December 2019 Flashcards Preview

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Flashcards in December 2019 Deck (22)
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1
Q

Who coined the term ‘aeroponics’?

A

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

2
Q

Who is the father of aeroponics?

A

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

3
Q

What are the advantages of aeroponics?

A

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

4
Q

Why is phytoplankton so important?

A
  • 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.
5
Q

When was the first microalgal custivated?

A

1890, and the first commercial production began in 1953.

6
Q

What methods are used to cultivate algae?

A
  1. Open ponds (still and agitated)
  2. Closed photobioreactors
  3. Biofilm (solid cultivation)
7
Q

eutrophication

A

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.

8
Q

Stoichiometry

A

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.

9
Q

Biological oxidation

A

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.

10
Q

How much fish feed is used by the fish?

A
  • 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
11
Q

What are the key challenges for aquaculture?

A
  • 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)
12
Q

What are the key aspects of sustainability?

A
  1. Environmental acceptability
  2. Social equitability
  3. Economic viability
13
Q

What geophytes can you grow in salt or brackish water?

A
  • 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
14
Q

Name some potential halophyte food cops

A
  • Glasswort (marsh samphire, long spiked)
  • Sea-agretti
  • Sea-aster
  • Buck’s horn plantin
  • Seaweed
15
Q

What is phytate acid?

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

* Phytate is considered anti-nutritional in monogastric animals.

16
Q

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

A
  • It puts pressure on already overfished stocks
17
Q

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

A

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.

18
Q

Why is fishmeal and fish oil important in fish diets?

A
  • 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
19
Q

What are the alternatives to fishmeal and oil in aquafeeds?

A
  • Plant based products
  • Microalgae
  • Animal products
  • Insects
20
Q

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

A

DHA: docosahexaenoic acid
EPA: eicosapentaenoic acid

21
Q

What are diurnal fish?

A

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

22
Q

What is pseudofungi?

A

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).