Aquaculture can take place in open, closed and semi-closed systems. Certification of aquatic products from open and semi-closed systems like sea-cages, ponds or flow-through systems have, in the past, been the main focus of the ASC farm standards .
In recent years the number of recirculating aquaculture systems (RAS) has significantly increased and thus facilitated the need to adapt the ASC standards to incorporate these highly technical systems.
To reflect the growing trend of RAS within the aquaculture industry, ASC has developed a RAS Module which details requirements specific to RAS farms. The requirements fall under two key principles reflecting the main impact areas of RAS: to minimise negative effects on water resources, and to use resources in an environmentally efficient and responsible manner. All requirements of the RAS Module need to be met by RAS farms, in addition to the requirements in the relevant species standard.
Minimise negative effect on water resources
Principle 1 of the RAS Module relates to water use, water quality, and water and waste disposal. Farms are required to always leave at least half of the natural flow in the water body to ensure sufficient water remains to support natural flora and fauna. Further requirements around effluent and biosolids need to be adhered to, including the implementation of best management practices.
Use of resources in an environmentally efficient and responsible manner
Principle 2 relates to energy consumption, greenhouse gas (GHG) emissions, and species-specific recording requirements. Farms are required to record their energy consumption and also develop a strategy to reduce their GHG emissions. Additional species-specific requirements, such as stocking density, need to be recorded to enable ASC to consider metric requirements on these indicators in the future.