Overwintering Distribution and Outmigration Timing of Noatak River Dolly Varden, 2012–2014

Fishery Data Series No. 16-01

Final Report for Study 12-104 USFWS Office of Subsistence Management Fishery Information Service by Corey J. Schwanke and Marci Johnson

January 2016 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. 16-01

OVERWINTERING DISTRIBUTION AND OUTMIGRATION TIMING OF NOATAK RIVER DOLLY VARDEN, 2012–2014

by Corey J. Schwanke and Marci Johnson

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

January 2016

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, 1300 College Road, Fairbanks, AK 99701-1599, USA 907-822-3309 [email protected]

and

Marci Johnson National Park Service, Western Arctic National Parklands PO Box 1029, Kotzebue, AK 99752 907-442-8313 [email protected]

This document should be cited as follows: Schwanke, C. J., and M. Johnson. 2016. Overwintering distribution and outmigration timing of Noatak River Dolly Varden, 2012-2014. Alaska Department of Fish and Game, Fishery Data Series No. 16-01, 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...... iii LIST OF FIGURES ...... iii LIST OF APPENDICES ...... iii ABSTRACT ...... 1 INTRODUCTION ...... 1 Objectives ...... 4 METHODS ...... 4 Study Area ...... 4 Study Design ...... 6 Overview ...... 6 Fish Capture and Telemetry Procedures ...... 6 Data Analysis ...... 8 Overwintering Distribution ...... 8 Outmigration Timing ...... 9 Distance and Direction Traveled ...... 9 RESULTS ...... 10 Summary of Fish Captured ...... 10 Radiotracking ...... 10 Overview ...... 10 Overwintering Distribution ...... 12 Outmigration Timing ...... 12 Distance and Direction Traveled ...... 12 DISCUSSION ...... 17 ACKNOWLEDGEMENTS ...... 19 REFERENCES CITED ...... 20 APPENDIX A ...... 21

ii LIST OF TABLES Table Page 1. Radiotagging locations, time, crew size, access and number of tags deployed, Noatak River, 2012– 2014...... 7 2. Tagging events and length information of radiotagged Dolly Varden, Noatak River, 2012–2014...... 11 3. Aerial tracking dates and the number of radiotagged Dolly Varden deemed alive, Noatak River, 2012– 2014...... 11 4. Summary of movement information for radiotagged Dolly Varden detected during consecutive surveys in the Noatak River, 2012–2014...... 16 5. Summary of distance moved from the place of tagging to overwintering areas, defined as the first time a fish was detected during a wintertime survey, Noatak River, 2012–2014...... 17

LIST OF FIGURES Figure Page 1. Map of the Noatak River drainage...... 2 2. Estimated harvest and fish released by sport fishers in the Noatak River drainage ...... 4 3. Map of the Noatak River drainage with radiotagging locations and fixed tracking stations...... 5 4. Overwintering distributions of radiotagged Dolly Varden ...... 13 5. Overwintering locations (by rkm from the mouth of the Noatak River) of Dolly Varden tagged from 5 general locations, Noatak River, 2012–2014 ...... 14 6. Outmigration timing of radiotagged Dolly Varden past the lower fixed tracking station, Noatak River, 2013–2014 ...... 15

LIST OF APPENDICES Appendix Page A1. Summary of data archives for the Noatak River Dolly Varden telemetry study, 2012–2014...... 22

iii

ABSTRACT A radiotelemetry study of Dolly Varden Salvelinus malma was initiated in the Noatak River during 2012 to collect information on overwintering areas and outmigration timing to sea. A total of 166 Dolly Varden were radiotagged from 6 unique areas during 4 separate tagging events. Over 360 rkm (river km) separated the most upstream tagging location from the furthest downstream tagging location. Surviving fish were generally confined to the mainstem Noatak River with all fish being located upriver from lat 67.352, long 163.076, a place approximately 3 rkm from where the morphology of the river changes from a single deep channel to braided with many gravel bars present. The uppermost overwintering fish was located specifically at lat 67.894, long 160.780, located within 1 rkm of the mouth of the Nakolik River. Wintertime movement of all surviving fish was typically less than 5 rkm between surveys. Two fixed tracking stations in the lower river monitored outmigration to sea during early summer. In the first summer (2013), all 8 outmigrating fish passed during a 3-day period from 13–15 June. During the second summer (2014), dates of passage past the lower fixed tracking station for 68 fish ranged from 20 May to 19 July, although all but one fish had migrated by 19 June. Over 70% of the fish passed during a 7-day period during 7–13 June. Key words: Dolly Varden, Salvelinus malma, telemetry, Noatak River, migration, overwintering areas, migration timing INTRODUCTION The Noatak River is 640 km long, drains 31,000 km2 of the western Brooks Range, and is designated as a National Wild and Scenic River (Figure 1). It originates in Gates of the Arctic National Park and Preserve (6,574,481 acres) in northwest Alaska and flows westward through the central portion of the preserve. The preserve is bordered on the west by Gates of the Arctic National Park and Preserve and to the south by Kobuk Valley National Park (Figure 1). Fish species found in the Noatak River drainage include Dolly Varden Salvelinus malma, Arctic grayling Thymallus arcticus, round whitefish Prosopium cylindraceum, humpback whitefish Coregonus clupeaformis, northern pike Esox lucius, burbot Lota lota, lake trout S. namaycush, longnose sucker Catastomas catstomas, chum salmon Oncorhynchus keta, coho salmon O. kisutch, and pink salmon O. gorbuscha. Inconnu Stenodus leucichthys utilize the lowermost section of the river for seasonal feeding. Many northwestern and North Slope Alaska residents maintain a traditional subsistence lifestyle and rely greatly on traditional harvests of Dolly Varden from the Noatak River. These fish are captured with gillnets or beach seines during open water periods and with hook-and-line during winter. In some communities they outrank salmon and whitefish in importance to subsistence. Currently, fisheries managers have little defensible information relative to distribution and abundance for the overwintering population of Dolly Varden in the Noatak River, which is needed to sustain subsistence harvest levels, evaluate the potential effects of habitat perturbations, and address regulatory proposals or climatic change. The number of Dolly Varden harvested for subsistence purposes is largely undocumented in northwestern Alaska. Intermittent community subsistence harvest estimates dating to 1959 for the villages of Kivalina and Noatak and personal observations suggest that 15,000 to 30,000 Dolly Varden are harvested annually in this area (Scanlon 2011; James Magdanz, ADF&G Commercial Fish Biologist, Kotzebue, personal communications). In 2007, the residents of Kivalina harvested 67,739 pounds of Dolly Varden, second only to bearded seal in terms of pounds of harvested subsistence foods; and in Noatak, 33,771 pounds of Dolly Varden were harvested, second only to caribou (Magdanz et al. 2010). Since 1994, estimated sport harvests have varied but remained much smaller relative to subsistence harvests (Figure 2; Scanlon 2014).

