/ (Accessed July 2016). Vincent-Lang, D., and M. Alexandersdottir. 1990. Assessment of the migrational habits, growth, and abundance of the Arctic grayling stocks in the Gulkana River during 1989. Alaska Department of Fish and Game, Fishery Data Series No. 90-10, Anchorage. Wagner, G. N., E. D. Stevens, and P. Byrne. 2000. Effects of suture type and patterns on surgical wound healing in rainbow trout. Transactions of the American Fisheries Society 129: 1196-1205. Williams, F. T., and W. D. Potterville. 1983. Inventory and cataloging of the sport fish and sport fish waters of the Copper River, Prince William Sound, and the Upper Susitna River drainages. Alaska Department of Fish and Game. Federal Aid in Fish Restoration, Annual Report of Progress, 1982-1983, Project F-9-15, 24(G-I-F), Juneau. Winter, J. D. 1983. Underwater telemetry. Pages 371-395 [In] L. A. Nielsen and D. L. Johnson, editors. Fisheries techniques. American Fisheries Society, Bethesda, Maryland.

APPENDIX A

25 Appendix A1.–Summary of data archival for the Gulkana River Arctic grayling telemetry study, 2016–2017.

Year Data filea Software 2017 Gulkana River_Arctic grayling_telemetrydata.xls Microsoft Excel a Data files are archived and available from the Alaska Department of Fish and Game, Division of Sport Fish, Research and Technical Services, 333 Raspberry Road, Anchorage, Alaska 99518-1599.

APPENDIX B

Appendix B1.–Date of capture, length, tag information, release location, final fate, date last found alive, days alive, and range of each radiotagged Arctic grayling, Gulkana River, 2016–2017. Radio Tag Radio Latitude Longitude FL Frequency Tag River decimal decimal Last date Days Maximum Date (mm) 148.xxx MHz Code Segmenta degrees degrees Final fate found alive alive range (km) 9/23/2016 375 410 53 AWF 62.8547 145.6710 Alive 11/3/2017 406 105.1 9/23/2016 360 340 7 AWF 62.8547 145.6710 Alive 11/3/2017 406 55.7 9/23/2016 350 340 17 AWF 62.8547 145.6710 Mortality 8/7/2017 318 37.8 9/23/2016 360 340 10 AWF 62.8547 145.6710 Missing 6/27/2017 277 81.2 9/23/2016 350 340 18 AWF 62.8547 145.6710 Alive 11/3/2017 406 60.0 9/23/2016 365 340 66 AWF 62.8547 145.6710 Mortality 11/7/2016 45 11.2 9/23/2016 365 340 8 AWF 62.8547 145.6710 Mortality 9/1/2017 343 111.7 9/23/2016 370 410 54 AWF 62.8547 145.6710 Mortality 6/27/2017 277 62.2 9/23/2016 335 340 12 AWF 62.8547 145.6710 Alive 11/3/2017 406 8.5 9/24/2016 335 340 15 AWF 62.8225 145.6640 Mortality 11/7/2016 44 62.5 9/24/2016 340 340 6 AWF 62.8225 145.6640 Alive 11/3/2017 405 109.8

28 9/24/2016 330 340 9 AWF 62.8225 145.6640 Mortality 11/7/2016 44 7.6

9/24/2016 375 340 11 AWF 62.8225 145.6640 Mortality 11/7/2016 44 6.8 9/24/2016 335 340 16 AWF 62.8039 145.6564 Mortality 9/24/2016 0 0.0 9/24/2016 330 410 52 AWF 62.8039 145.6564 Mortality 9/24/2016 0 0.0 9/24/2016 330 410 55 AWF 62.8039 145.6564 Mortality 11/7/2016 44 0.4 9/24/2016 340 340 13 AWF 62.8039 145.6564 Mortality 9/24/2016 0 0.0 9/24/2016 355 340 19 AWF 62.8039 145.6564 Mortality 6/20/2017 269 84.6 9/24/2016 335 340 14 AWF 62.8039 145.6564 Mortality 7/19/2017 298 89.7 9/24/2016 330 340 20 AWF 62.8039 145.6564 Mortality 6/6/2017 255 56.6 9/24/2016 340 410 26 AWF 62.8039 145.6564 Alive 11/3/2017 405 73.0 9/24/2016 340 410 19 AWF 62.7814 145.6261 Mortality 9/24/2016 0 0.0 9/24/2016 355 410 12 AWF 62.7814 145.6261 Mortality 11/7/2016 44 2.6 9/24/2016 335 410 28 AWF 62.7814 145.6261 Mortality 9/24/2016 0 0.0 9/24/2016 335 410 22 AWF 62.7814 145.6261 Mortality 3/22/2017 179 43.0 -continued-

