Inventory and Cataloging of Arctic Area Waters. Alaska Dept

Volume 25 Study G-I

STATE OF ALASKA Bill Sheffield, Governor

Annual Performance Report for

INVENTORY AND CATALOGING OF ARCTIC AREA WATERS

BY Terrence N. Bendock and John Burr

ALASKA DEPARTMENT OF FISH AND GAME Don W. Collinsworth Commissioner

SPORT FISH DIVISION Richard Logan, Director ..

TABLE OF CONTENTS (CONT'D) STUDY NO . G-I INVENTORY AND CATALOGING Page Job No . G-I-P-B Inventory and Cataloging of Sport Fish and Sport Fish Waters of Western Alaska By: Kenneth T. Alt Abstract ...... 70 Keywords ...... 70 Background ...... 71 Recommendations ...... 71 Research ...... 71 Management ...... 73 Objectives ...... 73 Techniques ...... 73 Findings ...... 73 Melozitna River survey ...... 73 Melozitna River fish ...... 77 Tozitna River stream survey ...... 81 Fishes of the Tozitna River ...... 85 Sheefish Utilization ...... 85 Survey of Fish-Niukluk River system ...... 88 Sheefish lake and river adaptability study ...... 89 Literature Cited ...... 90

LIST OF TABLES AND FIGURES Table 1. List of common names. scientific names and abbreviations ...... 72 Table 2 . Age-length and age-weight relationships for 27 grayling from Melozitna River. Alaska . Fork length in millimeters. weight in grams ...... 78 Table 3 . Age-length and age-weight relationships for 9 Dolly Varden char from Melozitna River. Alaska . Fork length in millimeters. weight in grams ...... 80 Table 4 . Age-length and age-weight relationships for 21 sheefish from Melozitna River. Alaska . Fork length in millimeters. weight in grams ...... 82 Table 5 . Age-length and age-weight relationship for 14 Tozitna River grayling. Sept., 1983. Length in millimeters. weight in g ...... 86 Figure 1. Melozitna River. Alaska study area . Upper Melozitna River including Little Melozitna River is not shown . . 74 Figure 2 . Tozitna River study area ...... 83

iv Volume 25 Study NO. G-1 RESEARCH PROJECT SEGMENT State: A1 aska Name: Sport Fish Investigations of Alaska

Project No.: F-9-16 Study No.: G- I Study Title: INVENTORY AND CATALOGING Job No.: G-1-1 Job Title: Inventory and Cataloging of Arctic Area Waters Cooperators: Terrence N. Bendock and John Burr Period Covered: July 1, 1983 to June 30, 1984

ABSTRACT

This report presents a description of overwintering habitat in the Sagavanirktok River, survey information from lakes adjacent to the Dalton Highway and from lakes and streams on the Arctic coastal plain, angling effort along the Dalton Highway, an evaluation of an experimental stocking of grayling, Thymallus arcticus (Pallas), near Pt. Barrow and aerial index counts of Arctic char, Salvelinus alpinus (Linnaeus), in the Sagavanirktok and Anaktuvuk Rivers.

Radio-tagged burbot, --Lota lota (Linnaeus), were used to locate and investigate overwintering habitat in the main stem of the Sagavanirktok River. Overwintering burbot, grayling, round whitefish, Prosopium cylindraceum (Pallas), and slimy sculpin, Cottus cognatus Richardson, were found. Two general overwintering habitat types, represented by five sites, are described.

Six small mountain lakes along the Dalton Highway were surveyed. Lake trout, Salvelinus namaycush (Walbaum) , Arctic char and . burbot were captured and life history data are given.

Sport fishing pressure along the Dalton Highway was monitored. Sport fishing pressure north of the Yukon River continues to be light and concentrated near Alyeska Pump Stations and road maintenance camps. The recent opening of the first 150 miles of the highway to the general public on a year-round basis did not appreciably affect sport. fishing pressure and harvest.

Fisheries surveys were conducted on waters in the Arctic coastal plain in an area bounded by the Ikpikpuk River on the west and the Colville River on the east. Teshekpuk Lake, 23 unnamed lakes, the Ikpikpuk River and 7 smaller streams were surveyed. The survey data from lakes are combined with lake survey data from previous work. Eighty-two percent of the lakes surveyed contained fish. Least cisco, Coregonus sardinella (Valenciennes), lake trout and broad whitefish Coregonus nasus (Pallas), were most common. Of the streams surveyed, grayling were the most common, followed by least cisco. Life history data from the species captured are presented.

An investigation of overwintering habitat in the Ikpikpuk and Chandler Rivers was initiated by radio-tagging five burbot.

A freshwater lagoon stocked with 50,000 grayling fry in 1981 near Pt. Barrow was netted to determine the status of the fish. No grayling were captured after extensive netting.

Aerial index counts of Arctic char in the Anaktuvuk and Sagavanirktok Rivers compared favorably with estimates of past years.

KEY WORDS

Winter habitat, Sagavanirktok River, Dalton Highway, Arctic Coastal Plain, Teshekpuk Lake, Ikpikpuk River, Arctic char, Salvelinus alpinus (Linnaeus), Lake trout, Salvelinus namaycush (Walbaum), whitefish, Coregonus nasus (Pallas).

BACKGROUND

The Alaska Department of Fish and Game, Sport Fish Division, has conducted fisheries investigations on the North Slope since 1968. Emphasis of this work has varied between drainages and species in an effort to meet the changing patterns of use and activities within this region. Construction of the Dalton Highway (North Slope Haul Road) has tied the North Slope into the existing state highway system. Improved access has increased the demand for sport fishing, as well as other recreational, municipal, and commercial endeavors in this remote region.

Petroleum exploration and development is the overriding force that is shaping the future on the North Slope; municipalities are viewing the newly-found state oil wealth as the key to funding capital improvement projects with costs that have long been out of reach. Many of these activities place increasing demands on the aquatic resources of the region and point to the need for more knowledge of the fish species inhabiting North Slope waters. The Alaska National Interest Lands Conservation Act, in 1980, withdrew vast areas of the North Slope into the National Wildlife Refuge, National Park, and National Wild and Scenic Rivers systems.

Table 1 lists the species of fish inhabiting waters of the North Slope and found along the highway north of the Yukon River. A map of the study area is shown in Fig. 1.

2 c 90

w . .?. 58"

58O

Figure 1. State of Alaska showing the North Slope and location of studies for 1983. Table 1. Fish speices found along the haul road and North Slope.

Common Name Scientific Name and Author Abbreviation

Alaska blackfish Dallia pectoralis (Bean) AB

Arctic char Salve1inus alp inus (Linnaeus) AC

Arctic cisco Coregonus autumnalis (Pallas) ACI

Arctic lamprey Lampetra japonica (Martens) AL Arctic grayling Thymallus arcticus (Pallas) GR

Broad whitefish Coregonus nasus (Pallas) BWF Burbot --Lota lota (Linnaeus) BB Chum salmon Oncorhynchus -keta (Walbaum) cs &* Fourhorn sculpin Myoxocephalus quadricornis (Linnaeus) FSC

Humpback whitefish Coregonus pidschian (Gmelin) HWF

King salmon Oncorhynchus tshawytscha (Walbaum) KS

Lake trout Salvelinus namaycush (Walbaum) LT

Least cisco Coregonus sardinella (Valenciennes) LCI

Longnose sucker Catostomus catostomus Forster LNS

Ninespine stickleback Pungitius pungitius (Linnaeus) NSB

Northern pike Esox lucius Linnaeus NP

Pink salmon Oncorhynchus gorbuscha (Walbaum) PS Round whitefish Prosopium cylindraceum (Pallas) RWF II Sheef ish Stenodus leucichthys (Guldenstadt) SF Slimy sculpin Cottus cognatus Richardson ssc

4 RECOMMENDATIONS

Research

1. Lake and stream surveys should continue on North Slope waters with emphasis on NPR-A and coastal plain lakes. .

2. Assessment of overwintering fish habitats in North Slope waters should continue with emphasis on the Sagavanirktok and Colville River drainages.

3. Fall aerial surveys of Arctic char in the Sagavanirktok and Anaktuvuk Rivers should continue.

Management

1. Assessment of the fishing potential of area waters adjacent to the Dalton Highway should continue.

2. Sport fishing pressure on area waters should be monitored. ., OBJECTIVES

1. To conduct fall aerial surveys of selected waters on the North Slope to determine locations and estimate the abundance of Arctic char stocks, with emphasis on the Sagavanirktok and Colville River drainages.

