Fish Culturists - Midterm

Question 1

What roles has fish culture played over the millennia for humans?

Answer 1

• First Nations (food, social, ceremonial)
• Commercial fising
• Sport fishing
• Aquaculture

Question 2

What are some organizations that culture fish in BC?

Answer 2

• Freshwater Fisheries Society (non-profit) (inland fishery)
• Chehalis Salmon Hatchery (inland fishery)
• Kootenay Trout Hatchery (inland fishery)
• DFO: federal hatchery

Question 3

What does the DFO produce?

Answer 3

• Chinook, Chum, Coho, Sockeye (fry/smolts) Pinks (sometimes)
• Steelhead, Cutthroat trout with Freshwater Fisheries Society

Question 4

What does the Freshwater Fisheries Society of BC produce?

Answer 4

• Trout
• Char
• Kokanee (fry and parr)
• Anadromous steelhead and cutthroat trout
• Rainbow trout (urban lakes)

Question 5

What are some specific strains produced by Freshwater Fisheries Society of BC (5)?

Answer 5

• Eastern Brook Char
• Coastal Cutthroat Trout
• Kokanee Salmon
• Steelhead
• Lake Char
• White Sturgeon

Question 6

Early fish hatchery and why did it start?

Answer 6

• Seton Lake Fish Hatchery (1902), McCloud River government fish hatchery
• Started because of historical damage to fish and their habitat

Question 7

What are some biological factors to consider when stocking trout in a lake or stream (5)?

Answer 7

• PRESENCE/ABSENCE of fish
• Presence of FORAGE fish
• Presence of PREDATOR species
• Presence of COMPETITOR species
• Presence of WILD POPULATIONS of rainbow trout

Question 8

What are some physical features to consider before stocking lake (5)?

Answer 8

• Temperature
• pH
• Depth
• Dissolved oxygen
• Surface area of lakes
• Presence of inlet/outlet streams

Question 9

What are some human factors that determine stocking strategies (5)?

Answer 9

• Fishery type
• Access
• Low/High use
• Urban settings
• Surface area/depth

Question 10

How do fisheries get brood stock (10 steps)

Answer 10

• 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

Question 11

What is the term ITEROPARITY and what species?

Answer 11

• The ability to spawn multiple times with out dying

- TROUT

Question 12

What are 3 different ways of incubating embryos?

Answer 12

• Heath trays/vertical trays
• Upwelling incubator (bell jar)
• California (horizontal) tray

Question 13

Embryo?

Answer 13

• Fertilized egg

Question 14

Alevin?

Answer 14

• Hatched, but not emerged from gravel

- Still feeds on yolk sac

Question 15

Fry?

Answer 15

• Free swimming, recently emerged from gravel

- Free feeding

Question 16

What is an ATU and how do you calculate it?

Answer 16

• 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

Question 17

What are some ways that fish culturalists try to increase production, provide specialty stock, or influence growth rates (provide 5)?

Answer 17

• Triploidy (3N)
• All Female (AF)
• All Female Triploid (AF3N)
• Use of different strains for stocking best option
• Applied research

Question 18

Why is AF or AF3N sometimes a better option than males?

Answer 18

• 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

Question 19

What are some water quality considerations and their range of tolerance?

Answer 19

• 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

Question 20

Why do we mark or tag fish?

Answer 20

• 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

Question 21

Provide 5 different forms of tagging/marking fish.

Answer 21

• Passive Integrated Transponder (PIT)
• Coded Wire Tag (CWT)
• Adipose fin clip
• Peterson Disk Tag
• T-bar Anchor Tag

Question 22

Describe how to use and read the Coded Wire Tag (CWT).

Answer 22

• 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

Question 23

Describe how to use and read a Passive Integrated Transponder.

Answer 23

• “bullet” looking, injected into side of fish using anesthesia
• Can be scanned and read from a distance
• Can be used for observing fish behaviour

Question 24

Describe how to use and read the t-bar anchor tag.

Answer 24

• 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