Aquaculture is the farming of fish, aquatic plants like seaweed, crustaceans like crabs and shrimp, mollusks like squid and cuttlefish, and various algae. The term aqua-farming is also frequently used to refer to aquaculture. The Aquaponic Farmer: A Complete Guide by Adrian Southern and Whelm King (find it on Amazon US, UK, IN) is a great resource for building and running an aquaponic system and is suitable for novice farmers or commercial scale operators. According to Aquaculture Alliance, produce from aquaculture provides ~61 kilos of eatable meat per 100 kilos of feed, as compared to 4 to 10 kilos per 100 kilos of feed for bovines or 21 kilos for poultry.
Types of aquaculture
Mariculture involves farming of fish and other marine creatures (and plants) in the open ocean using enclosures or in tanks, ponds or seawater filled channels. Other than cultivation for human/animal consumption, mariculture is even used to produce fish-meal (fish-food) and ingredients for cosmetics.
Various shellfish are grown on anchored ropes, or in cages. Some aquaculture farmers also use bags or rock surfaces. Artificial reefs have been used to grow abalone which are seeded from a hatchery. Most open ocean mariculture farms do not require any feeding and tend to be self-sustaining.
An interesting read is about a commercial oyster ocean mariculture farm which began operations in 1932. Shellfish Mariculture in Drakes Estero (find it on Amazon US, UK, IN) covers the scientific issues related to shellfish mariculture.
An integrated aquaculture system or Integrated multi-trophic aquaculture (IMTA) is a farming technique where waste from one species is used as feed or input for another. Fish and shrimp for example can be combined with shellfish (which are organic extractive), within a managed system. This ensures environmental sustainability and acceptability while reducing risk through produce diversity. Multi-trophic systems utilize aquatic multi-culture design and thinking to grow different fish and aquatic species, which individually occupy a wide verity of aquatic niches. This often results in better ecosystem health, mutual benefits between species and higher overall production.
Recirculating Aquaculture Systems by Andy Davison (find it on Amazon US, UK, IN) provides detailed information for a land-based system and includes equipment, construction, treatment, business and operations considerations along with useful illustrations.
Aquaponic systems utilize a combination of aquaculture and hydroponics (growing plants in water). These have become popular, with individuals, small farmers as well as large corporations jumping in to capitalize on the advantages. Normally, water utilized for aquaculture (and into which marine creatures excrete), is fed into a nitrifying bacteria system (to convert natural marine effluents into nitrates). The nitrate rich water is then fed to plants in the hydroponic system which soak up naturally produced nutrients.
Sylvia Bernstein outlines the ins-and-outs of a DIY aquaponics system in her book Aquaponic Gardening (find it on Amazon US, UK, IN). She covers location and hardware requirements, and the aquatic and soil-based creatures which may be safely introduced into an operation. Sylvia details use of completely organic techniques which are between four to six times more productive than conventional methods while utilizing ninety percent less water. Look at experimenting with your own scale aquaponics system first before investing in anything large scale (explore aquaponic kits on Amazon US, UK, IN).
Downsides of aquaculture
Occasionally, aquatic species like fish or seaweed may be introduced which conflict with the local species, with disastrous effects like wiping out well integrated species or plant life. Invasive species have been known to wreak havoc when introduced into local systems which aren’t prepared for them.
Before embarking on an aquaculture project, be sure to acquaint yourself with enough information to ensure you’re committing to a viable operation that’s environmentally safe, and sustainable over the long term with minimal interventions.