Unit 4.3 Aquatic food production systems

Question 1

Understanding of aquatic ecosystems with scientific developments

Answer 1

improved understanding of aquatic ecosystem functioning and global awareness of the need to manage in a sustainable manner

Question 2

Aquatic vs terrestrial food production systems

Answer 2

compares in terms of trophic levels and efficiency of energy conversion:

Aquatic
1. Phytoplankton
2. Zooplankton
3. Juvenile fish
4. Carnivorous
5. Salmon

Terrestrial (more energy efficient)
1. Gras, wheat, maize, potatoes and corn
2. Cows, goats

Question 3

Demand for aquatic food

Answer 3

Resources continue to increase as the human population grows.
- change in diets

Question 4

Global fish production

Answer 4

reached about 179 million tons in 2018 (most was aquaculture)

Question 5

Modern fisheries

Answer 5

ships stay at sea for months, freezing and storing their catch.

fish further than ever possible, in international waters.

OVERFISHING

Question 6

UN FAO State of World Fisheries and Aquaculture

Answer 6

Report that examines global fisheries production

Shows that overfished fisheries gradually increased up to a peak of 34 per cent of global fisheries in 2017.

Question 7

Sustainable yield of an aquifer

Answer 7

amount of water that can be taken each year without permanently decreasing the amount of water stored.

Question 8

Evaluate strategies that can be used to avoid unsustainable fishing.

Answer 8

Maximum sustainable yield: interest for commercial ventures so harvest is not compromised in subsequent years

1. Increase the biomass of severely distressed stocks.
2. Reduce bycatch of non-target species or juvenile age cohorts of target stocks.
3. Where possible and relevant, protect and restore critical marine habitats such as mangroves and coral reefs.

Question 9

Disadvantage of maximum sustainable yield and reasons

Answer 9

Normally leads to population decline and unsustainable fishery

1. Population dynamics predicted (models) rather than being quantitatively measured (counted)
2. Estimates are made on previous experiences.
3. If harvest affects reproductive females, there is a greater impact
4. Disease may strike the population.

Question 10

Technology in fisheries

Answer 10

Technological developments that can lead to overfishing can also contribute to a solution.

Question 11

The Marine Stewardship Council

Answer 11

Independent non-profit organization which sets a standard for sustainable fishing.

Fisheries are assessed by a team of experts who are independent of both the fishery and the MSC.

Question 12

Harvesting marine animals and ethical issues

Answer 12

Ethical issues arise over bio rights, rights of indigenous cultures and international conservation legislation.

Question 13

CASE STUDY: The International Whaling Commission (IWC) commercial whaling moratorium

Answer 13

Established under the International Convention for the Regulation of Whaling, signed in 1946 in Washington DC.

1. Purpose: ensure proper conservation of whale stocks for sustainable development of the industry.
2. 1982 Decision: IWC imposed a pause on commercial whaling starting from the 1985/1986 season (commercial whaling moratorium) still in effect.
3. Indigenous Whaling Recognition: acknowledges differs from commercial, not aim for maximum catches and profit
   - not subject to the commercial whaling moratorium and categorized differently by the IWC

Question 14

Aquaculture (fish farming)

Answer 14

farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants in both coastal and inland areas

Question 15

Open aquaculture systems

Answer 15

fish farming in natural water bodies such as oceans, bays, estuaries, coastal lagoons, lakes, or rivers.

Question 16

Capture fisheries vs aquacultures

Answer 16

Capture fishery: catching fish directly from water bodies i.e. lakes, seas, ponds, etc.

Aquaculture: growing, rearing, and then capturing fishes from fish tanks

Question 17

Environmental impacts of aquaculture

Answer 17

• Loss of habitat for local species
• Disruption of natural food chains and webs
• Spread of disease from farmed species going into the wild
• Pollution of the local environment with excess food, antibiotics and medicines used to treat the fish
• Killing of predators that prey on the farmed species

Question 18

Semiclosed aquaculture systems

Answer 18

land-based production of a species, in which water is exchanged between the farm and a natural waterway.