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

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 Index of Natural Fish Integrity (Alberta NE Boreal) INFI = Sensitives (rare + predators + specialists) – resilients (generalists + irruptives) Sensitive to disturbance Resilient to disturbance Index is scaled from 1 (undisturbed) to 0 (heavily disturbed) 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. Test-netting large lakes Electrofishing small streams

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 Streams Small streams Large lakes Small lakes

Index of Natural Fish Integrity (Alberta NE Boreal) Fish communities in each aquatic habitat type differ in their sensitivity to disturbance Very large lakes and rivers 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 Moderate-size lakes and large streams 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 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 To detect changes, must not focus sampling on resilient habitats

Index of Natural Fish Integrity (Alberta NE Boreal) INFI = 1, describes fish community that is undisturbed by human activities 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. Historical information, sampling in remote sites, and backcasting from known effects would be used to quantify an INFI of 1 (undisturbed) Likely descriptions of fish community Summary: abundant & large sport fish, few minnows

Index of Natural Fish Integrity (Alberta NE Boreal) INFI = 0.5, describes fish community that is moderately disturbed by human activities 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. 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 Likely descriptions of fish community Summary: sport fish common, but usually small; many minnows

Index of Natural Fish Integrity (Alberta NE Boreal) INFI = 0, describes fish community that is heavily disturbed by human activities 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. Sampling at heavily disturbed locations in the study area would be used to describe the fish community corresponding to an INFI of 0 Likely descriptions of fish community Summary: few sport fish, abundant minnows