Seasonal Distributions and Migrations of Arctic Grayling in the Goodpaster River

Fishery Data Series No. 19-11

by Andrew D. Gryska

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 REPORT NO. 19-11

SEASONAL DISTRIBUTIONS AND MIGRATIONS OF ARCTIC GRAYLING IN THE GOODPASTER RIVER

By Andrew D. Gryska Division of Sport Fish, Fairbanks

Alaska Department of Fish and Game Division of Sport Fish, Research and Technical Services 333 Raspberry Road, Anchorage, Alaska, 99518-1599

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-10-30, Job No. R-3-2(d)

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.

Andrew D. Gryska, Alaska Department of Fish and Game, Division of Sport Fish, 1300 College Road, Fairbanks, AK 99701-1599 USA

This document should be cited as follows: Gryska, A. D. 2019. Seasonal distributions and migrations of Arctic grayling in the Goodpaster River. Alaska Department of Fish and Game, Fishery Data Series No. 19-11, 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 ...... iii LIST OF APPENDICES ...... iii ABSTRACT ...... 1 INTRODUCTION ...... 1 OBJECTIVES ...... 2 METHODS ...... 2 Study Area ...... 2 Experimental And Sampling Design ...... 2 Data Collection ...... 6 Data Analysis ...... 6 Objective 1–Overwintering distribution of Arctic grayling ...... 6 Objective 2–Seasonal distributions and migrations of Arctic grayling ...... 6 RESULTS ...... 7 Objective 1 ...... 7 Objective 2 ...... 7 DISCUSSION ...... 19 Objective 1 ...... 19 Objective 2 ...... 30 Evaluation of study ...... 30 Conclusions and recommendations ...... 31 ACKNOWLEDGEMENTS ...... 32 REFERENCES CITED ...... 33 APPENDIX A: TABLE OF RADIOTAGGED ARCTIC GRAYLING ...... 35 APPENDIX B: DATA FILE LISTING ...... 43

LIST OF TABLES Table Page 1. List of possible fates of Arctic grayling radiotagged in the Goodpaster River ...... 5 2. Number of live and dead fish observed in each area during each survey...... 9 3. Number of live and dead fish observed in each area during each survey when locations of at-large fish were interpolated using other survey data for those fish...... 11 4. Proportion of fish observed in each area during each survey when locations of at-large fish were interpolated using other survey data for those fish...... 12 5. Standard error of proportions of fish observed in each area during each survey when locations of at- large fish were interpolated using other survey data for those fish...... 13 6. Average movement, standard deviation, maximum upstream distance, and maximum downstream distance of radiotagged Arctic grayling in the Upper Goodpaster River from preceding survey and initial tagging location ...... 15

LIST OF FIGURES Figure Page 1. The Goodpaster River study area...... 3 2. Length–frequency histogram of the frequency of radiotagged fish by each 20 mm FL length group...... 10 3. Tagging locations in the Goodpaster River during August 11–16, 2014 ...... 14 4. Locations of radiotagged Arctic grayling during an aerial survey September 19, 2014 ...... 16 5. Locations of radiotagged Arctic grayling during an aerial survey October 16, 2014 ...... 17 6. Locations of radiotagged Arctic grayling during an aerial survey December 11, 2014 ...... 18 7. Locations of radiotagged Arctic grayling during an aerial survey February 26, 2015 ...... 20 8. Locations of radiotagged Arctic grayling during an aerial survey March 31, 2015 ...... 21 9. Locations of radiotagged Arctic grayling during an aerial survey April 29, 2015 ...... 22 10. Locations of radiotagged Arctic grayling during an aerial survey May 12, 2015 ...... 23 11. Locations of radiotagged Arctic grayling during an aerial survey May 27, 2015 ...... 24 12. Locations of radiotagged Arctic grayling during an aerial survey July 3, 2015 ...... 25 13. Locations of radiotagged Arctic grayling during an aerial survey August 12, 2015 ...... 26 14. Locations of radiotagged Arctic grayling during an aerial survey September 24, 2015 ...... 27 15. Locations of radiotagged Arctic grayling during an aerial survey December 11, 2015 ...... 28 16. Higher densities of radiotagged Arctic grayling in the Upper and Lower Goodpaster during an aerial survey February 26, 2015 ...... 29

LIST OF APPENDICES Appendix Page A1. Date of capture, length, release location, and final fate assignments for each radiotagged Arctic grayling...... 36 B1. Data files for radiotagged Arctic grayling in the Goodpaster River...... 44

iii

ABSTRACT The Alaska Department of Fish and Game and the Sumitomo Metal Mining Pogo LLC cooperated on a radiotelemetry project that investigated the seasonal distributions and migrations of Arctic grayling Thymallus arcticus inhabiting the Middle and Upper Goodpaster River, relative to the Pogo Mine. Radio tags were surgically implanted into 178 Arctic grayling of adult size (281–460 mm fork length [FL]) during August 2014, and locations were periodically determined through 12 aerial surveys occurring between September 2014 and December 2015. Before winter arrived, Arctic grayling vacated all small tributaries and most fish (95%) overwintered throughout the mainstem Goodpaster River, while a few individuals resided in the Tanana River. The largest concentration of radiotagged fish (57%; SE = 4.3%) was located in the 32.5 km Upper Goodpaster River section, between Glacier Creek and the Eisenmenger Fork (), and the smallest concentration (8%; SE = 2.4%) was located adjacent to the mine in the Middle Goodpaster River section, between Glacier and Central creeks (32.5 km). The Lower Goodpaster River section, from Central Creek to the mouth (104 km), held 30% (SE = 4.0%) of fish during winter, half of which were in the lower 25 km. Most grayling spawned near their overwintering area. After spawning, the tagged fish quickly vacated the Lower Goodpaster River and dispersed throughout the Middle and Upper Goodpaster River mainstem and tributaries. Fidelity to their summer feeding areas was observed but varied among individuals, including one fish that left the Goodpaster River and migrated to the Delta Clearwater River. These results indicate that impacts to the Arctic grayling population by a disturbance are lessened because the population is widely distributed and has an ability to disperse and recolonize. Nonetheless, the water quality and quantity of the migration corridor are key to the resilience of the population. Finally, these seasonal locations and the timing to and from all seasonal habitats can be used to avoid or greatly reduce impacts due to ongoing and future development. Key words: Arctic grayling, Thymallus arcticus, radiotelemetry, seasonal distributions, Goodpaster River, Alaska INTRODUCTION Arctic grayling Thymallus arcticus are widely distributed throughout most large interior Alaska rivers, and they are an important recreational species. Within the upper reaches of the Goodpaster River, a population of Arctic grayling has long existed virtually undisturbed. During the 1990s, successful gold exploration occurred in the area, and plans to construct a mine were developed. Prior to construction of the mine, Teck-Cominco (the original owner) and the Alaska Department of Fish and Game (ADF&G) agreed to proactively fund and collect baseline data on Arctic grayling to be used in the future for monitoring ecosystem health and understanding their population dynamics. ADF&G has estimated abundance of the springtime spawning population of Arctic grayling in the lower river (1995–2002; Ridder 1998a; Parker 2002, 2003) and of the summer population adjacent to Pogo mine (2003, 2004, and 2012; Parker 2006; Parker et al. 2007; Gryska 2013). Although these estimates provided information about abundance at a specific time and place, there was little known about the migrations and seasonal locations of Arctic grayling occupying the Goodpaster River drainage upstream of and including Central Creek during summer. During autumn, Arctic grayling typically vacate small tributaries and upper portions of a drainage because of the impending loss of habitat during winter, when river discharge reaches annual lows and some streambeds go dry or freeze to the bottom (Tack 1980; Gryska 2011). For winter, Arctic grayling seek habitat that minimizes energy expenditure (e.g., low-velocity water), has physiochemically suitable water (e.g., adequate depth and oxygen, no frazil ice), and provides cover from predators (e.g., overhead ice; Cunjak 1996). Winter habitat may be limited, and in conjunction with reduced metabolism (less feeding and competition for food and space), normally competitive fish may be restricted to large overwintering congregations (Cunjak 1996; Gryska 2015). As winter ends, Arctic grayling typically migrate short distances to their spawning areas just before and after breakup (Gryska 2011). After spawning, Arctic grayling redistribute to summer feeding areas often located in the headwaters (Gryska 2006, 2011).

