Tassal employees shot more than 50 great cormorants as part of a "shoot-and-scare" tactic that failed to deter the native seabirds from entering salmon-farming pens in Tasmania's south-east, documents have revealed.
The large birds, which can live to the age of about 20 years and mate for life, are a protected species in Australia but are not considered endangered.
Documents requested by media website the Tasmanian Inquirer under Right to Information laws have shown more than 500 cormorants entered fish cages at Tassal's Sheppards salmon lease, near Coningham, between November and December 2023.
In December, Tassal applied for a permit to shoot up to 50 cormorants because the birds were squeezing through the 100-millimetre netting used to protect the pens, causing damage Tassal estimated at between $10,000 and $20,000 per day.
The Department of Natural Resources and Environment Tasmania (NRETas) approved the permit on the condition the lethal control of the birds would be used as a "last resort".
"Tassal want to shoot to scare to disrupt feeding patterns," the document said.
"We had discussions [with Tassal] around the need for lethal control on a small number [of birds] to deter the rest from settling.
"Pens are in a secluded area offshore with no dwellings within 250 metres. It is safe to shoot and Tassal only want to use it as a last resort."
Tassal, the largest of Tasmania's three major salmon producers, was acquired by Canadian seafood giant Cooke in 2022.
Birds didn't fly away when one of them was shot, document reports
However, the shoot-to-scare tactic did not work.
"[Tassal] noted that a cormorant would not move away even if the cormorant next to it was shot," an NRE document reported.
Tassal noted in the documents that the method had worked on other bird species.
Independent bird ecologist Eric Woehler said he was not surprised the shootings did not work.
"Birds learn very quickly that many times these loud noises are very ineffective," he said.
"The cormorant is a species native to Tasmania. They've been around longer than the aquaculture industry.
"What the aquaculture industry is doing is providing structures for these birds to roost on and should the opportunity present itself, as it did in this case, an opportunity for supplementary feeding."
While the size of Tasmania's cormorant population was unknown, Dr Woehler said the Tassal pen deaths would not interfere with the state's total population.
"I'm not condoning what Tassal did, but the scale of the shooting on the population would be undetectable when we're looking at the statewide population," he said.
"Shooting any animal has to be the last resort and unfortunately in Tasmania we've seen … farmers and landowners using crop protection permits to shoot significant numbers of mammals and birds.
"The important thing is that we need to make sure that something like this doesn't happen again."
Dozens of cormorants died tangled in netting
In addition to the 53 cormorants that were legally shot by Tassal in December, a further 36 died while tangled in the netting covering salmon pens, the documents show.
In its application for a second permit, Tassal noted it had replaced the 100mm netting on its pens with a smaller 70mm mesh to block the birds from entering through holes.
Tassal acknowledged some nets were second-hand and require ongoing tensioning and repair.
They also mentioned other efforts to keep birds from entering pens including firing non-lethal shots near the birds but away from the pens' exit points.
"We have a will to continue to invest considerable time and energy into our priority focus of exclusion and then removal without harm," a Tassal spokesperson said in its application.
"However, this continues not to be 100 per cent effective and this is evidenced in the number of entanglements we have experienced."
Tassal has described the "bird event" as an "anomaly".
"We are committed to reducing negative wildlife interactions through responsible management to ensure minimum harm to wildlife, our employees and our salmon. Despite our very best efforts, a very small portion of wildlife can die or suffer injury as a result of interacting with farms," the company said.
LoadingLoading...