Appendix B1.–Page 2 of 5. Radio Tag Radio Latitude Longitude FL Frequency Tag River decimal decimal Last date Days Maximum Date (mm) 148.xxx MHz Code Segmenta degrees degrees Final fate found alive alive range (km) 9/24/2016 340 410 27 AWF 62.7814 145.6261 Mortality 9/24/2016 0 0.0 9/24/2016 330 410 20 AWF 62.7814 145.6261 Mortality 9/24/2016 0 0.0 9/25/2016 320 410 25 AWF 62.7547 145.5867 Mortality 5/23/2017 240 3.0 9/25/2016 325 410 16 AWF 62.7547 145.5867 Mortality 11/28/2017 429 110.5 9/25/2016 320 410 11 AWF 62.7547 145.5867 Mortality 9/25/2016 0 0.0 9/25/2016 325 410 21 AWF 62.7547 145.5867 Mortality 11/7/2016 43 30.2 9/25/2016 320 410 24 AWF 62.7547 145.5867 Mortality 5/30/2017 247 6.8 9/25/2016 320 410 17 AWF 62.7547 145.5867 Mortality 7/19/2017 297 20.2 9/25/2016 320 410 18 AWF 62.7547 145.5867 Mortality 5/8/2017 225 57.1 9/25/2016 365 410 13 AWF 62.7547 145.5867 Mortality 11/7/2016 43 36.4 9/25/2016 375 410 23 AWF 62.7547 145.5867 Mortality 6/13/2017 261 69.3 9/25/2016 340 410 15 AWF 62.7278 145.5686 Alive 11/3/2017 404 58.7

29 9/25/2016 350 410 14 AWF 62.7278 145.5686 Mortality 9/25/2016 0 0.0 9/25/2016 345 410 30 AWF 62.7278 145.5686 Alive 11/3/2017 404 88.1 9/26/2016 325 410 29 AWF 62.7151 145.5884 Missing 9/1/2017 340 61.7 9/26/2016 335 430 78 AWF 62.7151 145.5884 Mortality 6/6/2017 253 57.1 9/26/2016 330 430 36 AWF 62.7151 145.5884 Alive 11/3/2017 403 90.0 9/26/2016 330 430 34 AWF 62.7151 145.5884 Mortality 9/28/2017 367 23.6 9/26/2016 330 430 32 AWF 62.7151 145.5884 Mortality 5/23/2017 239 42.4 9/26/2016 325 430 80 AWF 62.7151 145.5884 Mortality 9/1/2017 340 66.3 9/26/2016 355 430 79 AWF 62.7028 145.6286 Mortality 9/26/2016 0 0.0 9/26/2016 330 340 67 AWF 62.7028 145.6286 Mortality 5/8/2017 224 41.0 9/26/2016 335 430 82 AWF 62.7028 145.6286 Mortality 7/19/2017 296 56.0 9/26/2016 320 340 71 AWF 62.7028 145.6286 Missing 5/8/2017 224 41.7 9/26/2016 340 430 31 AWF 62.6670 145.7330 Mortality 8/7/2017 315 23.5 9/26/2016 325 340 72 AWF 62.6670 145.7330 Mortality 11/7/2016 42 19.1 -continued-

