Fish Culturists - Midterm Flashcards
What roles has fish culture played over the millennia for humans?
- First Nations (food, social, ceremonial)
- Commercial fising
- Sport fishing
- Aquaculture
What are some organizations that culture fish in BC?
- Freshwater Fisheries Society (non-profit) (inland fishery)
- Chehalis Salmon Hatchery (inland fishery)
- Kootenay Trout Hatchery (inland fishery)
- DFO: federal hatchery
What does the DFO produce?
- Chinook, Chum, Coho, Sockeye (fry/smolts) Pinks (sometimes)
- Steelhead, Cutthroat trout with Freshwater Fisheries Society
What does the Freshwater Fisheries Society of BC produce?
- Trout
- Char
- Kokanee (fry and parr)
- Anadromous steelhead and cutthroat trout
- Rainbow trout (urban lakes)
What are some specific strains produced by Freshwater Fisheries Society of BC (5)?
- Eastern Brook Char
- Coastal Cutthroat Trout
- Kokanee Salmon
- Steelhead
- Lake Char
- White Sturgeon
Early fish hatchery and why did it start?
- Seton Lake Fish Hatchery (1902), McCloud River government fish hatchery
- Started because of historical damage to fish and their habitat
What are some biological factors to consider when stocking trout in a lake or stream (5)?
- PRESENCE/ABSENCE of fish
- Presence of FORAGE fish
- Presence of PREDATOR species
- Presence of COMPETITOR species
- Presence of WILD POPULATIONS of rainbow trout
What are some physical features to consider before stocking lake (5)?
- Temperature
- pH
- Depth
- Dissolved oxygen
- Surface area of lakes
- Presence of inlet/outlet streams
What are some human factors that determine stocking strategies (5)?
- Fishery type
- Access
- Low/High use
- Urban settings
- Surface area/depth
How do fisheries get brood stock (10 steps)
- Adult fish are collected from wild locations
- Spawn and fertilize salmonids
- Collect milt (put into whirl bags for transport)
- Eggs transported into coolers
- Eggs and milt mixed with water to harden eggs
- Incubation trays
- Troughing
- Ponding
- Ovidine to disinfect eggs
- Fish held in hatchery
What is the term ITEROPARITY and what species?
- The ability to spawn multiple times with out dying
- TROUT
What are 3 different ways of incubating embryos?
- Heath trays/vertical trays
- Upwelling incubator (bell jar)
- California (horizontal) tray
Embryo?
- Fertilized egg
Alevin?
- Hatched, but not emerged from gravel
- Still feeds on yolk sac
Fry?
- Free swimming, recently emerged from gravel
- Free feeding
What is an ATU and how do you calculate it?
- Accumulated Thermal Unit
- Describes cumulative effects of temperature over time
- 1 degree Celsius = 1 ATU for 1 day
- 5 degrees Celsius = 15 ATU for 3 days
- *Temp x #of days = #ATU
What are some ways that fish culturalists try to increase production, provide specialty stock, or influence growth rates (provide 5)?
- Triploidy (3N)
- All Female (AF)
- All Female Triploid (AF3N)
- Use of different strains for stocking best option
- Applied research
Why is AF or AF3N sometimes a better option than males?
- Males mature earlier than females and die after spawn
- Females mature a year later generally meaning they can grow larger
- Production is maximized because they have an extra year to work with.
- Females can spawn over and over
- Females do not look as rough as they mature
What are some water quality considerations and their range of tolerance?
- Temperature: 10 - 15 degrees C (18 for fastest growth rate)
- pH: 6.4 - 8.4 (7.0 - 7.4 optimum!)
- Dissolved oxygen: minimum of 8 ppm
- C02 levels
- Nitrogen waste
Why do we mark or tag fish?
- Determine population size for managers
- Determine release survival
- Compare strategies (effects of triploid)
- Allows for anglers to keep cultured, and release wild
- Recognise strains of broodstock
Provide 5 different forms of tagging/marking fish.
- Passive Integrated Transponder (PIT)
- Coded Wire Tag (CWT)
- Adipose fin clip
- Peterson Disk Tag
- T-bar Anchor Tag
Describe how to use and read the Coded Wire Tag (CWT).
- Wire stuck into nose of fish
- A sliver of metal that has code (not scanned)
- Metal detector used to find the tag
- Microscope used to read code
Describe how to use and read a Passive Integrated Transponder.
- “bullet” looking, injected into side of fish using anesthesia
- Can be scanned and read from a distance
- Can be used for observing fish behaviour
Describe how to use and read the t-bar anchor tag.
- Tagging gun used to shoot tag just below dorsal fin (where the pteriogeophore connects to the dorsal ray)
- Information is along the length of the tag