Figure 1.–Map of the Noatak River drainage.

Several investigators have provided life history information on anadromous Dolly Varden in northwestern Alaska (Craig and McCart 1976; DeCicco 1989, 1997, and 2001). Dolly Varden display a wide range of life-history strategies, but in general, these fish spawn in freshwater streams and young fish will rear for 2 to 5 years before first migrating to saltwater during summer. Thereafter, they feed annually in saltwater during summer and migrate to freshwater systems each fall to overwinter or spawn. Mature fish ready to spawn enter rivers in mid-to-late summer and migrate directly to spring-fed areas in headwater streams where they spawn in August and September. The nonspawning, overwintering fish return to freshwater in September. For winter, post-spawning fish will drop back downstream to the preferred overwintering areas already occupied by nonspawners. Dolly Varden return to natal streams to spawn but do not necessarily return to natal streams to overwinter, and therefore, various stocks commonly mix during the winter (DeCicco 1985 and 1992). For example, overwintering aggregations in the Noatak, Wulik, and Kivalina rivers are composed of a mixture of stocks from the immediate area, Norton Sound, and as far as the Russian Far East (DeCicco 1985 and 1989). Overwintering distribution of Dolly Varden in the Noatak River has not been thoroughly defined. In 2002, 24 spawning Dolly Varden were radiotagged in the Kugururok River drainage to describe overwintering distribution (Scanlon 2004). Nearly all of these fish overwintered near the mouths of major tributary streams (e.g., Kelly and Kugururok rivers), upstream of the Village of Noatak in the mainstem where most wintering subsistence fishing areas exist, and a few fish remained within tributary streams. Dolly Varden move downstream soon after breakup, but the exact timing of these downstream migrations has not been fully described. In the nearby Wulik River, Dolly Varden are still present in large numbers two weeks after breakup when water levels have dropped and visibility is high (William Morris, Habitat Biologist, ADF&G, Fairbanks, personal communication). Prior to this study, comprehensive information on overwintering locations of Dolly Varden in the Noatak River did not exist. The water conditions in the Noatak River are not conducive for aerial surveys, in contrast to the clear flowing Kivalina and Wulik rivers nearby where over 100,000 fish have been counted. Also, little is known about the outmigration timing of Dolly Varden as they leave freshwater in the spring. This information is important to managers to evaluate the potential effects of habitat perturbations. More importantly, this information can be used in the design of future studies such as mark–recapture or sonar-based abundance estimation projects.

5,000

4,500 Released Harvested 4,000

3,500

3,000

2,500

2,000

1,500 Number of Dolly Varden Number Dolly of

1,000

500

0 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 Year

Figure 2.–Estimated harvest and fish released by sport fishers in the Noatak River drainage. The sum of these is total estimated catch. OBJECTIVES The objectives of this study during 2012–2014 were to: 1) document overwintering locations of Dolly Varden in the Noatak River during the winters of 2012/2013 and 2013/2014; 2) document outmigration timing of Dolly Varden in spring 2013 and 2014; and 3) describe movements of radiotagged Dolly Varden during the winters of 2012/2013 and 2013/2014 and the proceeding springs. Objective 3 was added to the study after the planning stage. Since multiple aerial surveys were flown during both winters and their respective springs, it became possible to document these movements. METHODS STUDY AREA The study area included the Noatak River mainstem from the Nimiuktuk River confluence to the ocean (Figure 3). Radio tags were deployed in portions of the Kelly, Kugururok, Nimiuktuk, and Nakolik rivers (all tributaries of the Noatak River), as well as in the Noatak River mainstem with most effort being concentrated near the village of Noatak and in the vicinity of the Agashashok River confluence. For aerial surveys, the study area was more expansive. The mainstem was periodically flown from a point about 10 river kilometers (rkm) above the Nimiuktuk River confluence down to saltwater, in all the tributaries in which tagging took place, and periodically in other smaller tributaries (e.g., Eli and Agashashok rivers).