Appendix B1.–Page 3 of 5. Radio Tag Radio Latitude Longitude FL Frequency Tag River decimal decimal Last date Days Maximum Date (mm) 148.xxx MHz Code Segmenta degrees degrees Final fate found alive alive range (km) 9/26/2016 355 430 76 AWF 62.6670 145.7330 Mortality 3/22/2017 177 23.0 9/26/2016 325 430 40 AWF 62.6670 145.7330 Mortality 6/20/2017 267 32.8 9/27/2016 355 410 81 AWF 62.6596 145.7394 Mortality 9/1/2017 339 93.2 9/27/2016 345 410 66 AWF 62.6596 145.7394 Mortality 9/27/2016 0 0.0 9/27/2016 320 410 80 AWF 62.6596 145.7394 Mortality 5/8/2017 223 34.2 9/27/2016 330 410 67 AWF 62.6596 145.7394 Mortality 5/8/2017 223 68.9 9/27/2016 335 410 72 AWF 62.6423 145.7302 Mortality 8/7/2017 314 43.9 9/27/2016 380 410 78 AWF 62.6423 145.7302 Mortality 6/6/2017 252 17.6 9/27/2016 330 410 82 AWF 62.6423 145.7302 Mortality 3/22/2017 176 2.2 9/27/2016 370 410 73 AWF 62.6423 145.7302 Alive 11/3/2017 402 31.7 9/27/2016 325 410 70 AWF 62.6423 145.7302 Mortality 8/7/2017 314 42.2 9/27/2016 335 410 83 AWF 62.6397 145.7167 Mortality 5/23/2017 238 22.8

30 9/27/2016 335 410 75 AWF 62.6397 145.7167 Mortality 6/27/2017 273 30.1 9/27/2016 330 410 79 AWF 62.6397 145.7167 Mortality 9/28/2017 366 109.0 9/27/2016 335 410 84 AWF 62.6397 145.7167 Mortality 9/27/2016 0 0.0 9/27/2016 325 410 76 AWF 62.6397 145.7167 Mortality 9/27/2016 0 0.0 9/27/2016 330 410 69 AWF 62.6397 145.7167 Mortality 7/19/2017 295 115.3 9/27/2016 325 410 65 AWF 62.6397 145.7167 Mortality 11/7/2016 41 21.5 9/27/2016 330 410 71 AWF 62.6240 145.6998 Mortality 8/7/2017 314 23.2 9/27/2016 355 410 77 AWF 62.6240 145.6998 Mortality 8/7/2017 314 28.4 9/27/2016 345 410 68 AWF 62.6240 145.6998 Mortality 6/27/2017 273 54.5 9/27/2016 335 410 74 AWF 62.6240 145.6998 Mortality 5/8/2017 223 16.0 9/27/2016 335 430 39 AWF 62.6240 145.6998 Alive 11/3/2017 402 70.6 9/27/2016 340 430 33 AWF 62.6240 145.6998 Mortality 8/7/2017 314 100.3 9/27/2016 330 340 70 AWF 62.6240 145.6998 Alive 11/3/2017 402 30.9 9/28/2016 360 430 37 AWF 62.5973 145.6159 Mortality 7/19/2017 294 62.3 -continued-

Appendix B1.–Page 4 of 5. Radio Tag Radio Latitude Longitude FL Frequency Tag River decimal decimal Last date Days Maximum Date (mm) 148.xxx Code Segmenta degrees degrees Final fate found alive alive range (km) 9/28/2016 330 340 68 AWF 62.5973 145.6159 Mortality 9/28/2016 0 0.0 9/28/2016 330 340 69 AWF 62.5973 145.6159 Mortality 6/27/2017 272 5.8 9/28/2016 325 430 35 AWF 62.5973 145.6159 Mortality 5/23/2017 237 41.2 9/28/2016 325 430 81 AWF 62.5973 145.6159 Mortality 5/16/2017 230 11.9 9/28/2016 335 430 77 AWF 62.5973 145.6159 Alive 11/3/2017 401 10.5 9/28/2016 365 340 73 AWF 62.5973 145.6159 Alive 11/3/2017 401 36.7 9/28/2016 330 340 74 AWF 62.5973 145.6159 Mortality 9/28/2016 0 0.0 9/30/2016 320 340 64 BWF 62.5529 145.5507 Mortality 11/7/2016 38 0.1 9/30/2016 325 340 58 BWF 62.5529 145.5507 Missing 6/27/2017 270 11.1 9/30/2016 320 410 85 BWF 62.5529 145.5507 Mortality 6/13/2017 256 11.2 9/30/2016 340 340 62 BWF 62.5529 145.5507 Missing 6/27/2017 270 79.2 9/30/2016 320 340 57 BWF 62.5529 145.5507 Missing 6/13/2017 256 19.5

