13. aquaculture Flashcards

(36 cards)

1
Q

aquaculture

A

farming of aquatic organisms

ex. Fish, Mollusks, Crustaceans, Reptiles, Aquatic plants

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2
Q

what % of animal protein comes from marine sources?

A

~20%

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3
Q

best choices of fishing methods

A

hook and line
trolls
harpoons
pot and traps

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4
Q

worst way of fishing methods

A

drift nets

dynamite and cyanide

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5
Q

how are fishing methods rated?

A

selectivity
bycatch rate
environmental damage

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6
Q

not-so-good way of fishing methods

A

midwater trawls
longlines
gill nets
dredges

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7
Q

sustainable fishing (3)

A

science and technology - scienced-based catch limits and less destructive fishing methods

policy and enforcement- reduced illegal fishing

informed markets- certification and traceability

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8
Q

Is the US a leading global importer of fish & fishery products?

A

yes, 91% of our seafood originates from abroad

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9
Q

supplying

A

US is a major supplier of advanced
technology, feed, equipment, & investment to other
producers around the world.

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10
Q

how much seafood consumed worldwide is produced by aquaculture (vs fishing)?

A

more than 50%

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11
Q

history of aquaculture

A

mid-1800s - started out as recreational fishing
after WWII - production og baitfish
1980s- Aquaculture became an important food
supplier

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12
Q

milt

A

fish sperm

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13
Q

broodstock

A

mature/adult animals kept for reproduction

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14
Q

spawn

A

to produce eggs, sperm, or young

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15
Q

spat

A

young shellfish

they settle down and attach to objects

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16
Q

fry

17
Q

hatchery

A

(1) Maintain the broodstock
(2) Spawn the broodstock
(3) Hatch fertilized eggs to produce larvae
(4) Nurture larvae to the appropriate stage to move to the nursery

18
Q

nursery

A
Raise the young fry (fish), postlarvae (shrimp, prawns),
or spat (shellfish) to the juvenile stage
19
Q

water and pathogens

A

pathogens are much more likely to survive in water

drying is a form of sterilization

20
Q

water quality

A
temperature
salinity
dissolved oxygen
ammonia
nitrites
pH
alkalinity
hardness
toxins
21
Q

Dissolved oxygen

A

mg/l or ppm
sources are surface absorption from the air and aquatic plants release O2 as a byproduct of
photosynthesis.
low DO kills more fish than all other problems
air = 20% oxygen (200,000 ppm)
pond - 3 to 12ppm

22
Q

hardness

A

measure of the divalent ions (salts with two positive charges: Ca2+, Mg2+, Fe2+)

23
Q

osmoregulation

A

maintaining precise levels of internal salts for normal heart, muscle and nerve function

24
Q

levee ponds

A

standing water impoundments built by excavating the
pond area to a shallow depth and using the soil
obtained to build a perimeter of levees or dikes
- O2-available all
the way to the
bottom.
- Costly to build.
- Need wells or other
water sources.

25
watershed ponds
``` Standing water impoundments built by damming ravines or small valleys. - Lack of O2 at greater depths - Less costly to build. - 5-30 acres of watershed to supply water for 1 acre of pond. - Can’t refill the pond at will. ```
26
Raceways & flow through tanks
``` Long channels or tanks with continuous flow of fresh water. - Easy to handle & harvest fish. - Easy to manage waste. - Difficult to find sites with abundant water at the right temp ```
27
recirculating system
Tank systems which filter and re-use water - Control environment - Locate almost anywhere - High production cost - Need constant attention
28
cages or net pens
``` Floating enclosures (+ feed) - Existing water (lakes, rivers, & off-coasts) - Vulnerable to disease, environment, theft, moderately low oxygen, and escape ```
29
health management
- Housing -Water & Feed Quality -Stocking Density (stress) -Infectious Diseases – bacteria, viruses, parasites Treatments: Dipping / Bathing Tank flushing Feeding Injecting
30
catfish production in the US
location: 94% of total US sales: MS>AL>AR>TX
31
channel catfishing production
Spawning (spring) may be in open ponds where adults are stocked in male:female ratios of 1:1 to 1:4. Catfish prefer to spawn in relatively dark & protected surroundings Eggsmay be allowed to hatch in the spawning pond (---adults are moved to another pond) OR eggs are collected every 3 to 4 days & moved to a hatchery.
32
sac-fry
have an attached yolk-sac, so they don’t need extra feed for 24-48 hours.
33
swim-up fry
Once the yolk-sac is absorbed and the fish start searching for food moved to rearing trough
34
fingerling
young fish Once fingerlings are 4 to 6 inches long, they are move to grow-out ponds
35
harvest weight of catfish
1.25 lb/ 18 months
36
seine
drag-net should be made of nylon or polyethylene twine and coated with plastic, tar or petroleum based materials to prevent catfish spines from becoming entangled in the net.