Marine aquaculture of the salmonids atlantic salmon (Salrno salar) and rainbow trout (Salmo gairdneri) is a rapidly growing industry in Tasmania. There is considerable damage to the fish on these farms by avian and mammalian predators. The mode by which these predators attack the fish on the farms allows for practical methods to reduce the loss of fish. Physically excluding predators from the fish is ultimately the only way to prevent this loss entirely. A total of six predators that interact with the farms are described and the necessity for the protection methods to be incorporated into the design of the farms prior to farm development is emphasised.