2. To continue monitoring sport fishing pressure on selected waters of the North Slope with emphasis on the Dalton Highway corridor north of the Yukon River.

3. To determine the availability and use of overwintering fish habitat in lakes and streams of the North Slope with emphasis on the Sagavanirktok' and Colville River drainages, and the Arctic Coastal Plain west of the Colville River Delta.

4. To continue inventory and cataloging of potential sport fish waters on the North Slope.

5. To provide recommendations for the management of sport fish resources of the job area.

TECHNIQUES USED

Lake And Stream Surveys

Techniques and equipment used were the same as described by Bendock (1981; 1983).

5 RECOMMENDATIONS

Research

1. Lake and stream surveys should continue on North Slope waters with emphasis on NPR-A and coastal plain lakes. .

2. Assessment of overwintering fish habitats in North Slope waters should continue with emphasis on the Sagavanirktok and Colville River drainages.

3. Fall aerial surveys of Arctic char in the Sagavanirktok and Anaktuvuk Rivers should continue.

Management

1. Assessment of the fishing potential of area waters adjacent to the Dalton Highway should continue.

2. Sport fishing pressure on area waters should be monitored.

9 OBJECTIVES

To conduct fall aerial surveys of selected waters on the North Slope to determine locations and estimate the abundance of Arctic char stocks, with emphasis on the Sagavanirktok and Colville River drainages.

To continue monitoring sport fishing pressure on selected waters of the North Slope with emphasis on the Dalton Highway corridor north of the Yukon River.

To determine the availability and use of overwintering fish habitat in lakes and streams of the North Slope with emphasis on the Sagavanirktok’ and Colville River drainages, and the Arctic Coastal Plain west of the Colville River Delta.

To continue inventory and cataloging of potential sport fish waters on the North Slope.

To provide recommendations for the management of sport fish resources of the job area.

TECHNIQUES USED

Lake And Stream Surveys

Techniques and equipment used were the same as described by Bendock (1981; 1983).

5 Winter Samples

Locations of overwintering burbot in the Sagavanirktok River were determined using radio telemetry. Snow machines were then us d to transport personnel and equipment to these sites during the sampling period. All other techniques used were the same as described by Bendock, (1983).

FINDINGS

Sagavanirktok River Overwintering Habitat Studies, Radio Telemetry

Background:

The Sagavanirktok River has been the subject of numerous fisheries investigations prompted by the development of the Prudhoe Bay Oil Field, the Trans-Alaska Pipeline and the Dalton Highway. A large run of anadromous Arctic char is found in the Sagavanirktok River system, of which detailed studies are available, (Yoshihara, 1972, 1973; Furniss, 1974; McCart, Craig and Bain, 1972; and Bendock, 1983). In addition to ' Arctic char, the river is inhabited by grayling, lake trout, broad whitefish, humpback whitefish, round whitefish, least cisco, burbot, pink salmon, chum salmon, ninespine stickleback, and slimy sculpin.

Fish in the Sagavanirktok drainage have been found to overwinter in deep, under-ice pools (Bendock, 1977; Dew, 1982) and in spring areas (Bendock, 1982; 1983); however, the middle stretches of the river are characterized by having neither large sources of ground water nor deep pools, yet probably support large numbers of overwintering fish. Grayling and round whitefish, the predominant summer species, undertake migrations into the smaller tributaries of the Sagavanirktok River at spring breakup and return to the river in the fall at freeze-up.

Radio Tagging:

Eleven burbot were radio-tagged and released in the Sagavanirktok River from September 18-21, 1982. Table 2 lists the length, weight, transmitter frequency and tagging locations of the 11 radio-tagged burbot. Lengths ranged from 535 mm to 910 mm, with an average of 703 mm. Weights ranged from 750 g to 5,000 g and averaged 1,977 g. Figure 2 shows the locations at which the burbot were captured, radio-tagged and released.

Fall and Winter Movements:

The movements of the radio-tagged burbot were monitored by aerial reconnaissance on three occasions between their release in September and the spring sampling periods in late February and mid April. Table 3 summarizes these movements.

In general, the radio-tagged burbot remained near their tagging sites. Tag #lo, which showed the most movement, traveled 5.5 mi downstream to

6 Table 2. Length, weight, transmitter frequency and tagging location of 11 burbot from the Sagavanirktok River.

Tag Transmitter Number Length (mm) Weight (g) Frequency Tagging Location

# 1 650 1,500 151.320 Just below Pump I11 water shack

# 2 910 5,000 151.440 Adjacent to MS-120-2A

#3 640 1,700 151.360 Ox Creek mouth

#4 603 1,300 151.400 Ox Creek mouth

#5 720 1,500 150.260 Water Hole, 4 mi S. of Happy Valley airstrip.

#6 570 1,100 150.690 Water Hole, g mi S. of Happy Valley airstrip

535 750 150.300 % mi N. of Happy Valley airstrip.

#8 830 2,700 150.660 Sagwon Bluff, just below notch.

#9 730 2,000 150.540 Upper Pump I1 bluff.

Ill0 7 10 2,200 150.520 Lower Pump I1 bluff.

ill 1 830 2,000 150,590 Upper Pump I1 bluff. Table 3. Summary of movements of 11 radio-tagged burbot in the Sagavanirktok River.

Miles Traveled By Each of 11 Radio-Tagged Burbot Date ill I2 ii 3 ill 4 il 5 /I6 ii 7 8 89 810 111 1

~ ~~ ~ ~ ~~

9/22/83 -% 0 0 0 0 0 0 0 0 -% 0

11/2/83 0 +% -4 0 0 0 0 +2 +1% -44 no signal

2/15/83 -% +1 -% 0 0 0 0 +% -4 -s no signal

2/22/83 no 0 0 no Preda- Preda- 0 0 no no no signal signal tion tion signal signal signal 3/15/83 no 0 0 no ...... 0 0 no no no signal signal signal signal signal net movement -+ +14 -1 0 0 0 0 +2% 0 -5% no in mi data

- Indicates downstream movement.

+ Indicates upstream movement. > I 14&00' I49O 00'

j9O 30' -

69OOO' -

1 i

Figure 2. Tagging locations of eleven radio-tagged burbot and locations of six overwintering habitat sites. 9 the mouth of the Ivishak River. Tags %2 and #8 moved upstream 1.5 and 2.5 mi, respectively. Tags #1 and 83 had net downstream movements of 0.5 and 1.0 mi. NQ net movement was observed in the remaining six tags. Tag /Ill ceased transmitting shortly after being put into service. Transmitters 85 and 86 were found lying on the riverbank near where the burbot were released. Although the transmitters were still functioning, they both had deep tooth marks in their cases. The location transmitters, the tooth marks in their cases and the pieces of fish flesh found near them indicate that these burbot were killed by predators.

Overwintering Site Investigations:

The locations of all radio-tagged fish were investigated for the presence of habitat suitable for overwintering fish from February 24-28 and April 15-20.

During February, the locations of each of the transmitters still functioning were visited on snowmachine. At that time the locations of the transmitters were more precisely determined and marked. In April each of the sites located and marked in February was further investigated. In addition, the last recorded locations of transmitters 9 and 10 were visited.

Six overwintering sites were investigated. Physical data collected and fish species found at each site are presented in Table 4. Seventy-seven burbot were sampled from the various overwintering sites. Lengths ranged from 380 mm to 810 mm, with a mean length of 566 mm. Weights ranged from 375 g to 3,500 g with a mean weight of 795 g. The male to female sex ratio was 1:0.95. The remaining fish species (grayling, round whitefish, and slimy sculpin), many of which were found in burbot stomachs, were not sampled.

The Ivishak mouth site was characterized by a wide, ice covered, braided river valley. Without the aid of a functioning radio transmitter, we were unable to locate overwintering habitat. The five remaining sites are grouped into two general habitat types which were consistent with winter habitat found in earlier studies.

Overwintering Habitat Types:

To date, two categories of winter habitat have been identified in the Sagavanirktok River; 1) deep, isolated under-ice pools and 2) habitat provided by ground water activity. Ground water areas have been further segregated into spring areas and overflow areas.

