71% of the Earth is covered with water compared to only 29% which is land of where one third is used for agriculture. Relative to agriculture, aquaculture of Earth’s seas and oceans are not as developed, especially of offshore nature, thus there is much more future potential in aquaculture than agriculture. Aquaculture (especially inclusion of offshore) is the future to food security and a blue ocean strategy to economic growth.
Fish has highest feed conversion ratio, highest edible yield, highest harvest yield, highest energy retention, and highest protein retention compared to land based farmed animals such as chicken, lamb, cow and pig. The reasons for such high efficiencies are because fish are cold blooded thus less energy and resources are expended, and the buoyancy of fish negates part of the effects of gravity whereby kinetic movement is also more energy and resource efficient compared to land based creatures.
Onshore and inshore aquaculture tend to suffer from over-nutrition and eutrophication which negatively affects benthic ecosystem such as acidication. Sudden algae bloom and decomposition create anoxic waters that are not conducive to aquatic life. Crowded nature of onshore and inshore aquaculture is also more conducive for harbouring and spreading of animal diseases, typically due to sewage runoff and poor water circulation rate.
Many wild fisheries have maxed out or exceeded sustainable supply capacities. As such, artisanal and small scale fishermen experience less income or loss of jobs. Aquaculture of omnivorous/carnivorous fish is highly dependent on unsustainable fish meal. In SE Asia, the main aquaculture limitations being the availability and high cost of feeds (more than 50% of the operational cost) and shortage of seed. Sustainable fish feed industry is the bottleneck to further development of aquaculture (especially finfish).
Latest development in aquaculture such as Integrated Multi-Trophic Aquaculture (IMTA) can provide employment to ailing coastal fishing communities, where fishermen are rendered jobless or experiencing reduced fishing income due to over-fishing of wild fisheries. IMTA enables multi-species cultivation with minimal environmental impact as any output waste from one species is an input nutritional source for another species. “Closed Loop” should be designed into IMTA whereby food waste and waste from processing fish can integrated back into aquaculture value chain in the form of sustainable fish feed.