Offshore aquaculture

Offshore aquaculture, also known as open water aquaculture or open ocean aquaculture, is an emerging approach to mariculture (seawater aquafarming) where fish farms are positioned in deeper and less sheltered waters some distance away from the coast, where the cultivated fish stocks are exposed to more naturalistic living conditions with stronger ocean currents and more diverse nutrient flow.^[2][3] Existing "offshore" developments fall mainly into the category of exposed areas rather than fully offshore. As maritime classification society DNV GL has stated, development and knowledge-building are needed in several fields for the available deeper water opportunities to be realized.^[4]

One of the concerns with inshore aquaculture, which operate on more sheltered (and thus calmer) shallow waters, is that the discarded nutrients from unconsumed feeds and feces can accumulate on the farm's seafloor and damage the benthic ecosystem,^[5] and sometimes contribute to algal blooms. According to proponents of offshore aquaculture, the wastes from aquafarms that have been moved offshore tend to be swept away and diluted into the open ocean. Moving aquaculture offshore also provides more ecological space where production yields can expand to meet the increasing market demands for fish. Offshore facilities also avoid many of the conflicts with other marine resource users in the more crowded inshore waters, though there can still be user conflicts offshore.

Critics are concerned about issues such as the ongoing consequences of using antibiotics and other drug pollutions, and the possibilities of cultured fish escaping and spreading disease among wild fish.^[3][6]