Aquaculture technology for several commercially important species of tropical marine fish has become or is quickly becoming available. Hatcheries are capable of producing juveniles of candidate species for offshore aquaculture such as cobia (Rachycentron canadum), hamachi/kampachi (Seriola rivoliana, S. lalandi/S. dorsalis), pompanos (Trachinotus carolinus), snappers (Lutjanus guttatus, L. peru and L. campechanus), yellowtail snapper (Ocyurus chrysurus), totoaba (Totoaba macdonaldi), red drum (Sciaenops ocellatus), mahi (Coryphaena hippurus), tripletail (Lobotes surinamensis) – among others. Steady supply of high-quality juveniles of certain species is still limited, but it is unlikely that this will remain a bottleneck for industry expansion.
Land-based recirculating aquaculture systems (RAS) and traditional flow-through ponds, raceways and tanks are all viable but limited options. Large scale production required to feed the world in the next decades will have to be produced in the open ocean - where stronger currents and greater depths increase the carrying capacity of the environment. Raising fish in exposed, high-energy areas offshore require advanced technologies demanding high levels of investment and long-term commitment. Hence, fish produced offshore must be sold at high prices to compensate the high capital and operating costs required, limiting their demand in a highly competitive white fish market.
Offshore aquaculture continues to expand the world over, yet the commercial viability of operations remains mostly elusive. Infrastructure and logistics are in place, and market demand is rising. Technology continues to expand rapidly. Tools for site assessment and selection and environmental monitoring have been established. However, as with any relatively new industry, hurdles still must be overcome before commercial viability can be secured. Some issues such as optimizing genetics, nutrition, and diseases control are inherent to all forms of aquaculture - whereas stocking, feeding, chemical treatments, net cleaning, predator avoidance, escapements, biomass estimates and crop management, mortalities collection and harvesting operations are exacerbated in offshore systems. Automation is progressing fast but still needs refinement. Machine learning and artificial intelligence tools are becoming available and being incorporated to perfect systems automation. The development of practical, specialized feeds for all developmental stages of species such as cobia and Seriola remains a challenge. FCRs are still very high, limiting performance and increasing production costs.
We present and discuss these challenges and how the industry is collectively working with researchers to address and resolve issues limiting the technological and commercial viability of offshore aquaculture.