Salmon farms prove deadly for protected seals and birds

Eight protected fur seals and 21 protected seabirds have died at Tasmanian salmon farms in the past 12 months,

Protected fur seals about 20km from a Tassal salmon farm. Picture: Matthew Denholm.

Eight protected fur seals and 21 protected seabirds have died at Tasmanian salmon farms in the past 12 months, with one seal ­deliberately killed, apparently for posing a risk to staff.

The state government in late December banned the practice of capturing and relocating seals from fish farms to the island’s north. While the ban was ­applauded by fishermen unhappy about seals being relocated to their fishing grounds, it has reduced options available to aquaculture companies.

This has forced an increased reliance on legal “deterrents” against seals, including explosive crackers and shot-filled bags fired from shotguns, as well as the roll-out of more predator-proof pens.

It is not known whether the use of deterrents contributed to any of the seal deaths and how many of the eight drowned after being trapped in pens or netting.

“On occasion, a small number of fur seals are located dead within marine farming leases,” a spokesman for the Department of Primary Industries, Parks, Water and the Environment said.

“Sometimes this is as a result of accidental interaction with marine farming infrastructure and in some instances the cause of death may be non-attributable to marine farming.”

The department sometimes gave permission for troublesome seals to be “humanely destroyed” by aquaculture companies, but only when there was “a demonstrated risk to health and safety of marine farm staff”.

Tassal Group, the largest salmon farmer, confirmed on its website that the six seal deaths at its leases since December included one “humane destruction”. Other deaths are listed as “accidental”. Competitor Huon Aquaculture lists two seal deaths since December but does not specify how the animals died.

Data released online by both companies also reveals 21 protected seabirds had died in salmon pen nets or infrastructure in the past 12 months.

Tassal listed a further 471 birds as being trapped in its nets in the past 12 months but released alive.

Neither company provided details of the seal deaths. Tassal confirmed it had requested an increase in permits to use seal deterrents, but said this had not translated to an increase in their use, thanks to the deployment of more seal-proof pens. Huon said there was an increased use of deterrents at its Storm Bay lease.

The department said it was still investigating Tassal for breaching wildlife guidelines more than two years after the company kept a group of seals in a fish pen together for some days.