CFP CFP Aquaculture & Hatchery Operations 2 — Questions and Answers
Question 1: What is the function of a raceway in a typical flow-through hatchery design?
- A tank used to store broodstock long-term
- An elongated tank with flowing water used to rear fish at controlled densities (Correct answer)
- A filtration system that removes ammonia from recirculating water
- A gravel channel used exclusively for egg incubation
Correct answer: An elongated tank with flowing water used to rear fish at controlled densities
Raceways are rectangular flow-through channels that provide a continuous supply of fresh water to maintain water quality as fish are reared at production densities.
Question 2: Which US federal agency operates the largest network of fish hatcheries for Pacific salmon restoration?
- US Fish and Wildlife Service (USFWS)
- National Oceanic and Atmospheric Administration (NOAA) Fisheries (Correct answer)
- Bureau of Land Management (BLM)
- Natural Resources Conservation Service (NRCS)
Correct answer: National Oceanic and Atmospheric Administration (NOAA) Fisheries
NOAA Fisheries oversees federal hatcheries involved in Pacific salmon and steelhead recovery programs under the Endangered Species Act.
Question 3: What is the primary genetic risk associated with large-scale hatchery supplementation of wild fish populations?
- Introduction of non-native parasites into wild stocks
- Genetic homogenization and reduced fitness of wild fish through interbreeding with domesticated strains (Correct answer)
- Depletion of wild broodstock used for egg collection
- Transmission of viral hemorrhagic septicemia to wild populations
Correct answer: Genetic homogenization and reduced fitness of wild fish through interbreeding with domesticated strains
Hatchery fish selected for domesticated traits can hybridize with wild fish and reduce the fitness and adaptive potential of wild populations over time.
Question 4: In recirculating aquaculture systems (RAS), what is the primary role of a biofilter?
- Remove suspended solids from the water column
- Convert toxic ammonia to less harmful nitrate through nitrification by bacteria (Correct answer)
- Oxygenate the water using fine-bubble diffusers
- Regulate water temperature using heat exchangers
Correct answer: Convert toxic ammonia to less harmful nitrate through nitrification by bacteria
Biofilters in RAS house nitrifying bacteria that oxidize ammonia (NH₃) through nitrite (NO₂⁻) to nitrate (NO₃⁻), protecting fish from ammonia toxicity.
Question 5: What does the term 'smoltification' refer to in Pacific and Atlantic salmon hatchery management?
- The process of sorting juvenile salmon by weight before stocking
- The physiological transformation of juvenile salmon from freshwater- to saltwater-adapted physiology (Correct answer)
- The disease conditioning protocol used prior to ocean release
- The chemical marking of otoliths in hatchery fish for later identification
Correct answer: The physiological transformation of juvenile salmon from freshwater- to saltwater-adapted physiology
Smoltification (parr-smolt transformation) prepares juvenile salmon for ocean entry by changing their osmoregulation, behavior, and morphology.
Question 6: Which chemical is most commonly used to anesthetize fish during hatchery handling procedures in the US?
- Formalin
- Tricaine methanesulfonate (MS-222) (Correct answer)
- Potassium permanganate
- Copper sulfate
Correct answer: Tricaine methanesulfonate (MS-222)
MS-222 (tricaine) is the most widely used fish anesthetic approved by the FDA for use in US hatcheries and research settings.
CFP CFP Aquaculture & Hatchery Operations 2
What is the function of a raceway in a typical flow-through hatchery design?