Limiting Factors



Blue Mountain Province

Asotin Subbasin 391, 393

BULL TROUT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability Freshwater-Instream Agricultural Practices; Forest Management Migration Impediments Juveniles, adults Seasonal water temperatures and poor habitat conditions exclude bull trout use of the mainstem Asotin Creek below the confluence of Charley Creek
Habitat Quantity and Quality Morphological Changes Freshwater - Floodplain Agricultural Practices; Urbanization Diking; Impervious Surfaces (Road Density); Riparian Degradation Juveniles, adults Confinement by roads and dikes, and resulting loss of riparian function affect most life stages.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater - Riparian Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation All Channel instability impacts egg incubation throughout the subbasin. Confinement by roads and dikes, and resulting loss of riparian function affect most life stages.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Wood/Structure Removal Juveniles, adults Lack of habitat diversity and quantity throughout the subbasin are primary factors limiting bull trout.
Water Quality Temperature -- Agricultural Practices; Forest Management; Riparian Degradation All Water temperature may be the most limiting factor for bull trout in the subbasin.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater - Floodplain Agricultural Practices; Urbanization Diking; Impervious Surfaces (Road Density); Riparian Degradation Juveniles, adults Confinement by roads and dikes, and resulting loss of riparian function affect most life stages.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater - Riparian Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation All Channel instability impacts egg incubation throughout the subbasin. Confinement by roads and dikes, and resulting loss of riparian function affect most life stages.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Wood/Structure Removal Juveniles, adults Lack of habitat diversity and quantity throughout the subbasin are the primary factors limiting spring Chinook.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Spring Chinook are primarily subject to freshwater harvest.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass eight mainstem dams
Water Quality Turbidity; Temperature -- Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation; Bank Destabilization All Sediment load impacts egg incubation, and high temperatures limit production.
SUMMER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability; Morphological Changes Estuary Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Wetland Loss Smolts Historical complex habitats have been modified through channelization, diking, development and other practices.
Habitat Quantity and Quality Morphological Changes Freshwater - Floodplain Agricultural Practices; Urbanization Diking; Impervious Surfaces (Road Density); Riparian Degradation Juveniles Confinement by roads and dikes, and resulting loss of riparian function affect most life stages.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater - Riparian Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation Eggs, juveniles Channel instability impacts egg incubation throughout the subbasin. Confinement by roads and dikes, and resulting loss of riparian function affect most life stages.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Forest Management Diking; Wood/Structure Removal Juveniles Lack of habitat quantity (pools) and diversity impact steelhead rearing in Hefflefinger and Coombs creeks, as well as most reaches of the South Fork of the North Fork. Habitat diversity and quantity are also the primary limiting factors for the Charley Creek watershed.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles Juveniles and adults must pass eight mainstem dams during migration.
Water Quality Turbidity; Temperature -- Agricultural Practices; Urbanization; Forest Management Diking; Filling; Impervious Surfaces (Road Density); Riparian Degradation; Bank Destabilization Eggs, fry, winter parr Sediment load impacts steelhead egg incubation in the mainstem, George Creek, lower South Fork, Ten Mile Creek, and Lick Creek. High temperatures limit steelhead production in Ten Mile Creek.