Figure 3.–Map of the Noatak River drainage with radiotagging locations and fixed tracking stations.

STUDY DESIGN Overview This study was designed to estimate the overwintering distribution of Dolly Varden in the Noatak River and to document specific outmigration timing. The initial study design was to radiotag 125 non-spawning (i.e., did not spawn that summer or fall) Dolly Varden during mid-to- late September during both 2012 and 2013 as they migrated from the ocean to the mainstem Noatak River for overwintering. The study design was modified multiple times throughout this project because it was determined through failed attempts that achieving sufficient sample sizes during this time period was unlikely. Instead, two other tagging strategies were incorporated. The first was to radiotag pre-spawn Dolly Varden during July 2013 in the Kelly, Kugururok, and Nimiuktuk rivers. Additionally, a final attempt was made to radiotag Dolly Varden in the mainstem of the Noatak River near the village of Noatak through the ice during March 2014. It was believed that the modified design was better because radio tags were dispersed throughout more of the drainage and were placed in both spawning and non-spawning populations. This expansion of the tagging area and types of fish tagged probably provided better representation of the overall population’s overwintering distribution. FISH CAPTURE AND TELEMETRY PROCEDURES Seven capture events occurred between September 2012 and March 2014. Dolly Varden were captured using two types of sampling gear over multiple time periods, locations, and modes of transportation (Table 1). The minimum size of fish to be radiotagged for this study was originally set at 400 mm FL to ensure that implanted transmitters would be less than 2% of the live weight of the fish, as recommended by Winter (1983). Due to difficulties with attaining desired sample sizes, this size limit was occasionally lowered by up to 25 mm in an attempt to increase sample size, mainly for the mainstem areas. All tagged fish less than 400 mm still achieved the <2% weight criteria. Transmitters used in this study operated on 3 frequencies (150.504, 150.510, and 150.532 MHz) with individual transmitters digitally coded for identification. The radio transmitters weighed about 11 g in the air and were about 54 mm long and 12 mm in diameter. Transmitters were operational over a 2-year period and were programmed to operate continuously at a rate of 14–17 pulses per minute. Motion sensors indicated when there was no movement for 24 hours or more, which could indicate that a fish had died or expelled its transmitter, or was too motionless to activate the sensor. Radio transmitters were surgically implanted following the basic surgical methods detailed by Brown (2006) and Morris (2003). Fish selected for radiotagging were anesthetized using procedures outlined by Brown et al. (2002) and measured to the nearest mm FL. Anesthetized fish were placed ventral side up in a padded cradle, and gills were irrigated with water/anesthesia solution throughout the surgical procedure. All surgical utensils were disinfected in a Nolvasan solution and rinsed with saline solution prior to surgery. Surgery began by cutting a 15 mm incision 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 ga 25.4 cm hypodermic needle inserted from posterior of the pelvic girdle towards 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.

Table 1.–Radiotagging locations, time, crew size, access and number of tags deployed, Noatak River, 2012–2014. Crew Gear Radio Tag Section Dates Size Type Access Deployment Lower Mainstem 11-20 September H&La, b 5 Riverboat from Kotzebue 19 Noatak River 2012 Seine

Kelly River 14-16 July 2013 3 H&L Helicopter from Red Dog Mine 40

Airplane charter from Kugururok River 14-18 July 2013 3 H&L 40 Kotzebue, raft on river Airplane charter from Nimiuktuk River 15-16 July 2013 3 H&L 29 Kotzebue, raft on river Airplane charter from Nakolik Riverc 18 July 2014 3 H&L 11 Kotzebue, sampled from shore Lower Mainstem 20-24 September H&L, b 5 Riverboat from Kotzebue 4 Noatak River 2013 Seine Mainstem Noatak 26-29 March d 3 H&L Snowmachine from Kotzebue 23 River 2014 a Hook and line. b Radiotagging efforts were concentrated in an area approximately 10 miles above and below the Agashashok River. c Radio tags were opportunistically deployed in the Nakolik River by the crew that sampled the Nimiuktuk River. d Radiotagging efforts were concentrated in an area approximately 10 miles above and below the village of Noatak. Upon exit, the needle and grooved director were removed and the radio tag 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 prior to being released in a slow-flowing portion of the river. A Floy T-bar anchor tag was applied to all radiotagged fish near the base of the dorsal fin. Each anchor tag was labeled with a unique number for external identification. During aerial surveys and at fixed tracking stations, Dolly Varden were relocated using radio receivers manufactured by Advanced Telemetry Systems (ATS) (Model R4500C). Aerial surveys were flown 150 to 300 m above ground elevation with a either a Cessna 206 or a Piper Super Cub fixed-wing aircraft equipped for telemetry. One radio receiver was used and each frequency was scanned at 5-second 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. Two Yagi antennas tuned for the 148–152 MHz frequency range (one mounted on each wing) were connected to a splitter and controlled by a selecting switch. A digitized map of the Noatak River system was obtained from the National Hydrography Dataset (NHD 2011). Individual segments of the study area were extracted and then dissolved together to form a precise track of the Noatak River drainage and imported into ArcGIS version 10.2.2. The NHD was chosen because of its accuracy and extensive coverage of the drainage. Multiple locations, times, and signal strengths of detected fish were logged with the radio receivers during each survey. All data were downloaded from the receiver using ATSWinRec software and converted to an Excel spreadsheet. Specific locations of individual fish were

