Closed Containment Aquaculture

Closed-containment aquaculture rears stock in a physical barrier that isolates the culture water from the surrounding environment, contrasting with open net-pen farming. The barrier, a tank, bag, or membrane on land or floating in water, blocks fish escapes, sea-lice transfer, and direct nutrient discharge, and lets operators treat or recapture effluent. Land-based recirculating aquaculture systems are the fully closed form, reusing more than 90 percent and often 97 to 99 percent of system water. Floating closed or semi-closed bags sit between net pens and full RAS. Higher capital and energy costs are the trade-off against the containment benefit.