Shellfish Culture in the Open Ocean: Lessons Learned for Offshore Expansion

Marine shellfish or bivalve aquaculture accounts for a large fraction of the total world production of cultured seafood, with production trailing only freshwater fish (mainly carps and similar species) and aquatic plants. However, growth of nearshore bivalve aquaculture is increasingly constrained by space, economics, human health, and environmental concerns. Offshore or open ocean waters offer a tremendous potential for expansion of the shellfish farming. Developments to date indicate that it is feasible to install, to maintain, and to operate bivalve culture systems in high-energy offshore waters with production rates often equaling or exceeding nearshore environments. Although production to date is limited and a number of technical, operational, economic, and social challenges must be addressed, a number of small to large-scale bivalve culture systems are in development or production. This article reviews the current production of bivalve shellfish, describes characteristics through case examples of offshore shellfish culture system, and assesses the future potential of this farming method.