Limiting Factors



Intermountain Province

Columbia Upper Subbasin 408

Burbot
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat Quantity and Quality Small-scale structural complexity; Morphological changes Freshwater Dam and hydropower facility management Water: Storage or withdrawal Juveniles, adults Severe fluctuations of reservoir elevation frequently changes the littoral zone, limiting productivity. The lack of stable littoral habitats has resulted in virtually no macrophyte communities and severely depressed benthic macroinvertebrate communities.
Instantaneous Mortality Predation - Fishery management Species introductions Juveniles and adults Walleye and smallmouth bass introductions have lead to community shifts and predation issues.
Toxic Vontaminants Water: Biota - Mining Activities; Pollution and Contamination Pollution: Heavy Metal; Pollution: Biological Wastes, Fertilizer, & Pharmaceuticals All Trace-element contamination is known to be widespread throughout Lake Roosevelt. recent studies report that Lake Roosevelt bed sediments are contaminated with high concentrations of trace elements, and that these high levels are impairing benthic invertebrate communities. The trace-elements have been linked to a smelter in Canada.
Water Quality Oxygen - Dam or hydrofacility management Water: Temperature and gas alteration Juveniles; adults Spillling at upriver reservoirs creates total dissolved gas levels in Lake Roosevelt that exceed state standards.
Water Quantity Altered flow timing - Dam or hydrofacility management Water: Storage or withdrawal Juveniles and adults The most significant limiting factor affecting fish in Lake Roosevelt is pool elevation fluctuations that result from hydro-operations. Due to a short water retention time (8-65 days), there is a lack of stratification during the summer that results in limited refugia of preferred temperature areas. Hydro-operations that reduce water retention time also reduce food availability for fish and reduce fish carrying capacity of the reservoir.
KOKANEE
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 Migration Impediments Juveniles, adults Dams obstruct fish migrations throughout the subbasin.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles, adults Severe fluctuations of reservoir elevation frequently changes the littoral zone, limiting productivity. The lack of stable littoral habitats has resulted in virtually no macrophyte communities and severely depressed benthic macroinvertebrate communities.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles, adults Entrainment of kokanee at Grand Coulee Dam limits the fishery in Lake Roosevelt.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Impervious Surfaces (Road Density); Sediment: Bank Destabilization All Increased sediment loads, altered seasonal water regimes, and destabilized streambanks affect water quality and limit productivity in the Kettle and Colville rivers.
Water Quality Oxygen -- Dam or Hydropower Facility Management Water: Temperature and Gas Alteration Juveniles, adults Spillling at upriver reservoirs creates total dissolved gas levels in Lake Roosevelt that exceed state standards.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles, adults The most significant limiting factor affecting fish in Lake Roosevelt is pool elevation fluctuations that result from hydro-operations. Due to a short water retention time (8-65 days), there is a lack of stratification during the summer that results in limited refugia of preferred temperature areas. Hydro-operations that reduce water retention time also reduce food availability for fish and reduce fish carrying capacity of the reservoir. Natural kokanee production is limited due to annual drawdowns that expose shoreline redds.
REDBAND TROUT
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Biological Viability Criteria Diversity -- Fishery Management Species Introduction Adults Non-native rainbow trout releases lead to hybridization with native redband trout.
Habitat Quantity and Quality Access and Availability Freshwater-Instream Dam or Hydropower Facility Management Migration Impediments Juveniles, adults Dams obstruct fish migrations throughout the subbasin.
Habitat Quantity and Quality Small-Scale Structural Complexity; Morphological Changes Freshwater-Instream Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles, adults Severe fluctuations of reservoir elevation frequently changes the littoral zone, limiting productivity. The lack of stable littoral habitats has resulted in virtually no macrophyte communities and severely depressed benthic macroinvertebrate communities.
Instantaneous Mortality Anthropogenic Mortality -- Dam or Hydropower Facility Management Migration Impediments Juveniles, adults Entrainment of kokanee at Grand Coulee Dam limits the fishery in Lake Roosevelt.
Instantaneous Mortality Predation -- Fishery Management Species Introduction Juveniles, adults Non-native species introductions have lead to community shifts, predation issues, and problems with hybridization with native species.
Sediment Conditions Increased Sediment Quantity Freshwater-Instream Agricultural Practices; Forest Management; Urbanization Impervious Surfaces (Road Density); Sediment: Bank Destabilization All Increased sediment loads, altered seasonal water regimes, and destabilized streambanks affect water quality and limit productivity in the Kettle and Colville rivers.
Water Quality Oxygen -- Dam or Hydropower Facility Management Water: Temperature and Gas Alteration Juveniles, adults Spillling at upriver reservoirs creates total dissolved gas levels in Lake Roosevelt that exceed state standards.
Water Quantity Altered Flow Timing -- Dam or Hydropower Facility Management Water: Storage or Withdrawal Juveniles, adults The most significant limiting factor affecting fish in Lake Roosevelt is pool elevation fluctuations that result from hydro-operations. Due to a short water retention time (8-65 days), there is a lack of stratification during the summer that results in limited refugia of preferred temperature areas. Hydro-operations that reduce water retention time also reduce food availability for fish and reduce fish carrying capacity of the reservoir. Natural kokanee production is limited due to annual drawdowns that expose shoreline redds.
White Sturgeon
Key Limiting Factor Impairment Habitat Affected Threat Type Threat Name Life Stage (s) Description
Habitat quantity and quality Small-scale structural complexity; Morphological changes Freshwater Dam and hydropower facility management Water: Storage or withdrawal Juveniles, adults Severe fluctuations of reservoir elevation frequently changes the littoral zone, limiting productivity. The lack of stable littoral habitats has resulted in virtually no macrophyte communities and severely depressed benthic macroinvertebrate communities.
Instantaneous Mortality Predation -- Fishery management Species introductions Juveniles; adults Walleye and smallmouth bass introductions have lead to community shifts and predation issues.
Toxic contaminants Water: Biota -- Mining Activities; Pollution and Contamination Pollution: Heavy Metal; Pollution: Biological Wastes, Fertilizer, & Pharmaceuticals All Trace-element contamination is known to be widespread throughout Lake Roosevelt. recent studies report that Lake Roosevelt bed sediments are contaminated with high concentrations of trace elements, and that these high levels are impairing benthic invertebrate communities. The trace-elements have been linked to a smelter in Canada.
Water Quality Oxygen -- Dam or hydrofacility management Water: Temperature and gas alteration Juveniles, adults Spillling at upriver reservoirs creates total dissolved gas levels in Lake Roosevelt that exceed state standards.
Water Quantity Altered flow timing -- Dam or hydrofacility management Water: Storage or withdrawal Juveniles and adults The most significant limiting factor affecting fish in Lake Roosevelt is pool elevation fluctuations that result from hydro-operations. Due to a short water retention time (8-65 days), there is a lack of stratification during the summer that results in limited refugia of preferred temperature areas. Hydro-operations that reduce water retention time also reduce food availability for fish and reduce fish carrying capacity of the reservoir.