“Aquatic ecosystem” = critters we expect to change (recover or decline) in response to us

1. “Aquatic ecosystem” = critters we expect to change (recover or decline) in response to us Sensitive Slimy sculpin Arctic grayling Walleye (big, resident) Northern pike (big) Burbot Longnose dace Northern pike (small) Trout-perch Ninespine sticklebacks Resilient Fathead minnows White sucker Brook stickleback Lake chub Guilds NE Boreal Streams • Rare animals • - endangered, rare, edge of range • - already stressed 2) Apex predators - not adapted to extrinsic mortality 3) Common specialists 4) Common generalists 5) Irruptives

2. Index of Natural Fish Integrity (Alberta NE Boreal) Resilient to disturbance Sensitive to disturbance Rare Slimy sculpin Grayling Predators Big walleye Big pike Burbot Specialists Small walleye Small pike Ninespine sticklebacks Trout-perch Longnose dace Generalists White suckers Lake chub Irruptives Fathead minnows Brook sticklebacks INFI = Sensitives (rare + predators + specialists) – resilients (generalists + irruptives) Aquatic habitat types (e.g., rivers, streams, large lakes, small lakes) are sampled with a variety of gear and the catch rates of each species and guild are used derive the index value for the entire study area. Index is scaled from 1 (undisturbed) to 0 (heavily disturbed) Test-netting large lakes Electrofishing small streams

3. Index of Natural Fish Integrity (Alberta NE Boreal) Index uses catch rates or occurrence values from a field sampling program that samples selections of each main aquatic habitat type in the study area Rivers Large lakes Streams Small lakes Small streams

4. Index of Natural Fish Integrity (Alberta NE Boreal) Moderate-size lakes and large streams Very large lakes and rivers Sensitive to disturbance (most sensitive) Habitat is large enough to support rare and predator fish, but small enough to be affected by disturbance e.g., Gregoire Lake, Christina Lake, House River Resilient to disturbance (less sensitive) Sensitive fishes (rares and predators) are buffered from disturbance by large habitat size .g., Lake Athabasca, Peace, Clearwater and Athabasca rivers Small lakes and small streams Very resilient to disturbance (least sensitive) Habitat is too small for sensitive species, and natural disturbances are frequent and allow only those species resilient to effects e.g., winterkill ponds, intermittent streams Fish communities in each aquatic habitat type differ in their sensitivity to disturbance To detect changes, must not focus sampling on resilient habitats

5. Index of Natural Fish Integrity (Alberta NE Boreal) INFI = 1, describes fish community that is undisturbed by human activities Likely descriptions of fish community Rivers = abundant walleye and pike (all sizes). Common catches of grayling, slimy sculpins, burbot, trout-perch, dace, and suckers. Streams = abundant grayling and small pike (depending on slope of stream). Common catches of larger walleye, pike, slimy sculpins, dace, suckers, and lake chub. Rare catches of fatheads and brook sticklebacks Small streams = abundant small grayling and small pike (depending on slope of stream). Common catches of dace, suckers, sticklebacks, and fatheads Large lakes (>300 ha) = abundant walleye and pike (all sizes). Common catches of burbot, trout-perch. Small lakes (<300 ha) = no larger fish. Abundant brook sticklebacks and fatheads. Common catches of suckers and some small pike. Summary: abundant & large sport fish, few minnows Historical information, sampling in remote sites, and backcasting from known effects would be used to quantify an INFI of 1 (undisturbed)

6. Index of Natural Fish Integrity (Alberta NE Boreal) INFI = 0.5, describes fish community that is moderately disturbed by human activities Likely descriptions of fish community Rivers = abundant small walleye and pike, few large fish. Common catches of burbot, trout-perch, dace, and suckers. Few grayling and sculpins. Streams = abundant small grayling and small pike (depending on slope of stream). Rare catches of larger walleye, pike, grayling. Common catches of suckers, lake chub, fatheads and brook sticklebacks Small streams = rare small grayling and small pike (depending on slope of stream). Common catches of suckers, sticklebacks, and fatheads Large lakes (>300 ha) = abundant small walleye and pike. Few large fish. Rare catches of burbot, trout-perch, common catches of suckers, lake chub. Small lakes (<300 ha) = Abundant brook sticklebacks and fatheads Common catches of suckers and some small pike. Summary: sport fish common, but usually small; many minnows Sampling at random locations(stratified by habitat type) in the study area would be used to determine the current INFI value of the study area

7. Index of Natural Fish Integrity (Alberta NE Boreal) INFI = 0, describes fish community that is heavily disturbed by human activities Likely descriptions of fish community Rivers = very few small walleye and pike, few large fish. Rare catches of of grayling, burbot, trout-perch, and dace. Abundant suckers and fatheads. Streams = few small grayling and small pike (depending on slope of stream). Very rare catches of larger walleye, pike, grayling. Abundant catches of suckers, lake chub, fatheads and brook sticklebacks Small streams = very rare small grayling and small pike (depending on slope of stream). Abundant catches of suckers, sticklebacks, and fatheads Large lakes (>300 ha) = very few small walleye and pike, few large fish. Rare catches of burbot, trout-perch. Abundant catches of suckers, lake chub. Small lakes (<300 ha) = Abundant brook sticklebacks and fatheads Common catches of suckers and some small pike. Summary: few sport fish, abundant minnows Sampling at heavily disturbed locations in the study area would be used to describe the fish community corresponding to an INFI of 0