APPENDIX A

Selected Freshwater Fish of the Northwest Territories

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

northern pike (jackfish) Esox lucius

Distribution in the NWT

• Throughout the NWT, except for Arctic islands and northern coastal area (Scott and Crossman, 1973).

Habitat Requirements

• Found in heavily vegetated slow-moving rivers or weedy bays of lakes. • Spawn in the spring in marshes, shallow bays of lakes, and vegetated

floodplains of rivers; eggs hatch later in the spring. • Young pike grow rapidly, feeding on zooplankton (very small aquatic animals)

and immature aquatic insects before switching to a diet of fish. • Young-of-the-year pike remain in the shallows after hatching for several weeks

before moving to deeper areas. • Pike usually move to deeper, cooler water in the summer and may return to the

shallows in the fall. Key Points

• Pike spawn in the spring in flooded grasses, marshes, or shallow bays of lakes. • Spawning habitat may appear dry (non-aquatic) in the summer. • Young-of-the-year may inhabit shallow, vegetated shorelines near roadways. • Weight: 21 kg, Length: 133 cm (North American angler record) • Life expectancy of slow-growing Arctic populations can be as long as 26 years,

more than double the Canadian average (Scott and Crossman, 1973).

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 1

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

Arctic grayling (bluefish) Thymallus arcticus

Distribution in the NWT

• Throughout the mainland NWT (Scott and Crossman, 1973). Habitat Requirements

• Inhabit lakes, rocky creeks, and large rivers. • Adults migrate to small, rocky streams from ice-covered lakes or rivers in the

spring to spawn on gravelly substrate, before returning to the lakes or rivers (Scott and Crossman, 1973).

• Eggs hatch later in the spring; grayling fry remain in tributary streams and backwater areas before migrating downstream later in the open-water season (Northcote, 1995).

• Young grayling eat zooplankton and immature insects. • Adult grayling eat aquatic and terrestrial insects, fish eggs, plankton

crustaceans, and sometimes fish. Key Points

• Arctic grayling spawn early in the spring in rocky streams. • Grayling fry may remain in these streams until late summer or fall. • Weight: 2.7 kg, Length: 76 cm (N. A. angler record - caught in the NWT) • Life expectancy: approximately 12 years (Scott and Crossman, 1973).

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 2

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

walleye (pickerel) Stizostedion vitreum

Distribution in the NWT

• Within the Mackenzie River system, including Great Slave and Great Bear Lakes (Scott and Crossman, 1973).

Habitat Requirements

• Inhabit lakes and large streams or rivers. • Spawn in the spring in tributary rivers and streams, over rock and gravel bottom

(Scott and Crossman, 1973). • Spawning may also occur over gravel shoals of lakes. • Eggs hatch later in the spring. • Young-of-the-year walleye move into deeper waters by the end of the summer. • Young walleye eat invertebrates and fish, primarily feeding on the surface. • As walleye grow, they shift to feeding on fish near the bottom (e.g. perch,

ciscoes, ninespine stickleback, suckers, shiners, burbot). Key Points

• Walleye spawn in the spring in rivers and streams over rocky substrate. • Young-of-the-year walleye may remain in these streams until late summer,

when they move downstream to deeper water. • Average length: 33 - 51 cm, Largest: 104 cm, 11.4 kg (N.A. angler record)

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 3

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

burbot (freshwater cod, lingcod) Lota lota

Distribution in the NWT

• Throughout the mainland NWT (Scott and Crossman, 1973). Habitat Requirements

• Inhabit deep waters of freshwater lakes and large rivers (Page and Burr, 1991). • May move into tributary rivers during the late winter/early spring (Scott and

Crossman, 1973). • Spawn in the winter under lake ice, in shallow water over gravel or sand; eggs

hatch about a month later. • Young-of-the-year burbot inhabit rocky shores of lakes or tributary streams. • Young burbot eat immature aquatic insects, molluscs, and crayfish. • Adult burbot eat primarily fish, such as ciscoes, sculpins, trout-perch, and

sticklebacks. Key Points

• Burbot may inhabit tributaries during the late winter or early spring. • Young burbot may live in streams during the open water season. • Burbot spawn in the shallows of lakes in the winter. • Average length: 38 cm, Maximum Canadian size: 94 cm, 8.4 kg (caught in the

NWT) • Maximum age attained in Canada is between 10 and 15 years (Scott and

Crossman, 1973).

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 4

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

lake trout Salvelinus namaycush

Distribution in the NWT

• Throughout the mainland NWT (Scott and Crossman, 1973). Habitat Requirements

• In the spring, lake trout can be found in lake shallows and in rivers and streams; they move to deeper water during the summer months.

• Spawn in the fall over a rubble or boulder bottom in the shallows of lakes (Scott and Crossman, 1973).