7 determined by selecting the highest signal strength from a series of logged locations. For the data analyses, GPS locations for each fish were adjusted to the nearest point on the river using basic snapping tools within ArcGIS version 10.2.2. 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 of this report. Two fixed tracking stations were also erected each winter (March or April) to track fish leaving the system migrating to the sea in early summer. During the first spring, one fixed tracking station was placed about 20 rkm above the Agashashok River and another about 12.5 rkm downstream of the Agashashok River at the old ADF&G sonar site (Figure 3). The upstream station was flooded during the 2013 breakup and no data were recorded. The second spring (2014), the upstream fixed tracking station was moved downstream to a location about 0.5 rkm below the Agashashok River. The unflooded fixed tracking station remained at the same location. Each station included 2 deep-cycle batteries, a solar array, an antenna switch box, a steel housing box, 2 Yagi antennas, and a receiver. The receivers monitored frequencies continuously and received from both antennas simultaneously. The fixed tracking stations remained operational all summer before being retrieved and downloaded in September. 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), and at-large or missing (AL). The fate of each fish (i.e., if and when the fish had died) by survey was determined by examining its movement history and data provided by the motion sensors. For example, if a fish had an inactive signal for one or more surveys, then later migrated down past the fixed tracking stations, it was considered alive for the inactive period. Conversely, when a fish emitted an active signal intermittently, all the while exhibiting no detectable movement throughout the tracking history, it was considered dead at the time when the first of consecutive inactive signals occurred. By the end, all fish were classified as alive, dead, or missing. All edited biological and telemetric data were entered and archived in an Excel spreadsheet (Appendix A). At-large (missing) fish were excluded from the data analyses for that particular flight. 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. Overwintering Distribution Only fish that were detected migrating past the fixed tracking stations in early summer and fish that remained in the Noatak River drainage after the migration period that made positive movement were included in the analysis (n = 74). Fish that did not do either of these were deleted out of the distribution analyses because they probably died during the study and their locations may not have exactly depicted a fish alive at the time. Two approaches were used to depict overwintering areas. The first approach plotted all survey records of fish known to survive the winter (based on the above criteria) to best illustrate all potential overwintering areas. Surveys chosen to depict overwintering locations were surveys 2 (2 April 2013) and 3 (29 May 2013) for the first year of the study and surveys 6 (8 February 2014), 7 (18 April 2014), and 8 (6 May 2014) for the second year of the study. The second

8 approach used only a single location for each fish deemed to have survived the winter to eliminate some of the clutter associated with some fish being located in multiple surveys and others over only one or two surveys. During this analysis, the first overwintering location for each fish that survived to summer during a specified year was chosen. These data were then categorized by original tagging location and summarized by rkm (from the mouth of the Noatak River) designations. Outmigration Timing A downstream run-timing profile at the fixed tracking stations was constructed where the cumulative proportion of migrating radiotagged fish was presented as a function of time. Profiles were presented annually for both years. The lower fixed tracking station was used to determine outmigration timing because it was at the same location both years and performed the best (it was located high on a hill overlooking the river). There was no evidence that this station missed any fish. When applicable, travel time was estimated between the two fixed tracking stations. This was done by taking the time stamps for each fish when it had its highest signal strength from each fixed tracking station and subtracting the upriver fixed tracking station time from the lower fixed tracking station time. Distance and Direction Traveled Movements of radiotagged fish were analyzed and summarized by plotting coordinates of all located fish deemed to be alive during consecutive surveys (regardless if they were deemed to have survived to summer) onto a digitized map of the drainage using ArcGIS. 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. Because the time between surveys varied throughout the study period, movements were summarized using descriptive statistics (i.e., mean, minimum, maximum, and SD). Fish that were not found alive during consecutive surveys were not used in the analysis. In addition to summarizing distance moved between each survey, distances moved from original tagging locations to overwintering locations (regardless if they were deemed to have survived to summer) were also summarized. This was done by measuring the distance between the original tagging location and the first time a fish was detected in the wintertime. Surveys that defined overwintering locations were surveys 2 (2 April 2013) and 3 (29 May 2013) for the first year of the study and surveys 6 (8 February 2014), 7 (18 April 2014), and 8 (6 May 2014) for the second year of the study. As with movement, direction (upstream or downstream) was only calculated for fish found alive on consecutive aerial surveys. When a fish either entered or left a tributary and traveled both upstream and downstream between surveys, the direction that the 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.

