December 2019

Question 1

Who coined the term ‘aeroponics’?

Answer 1

F. W. Went in 1957, to describe his method of growing coffee and tomato plants.

Question 2

Who is the father of aeroponics?

Answer 2

Richard J Stoner II: a method for studying the morphology of the roots of a plant, inspired by nature (orchids).

Question 3

What are the advantages of aeroponics?

Answer 3

Water use reduced by 98%
Fertilizer use reduced by 60%
Elimination of pesticide use
No soil/media: clean, efficient, sterile
Continuous year round plant growth
No contamination from soil or pesticides
Plants absorb more minerals and vitamins
Seedlings don’t stretch and wilt
Seedlings easily transplanted without shock
Seedlings grow faster - faster crop cycles

Question 4

Why is phytoplankton so important?

Answer 4

• It is the primary producer in the oceans, feeding 45% of creatures.
• They generate 50% of atmospheric O2
• Their biomass is upto 50% carbon, and their fast growth means they are absorbing a considerable about of CO2 from the atmosphere. Over 26% of the CO2 produced by burning fossil fuels is absorbed by the oceans.

Question 5

When was the first microalgal custivated?

Answer 5

1890, and the first commercial production began in 1953.

Question 6

What methods are used to cultivate algae?

Answer 6

1. Open ponds (still and agitated)
2. Closed photobioreactors
3. Biofilm (solid cultivation)

Question 7

eutrophication

Answer 7

excessive richness of nutrients in a lake or other body of water, frequently due to run-off from the land, which causes a dense growth of plant life.

Question 8

Stoichiometry

Answer 8

A section of chemistry that involves using relationships between reactants and/or products in a chemical reaction to determine desired quantitative data.

In Greek, stoikhein means element and metron means measure, so stoichiometry literally translated means the measure of elements.

Question 9

Biological oxidation

Answer 9

Biological oxidation is an energy-producing reaction in living cells, and it is coupled with a reduction reaction. When a compound loses an electron, or is oxidized, another compound gains the electron, or is reduced. Oxidation-reduction (redox) reactions represent the main source of biological energy.

Question 10

How much fish feed is used by the fish?

Answer 10

• 95% ingested and digested (5% not eaten)
• of the 95% digested, 30-40% converted into biomass
• remaining 30-40% excreted as ammonia, feaces, and urine

Question 11

What are the key challenges for aquaculture?

Answer 11

• Reduction in antibiotic use (and other meds)
• Development of efficient equipment
• Species diversification and sustainability for feed production and use
• Shift from fishmeal to other protein sources
• Improving the Food conversion ratio (FCR)

Question 12

What are the key aspects of sustainability?

Answer 12

1. Environmental acceptability
2. Social equitability
3. Economic viability

Question 13

What geophytes can you grow in salt or brackish water?

Answer 13

• Brassicas (broccoli, cauliflower, cabbage, choy sum, rutabaga, turnip, mustard)
• Basil
• Tomatoes (common and cherry)
• Radish
• Lettuce
• Sweet potato
• broad beans
• Corn
• Spinach
• Asparagus
• Beets
• Squash
• Cucumber

Question 14

Name some potential halophyte food cops

Answer 14

• Glasswort (marsh samphire, long spiked)
• Sea-agretti
• Sea-aster
• Buck’s horn plantin
• Seaweed

Question 15

What is phytate acid?

Answer 15

• Phytate is the major storage form of phosphorus in plants.

* Phytate is considered anti-nutritional in monogastric animals.

Question 16

Why do we need to reduce reliance on fishmeal in fish feed?

Answer 16

• It puts pressure on already overfished stocks

Question 17

Why is fishmeal hard to replace in the diet of carnivorous fish ?

Answer 17

Fishmeal is an excellent protein source with a unique amino acid profile, with a high nutrient density, high palatability, and adequate amounts of micronutrients.

Plant based alternatives contain anti-nutritional substances, that interferes with digestion and protein metabolization.

Question 18

Why is fishmeal and fish oil important in fish diets?

Answer 18

• It is the main source of omega 3 fatty acids
• its an excellent protein source
• has a unique amino acid profile
• high nutrient digestibility
• high palatability
• adequate amounts of micronutrients
• lack of anti-nutritional factors

Question 19

What are the alternatives to fishmeal and oil in aquafeeds?

Answer 19

• Plant based products
• Microalgae
• Animal products
• Insects

Question 20

What are the main omega 3 fatty acids found in fish?

Answer 20

DHA: docosahexaenoic acid
EPA: eicosapentaenoic acid

Question 21

What are diurnal fish?

Answer 21

Fish species that are awake during the day, as opposed to nocturnal species.

Question 22

What is pseudofungi?

Answer 22

Pseudofungi is a grouping of heterokonts (a major line of eukaryotes), that includes Oomycota. They are a problem in aquaponics as the oomycota include Phytophthora and Pythium (responsible root rot).