During early spring 2005, sampling conducted just prior to spawning indicated that substantial numbers of Arctic grayling were present between Central Creek (14.5 km downstream of Pogo Mine) and Rock Creek (40 km upstream of Pogo Mine; A. Gryska, field notebook, Fairbanks). It was hypothesized that these fish probably overwintered nearby, between Central Creek and the Eisenmenger Fork (52 km upstream of Pogo Mine), and that this stretch of river contained a finite number of locations with suitable overwintering habitat where substantial numbers of Arctic grayling could aggregate. During winter, some of these locations may become isolated refugia from which fish cannot migrate. For these reasons, Arctic grayling, as well other fishes, are most vulnerable to declines in water quality and quantity during late winter. Identification of overwintering habitats and timing of migrations to and from all seasonal habitats were needed to avoid or greatly reduce impacts associated with ongoing and future development. To facilitate this study’s design and implementation, the Goodpaster River (GPR) mainstem was divided into 3 areas: 1) Upper (Glacier Creek to the North Fork GPR), 2) Middle (Central Creek to Glacier Creek), and, 3) Lower (downstream of Central Creek). OBJECTIVES For mature Arctic grayling radiotagged upstream of and including Central Creek, the objectives were to: 1) estimate the proportion that overwinter in the Upper, Middle, and Lower Goodpaster River such that the estimates would be within 8.5 percentage points of the true value 90% of the time; and 2) describe the seasonal movements and locations with an emphasis on documenting overwintering, spawning, and summer resident areas. METHODS STUDY AREA The tagging area was inclusive of all drainages beginning with Central Creek, and it is approximately 2,150 km2 (Figure 1). The telemetry survey area was much larger, encompassing the entire Goodpaster River drainage, the Delta Clearwater River, the Richardson Clearwater River, Shaw Creek, and the Tanana River between each of these tributaries. Previous studies of spawning Arctic grayling in the lower river indicated migrations to all of the described survey areas, and Arctic grayling tagged in the upper river have been recaptured in the Delta Clearwater River (Gryska In prep; Ridder 1998a; Wuttig and Gryska 2010). EXPERIMENTAL AND SAMPLING DESIGN Radiotelemetry techniques were used to collect location and movement data to describe seasonal locations and migrations of Arctic grayling that occupy the waters upstream of and including Central Creek during summer (Figure 1). Radio tags were surgically implanted in 178 Arctic grayling captured throughout this area (Appendix A1). The mainstem Goodpaster River (from the North Fork GPR to Central Creek) and larger tributaries were selected for the distribution of tags. The majority of the mainstem river in this area had a recent stock assessment (Gryska 2013); however, the remaining sample reaches had no previous stock assessments or sampling to determine densities or even presence of Arctic grayling.

Lower

Figure 1.–The Goodpaster River study area.

Radio tags were distributed throughout the study area systematically; each sample reach was allocated a proportion of the radio tags roughly based on the length of each reach. All sample reaches were remote and were accessed using helicopter transport. While flying, the chosen sample reaches were inspected for habitat likely to hold fish adjacent to suitable landing terrain. Some reaches did not hold Arctic grayling, and consequently, modifications to the distribution of tags and of the sample reaches occurred as needed. Unbiased total population estimates could not be made for the Goodpaster River drainage because radio tags could not be allocated by abundance and size composition of Arctic grayling in each sample reach. However, the systematic distribution of the tags through the drainage minimized bias and maximized identification of seasonal habitats and migratory behavior for the majority of the population from August 2014 through December 2015. Arctic grayling were captured by angling with both spin and fly gear. Terminal spin gear consisted of rubber-bodied jigs of varied size (1/16–1/4 oz and size 2–6 hooks) and fly gear consisted of an assortment of flies (e.g., Adams fly, Blue Dunn fly, or bead-head nymphs). Sampling was conducted during late summer, when Arctic grayling were widely distributed in their upper river summer locations and water temperatures were beginning to cool as fall approached. Warm water is stressful to grayling (LaPerriere and Carlson 1973; Lohr et al. 1996; Schrank et al. 2003), and by avoiding it, it was expected that healing and survival would be enhanced. Only fish that appeared to be healthy were surgically implanted with a radio tag. Radio tags were surgically implanted following the basic surgical methods detailed by Brown (2006) and Morris (2003). To ensure that most tagged fish were mature, fish ≥320 mm fork length (FL) were targeted because Clark (1992) found that 98% of grayling were mature by this size, but in 15 instances, smaller fish (281–319 mm FL) were radiotagged because some sample locations had limited catches. Fish smaller than 330 mm and larger than 270 mm are reliably recruited to sampling gear, and a significant number (≥80%) are likely to be mature within the timeframe of this study (Clark 1992). Additionally, gonads were inspected through the incision when possible, and gender was identified and recorded, although gender was usually difficult to identify because fish were captured 8 months prior to spawning. The radio tags were model MST-930 by Lotek, which are small (9.5 mm x 26 mm), lightweight (4 g), and have at least a 15-month operational life when programmed appropriately. These radio tags were programmed to emit radio signals 10 h/day between 8 AM and 6 PM (Alaska Daylight Time). Each tag emitted an individual code on a single radio frequency (148.660 MHz). Locations of radiotagged Arctic grayling were determined using periodic flights in a fixed wing aircraft. Tracking flights utilized a Lotek SRX 600 receiver with an internal GPS that recorded time and location data. Flights occurred during a 16-month period primarily to determine locations of winter refuge, pre-spawning, spawning, and subsequent summer feeding habitats. The periodicity of flights varied between 2 weeks and 3 months dependent upon typical Arctic grayling behavior (e.g., more flights were conducted before, during, and after spawning). To facilitate data analysis, all radiotagged Arctic grayling were assigned a “fate” during each tracking survey (Table 1). Fates (tagging mortality, post-tagging mortality, alive, and at-large) were assigned based on information collected from aerial surveys and returned tags from harvested fish. Fish with an at-large designation during a survey were assigned a location (e.g., Upper, Middle, or Lower GPR) if its location could be interpolated from surveys before and after. Following fate assignments, seasonal locations and migratory periods were described and depicted on maps.

Table 1.–List of possible fates of Arctic grayling radiotagged in the Goodpaster River (GPR).

Fate Description Alive (A) A fish alive on final survey; not indicative of location. At-large (AL) A fish that was not located during an aerial survey. Unknown (U) A fish that was not located on an aerial survey and all subsequent surveys. Mortality (M) 1. Tagging Mortality (TM) – a fish that died in response to tag implantation or died between tagging and the first aerial survey (as inferred from aerial surveys). Fish with this fate were not used for calculating proportions. 2. Angling Mortality (AM) – a fish that was reported harvested. Fish with this fate were not used for calculating proportions following the report. 3. Post-Tagging Mortality (PM) – a fish that was known to be alive during at least one prior survey but was judged to be dead at the time of the survey being conducted. Fish with this fate were not used for calculating proportions subsequent to the survey it was known to be dead. Upper GPR A fish known to be alive at the time of survey within the GPR between the mouth of the North Fork GPR and the mouth of Glacier Creek. Middle GPR A fish known to be alive at the time of survey within the GPR between the mouth of Glacier Creek and the mouth of Central Creek. Lower GPR A fish known to be alive at the time of survey within the GPR from the mouth of Central Creek to the Tanana River. North Fork GPR A fish known to be alive at the time of survey within the North Fork GPR. Eisenmenger Fork A fish known to be alive at the time of survey within the Eisenmenger Fork. Eisenmenger tributary 1 A fish known to be alive at the time of survey within the Eisenmenger tributary No 1. Eisenmenger tributary 2 A fish known to be alive at the time of survey within the Eisenmenger tributary No 2. Boulder Creek A fish known to be alive at the time of survey within Boulder Creek. Tibbs Creek A fish known to be alive at the time of survey within Tibbs Creek. Central Creek A fish known to be alive at the time of survey within Central Creek. Slate Creek A fish known to be alive at the time of survey within Slate Creek. Delta Clearwater River A fish known to be alive at the time of survey within the DCR. (DCR) Tanana A fish known to be alive at the time of survey within the Tanana River.

DATA COLLECTION For each fish implanted with a radio tag, length (nearest mm FL), gender, GPS waypoint of capture/release location (decimal degree NAD27 Alaska datum), radio tag frequency and code, and Floy tag number and color 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 internal GPS. DATA ANALYSIS Objective 1–Overwintering distribution of Arctic grayling The proportion of Arctic grayling that resided in a section of the Goodpaster River during winter was estimated as a binomial proportion:

nl pˆl = n ; (1) where:

nl = the number of radiotagged Arctic grayling located within a section (l) during the February survey. Possible locations were as follows: • Upper GPR • Middle GPR • Lower GPR • other n = the number of working radio tags at the time of the February survey. The variance of the proportion was estimated by the following (Cochran 1977): pˆ (1− pˆ ) var(pˆ ) = l l l n −1 l (2) Objective 2–Seasonal distributions and migrations of Arctic grayling Data analysis consisted of plotting locations of radiotagged Arctic grayling on maps and constructing a data profile of each radiotagged fish. Maps depicting each survey were constructed using ArcGIS software. Profiles included all relevant data collected from each radiotagged fish: length at capture, sex, capture location, and location or status (at-large, mortality, or unknown) during each survey. For each radiotagged Arctic grayling, a location and status history was recorded in a table and tallied by survey. Status was determined by interpreting information collected during aerial tracking surveys (Table 1). Because Arctic grayling are highly migratory, mortality was inferred if an Arctic grayling was located more than once and failed to move a significant distance (>5 km) when migrations were expected and apparent among other radiotagged fish. Distance traveled between each survey was measured in river km, and the average and SD were calculated and recorded in a table as well as minimum and maximum distances.

