Aquaculture

Question 1

Types of aquaculture?

Answer 1

Fish farming: Sea cages (eg: Scottish salmon).
Mussel farming: Rope culture (eg: Lyme Bay).
Shrimp farming: Pond culture (eg: Saudi Arabia - 100,000 tonnes/yr from 1 farm).
Turbot farming: Land-based production (eg: China).
Scallop farming: Ranching (eg: Orkney, UK).
Ornamental fish farming (pet shops).

Question 2

Aquaculture + mariculture definitions?

Answer 2

Cultivating aquatic organisms under controlled conditions (mariculture = marine organisms).

Question 3

Seafood production stats?

Answer 3

Feed 10 billion by 2050.
Seafood provides 6.7% of all animal protein.
Seafood crucial for first 1000 days of life.
Employs 12% of the pop.
Fastest growing food production method.

Question 4

Aquaculture stats?

Answer 4

Aquaculture produces 47% global seafood production.
598 species cultured.
Mostly finfish farmed inland (esp China).

Question 5

Future seafood production?

Answer 5

Aquaculture overtook wild-caught fishing.

Aquaculture must double by 2050 to meet demand.

Question 6

Challenges faced by aquaculture?

Answer 6

Prevent hunger + poverty (UN Sustainable Development Goals) w/o negatively affecting biodiversity + climate.
Society more conscious of sustainable farming practices, but aquaculture younger practice than terrestrial agriculture.
Disease = $6 billion annual losses.
- Eg: Shrimp white spot syndrome virus can collapse production in some nations.
- Solution = breed in resistance + increase biosecurity.

Question 7

Farming up food web?

Answer 7

Produce carnivores (eg: salmon) rather than herbivores/omnivores.
70% global aquaculture = fed (need protein, fish oils, + fish meals).
2 of top 6 captive species (anchovies + herring) used mostly as fish feed.
12% total landings directed from human consumption to feed agriculture.

Question 8

Non-fed aquaculture?

Answer 8

30% (eg: molluscs).

Molluscs = lowest-impact food production (bioremediate by removing pollutants + nutrients).

Question 9

Problems w/ original salmon aquaculture?

Answer 9

Pens in sheltered lochs = low flow rate = waste buildup = negative effect on benthic ecosystem + consumer perception of aquaculture.

Question 10

Integrated multi-trophic aquaculture?

Answer 10

Sea cucumber/urchin pens under salmon pens consume waste.
Kelp + algae grown nearby = improves water quality + removes nutrient build-up.
Improved coastal environment + perception of aquaculture.

Question 11

Moving aquaculture offshore?

Answer 11

Lower + raise cage system = can be put in open-water systems = high flow = no nutrient buildup.

Question 12

Aquaculture + mangrove removal?

Answer 12

Shrimp aquaculture caused 30,000Ha of mangrove removal in SE Asia (30% total loss) from 2000-12.
Oct 1999: Cyclone in India. Villages w/ better mangrove systems had fewer deaths.
Integrated mangrove aquaculture systems:
- Trial in Vietnam: 12,000Ha restored + trees planted on berms.
- Provided coastal protection, required less input (higher profit), + increased biodiversity.

Question 13

Recirculating aquaculture systems?

Answer 13

Move aquaculture indoors = intensive production. 
Recirculating = less water use. 
Smaller environmental footprint.
Increased biosecurity (less disease). 
More stable chemistry.

Question 14

Aquaculture + space?

Answer 14

65% aquaculture is inland. More space needed to meet increased food demand.
Wild-capture fishery landings could be produced using 0.015% global ocean area.

Question 15

Willapa Bay oyster seed crisis?

Answer 15

C. gigas recruitment failures on Oregon coast due to climate change + ocean acidification (Barton et al, 2012).
Decided to move hatcheries to Hawaii instead of acting against climate change.

Question 16

Froehlich et al (2018).

Answer 16

Indo-Pacific region will be worst affected by declines in aquaculture due to climate change.
Bivalves at highest risk - temp change, primary production, + ocean acidification affect food + shell formation.
Finfish more resilient, but at risk from indirect effects (eg: harmful algal blooms, disease outbreaks, hypoxia).

Question 17

Martins et al (2010).

Answer 17

Slow adaptation of RAS due to high initial capital investment required + possible welfare concerns (high stock densities).
- But able to maintain constant water quality should improve welfare compared to other aquaculture.
RAS developed to produce freshwater fish = more tolerant to poor water quality. Expansion of RAS to marine species = further innovation needed to improve water quality.