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AQUACULTURE
Contents
1
...
a
...
b
...
c
...
Aquacultural methods
2
...
Extensive aquaculture
2
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Intensive aquaculture

3
...
a
...
b
...
c
...
d
...
e
...
f
...
Conservation efforts
4
...
Multi-trophic aquaculture

1
...
a
...

1
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Importance of fish:
- Vital protein source for many countries – fish accounts for >60% protein in Indonesia
...
c
...

- 10 species of fish account for >32% total annual landings – lots of pressure on a few
species
...

2
...
a
...

- Less effort
- Most shellfish/crustacean/macroalgae farms
...
b
...

- Greater control and greater yield
...


3
...
a
...
g
...

- Other farming such as carp and molluscs which are herbivorous may be contributing to food
security (Naylor et al
...

3
...
Eutrophication:
- Waste food from feeding fish
...

- Algae grow on the side of the cage – reduces flow of water through cage, reducing O2 and
waste removal
...
c
...

- E
...
Tributyltin
...
d
...

- Causes stress
- Increases disease risk
...

- Have tried to introduce cleaner species such as wrasse instead
...
e
...
g
...

- This prevents fish investing energy into reproduction instead of growth
...

- In the North Atlantic Ocean, up to 40% of the Atlantic Salmon caught by fishermen are of
farmed origin (Naylor et al
...

3
...
Diet:
- Problem with intensively reared carnivorous fish
...
2000)
...
g
...

- Cod/Salmon – carnivorous – farmed in the UK
...
2000)
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9kg of wild fish is required for 1kg of
farmed fish raised, with only three of the 10 species requiring less than they produce (catfish,
milkfish, carp) (Naylor et al
...

- Moves the pressure from one stock and places it on another – E
...
sand eel fishery in
Scotland is massive
...


4
...
a
...
2009)
...
g
...
2009)
...
g
...
2004)
...
2009)

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