RESULTS Arctic grayling were captured and tagged at 32 locations in 8 of the 10 sample areas. Slate and Indian creeks did not yield any fish, and Glacier Creek had only one fish tagged. A total of 121 (68%) radio tags were deployed in tributaries of the Goodpaster River, and 57 (32%) were deployed in the Middle and Upper Goodpaster River (Table 2). Tagged fish ranged in size from 281 to 460 mm FL, of which only 15 were less than 320 mm FL (Figure 2). Gender was identified for 148 fish (84 females and 64 males; Appendix A1). Within the first 4 months, there were 41 cumulative mortalities (Table 2). Two fish were deemed tagging mortalities because they never moved following surgery. Two other fish were captured and killed by anglers about 1 month after deployment. The other 37 fish made definitive movements after tagging, suggesting survival for 1 to 4 months post-surgery, but it is impossible to determine what proportion of mortality was due to complications from surgery as opposed to other natural causes. It is reasonable to expect that most (>75%) mortalities were due to complications from surgery because mortality was negligible thereafter, with only 6 more fish dying between early May and December 2015. The unknown fate became prominent in the latter part of the study. Only 5 fish were assigned this fate through the April survey, but each survey from early May through September 2015 had 8 to 17 unknown fates assigned to fish. An additional 23 fish were at-large during the last survey during December 2015, and because there were no subsequent surveys to verify status, these fish essentially had unknown fates. Many radiotagged Arctic grayling were assigned an at-large fate (Table 2). Fish with an at-large designation during a survey were assigned a location (Upper, Middle, or Lower GPR) if a fish’s location could be interpolated from locations determined by surveys before and after (Table 3). In particular, the interpretations were most feasible during the December and March surveys when fish were not migrating. Objective 1 The February 26, 2015 survey was utilized to address Objective 1 while the December 2014 and March 2014 surveys provided additional support (Tables 2–5). The Middle GPR had 11 radiotagged fish (p = 0.08, SEp = 0.024), and the Lower GPR had 41 radiotagged fish (p = 0.30, SEp = 0.040). The remaining fish were in the Upper GPR (n = 77, p = 0.57, SEp = 0.043), the Tanana River (n = 3, p = 0.02, SEp = 0.013), and at-large (n = 3, p = 0.02, SEp = 0.013). The December 2014 and March 2015 surveys had similar distributions; however, each survey had 32 and 30 fish at-large, respectively, which resulted in reduced proportions particularly for the Upper GPR (Table 2). The proportions of tagged fish in the Upper GPR during December (2014), February (2015), and March (2015) were 0.35, 0.53, and 0.37 (SEp = 0.040, 0.043, and 0.041), respectively. By interpolating the locations of at-large fish, the Upper GPR proportions during each survey became 0.55, 0.57, and 0.54 (SEp = 0.042, 0.043, and 0.043), respectively. Objective 2 The project began by tagging Arctic grayling captured at their late summer locations throughout the GPR drainage upstream of and including Central Creek (Tables 3 and 4, Figure 3). By the first survey on September 19, the radiotagged fish had traveled an average of -22.6 km downriver (Table 6). Nearly all fish (65 of 73) had vacated the smaller tributary streams (Central, Tibbs,

Boulder, and Glacier creeks; North Fork GPR; and 2 unnamed tributaries of the Eisenmenger Fork) and migrated into the Eisenmenger Fork, and the Upper, Middle, and Lower GPR (Figure 4). Simultaneously, some of the Arctic grayling radiotagged in the Eisenmenger Fork and Upper and Middle GPR moved downstream toward Lower GPR overwintering areas. Movements downstream (average of -22.1 km) continued through October 2014, such that the Eisenmenger Fork was nearly devoid of tagged fish (Figure 5). By December 2014, downstream migrations (average -2.1 km; Figure 6) were complete, and average down and upstream movements were minimal between the next 2 surveys (average -0.4 and 0.1 km, for February and March 2015, respectively; Figures 7 and 8). By April 2015, significant movements of some individuals were detected (Figure 9) downstream (-33 km) and upstream (25.0 km), including 12 fish moving upstream to the Eisenmenger Fork, but the average movement was only 2.1 km. A flight 2 weeks later (May 12), during the likely spawning period, indicated that the average distance moved was -5.0 km, but some individuals traversed large distances as indicated by the maximum upstream (55.5 km) and downstream (-86.0 km) distances (Table 6). An additional 7 fish had entered the Eisenmenger Fork, which amounted to 15% of fish during the survey. The other fish were located in Upper GPR (34%), the Lower GPR (31%), Central Creek (3%), and North Fork GPR (1%; Figure 10). By May 27, 2015, radiotagged Arctic grayling had vacated spawning areas and were infiltrating tributaries, traveling an average of 29.0 km between surveys (Figure 11). Migrations to summer habitats were complete by July 2015 (average travel distance between surveys was 12.7 km; Figure 12). At that time, only 2 fish (2%) remained in the Lower GPR, but they had moved upstream to locations just downstream of Central Creek. The Middle GPR retained 4% of fish, and the Upper GPR retained 13% of fish after having a majority (57%) of the overwintering fish in February. The remaining fish (72%) were dispersed into large and small tributaries (with one fish in the Delta Clearwater River) and 9% were at-large. The August 2015 survey yielded no real changes from July (average travel distance was 0.1 km; Figure 13). By September 2015, most tributaries were vacated (average travel distance was -18.8 km) and the Eisenmenger Fork (38%), Upper GPR (20%), and Lower GPR (11%) had most of the radiotagged fish (Figure 14). Migrations continued in the fall, and by December 2015 (Figure 15) fish had traveled -19.1 km on average since September. The survey was similar to the previous December survey; most radiotagged fish were in the Upper GPR (36%) and the Lower GPR (21%), with a few fish (4%) in the Middle GPR (Table 4; Figures 6 and 15). The undetermined fate of at-large fish during this last survey accounted for 33% of all tagged fish. When the at-large fish and fish with an unknown fate were excluded from the denominator for the final survey, the proportions for the Upper, Lower, and Middle GPR were 53%, 32%, and 6%, respectively.

Table 2.–Number of live and dead fish observed in each area during each survey.

Survey Date 2014 2015 Location Tagged 9/19 10/16 12/11 2/26 3/31 4/29 5/12 5/27 7/3 8/12 9/24 12/11 a Upper GPR 31 55 56 (7) 49 (1) 71 50 57 41 (1) 16 12 8 14 25 b Middle GPR 27 13 (2) 12 (3) 11 11 11 12 14 13 4 3 4 3

Lower GPR 0 23 (2) 38 (6) 40 (3) 39 40 39 39 14 (1) 2 0 8 15

North Fork GPR 15 1 0 0 0 0 0 1 8 10 6 4 1

Eisenmenger Fork 47 40 1 (6) 0 (1) 0 1 12 19 25 15 11 26 2 (1)

Tributary 1 5 1 0 0 0 0 0 0 1 4 3 1 0

Tributary 2 10 0 0 0 0 0 0 0 5 6 (1) 6 1 0

Boulder Creek 14 0 (2) 0 0 0 0 0 0 9 12 12 1 (1) 0

Tibbs Creek 9 3 0 0 0 0 0 0 2 6 4 2 0

Central Creek 20 4 0 (1) 0 0 0 1 3 5 9 10 4 0 Slate Creek 0 0 0 0 0 0 0 0 1 1 0 0 0 Tanana River 0 0 3 (2) 3 (1) 2 3 1 0 0 0 0 (1) 0 0 DCRc 0 0 0 0 0 0 0 0 1 1 1 1 0 At-large 0 28 31 32 12 31 10 6 10 9 13 4 23

d e f

9 Mortality 2 8 25 6 0 0 0 1 1 1 1 1 1

Unknown 0 0 2 0 0 1 2 8 12 18 13 6 0 a GPR = Goodpaster River b Middle GPR includes one fish tagged in Glacier Creek. No tagged fish were present in Glacier Creek during any subsequent surveys. c DCR = Delta Clearwater River d The number of radiotagged fish observed in each area during each survey includes mortalities. If mortalities were included, the number has been indicated within parentheses. e Tagging mortalities. f In addition to 6 mortalities that had moved by the first survey, there were 2 angling mortalities.

Figure 2.–Length-frequency histogram of the frequency of radiotagged fish by each 20 mm FL length group.

Table 3.–Number of live and dead fish observed in each area during each survey when locations of at-large fish were interpolated using other survey data for those fish. Survey Date 2014 2015 Location Tagged 9/19 10/16 12/11 2/26 3/31 4/29 5/12 5/27 7/3 8/12 9/24 12/11 Upper GPRa 31 60 71 (7) 76 (1) 77 72 63 41 (1) 16 12 8 14 25 Middle GPRb 27 15 (2) 14 (3) 11 11 12 12 16 13 4 3 4 3 Lower GPR 0 23 (2) 38 (6) 40 (3) 41 41 40 39 14 (1) 2 0 8 15 North Fork GPR 15 1 0 0 0 0 0 1 8 10 7 4 1 Eisenmenger Fork 47 40 1 (6) 0 (1) 0 1 12 19 25 15 11 27 2 (1) Tributary 1 5 1 0 0 0 0 0 0 1 4 3 1 0 Tributary 2 10 0 0 0 0 0 0 0 5 6 (1) 6 1 0 Boulder Creek 14 0 (2) 0 0 0 0 0 0 9 12 12 1 (1) 0 Tibbs Creek 9 3 0 0 0 0 0 0 2 6 4 2 0 Central Creek 20 4 0 (1) 0 0 0 1 3 6 10 10 4 0 Slate Creek 0 0 0 0 0 0 0 0 1 1 0 0 0 Tanana River 0 0 3 (2) 3 (1) 3 3 1 0 0 0 0 (1) 0 0 DCRc 0 0 0 0 0 0 0 0 1 1 1 1 0 At-large 0 21 14 5 3 5 3 4 9 8 12 3 23 Total 178 174 166 141 135 134 132 124 111 92 78 71 70 11 Mortalityd 2e 8f 25 6 0 0 0 1 1 1 1 1 1 Unknown 0 0 2 0 0 1 2 8 12 18 13 6 0 a GPR = Goodpaster River b Middle GPR includes one fish tagged in Glacier Creek. No tagged fish were present in Glacier Creek during any subsequent surveys. c DCR = Delta Clearwater River d The number of radiotagged fish observed in each area during each survey includes mortalities. If mortalities were included, the number has been indicated within parentheses. e Tagging mortalities. f In addition to 6 mortalities that had moved by the first survey, there were 2 angling mortalities.