9 RESULTS SUMMARY OF FISH CAPTURED A total of 166 radio tags were deployed spanning 360 rkm (Table 1; Figure 3). The majority of the tags (120) were deployed in tributaries of the Noatak River during July 2013 (Table 1). Capturing Dolly Varden in the mainstem Noatak River proved to be difficult with 46 fish being tagged during 3 separate attempts. The mean length of all sampled fish was 588 mm FL (SD = 125; Table 2). The smallest radiotagged fish was 375 mm FL and the largest was 920 mm FL. Spawning fish captured in the tributaries were larger than those captured in the mainstem. The mean length of spawning fish sampled from the tributary streams in July 2013 ranged from 607 to 662 mm FL (Table 2). Mean length of fish from the 3 sampling periods in the mainstem ranged from 431 to 533 mm FL. RADIOTRACKING Overview A total of 12 tracking flights were performed with the first one being flown on 3 December 2013 and the last one on 24 November 2014 (Table 3). The frequency of surveys was highest during the outmigration period (June) to better assess early summer movements to the sea. Survival of radiotagged fish could not be clearly assessed during the first year of the study due to poor detection rates from the air. Minimum survival could be estimated by determining what proportion of tagged fish migrated to the ocean the following summer. Of the 19 fish radiotagged in the mainstem during September 2012, 8 (42%) of them migrated to sea the following summer (June 2013). In 2013 and 2014, aerial detection rates improved and both fixed tracking stations performed well. Of the 147 Dolly Varden tagged in 2013 and 2014, 68 (46%) outmigrated to the sea during the following summer. Five other fish survived the winter but never migrated back to sea – these made upstream movements after the outmigration period. The lower fixed tracking station detected 5 additional fish that were tagged in the tributary streams in July 2013 leaving the system that same fall. Of these five fish, one passed the lower fixed tracking station on 16 August 2013, and the other four passed on 2, 16, 17, and 21 September 2013. The last of these fish migrated past the fixed lower tracking station one day before it was pulled for the winter. It is quite possible that more fish may have left the system after the fixed tracking station was dismantled. Lastly, four fish were reported as harvested by subsistence users during the winters of this study. Three of these were tagged during the mainstem tagging events, and one was tagged in the Kelly River in July 2013.

Table 2.–Tagging events and length information of radiotagged Dolly Varden, Noatak River, 2012–2014. Fork Length (mm) Section Tagging Dates N Mean SD Min. Max. Lower Mainstem Noatak Rivera 11-20 September 2012 19 431 39 375 550 Kelly River 14-16 July 2013 40 607 113 405 900 Kugururok River 14-18 July 2013 40 662 83 485 800 Nimiuktuk River 15-16 July 2013 29 636 133 445 920 Nakolik Riverb 18 July 2013 11 640 76 475 740 Lower Mainstem Noatak Rivera 20-24 September 2013 4 533 39 505 590 Mainstem Noatak Riverc 26-29 March 2014 23 480 80 385 725 All Locations Combined All Dates 166 588 125 375 920 a Radiotagging efforts were concentrated in an area 7 miles above and below the Agashashok River. b Radio tags were opportunistically deployed in the Nakolik River by the crew that sampled the Nimiuktuk River. c Radiotagging efforts were concentrated in a an area 10 miles above and below the village of Noatak.

Table 3.–Aerial tracking dates and the number of radiotagged Dolly Varden deemed alive, Noatak River, 2012–2014.

Survey Number of fish number Survey date found alive 1 12/3/2012 9 2 4/2/2013 9 3 5/29/2013 7 4 6/13/2013 7 5 7/4/2013 0 6 2/8/2014 64 a7 4/18/2014 38 8 5/6/2014 63 9 6/3/2014 63 10 6/12/2014 19 11 6/26/2014 8 12 11/24/2014 9 a Tracking was conducted by a person with limited experience and many fish were not found. Another survey was flown 3 weeks later.

Overwintering Distribution Overwintering distribution of all surviving fish detected during the winter surveys was limited to the braided stretches of the Noatak River and the Lower Kugururok River (Figure 4). The lowest overwintering fish was located specifically at lat 67.352, long 163.076. This location was about 3 rkm up into the braided section of the river (the river is essentially a single deep, slow-moving main channel below this point with very few gravel bars). The highest fish was located specifically at lat 67.894, long 160.780, located within 1 rkm of the mouth of the Nakolik River. This fish was originally tagged at the mouth of the Nimiuktuk River. Although overwintering areas overlapped among the fish tagged from the tributary streams in July 2014, there was a tendency for fish originally tagged from the Kelly River to be distributed lower than those tagged from the Kugururok and Nimiuktuk rivers (Figures 4 and 5). Additionally, the fish originally tagged from the Nimiuktuk and Nakolik rivers tended to overwinter higher in the drainage. Several fish overwintered in the Lower Kugururok River, all of which were originally tagged from there. Although sample sizes were limited, fish that were tagged in the tributaries predominately overwintered higher in the drainage than the fish that were tagged as non-spawning fish in the mainstem below (Figures 4 and 5). Outmigration Timing In 2013, only the downstream fixed tracking station (the old ADF&G sonar site) recorded information from outmigrating fish. A total of 8 fish were tracked migrating to sea, and all the fish passed during a 3-day period from 13–15 June 2013 (Figure 6), with 5 swimming by the fixed tracking station on 13 June. In 2014, both fixed tracking stations recorded data from outmigrating fish. A total of 66 fish were tracked passing both fixed tracking stations (Figure 6). Two others were tracked by only the downstream fixed tracking station. The median and mode of travel time between the fixed tracking stations (13 rkm apart) for these 66 fish was 2.1 hours. All 68 fish were used to illustrate outmigration timing (Figure 6). Dates of passage by the lower fixed tracking station ranged from 20 May through 19 July, although all but one fish had migrated by 19 June. Over 70% of the fish passed the lower fixed tracking station during a 7-day period from 7–13 June. Distance and Direction Traveled Movement of fish between consecutive surveys revealed that fish were relatively stationary during winter with a moderate tendency to move upstream. Mean movement between the first winter surveys was 4.1 rkm (SD = 4.0) with all 7 fish moving upstream (Table 4). During the second winter, sample sizes were increased considerably and mean movement was ≤3.6 rkm between winter surveys. There was a slight tendency for these fish to move upstream, with 68% of fish moving upstream between the 8 February and 18 April surveys, and 52% moving upstream between the 18 April and 6 May surveys (Table 4).