• Eggs hatch the following spring; young lake trout may remain in shallow, near-shore waters of lakes before moving to deeper areas later in the season.

• Young lake trout eat invertebrates. • Adult lake trout feed primarily on fish, such as cisco, whitefish, perch, smelt,

sculpins, ninespine sticklebacks, emerald shiners, trout-perch, and longnose suckers (Scott and Crossman, 1973).

Key Points

• Lake trout spawn in the fall over boulders in near-shore areas of lakes. • In the spring, lake trout may inhabit lake shallows, as well as rivers and streams. • Average length: 38 - 51 cm, Largest (Canadian): 46.3 kg, 126 cm (gillnet) • Largest fish caught (angling) in the world are from Great Bear Lake.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 5

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

bull trout ( red spotted char, salmon trout, bull char) Salvelinus confluentus

Distribution in the NWT

• Within the southwestern NWT (Scott and Crossman, 1973). • More recently found to be established in the central NWT (Reist, et. al., 2002)

Habitat Requirements

• Primarily oligotrophic lakes and deep pools in coldwater rivers and streams. • Spawn in the late summer/fall in rivers and streams over a gravel bottom (Scott

and Crossman, 1973). Lake populations move to inlet streams and tributaries for spawning.

• Eggs hatch in the spring. • Young Bull trout may remain in streams and rivers for their first few years. • Adults migrate from lakes to rivers in late summer/early fall. • Diet consists of insects, crustaceans (snails), molluscs and other forage fish.

Key Points

• Bull trout spawn in the late summer/fall in rivers and streams. • Young Bull trout may inhabit tributaries for 3-4 years. • Often mistaken as Dolly Varden, but can de differentiated:

Identification features (refer to arrows in diagram):

eye close to top of head upper jaw long and curved down large, flat head unforked tail with square tips pupil-sized pale yellow, orange, or red

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 6

spots on body, and no spots on fins

Lake trout (Salvelinus namaycush)

Arctic char (Salvelinus alpinus)

Rainbow trout (Oncorhynchus mykiss)

Dolly Varden (Salvelinus malma)

Box 1871Inuvik, NTX0E 0T0

(867)777-7503

Bull trout (Salvelinus confluentus)

42043 Mackenzie HwyHay River, NT

X0E 0R9(867)874-5575

Fisheries and Oceans Canada is seeking a limited number of bull trout specimens to obtain information on distribution, genetics, population size, and habitat requirements of this and related fish in the Northwest Territories (NT). You can help conserve and protect this species by reporting capture locations of chars and trout within the region.

Fisheries and Oceans will buy bull trout, Dolly Varden, Arctic char, or rainbow trout from you, that are caught in locations other than stocked waters in the Sahtu, Deh Cho, North Slave, and South Slave regions (see red border on maps below). Lake trout are NOT REQUESTED for this study. All landed fish should be frozen whole as soon as possible after capture. Information on date and location of capture is required. The diagrams below show external distinguishing characteristics of each species and the general areas where they are likely to be found. Areas of uncertain distribution are identified on maps by question marks (?).

For additional information, contact your local Hunters and Trappers Committee (HTC)/Renewable Resource Council (RRC) or the Fisheries Management Biologist at Fisheries and Oceans Canada,

- eye close to top of head- upper jaw long and curved down- large, flat head- unforked tail with square tips- pupil-sized pale yellow, orange, or red spots on body, and no spots on fins- found in rivers throughout southern NT

- eye in centre of head- upper jaw long and straight- medium, rounded head- unforked tail with square tips- pupil-sized pale pink/red spots with bluish halos on body, and no spots on fins- rivers in northwestern NT and Yukon Territory

- eye in centre of head- upper jaw short and straight- medium, rounded head- slightly forked tail with rounded tips- eye-sized pale white/pink spots on body without halos, and no spots on fins- rivers and lakes in northeastern NT

- eye in centre of head- upper jaw long and straight- large, rounded head- deeply forked tail with sharp tips- numerous small white spots on head, body and fins - lakes throughout NT

- eye in centre of head- upper jaw short and straight- medium, rounded head- slightly forked tail with rounded tips- small black spots on body and fins- introduced to lakes in southern NT

Help Conserve and Protect Bull Trout

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Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

kokanee Oncorhynchus nerka

♀ ♂

Distribution in the NWT

• single occurrence in Great Slave Lake reported (Babaluk et al. 2000). Habitat Requirements

• Spends entire life in freshwater • Spends more time in a lake environment, than a river environment (Morrow,

1980) • Small barriers will stop kokanee movement, due to their weak swimming

capabilities, relative to sockeye (Morrow, 1980) • Mainly plankton feeders (Morrow, 1980)

Key Points

• Freshwater (non-anadromous) form of sockeye • Lifespan varies from two to seven years (morrow, 1980) • There is currently not a spawning population in great slave lake. It is suspected

that the individual that was captured originated from the Williston Reservoir, in central British Columbia. This fish would have then successfully navigated the W.A.C. Bennet Dam, then the Peace River, into Great Slave Lake (Babaluk et al. 2000).