Table 4.–Proportion of fish observed in each area during each survey when locations of at-large fish were interpolated using other survey data for those fish. Survey Date 2014 2015 Location Tagged 9/19 10/16 12/11 2/26 3/31 4/29 5/12 5/27 7/3 8/12 9/24 12/11

Upper GPRa 0.17 0.34 0.47 0.55 0.57 0.54 0.48 0.34 0.14 0.13 0.10 0.20 0.36

Middle GPRb 0.15 0.10 0.10 0.08 0.08 0.09 0.09 0.13 0.12 0.04 0.04 0.06 0.04

Lower GPR 0.00 0.14 0.27 0.30 0.30 0.31 0.30 0.31 0.14 0.02 0.00 0.11 0.21

North Fork GPR 0.08 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.07 0.11 0.09 0.06 0.01

Eisenmenger Fork 0.26 0.23 0.04 0.01 0.00 0.01 0.09 0.15 0.23 0.16 0.14 0.38 0.04

Tributary 1 0.03 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.04 0.04 0.01 0.00

Tributary 2 0.06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.09 0.08 0.01 0.00

Boulder Creek 0.08 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.08 0.13 0.15 0.03 0.00

Tibbs Creek 0.05 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.06 0.05 0.03 0.00

Central Creek 0.11 0.02 0.01 0.00 0.00 0.00 0.01 0.02 0.05 0.11 0.13 0.06 0.00 Slate Creek 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.00 Tanana River 0.00 0.00 0.03 0.03 0.02 0.02 0.01 0.00 0.00 0.00 0.01 0.00 0.00 DCRc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.00 12 At-large 0.00 0.12 0.08 0.04 0.02 0.04 0.02 0.03 0.08 0.09 0.15 0.04 0.33

Total 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

Cumulative Proportions Mortality 0.01 0.06 0.20 0.23 0.23 0.23 0.23 0.24 0.24 0.25 0.25 0.26 0.26 Unknown 0.00 0.00 0.01 0.01 0.01 0.02 0.03 0.07 0.14 0.24 0.31 0.35 0.35 a GPR = Goodpaster River b Middle GPR includes one fish tagged in Glacier Creek. No tagged fish were present in Glacier Creek during any subsequent surveys. c DCR = Delta Clearwater River

Table 5.–Standard error of proportions of fish observed in each area during each survey when locations of at-large fish were interpolated using other survey data for those fish. Survey Date 2014 2015 Location 9/19 10/16 12/11 2/26 3/31 4/29 5/12 5/27 7/3 8/12 9/24 12/11

Upper GPRa 0.036 0.039 0.042 0.043 0.043 0.044 0.043 0.033 0.035 0.035 0.048 0.058

Middle GPRb 0.022 0.024 0.023 0.024 0.025 0.025 0.030 0.031 0.021 0.022 0.028 0.024

Lower GPR 0.026 0.034 0.039 0.040 0.040 0.040 0.042 0.033 0.015 0.000 0.038 0.049

North Fork GPR 0.006 0.000 0.000 0.000 0.000 0.000 0.008 0.025 0.032 0.033 0.028 0.014

Eisenmenger Fork 0.032 0.016 0.007 0.000 0.007 0.025 0.032 0.040 0.038 0.040 0.058 0.024

Tributary 1 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.009 0.021 0.022 0.014 0.000

Tributary 2 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.020 0.029 0.030 0.014 0.000

Boulder Creek 0.008 0.000 0.000 0.000 0.000 0.000 0.000 0.026 0.035 0.041 0.020 0.000

Tibbs Creek 0.010 0.000 0.000 0.000 0.000 0.000 0.000 0.013 0.026 0.025 0.020 0.000

Central Creek 0.011 0.006 0.000 0.000 0.000 0.008 0.014 0.022 0.032 0.038 0.028 0.000 Slate Creek 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.009 0.011 0.000 0.000 0.000 Tanana River 0.000 0.013 0.014 0.013 0.013 0.008 0.000 0.000 0.000 0.013 0.000 0.000 DCRc 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.009 0.011 0.013 0.014 0.000 13 At-large 0.025 0.022 0.016 0.013 0.016 0.013 0.016 0.026 0.029 0.041 0.024 0.057

a GPR = Goodpaster River b Middle GPR includes one fish tagged in Glacier Creek. No tagged fish were present in Glacier Creek during any subsequent surveys. c DCR = Delta Clearwater River

Figure 3.–Tagging locations in the Goodpaster River during August 11–16, 2014. Each symbol represents one or more fish, and each color represents the area where a fish was tagged, as indicated in the legend.

Table 6.–Average movement, standard deviation, maximum upstream distance, and maximum downstream distance of radiotagged Arctic grayling in the Upper Goodpaster River from preceding survey and initial tagging location (in the case of the September 19, 2014 survey). Survey Date 2014 2015 Statistics 9/19 10/16 12/11 2/26 3/31 4/29 5/12 5/27 7/3 8/12 9/24 12/11

Average (km)a -22.6 -22.1 -2.8 -0.4 0.1 2.1 -5.0 29.0 12.7 0.1 -18.8 -19.1

Standard Deviation 31.15 35.86 12.79 2.75 2.04 8.92 20.80 36.33 23.20 4.67 28.81 26.65

Maximum upstream distance (km) 29.0 13.0 23.0 15.0 5.5 25.0 55.5 169.5 129.0 13.0 14.0 4.5

Maximum downstream distance (km) -167.0 -167.0 -103 -8.5 -9.0 -33.0 -86.0 -54.0 -26.0 -17.0 -127.0 -163.0 a Movement upstream is positive and movement downstream is negative. 15

Figure 4.–Locations of radiotagged Arctic grayling during an aerial survey September 19, 2014. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 5.–Locations of radiotagged Arctic grayling during an aerial survey October 16, 2014. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 6.–Locations of radiotagged Arctic grayling during an aerial survey December 11, 2014. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

DISCUSSION Objective 1 This study was designed to evaluate whether Arctic grayling from the GPR drainage upstream of and including Central Creek were congregated in discrete areas during winter, and if so, to determine the spatial relationship of overwintering areas relative to the location of the Pogo Mine. The radiotagged fish indicated that Arctic grayling disperse throughout the mainstem GPR for the winter, although the Upper GPR held a little more than half of all radiotagged fish. Two areas of the river had larger concentrations of radiotagged fish than others, and both areas were distant from the mine (Figure 16). One area was located in the Upper GPR, from the mouth of Tibbs Creek continuing downstream approximately 25 km. The other area began at the mouth of the GPR and extended upstream about 25 km, which is also where Ridder (1998b) observed 20–35% of the overwintering Delta Clearwater River fish. Although these two areas had high densities of radiotagged fish relative to the rest of the GPR, densities did not approach that observed in the Delta River (Gryska 2015). During the winter surveys, a large number of radiotagged Arctic grayling in the Upper GPR were assigned an at-large fate. It is possible the receiver had difficulty decoding tags due to interference between radio tag codes among the large congregation of fish under the ice in the narrow valley of the Upper GPR. Fish with an at-large designation during a survey were assigned a location (Upper, Middle, or Lower GPR) if a fish’s location could be interpolated from locations determined by surveys before and after. The interpretations were most feasible during the December and March surveys when fish were not migrating. These interpretations tended to equalize the proportion of fish found in each overwintering area of the GPR during the December (2014), February, and March surveys (Table 4). They also bolstered the conclusion that the majority of summer resident Arctic grayling from the GPR drainage upstream of and including Central Creek overwinter in the GPR upstream of Glacier Creek. Nonetheless, relative precision of the overwintering distribution estimates did not meet objective criteria for all surveys because of the number of mortalities and fish with an at-large status. For example, during the February survey, 3 fish were deemed at-large and a cumulative total of 41 fish had died.

