“Aquatic ecosystem” = critters we expect tochange (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 suckerLake chub

Longnose daceNorthern pike (small)Trout-perchNinespine sticklebacks

Slimy sculpinArctic grayling

5) Irruptives Fathead minnowsBrook stickleback

Guilds

RareSlimy sculpinGrayling

PredatorsBig walleyeBig pikeBurbot

SpecialistsSmall walleyeSmall pikeNinespine sticklebacksTrout-perchLongnose dace

GeneralistsWhite suckersLake chub

IrruptivesFathead minnowsBrook 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-nettinglarge lakes

Electrofishingsmall 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) arebuffered from disturbance by large habitatsize.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 disturbancee.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 effectse.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 ofstream). 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 onslope 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 ofstream). 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 ofof grayling, burbot, trout-perch, and dace. Abundant suckers and fatheads.

Streams = few small grayling and small pike (depending on slope ofstream). 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 thestudy 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