Deep, isolated pools result from irregularities in contours of the stream bed which allow for water depths exceeding the thickness of winter ice. These areas are deep holes in summer, generally greater than 10 ft, arid are either naturally occurring or can be created by man- made structures (e.g. spur dikes) that affect stream bed mechanics and erosion. Typically, these are pools without flow, found beneath moderately thick ice. Dissolved oxygen is relatively low and water

in Table 4. Sagavanirktok River overwintering sites, April 1983.

Dissolved oxygen Snow Ice Water Fish Tag W Site (ppm) depth depth depth Temp. Species Comments

07 HV Airstrip 9 5 48" 10" ooc GR, BB, RWF, Ice covered spring area with a single open water ssc area present In Feb. No open water in April. Bottom: gravel, cobble. Plecoptera larvae observed.

#2 Pump 111 9 2 24" 12" o0C GR, BB, RWF, Ice covered spring area with open water area estimated ssc flow of 2 fps. NO open water present in April and no flow. Bottom: Cobble, gravel.

83 Ox Creek 11 3 174" 8" O°C BB Large active overflow area, presumably generated by ground water source. Overflow ice 2-3 feet thicker in April than in Feb. Stream bottom covered with ice.

18 Sagwon (0.2 6 108" 36" O°C BB Large overflow area, presumably generated by ground water source. No additional overflow between Feb. and April. Slush present in water. Low DO and strong odor of rotting fish indicate winter kill. Bottom: gravel, dead insect larvae.

#9 Sag Notch 3.6 16 72" 108" O°C BB Isolated pocket of water created by deep basin in river bed. Layer of slush present about 12" beneath bottom of ice with free water below the slush. Bottom: gravel and cobble. Live plecoptera larvae.

#lo Ivishak ... '0 >84" ...... Large overflow area. No water located. Radio transmitter not working during sampling period. 0 temperature is at or near 0 C. In late winter, under-ice slush is often found in these pools. The slush may completely occupy portions of the pool or may be present as a layer in the water column. Fish species which have been found in this type of habitat include all those present during summer months. Isolated pool type habitat has been found in the lower section of the Sagavanirktok River (Bendock,l981) the Sagavanirktok River delta (Bendock, 1977; Dew, 1982), the Kuparuk River delta (Bendock, 1977), and in the Colville River (Bendock, 1981). The Sagavanirktok Notch overwintering site is an example of this type of habitat.

Spring area type habitat is formed by ground water that flows for much or all of the winter but may cease by late winter. Subterranean flow may persist but may not be detectable in the water column. Surface ice is often caved-in or broken in places, and there is occasional overflow downstream. The under-ice channel is typically very narrow and shallow. Water temperature is 00C and dissolved oxygen is high. Substrate is gravel and cobble. Water depth in summer is shallow and the water source is often not obvious. Fish species which have been found in this type of habitat include Arctic char, burbot, grayling, lake trout, round whitefish and slimy sculpin. Spring area habitat has been found in the upper portion of the Sagavanirktok River and its tributaries (Bendock, 1983), the Atigun River (Chihuly and Shideler, 1982), and the Anaktuvuk River (Bendock, 1982). The Happy Valley Airstrip site and the Pump I11 site are examples of this type of overwintering habitat.

Overflow areas are characterized by shallow water under very thick ice. The thick ice is formed when water, presumably from ground water activity upstream, is blocked by grounded ice and is incorporated into the ice field. The ice can become 14 ft. thick or more by late winter. The water layer beneath the ice may be only 6-10 in thick and flow is generally not detectable.

The gravel and cobble substrate is often covered by a layer of ice, thereby creating channels or pockets of water completely surrounded by ice. Water temperature is O°C and the dissolved oxygen is high. Summer water depths are shallow. Fish species found in overflow areas to date include Arctic char, lake trout, and burbot. This type of overwintering habitat has been found in the Anaktuvuk River (Bendock, 1982) and the Sagavanirktok River and its tributaries (Bendock, 1983). The Ox Creek and Sagwon overwintering sites are examples of this type of habitat.

Dalton Hiehwav - Lake Survevs

Six small mountain lakes along the Dalton Highway in the Campsite Lake area (lat. 68' 35'N, long. 149O 10' W) of the Sagavanirktok River drainage were surveyed during early May 1983 (Fig. 3). The lakes were completely ice-covered during the survey period. Baited set lines and a single 125' experimental gill net were set under the-ice for 24 hour intervals in each lake. Table 5 lists the physical and chemical data, as well as fish species captured, for each lake.

Twenty lake trout were taken from the Campsite Lake area. Fork lengths ranged from 155 to 765 mm, with a mean of 409 mm. Weights ranged from

12 Figure 3. Locations of six mountain lakes surveyed along the Dalton Highway.

13 Table 5. Locations, physical characteristics and species present in six mountain lakes adjacent to the Dalton Highway Milepost 295.

Approx. Max. iat. Long. Elevation Surface Depth Species 0 Ref. # N W (ft) Acres (ft.) DO Hardness pH Captured

M - 72 68' 34" 149' 1O'W 2,918 20 >30 12ppm 5lppm 7.0 LT M - 73 68' 36" 149' 08'W 2,840 40 >30 llppm 5lppm 7.5 AC, LT

M - 74 68' 37" 149O 08'W 2,824 60 >30 llppm 5lppm 7.5 AC, LT

M - 75 68' 38" 149' 09'W 2,815 20 >30 12ppm 5lppm 7.0 AC, LT, BB

M - 76 68' 38" 149' 11'W 2,750 20 >20 lOppm 68ppm 7.0 BB t- .P M - 77 68' 36" 149' 08'W 2,825 20 >30 llppm 5lppm 7.5 AC, LT

... .-

_--_ I 30 to 6,500 g with a mean of 1,003 g. The male to female sex ratio was 1:l.S. Ages ranged from 5 to 40 years. About fifty percent of the trout had food in their stomachs. Snails, clams and fish remains were the predominant food items. Six Arctic char were captured in these lakes. Fork lengths ranged from 310 to 430 mm, with a mean of 357 mm. Weights ranged from 270 to 850 g, with a mean of 475 g. The male to female sex ratio was 1:l. All of the char had food in their stomachs and snails and caddis larvae were the predominant food items.

Dalton Highway Sport Fishing

The Dalton Highway (North Slope Haul Road), built in 1974 and transferred to the State in 1978, was reopened to sport fishing in 1979. Access during 1979 was limited to permitted commercial users, which restricted sport fishing opportunities primarily to truckers and employees of Alyeska Pipeline Co. and the State Department of Transportation. Starting in 1981, the highway was opened during June, July and August for public travel from the Yukon River to Disaster Creek, approximately 150 mi north. In 1983, this section of the highway was opened on a year-round basis.

Sport fishing pressure along the haul road has been monitored. Staff observed fishermen, conducted creel census interviews and observed the location and intensity of fishing from overflights in fixed-winged aircraft.

Sport fishing pressure continues to be light throughout the Dalton Highway corridor north of the Yukon River. Effort remains concentrated near Alyeska pump stations and state road maintenance camps. The most frequently fished locations south of Atigun Pass are Prospect Creek, Jim River and Grayling Lake. North of Atigun Pass, the lakes in the vicinity of Toolik Lake and the upper Kuparuk and Sagavanirktok Rivers are most frequently fished. Grayling are the principal species taken along the highway, while lake trout and Arctic char are taken in smaller numbers north of the Brooks Range.

Data from the Alaska Statewide Sport Fish Harvest Studies (Mills, 1983) indicate similar intensity and distribution of fishing effort, although sample size is small. Lake and Stream Surveys - Arctic Coastal Plain The Arctic coastal plain on the North Slope extends from Cape Lisburne to the Canadian Border. At its greatest depth south of Barrow, the coastal plain extends 115 mi inland, while on the eastern border it is ! less than 10 mi deep. The coastal plain is characterized by abundant lakes, wet tundra, meandering streams, low relief and thermokarst features. Precipitation is low (5" to 7" annually) and surface drainage is poor, due to flatness of terrain, continuous permafrost and low rates of evaporation. Lakes within the region are "thaw lakes" and cover nearly half of the total plain area. Four lakes within the region are

15 greater than 10 sq mi in area. The largest, Teshekpuk Lake, is 25 mi long and covers 315 sq mi. Lakes within the region generally tend to be shallow; however, a significant number have deep basins and provide year-round habitat for fish. Deep basins, where they exist, are considerably smaller than the total surface area of the lake, thus surface area alone does not adequately indicate which lakes support populations of fish. The amount of basin area may also limit species diversity and population size within a lake. Shallow lakes usually do not support fish except where seasonal access is provided by inlet and outlet streams.

