Limiting Factors



Lower Columbia Province

Lewis Subbasin 362, 371

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 Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Juveniles, adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles, adults Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization All Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
CHUM
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 Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Adults Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs, adults Impacts due to sediment occur throughout the subbasin.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration All Altered flows from hydro operations impact egg survival.
COASTAL CUTTHROAT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Juveniles, adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
Habitat Quantity and Quality Morphological Changes Freshwater-Floodplain Agricultural Practices; Urbanization Diking; Filling; Riparian Degradation; Juveniles, adults Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles, adults Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization All Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity -- Forest Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed.
COHO
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry, summer parr Hatchery releases lead to competition with naturally produced juveniles.
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; Filling; Riparian Degradation; Juveniles Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Fry, summer parr Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Fry, summer parr Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Coho are subject to both ocean and freshwater harvest.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Fry, summer parr Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Summer parr Impacts due to sediment occur throughout the subbasin.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration All Altered flows from hydro operations impact egg survival.
FALL CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry Hatchery releases lead to competition with naturally produced juveniles.
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; Filling; Riparian Degradation; Fry, adults Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Fry, adults Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Fry, adults Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Anthropogenic Mortality -- Fishery Management Harvest Adults Fall Chinook are subject to both ocean and freshwater harvest.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs, fry, adults Impacts due to sediment occur throughout the subbasin.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Hydrologic Cycle Alteration All Altered flows from hydro operations impact egg survival.
SPRING CHINOOK
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
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; Filling; Riparian Degradation; Fry, adults Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Fry, summer parr Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Fry, summer parr Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry, summer parr Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs, fry, summer parr Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Forest Management; Dam or Hydropower Facility Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed. Hydropower actions alter flow regimes and impair spawning and rearing in the Lower North Fork watershed.
SUMMER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
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; Filling; Riparian Degradation; Juveniles Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Forest Management; Dam or Hydropower Facility Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed. Hydropower actions alter flow regimes and impair spawning and rearing in the Lower North Fork watershed.
WINTER STEELHEAD
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Food Competition -- Artificial Propogation Intraspecific Interaction Fry, summer parr Hatchery releases lead to competition with naturally produced juveniles.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management; Forest Management; Urbanization Migration Impediments Adults Merwin Dam (river mile 20) blocks anadromous fish passage to the Upper North Fork watershed. Culvert-related passage problems exist on Johnson, Cedar, Beaver, John, Brush and Unnamed creeks (Upper North Fork watershed).
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; Filling; Riparian Degradation; Juveniles Diking and land use practices have decreased floodplain connectivity and function.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Riparian Forest Management; Agricultural Practices; Urbanization Diking; Riparian Degradation Juveniles Riparian areas are degraded throughout Cedar Creek. Channelization (diking) and degraded riparian areas are present throughout the mainstem and the East Fork. Invasive plants contribute to habitat degradation along the mainstem.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Agricultural Practices; Urbanization Riparian Degradation; Wood/Structure Removal Juveniles Low levels of large woody debris contribute to the lack of habitat diversity throughout the subbasin.
Instantaneous Mortality Pathogens -- Artificial Propogation Disease Amplification and Transfer Fry, summer parr Pathogens from hatcheries may limit productivity.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Fry Non-native species introductions have lead to community shifts and predation issues.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Urbanization Impervious Surfaces; Riparian Degradation; Sediment: Bank Destabilization Eggs Impacts due to sediment occur throughout the subbasin. In Cedar Creek, excessive sedimentation is caused by cattle grazing and residential impacts.
Water Quantity Decreased Water Quantity; Increased Water Quantity; Altered Flow Timing -- Forest Management; Dam or Hydropower Facility Management Impervious Surfaces (Road Density); Water: Runoff Coefficient Alteration; Water: Hydrologic Cycle Alteration Juveniles, adults Flow alterations are related to forest condition and roads in the upper reaches of the East Fork watershed. Hydropower actions alter flow regimes and impair spawning and rearing in the Lower North Fork watershed.