In Tasmania, farmed Atlantic salmon may be vulnerable to attack by sea birds and fur seals. Protecting the welfare of the fish is as important as protecting the welfare of the predator. Salmon farms may be subject to hundreds of seal interactions each year, with seals capable of biting fish through the pen nets, jumping into pens, ripping holes in the netting and sometimes threatening staff. Cormorants are the main aerial predators that are attracted to salmon in the marine pens. Although the marine pens are completely covered by bird netting, some birds find their way in through holes or may become ensnared in the netting. Once inside, birds that are able to perch within the enclosure will generally survive but those that cannot, may die.

The RSPCA Approved Farming Scheme standards for farmed Atlantic salmon do not allow acoustic deterrent devices to be used to keep predators away from the fish. Lethal control methods (anaesthetic overdose) may only be used as a measure of last resort where several translocation attempts have been unsuccessful, if the animal poses a serious threat to staff and all other exclusion and control methods have failed. Control of protected wildlife species must only be carried out under a permit from the relevant regulatory authority.

The RSPCA believes exclusion measures, both above and below the water, should be the primary method of deterring predators. Pen net technology is increasingly sophisticated and effective in keeping predators out, thus significantly reducing the number of interactions between fish and predator.