Figure 4.–Overwintering distributions of radiotagged Dolly Varden. Dots represent all fish found alive during surveys 2 (2 April 2013) and 3 (29 May 2013) for the first year of the study and surveys 6 (8 February 2014), 7 (18 April 2014), and 8 (6 May 2014) for the second year of the study. This figure illustrates distribution spatially throughout the winter. Each fish may have from 1–3 locations, depending on how often it was found.

Figure 5.–Overwintering locations (by rkm from the mouth of the Noatak River) of Dolly Varden tagged from 5 general locations, Noatak River, 2012–2014. Data are single locations of each individual fish that survived to summer. The heavy line represents the median distance, the box represents the inner quartile range (25th percentile to 75th percentile distances), and the whiskers represent the most extreme data points.

12 2013 n=8 2014 n=68 10

Number of Fish 4

0 1-Jul 4-Jul 7-Jul 1-Jun 4-Jun 7-Jun 10-Jul 13-Jul 16-Jul 19-Jul 10-Jun 13-Jun 16-Jun 19-Jun 22-Jun 25-Jun 28-Jun 20-May 23-May 26-May 29-May Date

1.0 2013 n=8 2014 n=68 0.8

0.6

0.4

0.2 Cumulative of Cumulative Passage Proportion

0.0 1-Jul 4-Jul 7-Jul 1-Jun 4-Jun 7-Jun 16-Jul 19-Jul 10-Jul 13-Jul 10-Jun 13-Jun 16-Jun 19-Jun 22-Jun 25-Jun 28-Jun 20-May 23-May 26-May 29-May Date

Figure 6.–Outmigration timing of radiotagged Dolly Varden past the lower fixed tracking station, Noatak River, 2013–2014. Top figure is daily passage and bottom figure is cumulative passage.

Table 4.–Summary of movement information for radiotagged Dolly Varden detected during consecutive surveys in the Noatak River, 2012–2014.

Absolute Days Movement (rkm) Upstream Movement Downstream Movement Dates of Between Sample Max Max Surveys Surveys Size Mean SD Proportion (rkm) Proportion (rkm) 12/3/12 4/2/13 120 7 4.1 4.0 1.00 9.6 0.00 NA

4/2/13 5/29/13 57 2 6.8 1.3 0.00 NA 1.00 7.8

5/29/13 6/13/13 15 4 46.8 31.6 0.00 NA 1.00 81.5

6/13/13 a7/4/13 21 0 NA NA NA NA NA NA a 7/4/13 2/8/14 219 0 NA NA NA NA NA NA

2/8/14 4/18/14 69 19 3.6 2.1 0.68 3.9 0.32 8.3

4/18/14 5/6/14 18 29 1.7 2.0 0.52 8.2 0.48 5.8

5/6/14 6/3/14 28 48 18.6 24.2 0.10 5.4 0.90 110.2

6/3/14 6/12/14 9 16 41.9 47.3 0.31 44.3 0.69 155.1

6/12/14 6/26/14 14 4 17.7 30.1 0.75 62.6 0.25 5.9

6/26/14 11/14/14 151 3 47.4 53.2 0.33 7.9 0.67 108.0 a All Dolly Varden left the system by 7/4/13, so no data exists for adjacent surveys. All data after this survey pertains to the Dolly Varden tagged after the 7/4/13 survey.