Figure 7.–Locations of radiotagged Arctic grayling during an aerial survey February 26, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 8.–Locations of radiotagged Arctic grayling during an aerial survey March 31, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 9.–Locations of radiotagged Arctic grayling during an aerial survey April 29, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 10.–Locations of radiotagged Arctic grayling during an aerial survey May 12, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 11.–Locations of radiotagged Arctic grayling during an aerial survey May 27, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 12.–Locations of radiotagged Arctic grayling during an aerial survey July 3, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 13.–Locations of radiotagged Arctic grayling during an aerial survey August 12, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 14.–Locations of radiotagged Arctic grayling during an aerial survey September 24, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 15.–Locations of radiotagged Arctic grayling during an aerial survey December 11, 2015. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged, as indicated in the legend.

Figure 16.–Higher densities of radiotagged Arctic grayling in the Upper and Lower Goodpaster during an aerial survey February 26, 2015 are encapsulated by ovals. Each symbol represents a fish, and the color of symbol represents the area a fish was originally tagged as indicated in the legend.

Objective 2 This study also described the seasonal movements and locations of Arctic grayling, and several key features were apparent. During fall 2014 (from tagging date to October), all tributaries were vacated, and movements were usually downstream; average movement was -22.0 km between each aerial survey, which included 2 individuals that moved -167 km between surveys. These results were reiterated during the final two surveys of September and December 2015 when nearly all fish migrated downstream into the mainstem GPR. Average movement between surveys was -18.8 and -19.1 km, respectively. During winter (October–April), movements nearly ceased, when the average distance traveled ranged from -2.8 to 0.1 km between surveys. Nonetheless, a few individuals made significant movements upstream (up to 23 km) and downstream (up to -33 km), including one fish traversing downstream -103 km between October and December (Table 6), which might have been a late fall migration. Arctic grayling were dispersed throughout the mainstem GPR during winter, as was observed in the Chena and Salcha rivers (Ridder 1998a-b; Gryska 2011), and several fish spent the winter in the Tanana River, unlike the Chena and Salcha river Arctic grayling. Additionally, fish demonstrated fidelity to overwintering areas. Using observations from December 2014 and 2015 surveys, there were 44 radiotagged fish that remained alive and were located during both surveys; 66% (SE = 7.2%) of these fish were within 4 km of the previous year’s location and 89% (SE = 4.8%) were within 14 km. Movements to spawning areas began between the April and May 12 surveys when the average distance moved was -5.0 km and some movements were substantial (-86.0 to 55.5 km). Spawning was likely occurring during the May 12, 2015 survey, and spawning fish were distributed from the Lower Eisenmenger Fork through the entire mainstem of the GPR. Arctic grayling usually moved short distances to spawning areas, and the areas with higher densities of fish during winter also had the highest densities of fish during spawning. After spawning, Arctic grayling were dispersing into the tributary streams, averaging 29.0 km of upstream movement between May 12 and May 27 surveys. Migrations were quick and, in some cases, substantial. One individual migrated 169.5 km for a daily average of 11.3 km. Between May 27 and July 3 surveys, fish continued to migrate (average of 12.7 km) to summer habitats until fully dispersed by early July. Most fish (80%; SE 4.5%) returned to areas within 14km of where they had been tagged the previous year; however, 20% (SE = 4.5%) were located more than 14 km away from their tagging locations, including one fish that was 185 km distant in the Delta Clearwater River. Fish remained nearly stationary (average 0.1 km) between July and August surveys. Evaluation of study Arctic grayling telemetry studies have relied on subjective interpretations of survey data to determine mortality (Blackman 2002; Fish 1998; Gryska 2006, 2011; Lubinski 1995; Morris 2003; Ridder 1995, 1998a, 1998b; West et al. 1992). A fish failing to move over several flights, particularly during migration periods, was assumed to have died or expelled its tag. Although this is a simple approach, it has proven useful because a significant number of Arctic grayling make substantial migrations between winter, spawning, and feeding areas; however, it can be difficult to accurately identify fish that do not move from multi-seasonal habitat or only make brief migrations, as was illustrated in the Salcha River (Gryska 2011).

Fish with unknown fates became prominent during the latter half of this project. Although the unknown fate can include fish that migrate out of the search area and are never found again, it also includes tag failures. The evidence of location history does not support the conclusion that fish migrated out of the search area, but rather, the tags failed. Additionally, a reference tag placed in a lake adjacent to the Upper Eisenmenger Fork failed to emit a signal by the May 12, 2015 survey. These tags and their batteries are quite small, and it is possible the batteries failed. This was the first time this radio tag model had been used for Interior Alaska Arctic grayling, and it is unknown if this is a typical outcome to consider when using this tag model. The high number of tag failures (65) was unprecedented in previous Arctic grayling radiotelemetry projects (Blackman 2002; Fish 1998; Gryska 2006, 2011; Lubinski 1995; Morris 2003; Ridder 1995, 1998a, 1998b; West et al. 1992). The impact of tag failures and mortalities on the spring and summer distributions was substantial, but there were 78 radiotagged Arctic grayling that remained viable by the August 12, 2015 survey. This was considered a reasonable number to describe seasonal migrations and locations because many other radiotelemetry studies were initiated with fewer radiotagged fish (Blackman 2002; Fish 1998; Gryska 2006, Lubinski 1995; Morris 2003; Ridder 1995, 1998a, 1998b; West et al. 1992). The design of this study was intended to ensure adequate numbers of radiotagged fish survived to evaluate the objectives. First, a large number (178) of radio tags were deployed; second, these tags were less than half the mass of previously used tags (4g versus 10g); and lastly, fish were tagged during mid-August when water temperatures were expected to be cooler than midsummer highs and would become progressively colder as fall and winter arrived. As a coldwater fish, warm temperatures are stressful to Arctic grayling, and in combination with surgery, mortality is more likely. While capturing and tagging fish during this project, stream water temperatures ranged from 4.4°C–11.6°C, which is considerably less than the 15°C–20°C water temperatures that typically occur during midsummer. There were 41 (23%) mortalities within the first 4 months and a total of 47 (26%) mortalities for the duration of the study. This mortality rate was lower than those observed in other Arctic grayling radiotelemetry studies (36–70%; Blackman 2002; Fish 1998; Gryska 2006, 2011; Lubinski 1995; Morris 2003; Ridder 1995, 1998a, 1998b; West et al. 1992). Although this study was not designed to determine if temperature and tag size could influence mortality, the mortality rate was less relative to other studies when these factors were controlled in ways considered beneficial for the fish. Additional testing, utilizing objective assignments of mortality, would be needed to verify cause and effect, but the results of this study support a recommendation to use the smallest tag feasible and to tag when thermally optimal, if possible, during future radiotelemetry projects. Conclusions and recommendations The only significant development in the GPR drainage is the Pogo Mine. This study has shown only 8% (SE = 2.4%) of radiotagged fish were located adjacent to the mine during winter. The majority (57%; SE = 4.3%) of Arctic grayling remained in the Upper GPR between North Fork GPR and Glacier Creek, and an additional 30% (SE = 4.0%) were located in the Lower GPR, largely downstream of the South Fork GPR. Within the Middle GPR, there may be fewer locations suitable for winter habitat, and therefore fewer Arctic grayling will occupy this area. In the absence of relevant habitat data, it is uncertain why a small proportion of radiotagged fish spent the winter in the Middle GPR. This study indicates that many locations throughout the mainstem GPR have suitable habitat during winter for Arctic grayling, and although two areas of the river had relatively higher

densities, these aggregations were distributed over 20–25 km of river in each area. Seasonal migrations were an important component of behavior, and therefore migratory corridors are important habitat. Similar to observations in the Salcha River (Gryska 2011), fidelity to summer habitats (80%; SE = 4.5%) and to winter habitats (89%; SE = 4.8%) was high, but a significant number of fish were found in different areas during these periods. These results are important considerations for evaluating the effects of development or perturbations (natural or manufactured) for several reasons. First, impacts of ongoing and future development can be avoided or greatly reduced. Second, the risk to the population of Arctic grayling posed from a localized disturbance is lessened because fish are widely dispersed. Third, a location that loses fish due to an impact will likely be recolonized by Arctic grayling after the impact area has recovered, because some individuals will occupy different areas from year to year. Nonetheless, the river remains an important corridor for seasonal migrations and of water destined for the lower river where a large aggregation of fish overwinters. For these reasons, it remains important to maintain water quality and quantity throughout the year, particularly during the winter when Arctic grayling are probably restricted to their overwintering areas. In the event of a disturbance within the migratory corridor, the ability of a population to recolonize an area will be dependent on the scale, timing, and longevity of any event. In regard to fisheries management, most Arctic grayling in the GPR drainage upstream of Central Creek will experience very little fishing pressure and harvest (about 1% based on the 2 angling mortalities of radiotagged fish during this study) because they are either inaccessible in small tributaries or difficult to access in remote areas of the mainstem. A substantial portion of radiotagged fish were located in the Lower GPR during the spawning period where most adult grayling from the DCR also spawn; however, most adult Arctic grayling only spend 2–3 weeks in the lower river after breakup (Gryska In prep). The Lower GPR is the most accessible part of the river for power boats, and it has slightly more than 30 recreational cabins. Although harvest is allowed year round in the GPR, the fishing pressure during the spawning period is minimal. ACKNOWLEDGEMENTS The author thanks Sumitomo Metal Mining Pogo, LLC for providing funding and logistical support for this project. The sampling crew of Brian Collyard, Rick Queen, Carmen Daggett, Loren St. Amand, and Matt Robinson are thanked for their assistance. Thanks to Don Roach, Matt Evenson, and Klaus Wuttig for their supervisory support, Rachael Kvapil for the editing and formatting of this report for publication, and Matt Tyers for his biometric review. An additional thanks to Keith Warren of Aurora Aviation Services for piloting sample surveys and Marty Webb of Tundra Air for piloting radiotelemetry surveys.

