CFP Fish Habitat & Ecosystem Health 2 — Questions and Answers
Question 1: Which physical habitat feature is most critical for providing refuge to juvenile salmonids during high-flow events?
- Deep runs with coarse substrate
- Large woody debris and off-channel alcoves (Correct answer)
- Glide habitats with fine sediment
- Mid-channel gravel bars
Correct answer: Large woody debris and off-channel alcoves
Large woody debris and off-channel alcoves create low-velocity refugia where juvenile salmonids can shelter during high discharge events.
Question 2: The term 'hyporheic zone' refers to which part of a stream ecosystem?
- The area of open water above the substrate
- The saturated sediment layer beneath and alongside the stream channel where surface and groundwater mix (Correct answer)
- The riparian zone immediately adjacent to stream banks
- The deepest portion of the thalweg
Correct answer: The saturated sediment layer beneath and alongside the stream channel where surface and groundwater mix
The hyporheic zone is the subsurface saturated sediment layer where stream water and groundwater actively exchange, supporting critical biogeochemical processes.
Question 3: Impaired macroinvertebrate communities with high proportions of Chironomidae and Tubificidae are most indicative of which stressor?
- Cold water thermal stress
- Organic pollution and low dissolved oxygen (Correct answer)
- Elevated conductivity from road salt
- High gradient substrate instability
Correct answer: Organic pollution and low dissolved oxygen
Chironomidae and Tubificidae are pollution-tolerant taxa that dominate when organic enrichment depletes dissolved oxygen, indicating poor water quality.
Question 4: Which U.S. federal program provides cost-share funding to landowners who voluntarily restore and protect wetlands and grasslands important to fish and wildlife?
- Conservation Reserve Program (CRP)
- Wetlands Reserve Easement (WRE) under ACEP (Correct answer)
- Environmental Quality Incentives Program (EQIP)
- Watershed Protection and Flood Prevention Act program
Correct answer: Wetlands Reserve Easement (WRE) under ACEP
The Wetlands Reserve Easement under USDA's Agricultural Conservation Easement Program pays landowners to restore and permanently protect wetland functions.
Question 5: In stream geomorphology, which channel type described in the Rosgen classification is most likely to exhibit high lateral mobility and frequent gravel bar formation?
- Type A — steep, incised cascade streams
- Type B — moderately sloped, plane-bed streams
- Type C — low-gradient meandering streams with floodplain access (Correct answer)
- Type F — incised, low-gradient streams
Correct answer: Type C — low-gradient meandering streams with floodplain access
Rosgen Type C streams have low gradients, high width-to-depth ratios, and well-developed floodplains that promote lateral migration and gravel bar formation.
Question 6: Elevated fine sediment deposition in spawning gravels primarily harms salmonid eggs and alevins by:
- Increasing substrate temperature beyond lethal thresholds
- Reducing intergravel flow and oxygen delivery to developing embryos (Correct answer)
- Attracting egg predators such as sculpins
- Increasing pH inside redds to toxic levels
Correct answer: Reducing intergravel flow and oxygen delivery to developing embryos
Fine sediment clogs interstitial spaces, reducing hyporheic flow and oxygen supply to embryos, causing suffocation and increased mortality rates.
Question 7: Which metric is commonly used to quantify the amount of large woody debris in a stream channel for habitat assessment?
- Pieces per 100 meters of stream length (Correct answer)
- Basal area per hectare of riparian zone
- Volume per unit catchment area
- Canopy cover percentage overhead
Correct answer: Pieces per 100 meters of stream length
Large woody debris abundance in stream habitat assessments is standardized as pieces per 100 meters of stream length to allow consistent comparisons across sites.
CFP Fish Habitat & Ecosystem Health 2
Which physical habitat feature is most critical for providing refuge to juvenile salmonids during high-flow events?