Species diversity and abundance vary throughout the coastal plain. Netsch et. al. (1977) surveyed several coastal lakes and streams north of the Colville River in the northern half of the National Petroleum Reserve - Alaska. This and other studies indicate that species diversity is lowest on both the eastern and western margins of the coastal plain and greatest in the central region, lying south of Teshekpuk Lake and west of the Colville River. Lake and stream surveys were conducted within the central portion of the coastal plain in an area bounded on the west by the Ikpikpuk River and on the east by the Colville River. In 1983, Teshekpuk Lake and 23 unnamed lakes were surveyed. Stream surveys were conducted on the Ikpikpuk River and on seven smaller streams within the area. Survey information gathered from each of these areas follows. A discussion of the fish species found in this area of the coastal plain is found at the end of this section.

Teshekpuk Lake:

Teshekpuk Lake (Fig. 4), lat. 70' 35'N, long. 153' 30'W, is the largest lake on the North Slope and is located 12 mi west of Harrison Bay. It is 25 mi across and covers 315 sq mi. The lake has a complex shoreline with features that include bays, spits, lagoons, vegetated and unvegetated islands, mud, sand and gravel beaches, and extensive shoal areas. The maximum reported depth is 50 ft. Extensive shoal areas exist at the east and west ends of the lake and, to a lesser degree, around the remaining perimeter. There is a single outlet on the west side, the Miguakiak River, that enters the lower Ikpikpuk River. The major inlets enter the lake on the southeast and southwest shores.

A fisheries survey of Teshekpuk Lake was conducted from August 10-16, 1983. During that time period,' a nearly constant northeast wind prevented netting in all but the southern portion of the lake. In early September we returned and set nets at site numbers 5-83 and 6-83 with a float plane. Sites 1 through 5-77 and 1 and 2-81 are from sampling trips in 1977 and 1981, respectively. The location of each of these sampling sites is illustrated in Fig. 4. The fish species captured and the water depth at each site are listed in Table 6. In addition to the gill netting effort, beach seines hauled along the southern beach near site 1-83 produced ninespine stickleback and young-of-the-year least cisco. Five man hours of angling effort produced no fish. Water .chemistry data taken at a single location near site 2-83 were: H 0 temp. 2 8OC; pH-8, hardness 136 ppm, Secchi disk - 8'.

16 1 c' I

17 Table 6. Date, depth of set and species composition of net catches in Teshekpuk Lake.

Site No. Date Depth (ft) Species

1 - 77 8/17/77 6 LCI, ACI, BWF, HWF 2 - 77 8/17/77 6 LCI, ACI, GR

3 - 77 8/17/77 6 LCI, BWF, GR

4 - 77 8/17/77 6 GR, BWF

5 - 77 8/17/77 20 LT, LCI, BWF

1 - 81 7/21 181 6 LCI, GR, BWF

2 - 81 7/21/a1 15 LCI, LT, GR

1 - 83 8113/83 8 LCI, BWF, GR

2 - 83 8/13/83 15 LCI, LT, BWF

3 - 83 8/13/83 21 LCI, LT, BWF

4 -, 83 8/13/83 8 LCI, BWF, LT, GR, ACI, HWF

5 - 83 9/10/83 6 LCI, BWF, ACI

6 - 83 9/10/83 6 LCI, BWF, ACI

18 Table 7. hngth-ap relsttonships of ffsh fra Te.hcrp* Lke, 1977-1983. -- 1

Ale At Capture Flah Species 0 I I1 1x1 xv V VI VII VIII IX X XI XI1 XI11 XIV xv XVf XVII XXI

Broad Hiteffsh x 198 227 223 252 330 330 368 389 447 457 429 430 *44 447 478 ... n-95 n 1 2 2 3 1 2 8 6 23 15 lz 5 8 3 4 Range 225-228 215-230 230-267 270-398 270-435 340-430 345-515 368-540 237-510 374-505 409-520 420-477 410-540

Hurpback Hirefish 43s 393 n-2 n 1 1 Range

Arctlc Cisco X 431 625 600 n-7 n 4 2 1 Range 403-500 550-100 kdSt CiSCO x u 127 1&3 165 255 266 249 251 267 262 268 253 295 308 363 325 Y6 n42 n 7 1 5 1 3 2 4 1 4 6 3 3 3 2 2 1 1 Range 37-55 133-155 183-291 258-274 223-282 228-322 160-303 243-297 225-288 288-308 290-325 328-398

Craylln8 X 137 206 235 339 344 374 390 427 432 419 n-77 n 1 1 1 8 20 ia 14 12 7 3 Ranst 309-359 312-372 335-103 355-609 380-462 400-461) 398-445

ABe At Capture VII VIII IX x-XIV xv-XIX Itx-XXIV xxv-XXIX Mx-XXXIV xxxv-xxxIx XL-XLIV XLV-XLIX L

Lke Trout x 472 500 555 680 791 825 820 825 837 863 797 12-24 n 3 1 2 2 2 1 3 3 2 3 2 Range 442-490 550-560 675-685 707-875 790-840 203-892 80s-868 855-875 778-835 TESHEKPUK LAKE LC I

I00 200 300 400 500 600 700 800

45-

40-

r u) ii 35- * 0 30- t# n E z 25- UNNAMED LAKES LC I 20-

IS-

10-

Figure 5. Length frequencies of least cisco captured in Teshekpuk Lake (n=86) and unnamed lakes in the Arctic Coastal Plain (~163). Length and age data for six of the species captured in Teshekpuk Lake are presented in Table 7. Ninespine sticklebacks captured in the seine hauls were not sampled. In addition to these seven species, burbot are also reported in the outlet of .the lake (Netsch et. al., 1977).

Eighty-six least cisco were sampled from gill net catches. Ages are available for only 42 of the 86 fish and are presented in Table 7 . Lengths ranged from 37 to 398 mm, with a mean length of 193 mm (see Fig. 5 for length frequency distribution). Weights range from 3 to 625 g with a mean of 103 g. Ages ranged from 0 to XXI. Maturity is first reached at Ages V and VI. A bimodal length distribution of mature fish exists with peaks at approximately 145 and 244 mm. This indicates that the "dwarf" and "normal" forms described by McPhail and Lindsey (1970) may sympatrically exist in the lake. The male to female sex ratio is 1:1.5. Least cisco food items, listed in descending frequency of Occurrence, include amphipods, aerial insects and isopods.

Grayling sampled from Teshekpuk Lake (n = 77) ranged from 137 to 468 mm with a mean of 374 mm (Fig. 6). Weights ranged from 40 to 1,175 g with a mean of 647 g. Ages ranged from I1 to XI. All grayling were mature by Age VI. The male to female sex ratio was 1:O.g. Grayling food items in Teshekpuk Lake included: fish remains, insect larvae (primarily caddis larvae) amphipods and isopods.

Twenty-four lake trout ranged in length from 442 to 892 mm, with a mean of 732 mm (Fig. 7). Weights ranged from 1,052 to 9,000 g, with a mean of 4,327 g. Maturity is first reached at Age IX and all trout sampled older than Age X were mature. The male to female sex ratio was 1:0.33. Food items were fish remains and isopods.

Lengths of 95 broad whitefish from Teshekpuk Lake ranged from 198 to 540 mm, with a mean of 415 mm (Fig. 8). Weights ranged from 40 to 2,300 g, with a mean of 950 g. Maturity is first reached in this population at Age X. The male to female sex ratio was 1:0.8. Stomach contents, listed in decreasing order of occurrence, were: snails, benthic insects (primarily caddis larvae), clams and zooplankton.