• Average length: 35 cm, Average weight: 0.5 kg or less (Morrow, 1980), • Largest: 53 cm, 3.6 kg (Scott and Crossman, 1973)

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 8

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

lake (humpback) whitefish Coregonus clupeaformis

Distribution in the NWT

• Throughout the mainland NWT (Scott and Crossman, 1973). Habitat Requirements

• Generally live in deep lake water in the summer, but may remain in relatively shallow water in the NWT during the summer months.

• Spawn in the fall in shallow water of lakes and rivers over a hard, rocky bottom or sometimes sand (Scott and Crossman, 1973).

• Eggs hatch the following spring, and young fish move to deeper water in the summer.

• Lake whitefish are bottom feeders, with a diet consisting of invertebrates and sometimes fish eggs.

Key Points

• Lake whitefish spawn in the fall in shallow areas of lakes and rivers. • The young emerge in the spring and move to deeper water by summer. • Average length: to about 28 cm, Largest (Canada):19 kg, Oldest (Canada): 28

years, recorded in Great Slave Lake (Scott and Crossman, 1973).

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 9

• Important as food for lake trout, northern pike, and burbot, and other predaceous fish.

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

round whitefish Prosopium cylindraceum

Distribution in the NWT

• Throughout the mainland NWT (Scott and Crossman, 1973). Habitat Requirements

• Inhabit lakes, rivers, and streams. • Smaller than lake and broad whitefish (grows up to 12 inches in length). • Spawn in the fall in shallow areas of lakes, at river mouths, or in rivers over

gravel substrate. • Eggs hatch in the spring. • Feed on the bottom, eating benthic invertebrates.

Key Points

• Spawn in the fall. • Average length: 20 - 30 cm, Maximum Size: 56 cm, taken from Great Slave

Lake, NWT (Scott and Crossman, 1973). • Provide food for lake trout.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 10

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

cisco (lake herring) Coregonus artedii

Distribution in the NWT

• Throughout the Mackenzie River system, and north to Great Bear Lake (Scott and Crossman, 1973).

Habitat Requirements

• Inhabit lakes in large schools. • Move to deeper waters in the summer and shallow waters at other times of the

year (Scott and Crossman, 1973). • Spawning takes place in the fall in shallow water of lakes and rivers, often in

large schools. • Usually spawn over gravel substrate.

Key Points

• Spawn in shallow, gravelly areas of lakes and rivers in the fall. • Average length: 20 - 30 cm, Largest caught in the NWT - length: 57.2 cm,

weight: 2.5 kg (Scott and Crossman, 1973). • Important food of lake trout, burbot, northern pike, and walleye.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 11

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

longnose sucker Catostomus catostomus

Distribution in the NWT

• Throughout most of the mainland NWT (Scott and Crossman, 1973). Habitat Requirements

• Inhabit freshwater lake bottoms; is a bottom feeder. • Spawn in the spring in gravelly streams or lake shallows (Scott and Crossman,

1973). • Eggs hatch later in the spring. • Young suckers move downstream to lake habitat in the summer. • Young-of-the-year suckers eat plankton and small invertebrates. • Diet of adults includes chironomids, cladocerans, molluscs, and other

invertebrates. Key Points

• Spawn in the spring in streams over gravel bottom. • Average length: 30.5 - 35.6 cm, Largest (North America): 64 cm, 3.3 kg, 19

years old (Great Slave Lake) (Scott and Crossman, 1973). • Young suckers provide food for northern pike, burbot, and walleye.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 12

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

white sucker Catostomus commersoni

Distribution in the NWT

• Found within the Mackenzie River drainage and Great Slave Lake (Scott and Crossman, 1973).

Habitat Requirements

• Inhabit tributary rivers and shallow lakes and bays. • Spawn in the spring in lake margins and streams, over a gravel bottom (Scott

and Crossman, 1973). • Eggs hatch later in the spring. • Young suckers move downstream to lake habitat in the summer. • Young-of-the-year suckers eat plankton and small invertebrates. • Diet of adults includes chironomids, cladocerans, molluscs, and other

invertebrates. Key Points

• Spawn in the spring in streams over gravel bottom or in lake margins. • Up to 139 000 eggs have been counted in one individual • Average length: 30 - 50 cm, Largest: 58 cm, 3.2 kg (Scott and Crossman,

1973). • Young suckers provide food for northern pike, burbot, and walleye.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 13

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

slimy sculpin Cottus cognatus

Distribution in the NWT

• Most of the mainland NWT (Scott and Crossman, 1973). Habitat Requirements

• Inhabit deep waters of lakes and rocky streams. • Spawn in the spring (Scott and Crossman, 1973). • Feed on benthic invertebrates.