REFERENCES CITED Blackman, B. G. 2002. Radio telemetry studies of Arctic grayling migrations to overwinter, spawning and summer feeding areas in the Parsnip River watershed 1996-1997. Peace/Williston Fish and Wildlife Compensation Program, Report No. 263. Brown, R. J. 2006. Humpback whitefish Coregonus pidschian of the upper Tanana River drainage. U.S. Fish and Wildlife Service, Alaska Fisheries Technical Report Number 90, Fairbanks. Clark, R. A. 1992. Age and size at maturity of Arctic grayling in selected waters of the Tanana drainage. Alaska Department of Fish and Game, Fishery Manuscript No. 92-5, Anchorage. Cochran, W. G. 1977. Sampling techniques, third edition. John Wiley & Sons, New York. Cunjak, R. A. 1996. Winter habitat of selected stream fishes and potential impacts from land-use activity. Canadian Journal of Fisheries and Aquatic Sciences 53(S1): 267-282. Fish, J. T. 1998. Radio-telemetry studies of Arctic grayling in the Jim River (Dalton Highway) during 1997 – 1998. Alaska Department of Fish and Game, Fishery Manuscript No. 98-4, Anchorage. Gryska, A. D. 2006. Vulnerability of Arctic grayling to the Brushkana Creek sport fishery. Alaska Department of Fish and Game, Fishery Data Series No. 06-73, Anchorage. Gryska, A. D. 2011. Salcha River Arctic grayling stock assessment, 2003-2004. Alaska Department of Fish and Game, Fishery Data Series No. 11-42, Anchorage. Gryska, A. D. 2013. Stock assessment of Arctic grayling in the upper Goodpaster River, 2012. Alaska Department of Fish and Game, Fishery Data Series No. 13-60, 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. Gryska, A. D. In prep. Seasonal distributions of Arctic grayling that spawn in the lower Goodpaster River. Alaska Department of Fish and Game, Fishery Data Series, Anchorage. LaPerriere, J. D., and R.F. Carlson. 1973. Termal tolerances of interior Alaskan Arctic grayling (Thymallus arcticus). University of Alaska, Institute of Water Resources. Lohr, S. C., P. A. Byorth, C. M. Kaya, W. P. Dwyer. 1996. High-temperature tolerances of fluvial Arctic grayling and comparisons with summer river temperatures of the Big Hole River, Montana. Transactions of the American Fisheries Society 125(6):933-939. Lubinski, B. R. 1995. Winter habitat of Arctic grayling in an interior Alaska stream. M. Sc. Thesis, University of Alaska. Morris, W. 2003. Seasonal movements and habitat use of Arctic grayling (Thymallus arcticus), burbot (Lota lota), and broad whitefish (Coregonus nasus) within the Fish Creek drainage of the National Petroleum Reserve-Alaska, 2001-2002. Technical Report No. 03-02, Alaska Department of Natural Resources, Fairbanks. Parker, J. F. 2002. Abundance and composition of Arctic grayling in the Goodpaster River, 1999. Alaska Department of Fish and Game, Fisheries Data Series No. 02-06, Anchorage. Parker, J. F. 2003. Abundance and age and length composition of Arctic grayling in the Goodpaster River in 2002. Alaska Department of Fish and Game, Memo to Teck-Pogo, September 10, 2003. Parker, J. F. 2006. Abundance and age and length composition of Arctic grayling in the North Fork Goodpaster River in 2003. Alaska Department Fish and Game, Fishery Data Series No. 06-53, Anchorage. Parker, J. F., K. W. Wuttig, and B. Taras. 2007. Abundance and age and length composition of Arctic grayling in the North Fork Goodpaster River in 2004. Alaska Department of Fish and Game, Fisheries Data Series No. 07-73, Anchorage. Ridder, W. P. 1995. Movements of Radio-tagged Arctic grayling in the Tok River Drainage. Alaska Department of Fish and Game, Fishery Data Series No. 95-36, Anchorage.

REFERENCES CITED (Continued) Ridder W. P. 1998a. Abundance, composition, and emigration of Arctic grayling in the Goodpaster River 1995 - 1997. Alaska Department of Fish and Game, Fishery Data Series No. 98-36, Anchorage. Ridder, W. P. 1998b. Radiotelemetry of Arctic grayling in the Delta Clearwater River 1995 to 1997. Alaska Department of Fish and Game, Fishery Data Series No. 98-37, Anchorage. Schrank, A. J., F. J. Rahel, and H. C. Johnstone. 2003. Evaluating laboratory-derived thermal criteria in the field: an example involving Bonneville cutthroat trout. Transactions of the American Fisheries Society 132(1):100-109. Tack, S. L. 1980. Distribution, abundance, and natural history of the Arctic grayling in the Tanana River drainage. Alaska Department of Fish and Game, Federal Aid in Fish Restoration, Annual Performance Report, 1971-1980. Project F-9-12, 21(R-1). West, R. L., M. W. Smith, W. E. Barber, J. B. Reynolds, and H. Hop. 1992. Autumn migration and overwintering of Arctic grayling in coastal streams of the Arctic National Wildlife Refuge, Alaska. Transactions of the American Fisheries Society 121(6):709-715. Wuttig K. G., and A. D, Gryska. 2010. Abundance and length composition of Arctic grayling in Delta Clearwater River, 2006. Alaska Department of Fish and Game, Fishery Data Series No. 04-22, Anchorage.

APPENDIX A: TABLE OF RADIOTAGGED ARCTIC GRAYLING

Appendix A1.–Date of capture, length, release location, and final fate assignments for each radiotagged Arctic grayling. Latitude Longitude Decimal Decimal FL Water Date Location Degrees Degrees Code (mm) Sexa Temperature °C Final Survey Fateb 8/11/2014 NF GPR #4 64.50586 -144.17566 18 367 M 9.0 12/11/2015 A 8/11/2014 NF GPR #4 64.50586 -144.17566 117 336 F 9.0 4/29/2015 U 8/11/2014 NF GPR #4 64.50586 -144.17566 54 336 F 9.0 5/12/2015 M 8/11/2014 NF GPR #4 64.50586 -144.17566 32 370 M 9.0 12/11/2015 AL 8/11/2014 GPR #2 64.48137 -144.33998 122 392 ? 10.6 12/11/2015 AL 8/11/2014 GPR #2 64.48137 -144.33998 26 370 ? 10.6 7/3/2015 U 8/11/2014 GPR #2 64.48137 -144.33998 125 407 ? 10.6 8/12/2015 U 8/11/2014 GPR #2 64.48137 -144.33998 49 381 ? 10.6 9/24/2015 AL 8/11/2014 GPR #2 64.48137 -144.33998 169 365 ? 10.6 5/27/2015 U 8/11/2014 GPR #2 64.48137 -144.33998 179 384 ? 10.6 8/12/2015 U 8/11/2014 Tibbs #1 64.39610 -144.27646 185 372 ? 6.0 12/11/2015 A 8/11/2014 Tibbs #1 64.39610 -144.27646 38 366 ? 6.0 12/11/2015 AL 8/11/2014 Tibbs #1 64.39610 -144.27646 160 295 ? 6.0 12/11/2015 AL

36 8/11/2014 Tibbs #1 64.39859 -144.28259 47 353 ? 6.0 12/11/2015 AL

8/11/2014 Tibbs #1 64.39859 -144.28259 161 281 ? 6.0 7/3/2015 U 8/11/2014 Tibbs #1 64.39859 -144.28259 165 Missing data ? 6.0 7/3/2015 U 8/12/2014 NF GPR #2 64.50589 -144.00053 144 314 ? 7.4 12/11/2015 M 8/12/2014 NF GPR #2 64.50589 -144.00053 108 384 M 7.4 5/12/2015 U 8/12/2014 NF GPR #3 64.51785 -144.06934 171 385 M 6.7 9/24/2015 U 8/12/2014 NF GPR #3 64.51785 -144.06934 188 405 M 6.7 12/11/2015 A 8/12/2014 NF GPR #3 64.51785 -144.06934 146 374 M 6.7 5/12/2015 U 8/12/2014 NF GPR #3 64.51785 -144.06934 181 305 M 6.7 8/12/2015 U 8/12/2014 Eis #4 64.40596 -144.04578 127 371 M 11.1 12/11/2015 A 8/12/2014 Eis #4 64.40596 -144.04578 139 368 M 11.1 8/12/2015 U 8/12/2014 Eis #4 64.40596 -144.04578 158 332 ? 11.1 10/16/2014 M 8/12/2014 Eis #4 64.40596 -144.04578 110 325 M 11.1 10/16/2014 M 8/12/2014 Eis #7 64.46394 -144.17532 133 396 F 9.6 10/16/2014 M 8/12/2014 Eis #7 64.46394 -144.17532 107 340 M 9.6 4/29/2015 U -continued-

Appendix A1.–Page 2 of 7.

