High-productivity marine aquafarms are enclosed areas for the breeding, rearing, and harvesting of marine plants and animals, including finfish like salmon, molluscs, crustaceans, and algae. These low-diversity communities are dominated by the harvested species, maintained at a high densities. Non-harvested species may be controlled as pests, using antibiotics, herbicides, or culling. Aquafarms in coastal or open ocean waters are exposed to associated physical processes, but on land they are in environmentally controlled tanks and ponds.