Key Points

• May be found in rocky stream crossings; spawn in the spring. • Habitat is susceptible to sedimentation. • Average length: 7.6 cm (Scott and Crossman, 1973). • Fed upon by lake trout, northern pike, and burbot.

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Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

spoonhead sculpin Cottus ricei

Distribution in the NWT

• Within Great Slave Lake and the Mackenzie River system (Scott and Crossman, 1973).

Habitat Requirements

• Inhabit lakes, rivers, and streams. • Spawning likely occurs in late summer/early fall (Scott and Crossman, 1973). • Feed on aquatic insects and plankton.

Key Points

• May be found in rivers and streams. • Very little known about life history • Average length: 4 - 6 cm, Largest: 13.4 cm (Scott and Crossman, 1973). • Fed upon by lake trout and burbot.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 15

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

yellow perch Perca flavescens

Distribution in the NWT

• In the Great Slave Lake area (Scott and Crossman, 1973). Habitat Requirements

• Lake water species that may inhabit quiet rivers. • Spawn in the spring/summer in lake shallows or tributary streams, over

vegetation, sand or gravel (Scott and Crossman, 1973). • Eggs may form a large floating egg mass. • Diet includes invertebrates, immature insects, and fish.

Key Points

• Yellow perch spawn in the spring in tributary streams or the shallows of lakes. • Average length: 10 - 25 cm, Largest: 2 kg, 36 cm (Scott and Crossman, 1973). • Food source for walleye, northern pike, and lake trout.

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Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

trout-perch Percopsis omiscomaycus

Distribution in the NWT

• Within the Mackenzie River system, and Great Bear and Great Slave Lakes (Scott and Crossman, 1973).

Habitat Requirements

• Typically inhabit deep waters of lakes and sometimes streams. • Spawn in the spring in rocky streams or lake shallows (Scott and Crossman,

1973). • Diet consists of insect larvae and sometimes small fish.

Key Points

• Spawn in the spring in rocky streams. • Average length: 7.6 - 10.2 cm, Largest: 15.2 cm (Scott and Crossman, 1973). • Important forage fish for walleye, northern pike, and burbot.

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Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

ninespine stickleback Pungitius pungitius

Distribution in the NWT

• Throughout the mainland NWT (Scott and Crossman, 1973), may enter brackish water.

Habitat Requirements

• Inhabit freshwater lakes. • Spawn in the summer in lakes or streams. • Eggs are laid in a tunnel-shaped nest built by the male (Scott and Crossman,

1973). • Diet includes small crustaceans and aquatic insects.

Key Points

• Spawn in the summer in lakes or streams. • Important forage fish for predatory fish species. • Sedimentation would have a negative effect on its food. • Males guard nest, protecting the young. As many as seven females may lay

eggs in one male’s nest (Scott and Crossman, 1973). • Average size: 6.4 cm (Scott and Crossman, 1973). • Provide food for walleye, lake trout, yellow perch, and burbot.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 18

Appendix A Selected Freshwater Fish

of the Northwest Territories

NOTES:

spottail shiner Notropis hudsonius

Distribution in the NWT

• Inhabits the Mackenzie River system, including Great Slave Lake (Scott and Crossman, 1973).

Habitat Requirements

• Found in large lakes and rivers. • Spawn in the spring and early summer over sandy shoals in lakes and sometimes

in the lower reaches of tributary streams (Scott and Crossman, 1973). • Diet consists of plankton and aquatic insect larvae.

Key Points

• May spawn in tributary streams in the spring. • Average length: 6.4 - 7.6 cm, Largest: 13.2 cm (Scott and Crossman, 1973). • Important food source for many predaceous fishes.

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 19

Appendix A Selected Freshwater Fish

of the Northwest Territories

Department Of Fisheries and Oceans Working Near Water: Considerations for Fish and Fish Habitat Reference and Workshop Manual Page A - 20

NOTES:

emerald shiner Notropis atherinoides

Distribution in the NWT

• Found in the Mackenzie River and its tributaries; Great Slave Lake (Scott and Crossman, 1973).

Habitat Requirements

• Inhabit large lakes and rivers. • Spawn in the late spring or early summer in open water (Scott and Crossman,

1973). • Young-of-the-year emerald shiners may school near river mouths and

lakeshores during the fall. • Diet consists of invertebrates and algae.

Key Points

• Young-of-the year emerald shiners may inhabit river mouths and lakeshores in the fall.

• Only live for three years (rarely longer) (Scott and Crossman, 1973). • Average length: 5.1 - 7.6 cm, Largest: 10.2 cm (Scott and Crossman, 1973). • Important food source for many predaceous fishes, including burbot, lake trout,

and northern pike.