Latitude Longitude Decimal Decimal FL Water Final Date Location Degrees Degrees Code (mm) Sexa Temperature °C Survey Fateb 8/12/2014 Trib 1 64.45852 -143.85234 168 346 F 8.1 12/11/2015 AL 8/12/2014 Trib 1 64.45852 -143.85234 175 355 M 8.1 8/12/2015 U 8/12/2014 Trib 1 64.45852 -143.85234 121 315 M 8.1 12/11/2015 AL 8/12/2014 Trib 1 64.45921 -143.85625 74 388 F 8.4 12/11/2015 A 8/12/2014 Trib 1 64.45921 -143.85625 30 322 M 8.4 12/11/2015 A 8/12/2014 Glacier Creek 64.50359 -144.68176 136 356 F 5.4 5/27/2015 U 8/13/2014 Eis #5 64.42289 -144.06630 67 319 M? 12.0 12/11/2015 A 8/13/2014 Eis #5 64.42289 -144.06630 101 317 M 12.0 5/12/2015 U 8/13/2014 Eis #5 64.42289 -144.06630 153 370 F 12.0 12/11/2014 M 8/13/2014 Eis #5 64.42289 -144.06630 137 395 M 12.0 5/12/2015 M 8/13/2014 Eis #5 64.42289 -144.06630 22 385 M 12.0 8/13/2014 TM 8/13/2014 Eis #5 64.42289 -144.06630 23 370 M 12.0 12/11/2015 A 8/13/2014 Eis #5 64.42289 -144.06630 66 360 F 12.0 12/11/2015 A

37 8/13/2014 Trib 2 64.29601 -143.90411 115 379 M 6.7 10/16/2014 U

8/13/2014 Trib 2 64.29601 -143.90411 151 335 F 6.7 12/11/2015 A 8/13/2014 Trib 2 64.29601 -143.90411 61 345 F 6.7 12/11/2015 AL 8/13/2014 Trib 2 64.29601 -143.90411 70 347 F 6.7 9/24/2015 U 8/13/2014 Trib 2 64.29601 -143.90411 148 340 F 6.7 7/3/2015 U 8/13/2014 Trib 2 64.29601 -143.90411 170 342 M 6.7 12/11/2015 AL 8/13/2014 Trib 2 64.29601 -143.90411 58 382 F 6.7 12/11/2015 A 8/13/2014 Trib 2 64.29601 -143.90411 189 362 F 6.7 12/11/2015 AL 8/13/2014 Trib 2 64.29601 -143.90411 57 360 F 6.7 5/27/2015 U 8/13/2014 Trib 2 64.29601 -143.90411 114 342 F 6.7 10/16/2014 U 8/13/2014 NF GPR #1 64.49364 -143.94144 124 399 M 4.4 12/11/2015 A 8/13/2014 NF GPR #1 64.49364 -143.94144 95 340 M 4.4 12/11/2015 A 8/13/2014 NF GPR #1 64.49364 -143.94144 46 323 F 4.4 5/12/2015 U 8/13/2014 NF GPR #1 64.49364 -143.94144 174 388 F 4.4 9/19/2014 M 8/13/2014 NF GPR #1 64.49369 -143.94073 13 419 F 5.9 12/11/2015 AL -continued-

Appendix A1.–Page 3 of 7. Latitude Longitude Decimal Decimal FL Water Final Date Location Degrees Degrees Code (mm) Sexa Temperature °C Survey Fateb 8/13/2014 Boulder #1 64.29062 -144.02826 123 371 F 9.7 9/19/2014 M 8/13/2014 Boulder #3 64.32387 -144.12376 190 334 F 10.5 8/12/2015 U 8/13/2014 Boulder #3 64.32387 -144.12376 156 324 M 10.5 9/19/2014 M 8/13/2014 Boulder #3 64.32681 -144.11964 99 380 F 11.0 12/11/2015 A 8/13/2014 Boulder #3 64.32681 -144.11964 130 347 F 11.0 12/11/2015 A 8/13/2014 Boulder #3 64.32681 -144.11964 187 316 F 11.0 12/11/2015 AL 8/13/2014 Tibbs #1 64.39468 -144.27588 135 355 F 5.6 9/24/2015 U 8/13/2014 Tibbs #1 64.39468 -144.27588 164 322 M 5.6 12/11/2015 AL 8/13/2014 Tibbs #3 64.46011 -144.26355 184 426 F 8.8 12/11/2015 A 8/14/2014 Eis #1 64.34570 -143.80421 84 330 F 7.6 7/3/2015 U 8/14/2014 Eis #1 64.34570 -143.80421 78 350 F 7.6 4/29/2015 U 8/14/2014 Eis #1 64.34570 -143.80421 12 364 F 7.6 5/27/2015 M 8/14/2014 Eis #1 64.34570 -143.80421 81 303 F 7.6 10/16/2014 M

38 8/14/2014 Eis #2 64.35644 -143.80666 93 305 M? 8.6 12/11/2014 M

8/14/2014 Eis #3 64.37495 -143.91740 72 320 F? 8.0 10/16/2014 M 8/14/2014 Eis #3 64.37495 -143.91740 59 312 M 8.0 12/11/2015 A 8/14/2014 Eis #3 64.37495 -143.91740 43 397 M 8.0 9/24/2015 M 8/14/2014 Eis #3 64.37495 -143.91740 90 387 M 8.0 10/16/2014 M 8/14/2014 Eis #8 64.46785 -144.20955 31 348 F? 11.4 5/27/2015 U 8/14/2014 Eis #8 64.46773 -144.21405 86 404 M 11.4 7/3/2015 U 8/14/2014 Eis #8 64.46773 -144.21405 97 366 M 11.4 8/12/2015 U 8/14/2014 Eis #8 64.46773 -144.21405 11 356 F 11.4 12/11/2015 A 8/14/2014 Eis #8 64.46773 -144.21405 120 369 F 11.4 12/11/2015 AL 8/14/2014 Eis #8 64.46773 -144.21405 24 389 M 11.4 12/11/2015 AL 8/14/2014 Goodpaster #1 64.47573 -144.25830 73 440 M 11.1 10/16/2014 M 8/14/2014 Goodpaster #1 64.47573 -144.25830 76 370 F 11.1 12/11/2015 A 8/14/2014 Goodpaster #1 64.47573 -144.25830 96 375 F 11.1 12/11/2015 A 8/14/2014 Goodpaster #1 64.47573 -144.25830 100 324 M 11.1 8/12/2015 U -continued-

Appendix A1.–Page 4 of 7. Latitude Longitude Decimal Decimal FL Water Date Location Degrees Degrees Code (mm) Sexa Temperature °C Final Survey Fateb 8/14/2014 Goodpaster #1 64.47573 -144.25830 79 326 M 11.1 8/12/2015 U 8/14/2014 Boulder #1 64.29155 -144.03259 129 366 F 9.7 12/11/2015 A 8/14/2014 Boulder #1 64.29155 -144.03259 40 395 F 9.7 12/11/2015 A 8/14/2014 Boulder #1 64.29155 -144.03259 128 320 F 9.7 12/11/2015 A 8/14/2014 Boulder #1 64.29155 -144.03259 55 360 F 9.7 3/31/2015 U 8/14/2014 Boulder #1 64.29155 -144.03259 126 315 M 9.7 12/11/2015 A 8/14/2014 Boulder #2 64.30145 -144.08197 141 368 F 9.0 10/16/2014 M 8/14/2014 Boulder #2 64.30102 -144.08881 134 378 F 9.6 12/11/2015 A 8/14/2014 Boulder #2 64.30102 -144.08881 162 397 F 9.6 5/12/2015 U 8/14/2014 Eisenmenger #6 64.45149 -144.10516 36 370 F 11.6 12/11/2015 A 8/14/2014 Eisenmenger #6 64.45149 -144.10516 42 420 F 11.6 12/11/2015 A 8/14/2014 Eisenmenger #6 64.45149 -144.10516 88 382 M 11.6 9/24/2015 U 8/14/2014 Eisenmenger #6 64.45149 -144.10516 140 415 F 11.6 12/11/2015 AL

39 8/14/2014 Eisenmenger #6 64.45149 -144.10516 33 359 M 11.6 5/27/2015 U

8/14/2014 Eisenmenger #6 64.45149 -144.10516 53 320 ? 11.6 7/3/2015 U 8/14/2014 Eisenmenger #6 64.45149 -144.10516 166 320 ? 11.6 10/16/2014 M 8/14/2014 Eisenmenger #6 64.45149 -144.10516 68 418 M 11.6 12/11/2015 AL 8/14/2014 Eisenmenger #6 64.45149 -144.10516 19 385 M 11.6 10/16/2014 M 8/14/2014 Eisenmenger #6 64.45149 -144.10516 16 387 ? 11.6 5/27/2015 U 8/14/2014 Eisenmenger #6 64.45149 -144.10516 172 378 F 11.6 12/11/2015 AL 8/14/2014 Eisenmenger #6 64.45149 -144.10516 35 401 M 11.6 8/12/2015 U 8/14/2014 Eisenmenger #6 64.45149 -144.10516 154 359 M 11.6 12/11/2015 M 8/14/2014 Eisenmenger #6 64.45289 -144.10802 51 365 F 11.6 12/11/2015 A 8/14/2014 Eisenmenger #6 64.45289 -144.10802 180 364 ? 11.6 10/16/2014 M 8/14/2014 Eisenmenger #6 64.45289 -144.10802 25 375 F 11.6 7/3/2015 M 8/14/2014 Eisenmenger #6 64.45289 -144.10802 143 389 ? 11.6 9/24/2015 U 8/14/2014 Eisenmenger #6 64.45289 -144.10802 167 344 F 11.6 12/11/2015 A 8/14/2014 Eisenmenger #6 64.45289 -144.10802 39 349 M 11.6 7/3/2015 U -continued-

