wehrly fish habitat - college of agriculture & natural ......important habitat features. title:...

Inland Lakes ConventionBoyne Mountain Resort

28 April 2016

Kevin Wehrly

Fish-Habitat Relationships

• Physical

What is Fish Habitat?

• Chemical • Biological

Why is Habitat Important?

Multiple views of Habitat

• Temperature

• Morphology

• Water quality

• Cover/shoreline

Important Habitat Features

Temperature

Climate

Summer Temperature

warm

cool

Growing Season

long

short

Winter Duration

short

long

Lake Depth

cold

cool

warm

warm

Water Quality

• Productivity

• Abundance

• Growth

Alkalinity

Nutrients

• Clarity

• Vegetation

• Oxygen

Oxygen Depletion

0

5

10

15

20

25

30

35

400 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Dep

th (feet)

TemperatureOxygen

Oxygen Depletion

Cover/Shoreline

• Reproduction

• Growth

Woody Cover

Shoreline Armoring

Quantifying Fish-Habitat Relations

Species Habitat Requirements

Walleye

Walleye Coldwater

Bluegill Largemouth

Justus von Liebig1803‐1873

• Area > 500 acres• MeanT < 62 F• Secchi < 12 feet• Oxygen

Walleye

• Area > 1,000 acres• DegDay < 3,900• Depth > 30 feet• Oxygen

Coldwater Fishes

• DegDay > 3,900• MeanT > 62 F• Area < 1,000 acres

Largemouth Bass

• Temperature

• Morphology

• Water quality

• Cover/shoreline

Important Habitat Features