Putting a dollar value on the ecosystem services provided by extractive aquaculture
Culturing seaweed and bivalves (mussels and oysters) provide a range of services that can benefit coastal and marine ecosystems. While the ecosystem services, which include bioremediation, coastal defence, and habitat provision for fish, have been studied extensively, the dollar-value of these services has not yet been calculated. With this in mind, Dr Luke Barrett along with collaborators from both Australia and the United States calculated the monetary value of regulating and supporting services that are provided by seaweed and bivalve aquaculture. They estimate 275-581 kg N ha-1 yr-1 is removed via bioextraction at oyster, mussel and seaweed farms, which could be worth 84-505 USD t-1 in the United States and Europe where nutrient management is a priority. Further, they estimate that the habitat structure provided by aquaculture supports 348-1110 kg ha-1 yr-1 of additional fish compared to reference habitats, which could potentially be worth an additional 972-2504 USD ha-1 yr-1 to commercial fishers, or 1087-2848 USD ha-1 yr-1 to recreational fishers. Clearly, the ecosystem services provided by extractive aquaculture species can be utilised to sustainably meet the increasing demand for food while generating positive ecological outcomes.