Only two humpback whitefish were taken in the sampling period. One was a male at 435 mm weighing 1,500 g. The other was a female at 393 mm weighing 800 g. Both fish were mature in prespawning condition. Amphipods were found as the primary food item. Seven Arctic cisco were captured in Teshekpuk Lake. Lengths ranged from 403 to 600 mm, with a mean of 377 mm. Weights ranged from 400 to 950 g, with a mean of 586 g. All Arctic cisco sampled were immature except for a single female at 403 mm and Age VIII which was in pre-spawning condition during the second week of August. The male to female sex ratio was 1:2.5. Food items from stomach contents included mysids and amphipods.

Unnamed Coastal Plain Lakes:

During the 1983 report period 23 lakes were surveyed within the central portion of the coastal plain. In 1981 16 lakes were surveyed within

21 40

35 TESHEKPUK 30 LAKE

25 GR

100 200 300 400 500 600 700 Length hm)

10 UNNAMED LAKES

GR 5

I I I I I I I I a I I I I I 100 200 300 400 500 600 700 Length (mm)

igure 6. Length frequencies of grayling captured in Teshekpuk Lake (n=77) and in unnamed lake (n=lO) in the Arctic Coastal Plain. 22 15 TESHEKPUK LAKE 10 LT 5 n!

20 UNNAMED LAKES 15 n LT 10

I I I I 7v I I I I v I 1 I 1 I I I I i 300 400 500 600 700 800 900 1000 Lengih (mm)

Lgure 7. Length frequencies of lake trout captured in Teshekpuk Lake (11x24) and in unnamed lakes in the Arctic Coastal Plain (n=60). 23 30

2.5 TESHEKPUK LAKE BWF 20

10 5 lu I 1 I 1 I 1 1 r 9 100 200 300 400 500 600 700 800

UNNAMED LAKES BWF

100 200 300 400 500 600 700 800 Length (mm)

Figure 8, Length frequencies of broad whitefish in Teshekpuk Lake (n=95) and unnamed lakes in the Arctic Coastal Plain (11-59).

24 !

this same area and these lakes are also included in this report (Fig. 9). These waters were moderately deep, ranging from 8 ft to 70 ft, soft and slightly basic. Many of the lakes had extensive, unvegetated shoal areas on which ice remains grounded throughout the winter. Submerged aquatic vegetation is sparse and sand is the most common substrate. None of the lakes surveyed are named on USGS 1:250,000 maps. Two 125-ft graduated mesh gill nets were set overnight in each of the 23 lakes surveyed in 1983. In addition, a baited burbot set was attached to one end of each of the gill nets. In each of the 16 lakes surveyed in 1981 a single 125 ft graduated mesh gill net was set overnight. Table 8 lists the locations, physical characteristics and fish species captured in each of the lakes surveyed. A discussion of fish species from this area follows survey information from the coastal plain streams.

Ikpikpuk River:

The Ikpikpuk River Fig. 10 originates at the conofluence of the Kigalik River and Maybe Creek at lat. 69' 20'N, lat. 154 42'W and flows north 195 mi to Smith Bay. It is the third largest stream on the North Slope, with a drainage area of 1,475 sq mi and an estimated average flow of 2,270 cfs. Two major tributaries flowointo the Ikpikpuk River, the Price River at lat. 69' %1'N, long. 154 42'W and the Titaluk River at lat. 69' 57' N, long. 154 43'W.

A fisheries survey of the Ikpikpuk River was conducted by raft during June 18-;4, 1983 between aopoint upstream of the Valley of the Willows (lat. 69 33' N, long. 154 44' W) and the mouth of the Titaluk River (Fig. 10). The section of the Ikpikpuk River that was surveyed is a single meandering channel. The stream bottom consists of fine material, predominantly sand/mud, interspersed with short stretches of gravel. The river bars and cutbanks are also predominantly sand. The river gradient is low and the water velocity sluggish (0.3-1.0 fps). The river is uniformly shallow with well separated pools near cutbanks. The deepest pool encountered was 18 ft deep and at the mouth gf the Titaluk River. The tea colored (Secchi 4.5') water was 10-11 C during the survey; pH was 8 and hardness 51 ppm. The Price River was more turbid and the Titaluk River less turbid than the Ikpikpuk. Upstream of the mouth of the Price River, the Ikpikpuk River emerges from the foothills onto the coastal plain. Downstream of this there is little topographic relief aside from the river cutbanks. During the float survey, four sites along this stretch of river were sampled (Fig. 10). Two gill nets and 4 set lines were set at each survey site.

Seven species of fish were captured in the Ikpikpuk River. These include: grayling (n=39), burbot (n=10), longnose sucker (n=10), northern pike (n=6), humpback whitefish (n=5), least cisco (n=5) and broad whitefish (~2). In addition, slimy sculpin, ninespine stickleback, and Arctic lamprey were found as food items in stomach analysis.

Site number 4, at the Titaluk River mouth, was again sampled on September 10. At that time grayling (n-6), broad whitefish (n=9),

25 I I I I I 1~000' I53 00' 00GI23 10 MILES

I I igure 10. Location of sampling sites on Ikpikpuk River June 18-24. Also, location of burbot radio tagging (Site 4).

27 *-. . . I .

Table 8. Locations, physical characteristics and species captured in 39 coastal plain lakes during 1981 and 1983.

Surf ace Approx. Max. Secchi H2° North West Elevation Length Depth Reading Hardness pH Temp Species Ref. # Lat. Long. (ft) (mi) (ft) (ft) (PPd (OF) Captured

C-32* 70: 34' 154' 18' 8 3.2 20 7 103 9 50 LCI, BWF C-40* 70 09' 153: 55' 164 3.0 18 16 68 9 55 LT, BWF, LCI, RWF C-41* 70' 12' 153 39' 160 2.1 22 20 86 9 53 LT, LCI C-43* 69' 46' 155' 18' 180 1.1 23 12 120 9 55 None C-44* 69' 42' 155: 08' 250 1.9 22 15 103 9 56 None C-45" 69: 39' 154 58' 290 1.6 8 8 137 9 54 GR C-46* 69 46' 153' 28' 280 2.0 10 8 68 9 57 None C-50* 70' 03' 153' 30' 145 3.6 45 20 86 9 54 LT, BWF C-52* 69' 57' 153' 15' 200 3.0 50 15 86 9 57 LT, BWF, LCI, RWF, BB, NSB, SSC h) C-57* 70' 17' 153' 00' 120 2.5 37 22 103 9 51 LT, LCI, NSB 0 C-58" 70' 18' 152' 56' 122 2.2 10 8 86 9 55 LT, BWF, NSB C-59* 70' 18' 153O 04' 123 2.3 44 20 103 9 55 LT, BWF, RWF, LCI, NSB C-61* 69' 51' 152' 27' 210 1.5 30 20 86 9 55 LCI C-62* 69' 53' 152' 11' 210 1.5 27 12 68 8.5 56 LCI, NSB C-63* 70' 06' 152' 37' 86 2.0 8 6 86 9 62 BWF, LCI, HWF, NSB C-65* 70' 10' 152' 23' 141 2.2 15 15 86 9 55 LCI, NSB

C-115 69' 53' 154' 20' 150 2.8 35 10 34 8 51 BWF, LCI, RWF C-116 69: 57' 154: 17' 150 2.5 63 18 68 8.5 48 BB. LCI, LT, NSB C-117 69 58' 154 16' 150 4.4 40 10 51 8 51 BB, BWF, LCT, LT, NSB C-118 69' 48' 151: 52' 198 2.0 10 8 17 7.5 51 LCI C-119 70' 06' 1520 53' 160 2.5 32 17 85 9 46 LT C-120 70' 01' 153 08' 150 1.8 32 8 34 8 50 BWF, LCI, LT, NSB , ssc (Continued) 2.0 27 13 102 9 50 BB, LT 32 14 C-121 70' 14' 153: 15' 160 1.8 102 9 50 LT 160 10 6 34 8 .. - I. n 4.0 52 BWF, GR, LCI C-122 70' 14' 153 05' 37 14 154: 40' 2.6 85 9 50 LT C-123 70' 22' 42 16 1530 1.2 51 8 54 BB, BWF, LT, RWF C-124 70' 22' 40' 70 15 C-125 70' 04' 153 37' 2.5 51 8.5 53 BB, LT 22" 9 8 - n 2.2 85 9 56 None C-126 69' 51' 153' 30' 18 8 69' 2.0 51 8 56 None C-127 39' 153: 03' 9 4.0 9 68 9 56 None C-128 69' 40' 1530 06' 17 15 C-129 69' 42' 153 45' 2.5 17 7.5 58 GR, NSB 27" 13 12 43' - nn 1.8 85 9 57 None C-130 69' 154' 38' 10 8 C-131 69' 46' 154: 26' 2"" 3.2 68 8.5 54 BWF, LCI 60 8 8 C-132 70' 25' 152- 40' 1.8 17 7.5 58 BWF, GR, LCI 7" 7 7 C-133 70' 26' 152: 22' 1.5 17 7.5 58 0 250 42 16 68 9 C-134 69' 47' 152~- 37' .a 1.8 56 BWF 2J7 1.8 9 ... 33 C-135 69' 51' 152: 24' 5 ...... LCI, NSB 7.6 8 ...... 34 C-136** 70' 45' 1530 20' 3 ... BWF, LCI C-137** 70' 40' 152 40'

* Surveys were conducted during ** Surveys were conducted Septeflbe last two weeks of July 1983. Table 9. Fish from Ikpikpuk River, 1983.

