L16-Aquaculture

Question 1

Benefit of aquaculture

Answer 1

wild fisheries collapsing
increasing demand of animal protein
aquaculture fill demand
therefore massive increase in aquaculture

Question 2

Early aquaculture and its problems

Answer 2

• Catch displacement-feeding small fish to big fish
• High trophic level
• Disease/Invasive species introduction
• Inefficient and polluting
• Genetic ‘pollution’ of native populations via escape

Question 3

Catch Displacement

Answer 3

36% of fish caught used to feed aquaculture
very inefficient
using mainly high trophic level fish therefore lots of energy waste

Question 4

High trophic level

Answer 4

as we overfished we fished at lower trophic level fish
then feed to aquaculture ton get high trophic level fish
because more money in high trophic level fish
but not increasing fish yield

Question 5

Aquacultures problem with Disease/Invasive species introduction?

Answer 5

Disease/Invasive species introduction
high density means easy spread
new pathogens thanks to high density
fish escape and evade forgin habitats
or fish escape and spread disease to native population

Question 6

Inefficient and polluting

Answer 6

lots of deoxygenation due to high density
lots of nutrients released that is eaten by bacteria which also consume oxygen
genetic pollution of native populations due to aquaculture escape(especially problem as aquaculture are more and more selective bread)

Question 7

example of genetic population?

Answer 7

aquaculture selects for small eggs
good for aquaculture but bad trait for wild survival
spread this trait to native population

Question 8

Aquaculture today

Answer 8

• Feed improvements
• Diversity of species used and increase in native species(barramundi australia)

Question 9

Feed improvements

Answer 9

Taking the fish out of fish food, new fish food is made from plants
much more trophic efficient
feed designed not to sink so it is not wasted
less feed being ocnverted into fish mass so less pollution

Question 10

Autotrophic aquaculture

Answer 10

agar for science
algae and seaweed for eating
very low impact
has been increasing greatly in recent years

Question 11

But aquaculture is no panacea

Answer 11

• Beware of excessive optimism regarding integrated aquaculture

• not good for carbon fixation
• integrated agriculture math does not work

Question 12

integrated agriculture what is it what is problem

Answer 12

math does not work seaweed area needed to absorb the fish nutrients would be to large do to trophic levels

Question 13

Remaining threats auiculture

Answer 13

• Disease management-pathogens can still get in out
• Climate change
• System destruction-ecoystems needs to not be degradeded for aquiculture to be worth it

Question 14

Australian context aquiculture

Answer 14

• Southern Blue Fin Tuna
• Abalone farm and disease
• Tasmanian Salmon
• Expanding native species production
• Native seaweed production

Question 15

AVG

Answer 15

virus in west victoria in abalone from an aquiculture wiped out abalone crashing fisheries

fisheries not as regulated as it should be

Question 16

Why is macquarie harbour good for aquaculture?

Answer 16

fresh water layer fish can survive but parasites can not so can be used to clear off pathogens

Question 17

Southern Bluefin Tuna

Answer 17

approximately 85% of total catch) are transferred to aquaculture farms near Port Lincoln

little regulation(only full stock assemesment every 3 years)

very profitible

Question 18

Domestication

Answer 18

enhancement of features that benefit production

little domesication delerberatly

but will still happen due to evolution

seaweed evolving for higher biomass but became less nutrients

Question 19

Summary

Answer 19

use to be bad for enviroment now argueibly dood for enviroment

• Aquaculture is the future of seafood
• It was bad, but getting better
• Beware of overly optimistic goals for integrated aquaculture – biology doesn’t care about feelings
• Australia is lagging behind, but has great potential