In-Stream Habitat Survey

1
In-Stream Habitat Survey
2
In-Stream Habitat Survey

• Modified from ODFW
• http//oregonstate.edu/Dept/ODFW/freshwater/invent
  ory/methods.html
• Quantitative method for assessing habitat for
  fish
• 2 steps to survey
• Data collection
• Summary
• Measurements are made at the unit type level

3
Habitat Units
3

1
2

• Unit Number
• Sequential starting downstream
• Unit Type
• Riffle, glide, or pool

Unit Number Unit Type
1 R
2 P
3 G
4
Unit Types Riffle
RI Riffle Fast, turbulent, shallow flow over
gravel or cobble substrate.
5
Unit Types Riffle
6
Unit Types Glide
GL Glide Fairly uniform depth and flow with no
surface turbulence. Deeper than riffle, but not
deep enough to be a pool.
7
Unit Types Glide
8
Unit Types Pool
9
Unit Measurements

• Length
• Width and Depth
• Wetted Surface
• Active Channel
• Depth at Pool Tail Crest (pools only)
• Channel Shade (left and right side)
• Percent Actively Eroding Bank
• Percent Undercut Bank

10
Pool Tail Crest

• Place where water leaks out of pool (measure at
  deepest spot)
• Measure for POOL units only

FLOW
11
Shade

• Measure using clinometer

90
80
12
Substrate

• Percent (within each unit)
• Silt/Organics
• Sand
• Gravel
• Cobble
• Boulder
• Bedrock
• Large Boulder Count (gt1.5 ft diameter)

13
Substrate
14
Large Boulders
Large boulders create pocket water
15
Large Woody Debris
16
Large Woody Debris

• Must be DEAD
• Overhanging or in channel

LWD Type Diameter Length
Root Wad gt6 -
Small gt6 gt10
Medium gt12 gt20
Large gt20 gt35
17
Diameter Circumference ? (approx. 3.14)
Circumference
Diameter
18
Habitat Summary

• Why did we take all those measurements?
• The Summary allows us to see whether our stream
  has desirable habitat for fish

19
Percent Pool Area

• Percent Pool Area Pool Area/Reach Area
• Pool Area Length x Width for pool units
• Reach Area Length x Width for ALL units

Percent of stream area which is pool
20
Percent Pool Area

• Pool Area (10 x 10) (10 x 10) 200
• Reach Area (5 x 20) 200 300
• Percent Pool Area 200/300 67

Pool W 10 L 10
Pool W 10 L 10
Riffle W 5, L 20
21
Percent Pool Area

• Percent Pool Area 200/300 67

Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks
Undesirable Between Desirable
Pool Area () lt 10 10-35 gt 35
67 gt 35, so Pool Area Desirable
22
Pool Frequency

• Pool Frequency Distance Between Pools / Channel
  Width
• Channel Width Average width for all units
  between pools

Pool
Pool
Riffle
Length/Width distance btwn pools relative to
stream width
23
Pool Frequency

• Pool Frequency Distance Between Pools / Channel
  Width
• Pool Frequency 20 / 5 4

Riffle W 5, L 20
Pool
Pool
24
Pool Frequency

• Pool Frequency 20 / 5 4

Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks
Undesirable Between Desirable
Pool Frequency gt 20 9 - 20 lt 8
4 lt 8, so Pool Frequency Desirable
25
Residual Pool Depth

• Residual Pool Depth Max Depth Pool Tail Crest
  Depth
• Important for low to no flow conditions

26
Residual Pool Depth

• Residual Pool Depth Max Depth Pool Tail Crest
  Depth
• Example
• Pool Depth 3
• Pool Tail Crest 1
• Residual Pool Depth 2

27
Residual Pool Depth

• Residual Pool Depth 2

Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks
Undesirable Between Desirable
Small Streams (lt23 feet wide) lt 0.5 0.5 1.5 gt 1.5
2 gt 1.5 , so Residual Pool Depth Desirable
28
Habitat Summary Riffles

• Width to Depth Ratio
• Percent Gravel
• Percent Sand-Silt-Organics

29
Riffle Width to Depth

• Width / Depth 5 / 0.5 10

Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks
Undesirable Between Desirable
Width to Depth gt 30 15 - 30 lt 15
Riffle W 5, D 0.5
Pool
Pool
30
Riffle Gravel

• If Gravel 25, Rating is Between

Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks
Undes Btwn Desir
Percent Gravel lt 15 15 - 35 gt 35
31
Riffle Sand-Silt-Organics

• If Sand-Silt-Organics 10, Rating is Between

Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks
Undes Btwn Desir
Percent Sand-Silt-Organics gt 15 8 - 15 lt 8
Values for streams with Volcanic Parent Material
32
Habitat Summary - LWD

• Number of Pieces / 300 Stream Reach
• Large LWD Pieces / 300 Stream Reach
• gt20 Diameter and 35 Length

Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks Habitat Benchmarks
Undesirable Between Desirable
Number of Pieces lt 10 10 20 gt 20
Large Pieces lt 1 1 3 gt 3
33
Habitat Summary

• Shade (average for entire reach)
• Left Right Bank Shade (degrees) / 180
• Final Shade in
• 90 80 170
• 170 / 180 94

34
Habitat Benchmarks
94 gt 70