Length (mm) Weight (g) - - Age Species n Range X Range X Range

Gray1ing 45 207-378 297 100-700 319 IV - x Burbot 10 375-1000 711 410-6000 2,586 VI-XXIII

Longno se 10 420-500 468 850-1400 1,135 ... Sucker

Northern 6 4 10-606 511 500-1675 1,058 V-XI1 Pike

Least 105 255-397 313 200-850 371 VI-XVIII Cisco

Broad 11 360-597 490 ...... Whitefish

Humpback 10 375-480 400 675-1525 828 XI-XV Whitefish

30 humpback whitefish (n=5) and least cisco (n=100) were captured. Length and weight data for fish from the Ikpikpuk River are presented in Table 9.

Mature grayling were taken throughout the section surveyed. Young-of- the-year grayling were captured at the farthest upstream site. Grayling had just completed spawning in the upper river (June 19) and three ripe females were taken at site number 4 on June 24 (H 0 temp. 2 ll°C). Grayling spawning occurs in the main stem of the Ikpikpuk and probably in the larger tributaries.

Small numbers of northern pike were found in the Ikpikpuk throughout the area surveyed. During the June 18-24 sampling period the pike had just completed spawning.

Longnose suckers were captured in the first three sampling sites. All suckers were mature and either ripe or spent (June 18-24).

Mature least cisco, humpback whitefish and broad whitefish were found throughout the surveyed section during the June 18-24 period. A large group of 250-400 mm least cisco was captured at site number 4 on September 10. Of the 100 that were sampled, all were mature prespawners, with some running sex products. In addition to the least cisco, humpback whitefish and broad whitefish in spawning condition were taken at this time.

Additional Stream Surveys - Coastal Plain:

In addition to the week-long survey of the Ikpikpuk River in June, spot surveys were conducted on seven smaller streams in the coastal plain (Fig. 11). These surveys were brief and emphasis was placed on determining fish species present.

The streams in this part of the coastal plain originate in the low foothills north of the Colville River. Most of these are small, single channel streams with low stream gradient which meander widely and terminate in braided deltas. Stream beds and banks are generally sand and silt, although several streams have gravel bottoms in upper reaches where they cut through the foothills. Aquatic vegetation was either absent or extremely sparse in the stream sections surveyed.

Stream discharge peaked shortly after breakup in early June and declined throughout the open water season. From July through freeze-up the low discharge exposed vast unvegetated sand bars in all of the major floodplains so that the shallow channels remaining represented only a fraction of the original stream size at breakup. While streams. did not become discontinuous during midsummer , most of the sampling sites had standing water or velocities of less than 1 fps. Freeze-up began during the third week of September.

Eleven species of fish were captured in the coastal plain streams. Additionally, pink and chum salmon enter the Colville River. Sample site locations and species captured are listed in Table 10.

31 ZE

4 0 0 Table 10. Location, width, depth, pH and species present at coastal plain stream survey sites, 1983.

~-~ ~~

Approx. Width Maximum Stream Site Location (ft) Depth (ft) PH Species Present

Ikpikpuk R. 81 69: 33' N, 154: 44'W ...... 8.0 GR, NP, SSC, NSB Ikpikpuk R. #2 6g0 36' N, 1540 56'W 150 10 8.0 BB, GR, HWF, LNS, NP Ikpikpuk R. 13 6g0 44' N, 154 45'W 175 5 8.0 BB, GR, HWF, LNS, NP Ikpikpuk R. #4 69 57' N, 154' 43'W 250 15 8.0 AL, BB, BWF, GR, HWF, LCI, NP, NSB Price R. #l 69' 50' N, 154' 37'W 60 12 8.0 BWF, GR, HWF, LCI Price R. #2 69' 45' N, 153' 51'W 80 10 8.0 BWF, GR, HWF, LCI Kealok Cr. #l 70: 31' N, 153' 1O'W 50 6 8.0 GR Kealok Cr. 12 70 16' N, 153' 35'W 50 4 8.0 GR, LCI Kalikpik R. #l 70; 17' N, 152' 21'W 40 5 8.0 GR Kalikpik R. 82 70 26' N, 152' 05'W 60 6 8.0 BWF, GR, LCI, RWF w w Inigok Cr 70' 10' N, 153: 13'W 80 7 8.0 BWF, GR, RWF Judy Creek #1 70' 00' N, 152 25'W 15 5 8.5 RWF Judy Creek #2 70: 02' N, 152' 35'W 16 4 8.0 BWF Kikiakrorak R. #I 69 48' N, 152' OO'W 15 2 8.5 Y. 0. Y. GR captured, SSC observed Kikiakrorak R. #2* 70: 00' N, 151' 36'W 150 4 ... BWF, CS, GR, HWF, LCI, PS Kogosukruk R. #1 69 39' N, 151' 50'W 60 25 8.5 GR, LCI, LNS, RWF Kogosukruk R. #2 69' 45' N, 151' 42'W 75 3 8.5 ssc Kogosukruk R. #3* 69' 56' N, 151' 35'W 125 5 ... BB, GR, LNS, NSB, RWF, SSC

~ ~ ~~ * From previous surveying work (Bendock, 1979).

I Life History Discussions of Coastal Plain Species

Of the 39 coastal lakes surveyed west of the Colville River, 32 (82%) contained populations of fish. The most common species in terms of frequency of occurrence and catch per unit effort were: least cisco, lake trout and broad whitefish, followed by burbot, round whitefish, grayling, and humpback whitefish. Burbot are not readily captured in gill nets and may therefore be more abundant than indicated, particularly in the waters sampled in 1981. Ninespine stickleback and slimy sculpin, while not captured, were found as food items in lake trout and burbot.

In the streams of the central coastal plain, grayling were the most frequently captured species and were taken at 15 of the 18 sampling sites. Ninespine stickleback and slimy sculpin were also widely distributed throughout the area. Least cisco, broad whitefish and humpback whitefish were the principal anadromous species in the area. Burbot and northern pike were limited in distribution to the Ikpikpuk River drainage.

The following discussions are based on fish taken during the 1981 and 1983 field seasons.

Least Cisco

Least cisco were captured in 21 (54%) of the coastal plain lakes surveyed and were the most abundant species encountered. A total of 163 least cisco was sampled from these lakes. Lengths of least cisco ranged from 115 to 462 mm and averaged 283 mm. Weights ranged from 10 to 1,600 g, with a mean of 341 g. Ages of the cisco sampled ranged from I1 to XX. Maturity is first reached at Age IV. The male to female sex ratio was 1:0.85. The following food items were found in descending frequency of occurrence: snails, aerial insects, clams, insect larvae (primarily caddis), fish (NSB), zooplankton, amphipods, and isopods.

Least cisco were found in six (75%) of the streams surveyed in the central coastal plain. Lengths (n=121) ranged from 142-397 mm, with a mean of 307 mm. Weights ranged from 50-850 g and averaged 323 mm. Ages of sampled fish ranged from 111-XVIII, with age of first maturity at Age I11 from the Kalikpik River. The male to female sex ratio was 1:0.36. Few data are available on food habits since 90% of the cisco sampled had empty stomachs. The remaining fish had only a trace of food (aquatic insect larvae) in their stomachs.

