Bivalves boost biodiversity

The development potential for sustainable food production in the ocean is vast, with aquaculture capable of meeting global seafood demand using less than 0.015% of the total ocean area^[1].

Marine bivalves, such as mussels, oysters and scallops, have become one of the fastest growing animal-food sectors and are increasingly sought after by consumers due to their taste, high nutritional value and perceived positive benefits to the environment. Global production of marine bivalves for human consumption has grown from less than 1m tonnes per year in 1950 to more than 16m tonnes per year in 2016, with 89% produced through aquaculture (Figure 1)^[2].

In addition to food supply, there is also growing awareness of the potential wider ecosystem benefits of bivalve aquaculture, including regulating services such as nutrient remediation, carbon sequestration and coastal defence^[3]. In fact, non-food ecosystem services provided by bivalve aquaculture globally have been estimated to be worth between $2.95bn to $9.99bn USD per year^[3]. The urgent need for sustainable food production systems capable of meeting a growing global demand for animal protein whilst removing the negative environmental impacts associated with wild bivalve harvesting^[4] and supporting a ‘Blue Growth’ agenda^[5] has boosted interest in bivalve aquaculture. Traditionally, bivalve aquaculture had largely been established in inshore areas either on the seabed or on structures fixed or floating in shallow sheltered waters. In this environment there have been notable negative environmental impacts. For example, farming bivalves in sheltered, poorly flushed inshore waters can result in the accumulation of waste products that pollute the seabed and reduce local biodiversity^[6].