Appendix A1.–Page 5 of 7. Latitude Longitude Decimal Decimal FL Water Date Location Degrees Degrees Code (mm) Sexa Temperature °C Final Survey Fateb 8/15/2014 Central Creek #1 64.35283 -144.72380 104 343 F 6.6 12/11/2015 A 8/15/2014 Central Creek #1 64.35283 -144.72380 142 340 F 6.6 12/11/2015 A 8/15/2014 Central Creek #1 64.35283 -144.72380 20 350 F 6.6 10/16/2014 M 8/15/2014 Central Creek #1 64.35283 -144.72380 60 352 F 6.6 12/11/2014 M 8/15/2014 Central Creek #1 64.35283 -144.72380 45 322 F 6.6 7/3/2015 U 8/15/2014 Central Creek #2 64.36234 -144.76785 176 412 M Missing 12/11/2014 M 8/15/2014 Central Creek #2 64.36234 -144.76785 27 398 M Missing 9/13/2014 AM 8/15/2014 Central Creek #2 64.36234 -144.76785 83 350 F Missing 12/11/2015 A 8/15/2014 Central Creek #2 64.36234 -144.76785 14 338 F Missing 7/3/2015 U 8/15/2014 Central Creek #2 64.36234 -144.76785 89 350 M Missing 12/11/2015 A 8/15/2014 Central Creek #2 64.36234 -144.76785 75 347 ? Missing 5/27/2015 U 8/15/2014 Central Creek #3 64.36691 -144.82365 102 367 M 9.0 5/27/2015 U 8/15/2014 Central Creek #3 64.36691 -144.82365 44 320 F 9.0 12/11/2015 A

40 8/15/2014 Central Creek #3 64.36691 -144.82365 116 328 F 9.0 10/16/2014 M

8/15/2014 Central Creek #3 64.36691 -144.82365 145 335 F 9.0 12/11/2015 A 8/15/2014 Central Creek #3 64.36691 -144.82365 182 329 F 9.0 12/11/2015 A 8/15/2014 Central Creek #4 64.38042 -144.86534 157 375 M? 8.3 12/11/2015 AL 8/15/2014 Central Creek #4 64.38042 -144.86534 82 349 M 8.3 12/11/2015 A 8/15/2014 Central Creek #4 64.38042 -144.86534 149 329 F 8.3 10/16/2014 M 8/15/2014 Central Creek #4 64.38042 -144.86534 77 336 F 8.3 12/11/2015 AL 8/15/2014 GPR #3 64.49404 -144.51816 163 460 F 8.0 12/11/2015 AL 8/15/2014 GPR #3 64.49404 -144.51816 65 386 F 8.0 12/11/2015 A 8/15/2014 GPR #3 64.49404 -144.51816 80 388 F 8.0 12/11/2015 A 8/15/2014 GPR #3 64.49404 -144.51816 132 402 F 8.0 10/16/2014 M 8/15/2014 GPR #3 64.49404 -144.51816 119 328 M 8.0 10/16/2014 M 8/15/2014 GPR #3 64.49404 -144.51816 173 330 M 8.0 12/11/2015 A 8/15/2014 GPR #3 64.49404 -144.51816 29 332 M 8.0 10/16/2014 M 8/15/2014 GPR #4 64.48304 -144.63254 147 346 M 8.7 10/16/2014 U -continued-

Appendix A1.–Page 6 of 7. Latitude Longitude Decimal Decimal FL Water Date Location Degrees Degrees Code (mm) Sexa Temperature °C Final Survey Fateb 8/15/2014 GPR #4 64.48304 -144.63254 21 407 F 8.7 5/27/2015 U 8/15/2014 GPR #4 64.48304 -144.63254 87 336 F 8.7 10/16/2014 M 8/15/2014 GPR #4 64.48304 -144.63254 178 356 F 8.7 10/16/2014 M 8/15/2014 GPR #4 64.48304 -144.63254 138 344 ? 8.7 9/24/2014 M 8/15/2014 GPR #4 64.48304 -144.63254 64 333 F 8.7 8/12/2015 M 8/15/2014 GPR #4 64.48304 -144.63254 37 325 ? 8.7 8/12/2015 U 8/15/2014 GPR #5 64.48499 -144.79413 111 345 F 10.1 8/12/2015 U 8/15/2014 GPR #5 64.48499 -144.79413 94 356 F 10.1 9/19/2014 M 8/15/2014 GPR #5 64.48499 -144.79413 152 372 F 10.1 9/19/2014 M 8/15/2014 GPR #5 64.48499 -144.79413 150 330 M 10.1 7/3/2015 U 8/15/2014 GPR #5 64.48499 -144.79413 85 326 ? 10.1 12/11/2015 A 8/15/2014 GPR #5 64.48499 -144.79413 105 351 F 10.1 10/16/2014 M 8/15/2014 GPR #5 64.48499 -144.79413 63 354 M 10.1 12/11/2015 A

41 8/15/2014 GPR #6 64.47662 -144.91275 186 338 M 10.1 12/11/2015 A

8/15/2014 GPR #6 64.47662 -144.91275 52 329 M 10.1 7/3/2015 U 8/15/2014 GPR #6 64.47662 -144.91275 34 362 M 10.1 10/16/2014 M 8/15/2014 GPR #6 64.47662 -144.91275 17 316 F 10.1 10/16/2014 M 8/15/2014 GPR #6 64.47662 -144.91275 41 357 ? 10.1 12/11/2015 AL 8/16/2014 Goodpaster #1 64.47821 -144.26907 106 369 F 7.7 9/24/2015 U 8/16/2014 Goodpaster #1 64.47821 -144.26907 103 362 F 7.7 12/11/2015 A 8/16/2014 Goodpaster #1 64.47821 -144.26907 71 360 F 7.7 7/3/2015 U 8/16/2014 Goodpaster #1 64.47821 -144.26907 118 362 M 7.7 10/16/2014 M 8/16/2014 Goodpaster #1 64.47821 -144.26907 131 408 M 7.7 12/11/2015 A 8/16/2014 Goodpaster #1 64.47821 -144.26907 91 398 M 7.7 12/11/2015 A 8/16/2014 GPR #7 64.44315 -144.94254 56 376 M 8.2 5/27/2015 U 8/16/2014 GPR #7 64.44315 -144.94254 109 355 F 8.2 5/12/2015 U 8/16/2014 GPR #7 64.44315 -144.94254 113 350 F 8.2 12/11/2015 A -continued-

Appendix A1.–Page 7 of 7. Latitude Longitude Decimal Decimal FL Water Date Location Degrees Degrees Code (mm) Sexa Temperature °C Final Survey Fateb 8/16/2014 GPR #7 64.44315 -144.94254 15 336 F 8.2 7/3/2015 U 8/16/2014 GPR #7 64.44315 -144.94254 48 321 M 8.2 7/3/2015 U 8/16/2014 GPR #7 64.44315 -144.94254 112 347 M 8.2 7/3/2015 U 8/16/2014 GPR #7 64.44315 -144.94254 92 357 F 8.2 9/13/2014 AM 8/16/2014 GPR #8 64.38030 -144.96257 62 375 ? 7.6 8/16/2014 TM 8/16/2014 GPR #8 64.38030 -144.96257 155 325 F 7.6 10/16/2014 M 8/16/2014 GPR #8 64.38030 -144.96257 50 336 M 7.6 8/12/2015 U 8/16/2014 GPR #8 64.38030 -144.96257 28 353 M 7.6 5/27/2015 U 8/16/2014 GPR #8 64.38030 -144.96257 177 347 F 7.6 12/11/2014 M 8/16/2014 GPR #8 64.38030 -144.96257 98 315 M 7.6 5/27/2015 U 8/16/2014 GPR #8 64.38030 -144.96257 183 310 F 7.6 7/3/2015 U a F = female, M = male, F? = possible female, M? = possible male, and ? = undetermined b The final fate of each fish as alive (A), mortality (M), tagging mortality (TM), angling mortality (AM), at-large (AL), and unknown (U)

APPENDIX B: DATA FILE LISTING

Appendix B1.–Data files for radiotagged Arctic grayling in the Goodpaster River. File name Location Goodpaster River Arctic grayling radiotelemetry files Data files are archived at and are available from the for archive.xls Alaska Department of Fish and Game, Sport Fish Division, 1300 College Road, Fairbanks, Alaska 99701- 1599.