Furthermore, this analysis also illustrated when fish probably started their outmigration. In 2013, a sample size of 2 fish limited results, but moderate movement was detected between the 2 April and 29 May surveys (6.8 rkm; SD = 1.3), indicating that spring migration probably started with some of the fish by 29 May (Table 4). In 2014, outmigration clearly did not start until sometime after the survey on 6 May 2014 where fish only moved an average of 1.7 rkm (SD = 2.0) between 18 April and 6 May. Distances moved from the time of tagging to overwintering varied (Table 5). The fish tagged in the Nimiuktuk and Nakolik rivers typically traveled the furthest distance for overwintering, averaging 151.3 rkm (SD = 64.3) per fish. The fish tagged in the Kugururok River moved a mean distance of 89.9 rkm (SD = 51.6) and the fish from the Kelly River traveled a mean distance of 72.9 rkm (SD = 46.6; Table 5). The fish sampled during the fall near the Agashashok River in 2012 traveled a mean distance of 35.9 rkm (SD = 13.5) to overwintering areas, and in 2013 fish tagged from the same area averaged 23.6 rkm (SD = 17.2). The maximum distance traveled for overwintering was 287.5 rkm, which was an individual fish tagged at the Nimiuktuk River. Table 5.–Summary of distance moved (rkm) from the place of tagging to overwintering areas, defined as the first time a fish was detected during a wintertime survey, Noatak River, 2012–2014. Mean SD Min Max Section Tagging Dates N (rkm) (rkm) (rkm) (rkm) Lower Mainstem 11-20 September 2012 11 35.9 13.5 4.2 60.6 Noatak Rivera Kelly River 14-16 July 2013 26 72.9 46.6 16.8 174.4 Kugururok River 14-18 July 2013 30 89.9 51.6 14.9 212.9 Nimiuktuk and Nakolik 15-18 July 2013 22 151.3 64.3 11.9 287.5 riversb Lower Mainstem 20-24 September 2013 3 23.6 17.2 3.8 34.9 Noatak Rivera Mainstem Noatak Riverc 26-29 March 2014 21 4.4 5.1 0 19.7 a Radiotagging efforts were concentrated in an area 7 miles above and below the Agashashok River. b Due to their geographic proximity and similar tagging dates, the Nimiuktuk and Nakolik rivers were combined for these analyses. c Radiotagging efforts were concentrated in a an area 10 miles above and below the village of Noatak. These fish were tagged on their overwintering grounds. DISCUSSION Problems were encountered with detection rates in both years’ aerial surveys. Initially, it was believed the problems stemmed from the limitations of the Cessna 206, which was used the first year (lack of ability to fly at slow speeds and reduced maneuverability). It was considered that the antennas were not working properly or that the tags were not emitting strong enough signals. Adjustments were made throughout the study, including using a Piper Super Cub with new antennas and connecting cables. Detection rates were improved with the use of a Piper Super Cub, but additional surveys were flown each winter to increase the total number of individual fish detected. The original intent of this study was to document overwintering locations and outmigration timing of Dolly Varden in the Noatak River to determine whether estimating abundance of overwintering Dolly Varden with DIDSON (Dual Frequency Identification Sonar) during the outmigration period was feasible. The critical biological information necessary would be to

17 know the lower overwintering distribution of these fish and their outmigration timing. The Lower Noatak River is probably too large and deep to ensonify, so it would be crucial to move the sonar as far upriver as possible, while still staying below the bulk of the overwintering distribution. Outmigration timing would also be important in the planning process. This study fully addressed these information needs if a sonar study were attempted in the future. The lowest overwintering fish was located specifically at lat 67.352, long 163.076, which was several rkm upstream from a point where the river morphology changes from a braided river with exposed gravel bars being prevalent to a single deep, silt-laden channel. Depending on land ownership and sonar capabilities, a population assessment within this vicinity would probably be most practical. Outmigration run timing probably varies year to year, but during this 2-year study the bulk of the fish left in short periods of time. In 2013, all 8 radiotagged fish passed the lower fixed tracking station from 13–15 June. In 2014, over 70% of the fish passed during a 7-day period from 7–13 June. Most fish would probably be accounted for if outmigration was monitored for a 3-week period from early to mid-June. Scanlon (2004) documented overwintering Dolly Varden in Evaingiknuk Creek, a small tributary that flows into the Noatak River just upstream of the village of Noatak. This creek was overlooked during this study, but because it flows into the Noatak River just upstream of the Village of Noatak, if fish were present there they would be well upstream of the lowest overwintering fish. Only a few out of 68 Dolly Varden detected outmigrating to sea were not found during any of the previous winter surveys, so it is unlikely that a significant portion of our fish overwintered there during this study. Scanlon (2004) used different methodology is his data analyses, so comparing this study to that one is difficult. The primary difference is that in this study we only illustrated and analyzed data from fish that were known to be alive, and the 2004 study used all located fish. Therefore, comparing overwintering locations between the studies is difficult (e.g., the 2003 overwintering maps illustrate Dolly Varden in Kagvik Creek). Despite these discrepancies, many of the fish from the previous study did overwinter in similar locations as this study (e.g., the confluences of the Kugururok and Kelly rivers). The radiotagging of pre-spawn Dolly Varden in the tributary streams in July 2013 revealed some interesting life history traits. The majority of known surviving fish stayed in the Noatak River to overwinter and then outmigrated the following summer; however, several fish did something different. First, at least 5 of these fish presumably outmigrated back to the ocean shortly after spawning, evidenced by the fixed tracking stations detecting these fish passing them between 16 August and 21 September 2013. None of these fish were located during the following winter surveys. Because the last fish passed the station the day before it was dismantled for winter, it is unknown how many more left after 22 September. Regardless, it appears that a portion of the spawning population leaves the drainage after spawning, presumably to overwinter in a different drainage. Secondly, a single fish passed the fixed tracking stations on 19 July presumably outmigrating to the sea, which was 30 days after when all the early summer fish left. Four of the surviving fish originally tagged in the tributary streams overwintered in the mainstem Noatak River and then stayed the following summer and winter. At first it appeared that these fish might have spawned consecutive years without going to the sea. Upon closer inspection, it was determined that these fish were probably not pre-spawning anadromous fish at the time of tagging. Three of these fish were categorized as females and had fork lengths of 465, 500, and

18 530 mm. The fourth fish was categorized as unknown sex and had a fork length of 460 mm. These fish probably were not anadromous because they were below published lengths of maturity and would have migrated to the ocean during this time period (DeCicco 1985). These fish were probably resident Dolly Varden and therefore provide little information for the objectives of this study.

