More than 8,700 beanbag bullets have been fired at seals around aquaculture sites in Tasmania since 2013, documents reveal.

Key points: Non-lethal beanbag bullets are being used by salmon farms against seals

Non-lethal beanbag bullets are being used by salmon farms against seals There are reports seals have been shot at close range and blinded

There are reports seals have been shot at close range and blinded WWF, which sponsors Tassal products, is "deeply concerned

The beanbag bullets are a non-lethal ammunition usually associated with riot control and law enforcement but the use of them as part of a seal-deterrent strategy was described as "unacceptable" by animal welfare proponents.

Right To Information documents reveal that 3,770 beanbag rounds were used and 39,024 underwater explosives in 2016.

In 2017, the number fell to 1,000 bean bags and 28,748 "crackers".

The non-lethal ammunition is used by police and law enforcement agencies. ( Supplied: Security Devices Inc )

For this year up to July 1, 1,250 beanbags and 8,856 crackers had been used.

The numbers were obtained from the Department of Primary Industries and are part of a self-reporting regime among aquaculture companies that is regulated by the department.

Former Chairman of Tasmania's Animal Welfare Advisory Committee Dr Rick Campbell said he was concerned by the numbers.

"From an animal welfare perspective beanbags are high risk, they are inappropriate and likely to injure the animal," he said.

"It is certainly a concern, especially if the animals are too close.

"These are fast-moving animals and it is most likely the head that is above water. The risks of significant injuries is high."

The measures are designed to discourage seals from damaging aquaculture infrastructure and endangering staff.

The strategies have been used alongside the relocating the seals, a practice which the State Government banned late last year after an outcry by fishers.

'Reports of seals being blinded and deafened'

Beanbag rounds are fired from 12-gauge shotguns.

The ammunition consists of hard pellets wrapped in a cloth sock and is regularly used by police in the United States and has been used to quell riots in Australia.

In some rare cases, people have died after being hit by beanbag rounds while others have been suffered facial and eye injuries.

Crackers, also referred as Seal Control Units, are small explosive devices.

Malcolm Caulfield, founder and principal lawyer of the Animal Welfare Community Legal Centre Tasmania, said he was surprised by the numbers.

"It's a scandal, it's outrageous and a completely unacceptable situation. And that there are reports of seals being blinded and deafened by these [devices]," he said.

"What we are seeing is an industrial-scale use of cruel measures against a protected species in Tasmanian waters."

"What it clearly highlights to me is that the Government isn't doing it's job.

"The fact of the matter is this is an unacceptable use of these very violent tactics against these marine mammals which have a high level of protected status under the law."

WWF 'deeply concerned by reports of seal injury'

The ABC spoke with two industry insiders who work in aquaculture in Tasmania and both independently claimed that on a number of occasions they had personally witnessed beanbag rounds blinding seals and hitting them in the head at close range.

DPIPWE regulations stipulate beanbags cannot be used in a manner likely to cause injury to a seal and to minimise risk or injury can not be fired towards the head of a seal or within two metres of the animal.

The protocols also state that no more than 20 crackers and five beanbag rounds can be used against a seal within a six-hour period.

World Wildlife Foundation, which has its logo on Tassal products, said it would be speaking with the company about the use of beanbag rounds and reports of seals being blinded.

"WWF is deeply concerned to hear of these reports and will look into them," a spokesperson for the charity said.

"It is unacceptable for technology to be misused in a manner that could injure seals."

The charity, which until last year permitted Tassal to use its logo on its products as an assurance that the salmon is "responsibly sourced", said bean bags should only be used as a "last resort".

It continues to work with Tassal, offering advice on sustainability strategies.

"WWF-Australia has been working with Tassal to increase the use of seal-proof pens and reduce the industry's interaction with seals," the spokesperson said.

"We will be seeking additional information from Tassal about its use of these technologies."

DPIPWE says anyone who has information about improper use of deterrents should contact authorities. ( ABC News: Henry Zwartz )

Beanbag use 'unacceptable': RSPCA

In a statement, DPIPWE said seals could cause "human safety and animal welfare concerns".

"Animal welfare is an important part of conditions in place for any of the authorised techniques," the department said.

"If anyone has information in relation to inappropriate use of deterrents or animal welfare concerns in relation to the use of deterrents, the department encourages them to report it to authorities to enable its investigation."

Huon said it took its duty of care to protect staff seriously.

"Seal deterrents assist in reducing negative interactions between staff, seals and our fish," the company said.

"Huon has not relocated any seals from our farms since August 2016. Huon has used other legally permissible deterrents such as crackers and beanbags.

"The number of permits approved is less than numbers approved in 2016 and on a par with numbers approved in 2017, the level of seal control units used is tracking to be 30 per cent less than last year, and nearly 50 per cent less than 2016."

In a statement, Tassal said it used deterrents to safeguard its staff.

"The use of seal deterrents across the salmon industry in Tasmania has remained relatively unchanged since 2013, and reduced since 2016, despite an increase in operations and production volume," it said.

"This is primarily due to the roll-out of seal-proof infrastructure by the salmon companies. Tassal has invested $70 million in its sanctuary pens, which so far have proved very effective in keeping seals, stock and people safe."

But Dr Andrew Byrne, CEO of RSPCA Tasmania, said the use of beanbag rounds was "unacceptable".

"It's noxious stimuli and therefore RSPCA Australia wouldn't accept it whatsoever.

"It's painful if not noxious, it's in the same category as shock collars on dogs, and citronella collars on dogs."

Dr Byrne questioned RSPCA Australia's relationship with Huon after the organisation granted the company its tick of approval earlier this year.

"I will be looking into the issue of beanbags further," Dr Byrne said.

Mr Caulfield is calling for an independent investigation into the use of the ammunition on seals.

The seal management framework is currently under review by DPIPWE.