Also dubbed the “Blue Revolution”, aquaculture can be simply defined as the farming of aquatic organisms. Mariculture refers to the farming of specifically marine species, as opposed to freshwater. Aquaculture may be conducted either in land-based artificial tanks and ponds in coastal areas or floating net cage enclosures at sea, usually in sheltered locations.
During the last two decades there has been a rapid global expansion of commercial aquaculture and it now contribute significantly to the total global seafood production. Local consumers may not realise it, but there are already many farmed seafood products in our retailer freezers, such as oysters, mussels, salmon and prawns. Some aquaculture methods are better than others, for example the farming of mussels and oysters also practised in South Africa, is seen as a good environmental seafood choice, as these animals are filter feeders and need no nutritional input.
On the other hand, farming of carnivorous fin-fish such as salmon in the northern hemisphere, especially under intensive conditions (not unlike cattle in a feedlot) is associated with numerous issues, ranging from pollution to the escape of farmed fish, disease and parasite transfer to wild salmon populations, to the composition of feeds used, and whether these are safe and sustainable. Aquaculture will undoubtedly become a more and more important source of seafood, but consumers need to bear in mind there are certain production methods that also have negative environmental, and sometimes human health, implications.
WWF’s position on Aquaculture
Aquaculture is the farming of aquatic organisms, conducted either in land-based artificial tanks and ponds in coastal areas, or floating net cage enclosures at sea, usually in sheltered locations. See here for a more detailed explanation of the most commonly used Production Systems
. During the last two decades there has been a rapid expansion of commercial and intensive farming.
WWF has two overriding concerns related to the expansion of the aquaculture industry: the intrusion of fish farms into vulnerable marine and coastal areas, with potentially detrimental environmental effects, and the overall unsustainability and potential negative ecological repercussions of an industry that is dependent on wild-caught fish used as fish feed in a conversion ratio of sometimes as high as 4:1.
The environmental effects of intensive fish farming include:
• Pollution into marine systems can have serious impacts through the release of nutrients, pathogens, chemicals and pharmaceuticals;
• Increased fishing pressure on species already exploited to produce fish-feed;
• The introduction of exotic fish and shellfish species that escape and compete with, infect, or prey on, native species;
• Dense farm populations that provide an incubator for diseases which can then infect wild stocks;
• Catching of juveniles and adults for on-growing in farms and for breeding in nurseries;
• Interbreeding of escaped farmed fish with local wild stocks of the same species;
• The unintended capture, illegal culling or disturbance of habitats of fish, mammals, birds or other animals can exert pressure on species that play no role in aquaculture.
WWF’s position on aquaculture:
Whilst WWF recognizes the potential value to society arising from aquaculture in terms of providing food security, revenue, job security and an alternative food source to that derived from wild-caught fish, the farming of marine and aquatic organisms can have detrimental effects on the environment, and thus be socially and economically unsustainable in both the short-term and in the long-term. WWF advises that:
• Before a new aquaculture development or expanding of the existing industry takes place, vulnerable species and habitats should be identified and sufficiently protected.
• Environmental Impact Assessments (EIA) should always be in place for large-scale projects, or for regions where several smaller projects are operating in close proximity and represent significant combined effect.
• A code of conduct for responsible aquaculture should be developed, and individual farms should set up operational guidelines and development plans that will control cumulative impacts and secure that any possible mitigation measures are taken.
Internationally, WWF has developed the Aquaculture Dialogues which are in the process of developing sustainability standards for aquaculture. These standards will then be adopted by the Aquaculture Stewardship Council (ASC), which will appoint certification bodies to certify individual farms as environmentally and socially sustainable. The products from these certified farms will then carry the ASC eco-label to inform consumers that the product has been certified environmentally and socially sustainable.
Locally the WWF SASSI (Southern African Sustainable Seafood Initiative) has recently taken the decision to include aquaculture species on the list and does acknowledge any farm which has the ASC certification when they become available. ASC certified farms will be placed on green on the SASSI list.For a more detailed position statement please contact us.