ACKNOWLEDGEMENTS We wish to thank the USFWS (United States Fish and Wildlife Service), Office of Subsistence Management, Fisheries Information Service for providing $223,321 in total funds. This money was administered through the Fisheries Resource Monitoring Program under agreement number F12AC00200. This project was done cooperatively with the National Park Service, which provided local knowledge and logistical support, as well as field supplies, boat gas, and assistance in performing all of the aerial tracking surveys. The staff at Red Dog Mine helped tremendously with lodging at times and helicopter support (transported a tributary tagging crew to and from the field and slung boat gas to the mainstem tagging crew). Individuals who helped radiotag Dolly Varden were Matt Albert, Eric Anderson, Matthew Evenson, Andrew Gryska, Matt Robinson, Mark Roti, James Savereide, Brendan Scanlon, Loren St. Amand, Dave Stoller, Tom Taube, and Tim Viavant. Thurston Booth and several residents from Noatak Village helped capture fish for radiotagging in March 2014. We would like to thank Eric Sieh with Arctic Backcountry Flying Service, who piloted the plane(s) for all the surveys. Matt Tyers provided biometric support and reviewed this report, and Klaus Wuttig reviewed it as well.

19 REFERENCES CITED 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. Brown, R. J., C. Lunderstadt, and B. Schulz. 2002. Movement patterns of radiotagged adult humpback whitefish in the upper Tanana River drainage. U. S. Fish and Wildlife Service, Alaska Fisheries Data Series Number 2002-1. Craig, P. C., and P. McCart. 1976. Fish use of nearshore coastal waters in the western Arctic: emphasis on anadromous species. Pages 361-388 [In] D.W. Hood and D.C. Burrell, editors. Assessment of the Arctic marine environment. Institute of Marine Science, University of Alaska, Fairbanks, Alaska. Cochran, W. G. 1977. Sampling techniques, third edition. John Wiley and Sons, New York. DeCicco, A. L. 1985. Inventory and cataloging of sport fish and sport fish waters of western Alaska with emphasis on Arctic char life history. Alaska Department of Fish and Game. Federal Aid in Fish Restoration Annual Performance Report 1984-1985, Project F-9-17, Volume 26: 41-134. DeCicco, A. L. 1989. Movements and spawning of adult Dolly Varden char (S. malma) in Chukchi Sea drainages of northwestern Alaska: evidence for summer and fall spawning populations. Physiology and Ecology Japan 1: 229-238. DeCicco, A. L. 1992. Long distance movements of anadromous Dolly Varden between Alaska and the U.S.S.R. Arctic 45(2):120-123. DeCicco, A. L. 1997. Movements of postsmolt anadromous Dolly Varden in northwestern Alaska. American Fisheries Society Symposium 19:175-183. DeCicco, A. L. 2000. Fishery management report for sport fisheries in the northwest Alaska management area. 1995-1997. Alaska Department of Fish and Game, Fishery Management Report No. 00-5. DeCicco, A. L. 2001. Genetic diversity of Dolly Varden populations in Norton and Kotzebue Sounds, and of Arctic char populations on the Noatak National Preserve. Federal Subsistence Fishery Monitoring Program, Final Report No. FIS00-01. U.S. Fish and Wildlife Service, Office of Subsistence Management, Fishery Information Services Division, Anchorage, Alaska. Magdanz, J. S., N. S. Braem, B. C. Robbins, and D. S. Koster. 2010. Subsistence harvests in Northwest Alaska, Kivalina and Noatak, 2007. Alaska Department of Fish and Game, Technical Paper No. 354, Division of Subsistence, Kotzebue. 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, Alaska. NHD (National Hrdrography Dataset). 2011. U.S. Department of the Interior, U.S. Geological Survey. http://nhd.usgs.gov/data.html (Accessed December 2011). Scanlon, B. P. 2004. Assessment of the Dolly Varden spawning population in Kagvik Creek, Alaska. Alaska Department of Fish and Game, Fishery Data Series No. 04-06, Anchorage. Scanlon, B. 2011. Fishery Management Report for sport fisheries in the Northwest/North Slope Management Area, 2009. Alaska Department of Fish and Game, Fishery Management Report No. 11-32, Anchorage. Scanlon, B. 2014. Fishery management report for sport fisheries in the Northwest/North Slope Management Area, 2012. Alaska Department of Fish and Game, Fishery Management Report No. 14-03, 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. 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. Wolfe, M. F., S. Schwarzbach, and R. A. Sulaiman. 1998. Effects of mercury on wildlife: a comprehensive review. Environmental Toxicology and Chemistry 17(2):146–160.

APPENDIX A

Appendix A1.–Summary of data archives for the Noatak River Dolly Varden telemetry study, 2012–2014. a Year Data file Software 2014 Noatak River_DollyVarden_telemtrydata.xls Microsoft Excel a Data files are archived and available from the Alaska Department of Fish and Game, Sport Fish Division, Research and Technical Services, 333 Raspberry Road, Anchorage, Alaska 99518-1599.