Active salmon breaking the surface of circular marine pen, Norway

salmon norwegian marine pen norway salmon farming fishery controversial salmo salar aquaculture fish farm circular aquafarm jumping round salmon farm seafood pisciculture fish jump aquafarming norway aquaculture breaking the surface stocked atlantic salmon controversy farming sustainability food production commercial salmonidae industry sustainable scandinavia cage marine ocean oceanfarmed atlantic arctic circle enclosed farmedsalmon production aquatic aerial drone antibiotics ammonia intensive pen fish mortality rate