Diving into farmed Atlantic salmon welfare, part 3

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Diving into farmed Atlantic salmon welfare, part 3

RSPCA Australia
Tuesday, 17 December 2024

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In this series of blogs, we’re looking at the welfare of farmed Atlantic salmon – part 1 describes some of the welfare issues that might be similar to those found in farming systems on land (like space allowance, handling, and slaughter), and part 2 dives into some of the unique issues we see with farming in an aquatic environment, like water quality and the environmental impact of salmon farming.

In this, final, part 3 of the series, we look at the animal welfare issues involved with managing wildlife who predate on farmed fish – a challenging area that needs attention.

A reminder: fish feel pain

We’ve said it before, but here more than ever, it’s worth repeating. Fish are sentient, which means they can experience different feelings, including pain and pleasure (although there is ongoing debate about the nature of this in the scientific community).

For a deeper exploration of fish sentience, we recommend reading this RSPCA Knowledgebase article.

Managing wildlife

Protecting farmed animals from predators who may severely injure or kill them is common practice in many farming systems. For example, in free-range environments, farmers give particular attention to protect their animals (particularly poultry and young animals such as piglets, calves, and lambs) from wild dogs, feral cats, foxes, or larger birds of prey.

Nearly all Atlantic salmon farming in Australia takes place in Tasmania, and a lot of it in open water. This means fish are vulnerable to predation by animals like sea birds, but mostly by seals and, in Tasmania, this is mainly the Australian fur seal. Fish farming has started to move offshore, where seal incursions (e.g., due to net damage from strong waves) are generally more frequent.

Seals are strongly attracted to the farmed salmon as a seemingly easy food source and are capable of biting through pen nets, jumping into pens, ripping holes in the netting and sometimes threatening staff just to get to the fish. If they get the chance, seals will injure and kill thousands of fish. Clearly, measures need to be put in place to prevent this as much as possible. But with seals also being sentient animals capable of experience pain and suffering, any way of dealing with this must balance the welfare of the fish and the welfare of the seal.

What can be done to protect fish?

From the RSPCA’s perspective, the primary answer is and must be to have measures in place to keep seals out in the first instance. On salmon farms in open water, these ‘exclusion measures’ (barriers, nets, fences, etc) include fish containment nets, reinforced predator nets (below water), fencing above water, and measures to check that nets are strong and not damaged.

However, this is not 100% effective – and in fact, we’re not aware of any pen net technology in the entire world that is. Seals will wait for opportunities to access the pens, including through damaged nets. They may also get trapped in pens, becoming entangled in nets or getting trapped between the containment net and the predator net.

When a seal does get in, parts of the pen nets are lowered to allow the seal to swim out on their own (which may be attempted over several days). The next option used by the salmon industry is what are called seal deterrents.

What are seal deterrents, and what are the welfare issues?

‘Seal deterrents’ refers to a range of devices that are deployed to try and remove a seal from the area, and represent one of the most challenging areas when it comes to balancing the welfare of farmed salmon and seals.

Under the Tasmanian Government’s Seal Management Framework, devices that are permitted to be used (subject to restrictions) are:

Seal crackers (an explosive device like a firework, that’s thrown into the water at >2m distance from the seal, and creates a flash/noise that detonates under the surface)

Bean bags (a lead-filled bag that’s shot towards the seal from >2m distance)

Scare caps (a dart with a blunt tip that’s shot towards the seal from >2m distance)

Seals may also be trapped, sedated and/or removed, and killed in exceptional circumstances where an unprovoked seal has threatened staff.

Deterrent devices, despite being restricted by the Tasmanian Government in how and how often they can be used, bring with them animal welfare issues. Projectiles like bean bags and scare caps that hit the seal can result in stress to seals and (even though they’re not meant to) cause injury and in some cases, death.

Seal crackers, which are the main deterrent device used in Tasmania, have welfare issues too even though they’re not physically coming into contact with seals. This can include stress and fear (indeed, inducing the fight or flight response is what makes the seals swim out of the pen), potential hearing damage, and physical injury to the seal if they’re not used properly.

What can be done to protect both salmon and seal welfare?

This is a challenge that the salmon industry in Tasmania must address. Taking away seal deterrents right now is not the answer – we’re not aware of any innovation globally that would keep seals out entirely and so taking away every single option to deter or remove seals, even as a last resort, is not a good outcome for fish welfare.

One way we work to improve salmon welfare is through the RSPCA Approved Farming Scheme, which prohibits bean bags and scare caps, has tight restrictions on how crackers can be used and when, requires a site-specific wildlife management strategy, and requires regular checking of pens to reduce predator entanglement risk.

But this isn’t a perfect solution. We want to see infrastructure improvements to protect fish and minimise interactions with seals, and we want to see research into alternative seal deterrent technology so that crackers, bean bags and scare caps can be phased out. 

That’s why we expect – something that is called out specifically in the RSPCA Approved Standard - that the salmon industry prioritise research and development around improved pen and seal exclusion technology, and better understanding of the impact of seal deterrent devices on seals, salmon, and other marine life. 

For as long as salmon farming continues in open water in Tasmania, this is going to be an issue – and one that we continue to call on the salmon industry and the Tasmanian government to address.

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Diving into farmed Atlantic salmon welfare, part 3

A reminder: fish feel pain

Managing wildlife

What can be done to protect fish?

What are seal deterrents, and what are the welfare issues?

What can be done to protect both salmon and seal welfare?

Stay informed on big issues and how you can help improve animal welfare across Australia.