Length frequencies for least cisco taken from coastal plain lakes are presented in Fig. 5 and from streams in Fig. 12. Lake resident least cisco attain a greater ultimate size and longevity than their anadromous counterparts. In coastal plain lakes, least cisco are an important forage fish for lake trout and burbot.

Broad Whitefish

Broad whitefish were captured in 17 (44%) of the coastal plain lakes surveyed. Lengths ranged from 295 to 632 mm and averaged 490 mm

34 6C r

40 COASTAL STREAMS

LCI

, I I I I I I I00 ' 200 I 300 '400 560 600 7i>o 8001 L)ength (mm)

35 COASTAL STREAMS

BWF 0 L 10 a P 55 7 r"r_I00 200 300 400 500 600 700 800 Length (rnrn)

Figure 13. Length frequencies of broad whitefish (n=37) captured in Arctic Coastal Plain streams.

COASTAL STREAMS 30 I GR c 25. cn E

Y- 20 O

L W 15 P E t 10 5

I I b I 1 1 I 1 I I I 1 I I I f I00 200 360'400 500'600 700 800 Length (rnm)

Figure 14. Length frequencies of grayling (nslll) captured in Arctic Coastal Plain streams 36 (Fig. 8). Weights ranged from 380 to 4,100 g and averaged 1,780 g. Ages of sampled fish ranged from V-XXI and the first age of maturity was Age X. The male to female sex ratio was 1:1.2. Food items in descending order of frequency were: snails, clams and insect larvae.

Broad whitefish were found in six (75%) of the streams surveyed in the coastal plain. Lengths ranged from 360 to 620 mm and averaged 470 mm (Fig. 13). Weights ranged from 500 to 3,050 g and averaged 991 g. Ages of broad whitefish from streams ranged from V-XXII and the first maturity was at Age IX. The male to female sex ratio was 1:O.Z. Few data were available on food habits. One broad whitefish was found with snails in its stomach.

Grayling

Grayling were captured in only five (13%) of the lakes in the central coastal plain. Lengths ranged from 347 to 426 mm, and averaged 400 mm (Fig. 6), while weights ranged from 540 to 1,250 g and averaged 863 g. Ages of grayling ranged from VI-X and all in the sample were mature. The male to female sex ratio was 1:2.3. Grayling food items were insect larvae (primarily caddis), and fish remains.

Grayling were captured in 7 (88%) of the streams surveyed in this portion of the coastal plain and were the most frequently captured fish in these streams. Lengths ranged from 75 to 435 mm, and averaged 306 mm (Fig. 14). Weights ranged from 10 to 880 g, and averaged 360 g. Ages ranged from 0 through X and first maturity was at Age IV. The male to female sex ratio was 1:0.7. Prey items were found in 89% of the stomachs investigated and insects (beetles, lamae, caddis and aerial insects) were the primary food item.

Lake Trout

Lake trout were captured in 17 (44%) of the lakes surveyed in the central coastal plain. Lengths ranged from 370 to 908 mm and averaged 588 mm (n==60), while weights ranged from 580 to 9,700 g and averaged 2,879 g. Ages of lake trout sampled ranged from Age VII to more than Age L. First maturity was at Age VIII. The male to female sex ratio was 1:1.36. Food items from stomach content analysis were: fish (least cisco, ninespine stickleback, burbot, lake trout), snails, clams and crustaceans.

Lake trout are occasionally found in the Colville River, however, no trout were captured in any of the coastal plain streams surveyed. Length frequency for lake trout is shown in Fig. 7.

Burbot

Burbot were captured in 6 (15%) of the lakes surveyed. Lengths ranged ’ from 450 to 694 mm and averaged 649 mm (n=6), while weights ranged from 700 to 2,700 g and averaged 2,360 g. Ages ranged from X-XX and all of the burbot sampled were mature. The male to female sex ratio was 1:4. Fish of various species were the primary food item and were found in 80% of the burbot stomachs.

37 Of the coastal plain streams surveyed, burbot were found only in the Ikpikpuk River. Ten burbot ranged from 375 to 1,000 mm and averaged 297 mm in total length. Weight ranged from 410 to 6,000 g and averaged 2,586 g. Ages ranged from VI through XXIII and all specimens were mature. The male to female sex ratio was 1:1.5. Ninety percent of the stomachs analyzed contained food, and fish remains and insect larvae were the primary food item.

Humpback Whitefish

Humpback whitefish were found in only 2 (5%) of the lakes surveyed (Teshekpuk and C-63). The fish from C-63 included a 350 mm, 575 g female which was not mature at Age X and a 470 mm, 1,350 g male mature at Age XIII.

Humpback whitefish were found in 3 (38%) of the streams surveyed. Lengths ranged from 365 to 480 mm and averaged 403 mm (n=17), while weights ranged from 525 to 1,525 g and averaged 819 g. Ages of the humpback whitefish ranged from XI to XV and all were mature. The male to female sex ratio was 1:0.7. Food items included snails, clams, insect larvae and burbot fry.

Round Whitefish

Round whitefish were found in five (13%) of the lakes surveyed. Lengths ranged from 163 to 417 mm, and averaged 307 mm (n=12>. Weights ranged 40 to 720 g and averaged 365 g, Ages of the fish sampled rangea III-XVIII. The age of first maturity was VII. The male to female sex ratio was 1:1.2. Round whitefish food items included snails and aerial insects,

Round whitefish were found in four (50%) of the streams surveyed in the central coastal plain. Lengths ranged from 149 to 407 mm and averaged 309 mm (n=8). Weights ranged from 50 to 725 g and averaged 339 g. Ages ranged from 111 to X and age at first maturity was VIII. The male to female sex ratio was 1:0.2. Food, from stomach contents, was insect larvae and snails.

Northern Pike

Northern pike were captured only in the Ikpikpuk River during our surveys. Netsch, et., al., (1977) report pike in an oxbow lake adjacent to the Ikpikpuk River at lat. 69' 59'N, long, 154' 34'W. Lengths for pike captured in the Ikpikpuk River ranged from 410 to 606 mm and averaged 511 mm (n=6). Weights ranged from 500 to 1,675 g and averaged 1,058 g. All fish sampled were mature and ranged from Age V.through XII. The male to female sex ratio was 1:0.5. Prey items identified from stomach contents were ninespine stickleback, burbot and grayling.

I Longnose Sucker

Longnose suckers were found in only two streams in the coastal plain, the Ikpikpuk and Kogosukruk Rivers. Lengths ranged from 125 to 500 mm

38 and averaged 370 mm (~16). The male to female sex ratio was 1: 1. All suckers greater than 400 mm were mature.

Overwintering Habitat Studies of the Chandler and Ikpikpuk Rivers Using Radio Telemetry

In a continuing investigation of fresh water overwintering habitat on the north slope, radio transmitters were surgically implanted in three burbot in the Chandler River and in two burbot in the Ikpikpuk River.

Chandler River:

Nearly all fishery survey information from the Chandler River is from the open water season. During the summer months, the Chandler River shows the greatest species diversity of any of the Colville River tributaries (Bendock, 1979). Fish species which have been found in the Chandler River include: grayling, lake trout, Arctic char, broad whitefish, humpback whitefish, round whitefish, burbot, longnose sucker, i slimy sculpin and ninespine stickleback. Overwintering habitat in the Chandler River appears to be limited primarily to a few holes up to 10 ft deep in the lower 40 mi of the river. Kogl and Schell (1974) made an aerial search of the Chandler River for potential overwintering habitat and observed a single open water stretch of river several hundred yards in length approximately 43 mi above the mouth. Juvenile grayling were the only fish found at this site.

To further investigate the presence of overwintering habitat in the Chandler River, three burbot were radio-tagged at two sites in the river (Fig.15). The lengths and weights of the fish tagged and the transmitter frequencies are listed in Table 11.

Ikpikpuk River:

Information is lacking on overwintering habitat in the Ikpikpuk River system. Fisheries investigations during the open water period are discussed elsewhere in this report. Radio transmitters were placed in two burbot at a site located at the mouth of the Titaluk River and the Ikpikpuk River (site 4, Fig. 10). The lengths and weights of the radio-tagged burbot and the transmitter frequencies are listed in Table 11.

The movements of these radio-tagged fish in the two river systems will be monitored throughout the winter and results of this study will be reported at a later date.

