Custom (Lewis and Ganshorn 2007): HSI Overwinter Coho & Depth
mbayly
View all records in the stressor response library
Species Common Name
Coho Salmon
Latin Name (Genus species)
Oncorhynchus kisutch
Stressor Name
Depth
Specific Stressor Metric
Water Depth
Stressor Units
m
Vital Rate (Process)
Habitat Suitability Index
Geography
British Columbia (composite)
Detailed SR Function Description
Generalized relationship from criteria in Lewis and Ganshorn (2007):
During winter, shallow riffles are abandoned in favour of deep structural pools that provide protection from predators and anchor ice:
- Unsuitable (HSI = 0.0): Water depths below 0.15 metres are highly unsuitable, providing zero cover.
- Marginal (HSI = 0.2 to 0.5): Depths from 0.15 to 0.40 metres offer marginal protection and are mostly used if heavy large woody debris (LWD) or complex overhead cover is present.
- Optimal (HSI = 1.0): Any water depths greater than 0.60 metres (up to about 1.5 metres or more) are fully optimal. Unlike velocity, which drops off tightly, depth suitability plateaus at 1.0 and stays open-ended; deeper water is inherently safer for overwintering pools.
During winter, shallow riffles are abandoned in favour of deep structural pools that provide protection from predators and anchor ice:
- Unsuitable (HSI = 0.0): Water depths below 0.15 metres are highly unsuitable, providing zero cover.
- Marginal (HSI = 0.2 to 0.5): Depths from 0.15 to 0.40 metres offer marginal protection and are mostly used if heavy large woody debris (LWD) or complex overhead cover is present.
- Optimal (HSI = 1.0): Any water depths greater than 0.60 metres (up to about 1.5 metres or more) are fully optimal. Unlike velocity, which drops off tightly, depth suitability plateaus at 1.0 and stays open-ended; deeper water is inherently safer for overwintering pools.
Function Derivation
Custom rule-based and expert opinion
Transferability of Function
Generalized assumptions
Function Type
continuous
Stressor Scale
linear
References Cited
Lewis, A. and K. Ganshorn. 2007. Literature Review of Habitat Productivity Models for Pacific Salmon Species. Consultant’s report prepared for the Department of Fisheries and Oceans, Habitat Management Division, Vancouver, B.C.
Citation Link
Stressor Response csv data
lg_depth.csv
(154 bytes)
| Stressor (X) | Mean System Capacity (%) | SD | low.limit | up.limit |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 100 |
| 0.15 | 0 | 0 | 0 | 100 |
| 0.3 | 40 | 0 | 0 | 100 |
| 0.4 | 70 | 0 | 0 | 100 |
| 0.6 | 100 | 0 | 0 | 100 |
| 1 | 100 | 0 | 0 | 100 |
Stressor Response Chart
Mean Response
±1 Standard Deviation
Upper/Lower Limits