Culture of microalgae in hatcheries

They are primary producers in the oceans that convert water and carbon dioxide to biomass and oxygen in the presence of sunlight.

[2] The oldest documented use of microalgae was 2000 years ago, when the Chinese used the cyanobacteria Nostoc as a food source during a famine.

[3] Another type of microalgae, the cyanobacteria Arthrospira (Spirulina), was a common food source among populations in Chad and Aztecs in Mexico as far back as the 16th century.

[15] However, a downside to using open pond systems is decreased productivity of certain commercially important strains such as Arthrospira sp., where optimal growth is limited by temperature.

used as a dietary supplement was attributed to higher productivity because of a better suited temperature range and an extended cultivation period over summer months.

[13] Mixing and deoxygenation are drawbacks of this system and can be addressed by bubbling air continuously at a mean flow rate.

[13] By using an electrocatalytic process to produce acetate from water, electricity and carbon dioxide, which is then used by the algae as food source, sunlight and photosynthesis is no longer required.

[20][21] Flat plate reactors(FPR) are built using narrow panels and are placed horizontally to maximise sunlight input to the system.

[22] This overcomes issues of circulation and provides an advantage of an open gas transfer unit that reduces oxygen build up.

FTRs have not developed hugely in the cultivation of microalgae and pose a disadvantage in the surface area to volume ratio and a decreased efficiency in utilizing sunlight.

Aquaculture farms rearing larvae of molluscs, echinoderms, crustaceans and fish use microalgae as a source of nutrition.

Brine shrimp produce dormant eggs, called cysts, which can be stored for long periods and then hatched on demand to provide a convenient form of live feed for the aquaculture of larval fish and crustaceans.

[24] This is achieved by the addition of natural pigments containing carotenoids such as astaxanthin produced from the microalgae Haematococcus to the diet of farmed animals.

[10] Arthrospira platensis is a blue-green microalga with a long history as a food source in East Africa and pre-colonial Mexico.

[32] Production of long chain omega-3 fatty acids important for human diet can also be cultured through microalgal hatchery systems.

[33] Australian scientists at Flinders University in Adelaide have been experimenting with using marine microalgae to produce proteins for human consumption, creating products like "caviar", vegan burgers, fake meat, jams and other food spreads.

By manipulating microalgae in a laboratory, the protein and other nutrient contents could be increased, and flavours changed to make them more palatable.

[36] Blue green alga was first used as a means of fixing nitrogen by allowing cyanobacteria to multiply in the soil, acting as a biofertilizer.