Experimental Fish Stocking - Pt. Barrow

1 Isatkoak Lagoon located at Barrow, Alaska is a series of three interconnected waters that formerly were a single salt water lagoon (Fig.16). Following dredging and the construction of three impoundment structures, the upper two impoundments are fresh and potable. The lower

39 Table 11. Fork length, weight, transmitter frequency and tagging location of five radio-tagged burbot in the Chandler and Ikpikpuk Rivers.

Fork Tag d Length Weight Frequency Tagging Location (g1 (MHZ1

c-1 663 1,300 150.191 Chandler River site A. Approximately 5 miles upstream from the Big Bend.

c-2 720 2,500 150.082 Chandler River site A. Approximately 5 miles upstream from the Big Bend.

c-3 800 1,300 150.152 Chandler River site B. Located at Paunagaktuk Bluff.

1-1 ~ 707 2,000 150.021 Ikpikpuk River at mouth of Tatalik f- 0 River.

1-2 810 3,600 150.280 Ikpikpuk River at mouth of Tatalik River I Table 12. Aerial Estimates of Arctic char on the North Slope from 1971 to 1983.

Location Year Ivishak River Anaktuvuk River Date

1971 24,470 ...

1972 11,937 ... 1973 8,992 ... 1974 11,000 ... 1975 8,306 9/20

1976 8,570 9/22 1977 ...... 1978 ......

1979 24,403 15,717 9/22 1980 ......

1981 24,873 10,536 9/14 1982 36,432 6,222 9/19

1983 27,820 8,743 9/18 0- 5 MILES

Figure 15. Location of two sites where burbot were radio-tagged on the Chandler River,

42 \ Am- I/L 1 ,uu. ,002 0 fl \ \ \ // \ S3lIS 9NIldWVS X-

i impoundment, which is separated from the middle and upper lagoons by a concrete dike, is the municipal sewage lagoon and contains the outfall from Barrow's water treatment facility. The upper lagoon is separated from the mid lagoon by a culverted gravel causeway and is the fresh water source for the City of Barrow.

In response to a request from the City of Barrow, the Isatkoak Lagoon system was evaluated for an experimental stocking program to enhance recreational fishing opportunities for local residents. Water quality analysis done in late winter and in summer and water depths after dredgings indicate that adequate fishery habitat exists throughout the year (Bendock, 1982). Both the upper and middle lagoons were sampled using graduated mesh gill nets and no fish were found. A single ninespine stickleback was found washed up on the gravel causeway separating the upper and middle lagoons.

In June 1981 50,000 unfed grayling fry were stocked in Isatkoak Lagoon. At the time of stocking, the lagoon was ice-covered, with only a small amount of open water in the lagoon south of the Barrow air strip.

In early August 1983 the upper and middle lagoons were again sampled with gill nets to determine the presence of grayling. Two graduated mesh gill nets were placed in the upper lagoon and a single net was placed in the middle lagoon Fig. 16. The nets fished for 1.5 net nights but no fish were captured in either lagoon. Workers at the Barrow water facility have, on occasion, observed a number of ninespine sticklebacks at the water intake in the upper lagoon. However, they have not observed any grayling or grayling size fish. Since no grayling were captured or observed after more than 2 years, it is probable that the experimental stocking of grayling in Isatkoak Lagoon did not succeed. There are no plans for restocking the lagoon at the this time.

Arctic Char Aerial Counts

Aerial counts of Arctic char have been attempted annually in the Sagavanirktok River Drainage since 1971. All of the major tributaries to the Sagavanirktok River determined to be char spawning areas were counted between 1971 and 1975. Since 1976, only the Ivishak and Echooka Rivers have been counted. The Ivishak River contains the largest aggregation of char in the system and is considered an index to overall population levels. Prior to 1977, counts were conducted by helicopter; however, subsequent counts have been made using fixed-wing (Piper PA-18) aircraft. All of the estimates have been made during mid-September. Aerial counts are not considered to be estimates of the char populations, but rather are a means of annually indexing both the distribution and general abundance of char. Safe flying weather has been a continual problem when conducting the char counts and poor weather has resulted in the loss of several years' counts.

Arctic char at two locations in the Anaktuvuk River drainage have been counted since 1979. At present, however, the counts in both drainages have been reduced to a single index area for each stream. Table 12

44 shows the estimates of anadromous Arctic char at index areas in the Sagavanirktok and Anaktuvuk River drainages. All of the counts have been conducted during the third week of September.

The 1983 estimates for the Ivishak and Anaktuvuk Rivers index areas compare favorably with those of past years. The counting conditions were excellent, with clear skies and ice-free water.

LITERATURE CITED

Bendock, T. N. 1977. Beaufort Sea estuarine fishery study. In: Alaskan OCS Principal Investigators Annual Reports, U.S. Dept. of Commerce, NOAA Research Unit 233. . 1979. Inventory and Cataloging of Arctic area waters. Alaska Dept. of Fish and Game. Federal Aid in Fish Restoration, Annual Report of Progress, 1978-1979, Project F-9-11. 20(G-1-1) : 1-64.

1981. Inventory and Cataloging of Arctic area waters. Alaska Dept. of Fish and Game. Federal Aid in Fish Restoration, Annual Report of Progress, 1980-1981, Project F-9-13, 22(G-1-1) : 1-33.

1982. Inventory and Cataloging of Arctic area waters. Alaska Dept. of Fish and Game. Federal Aid in Fish Restoration, Annual Report of Progress, 1981-1982, Project F-9-14, 23(G-1-1): 1-43.

1983. Inventory and Cataloging of Arctic area waters. Alaska Dept. of Fish and Game. Federal Aid in Fish Restoration, Annual Report of Progress, 1982-1983, Project F-9-15, 24(G-1-1): In press.

Chihuly, M and R Shideler. 1982. Report on ADF&G - Surveillance Participation in Northwest Alaskan Pipeline 1982 Overwintering Study. ADF&G memorandum May 17, 1982, File No: NGL 801.2-1, 801.3-2 & 1002.2. 5pp.

Dew, C. B. 1982. Under-Ice Survey of Overwintering fish in the Sagavanirktok River in the vicinity of the Sag River bridge. Woodward-Clyde Consultants, 701 Sesame Street, Anchorage, Ak. 19p.

Furniss, R. A. 1974. Inventory and Cataloging of the Arctic Area Waters. Alaska Department of Fish and Game, Federal Aid. in Fish Restoration, Annual Report of Progress, Project F-9-6. Volume 15.

Kogl, D. and D. Schell. 1974. Colville River Delta Fisheries Research. P. 483-504 In: Environmental Studies of an Arctic Esturaine System. U.S. Environmental Protec. Agency, Ecol. Res. Series. EPA-660/3-75-026.

45 McCart, P., P. Craig, and H. Bain. 1972, Report on fisheries investigations in the Sagavanirktok River and neighboring drainages. Alyeska Pipeline Services CO.

McPhail, J. D. and C. C. Lindsey. 1970. Freshwater Fishes of northwestern Canada and Alaska. Fish Res. Bd. Can. Bul 173. 381 p.

Mills, M. 1983. Statewide Harvest Survey, 1982 Data. Alaska Dept. of Fish and Game. Federal Aid in Fish Restoration and Anadromous Fish Studies, 1982-1983, 24(SW-I): 1-118. Netsch, N., E. Crateau, G. Love, and N. Swanton. 1977. Freshwater fisheries reconnaissance of the coastal plain of the National Petroleum reserve-Alaska (NPR-A), July and August 1977, preliminary report. U.S. Fish and Wildlife Service, Anchorage, Alaska. 214p.

Yoshihara, H. T. 1971-72, Monitoring and Evaluation of Arctic Waters with Emphasis on North Slope Drainages. Alaska Department of Fish and Game. Federal Aid in Fish Restoration, Annual Progress Report, Project F-9-4. 13(G-1-1) : 1-49. . 1973. Monitoring and Evaluation of Arctic Waters with Emphasis on North Slope Drainages. Alaska Department of Fish and Game. Federal Aid in Fish Restoration, Annual Progress Report, Project F-9-5. 14(G-1-1): 1-83.

Prepared by: Approved by :

Terrence N. Bendock Richard Logan. Ph.D. Fishery Biologist Director, Division of Sport Fish

John Burr Louis S. Bandirola, Deputy Director Fishery Biologist Division of Sport Fish