31 9/30/2016 320 410 59 BWF 62.5529 145.5507 Missing 9/28/2017 363 95.4 9/30/2016 340 410 58 BWF 62.5575 145.5612 Alive 11/3/2017 399 10.9 9/30/2016 325 340 59 BWF 62.5575 145.5612 Mortality 6/13/2017 256 70.8 9/30/2016 320 410 61 BWF 62.5575 145.5612 Alive 11/3/2017 399 36.0 9/30/2016 355 410 57 BWF 62.5575 145.5612 Mortality 5/23/2017 235 17.2 9/30/2016 330 430 38 BWF 62.5575 145.5612 Mortality 6/20/2017 263 42.6 9/30/2016 375 410 64 BWF 62.5575 145.5612 Mortality 11/7/2016 38 6.8 9/30/2016 335 340 63 BWF 62.5575 145.5612 Mortality 11/7/2016 38 13.4 9/30/2016 335 340 60 BWF 62.5575 145.5612 Mortality 11/7/2016 38 19.0 9/30/2016 355 340 65 BWF 62.5575 145.5612 Missing 11/7/2016 38 42.1 9/30/2016 325 410 60 BWF 62.5575 145.5612 Mortality 5/23/2017 235 15.7 9/30/2016 335 340 61 BWF 62.5575 145.5612 Missing 9/30/2016 0 0.0 9/30/2016 330 410 62 BWF 62.5575 145.5612 Mortality 3/22/2017 173 17.9 9/30/2016 340 340 56 BWF 62.5575 145.5612 Alive 11/3/2017 399 75.0 -continued-

Appendix B1.–Page 5 of 5. Radio Tag Radio Latitude Longitude FL Frequency Tag River decimal decimal Last date Days Maximum Date (mm) 148.xxx Code Segmenta degrees degrees Final fate found alive alive range (km) 9/30/2016 335 410 63 BWF 62.5575 145.5612 Mortality 5/23/2017 235 18.0 9/28/2016 335 410 56 AWF 62.5575 145.5612 Missing 11/7/2016 38 2.4 9/28/2016 325 410 31 AWF 62.5575 145.5612 Mortality 6/27/2017 270 28.1 9/28/2016 325 410 35 AWF 62.5575 145.5612 Mortality 6/6/2017 249 26.1 9/28/2016 340 410 42 AWF 62.5575 145.5612 Mortality 9/1/2017 336 37.0 10/1/2016 345 410 32 AWF 62.5737 145.6260 Alive 11/3/2017 398 111.9 10/1/2016 345 410 47 AWF 62.5737 145.6260 Missing 6/13/2017 255 70.5 10/1/2016 340 410 51 BWF 62.5737 145.6260 Alive 11/3/2017 398 96.8 10/1/2016 330 410 37 BWF 62.5737 145.6260 Alive 11/3/2017 398 7.1 10/1/2016 325 410 39 BWF 62.5737 145.6260 Mortality 5/30/2017 241 22.4 10/1/2016 355 410 41 BWF 62.5737 145.6260 Mortality 9/1/2017 335 38.5 10/1/2016 325 410 50 BWF 62.5737 145.6260 Mortality 5/30/2017 241 22.6

32 10/1/2016 360 410 44 BWF 62.5737 145.6260 Alive 11/3/2017 398 80.5 10/1/2016 320 410 43 BWF 62.5737 145.6260 Mortality 11/7/2016 37 13.4 10/1/2016 355 410 34 BWF 62.5639 145.6057 Missing 9/28/2017 362 56.0 10/1/2016 375 410 33 BWF 62.5639 145.6057 Missing 10/1/2016 0 0.0 10/1/2016 360 410 36 BWF 62.5639 145.6057 Mortality 6/27/2017 269 33.8 10/1/2016 330 410 38 BWF 62.5639 145.6057 Mortality 10/1/2016 0 0.0 10/1/2016 355 410 49 BWF 62.5639 145.6057 Mortality 3/22/2017 172 16.5 10/1/2016 340 410 46 BWF 62.5639 145.6057 Mortality 6/13/2017 255 10.2 10/1/2016 350 410 48 BWF 62.5639 145.6057 Mortality 9/28/2017 362 69.3 10/1/2016 355 410 40 BWF 62.5639 145.6057 Mortality 9/1/2017 335 13.4 10/1/2016 330 410 45 BWF 62.5639 145.6057 Mortality 5/16/2017 227 11.6 a AWF = Above West Fork Gulkana River confluence; BWF = Below West Fork Gulkana River confluence.