Diving into farmed Atlantic salmon welfare, part 2

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Diving into farmed Atlantic salmon welfare, part 2

RSPCA Australia
Friday, 29 November 2024

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In a previous blog, we looked at some of the welfare issues with farmed Atlantic salmon – and in particular, some similarities to animals who are farmed in land-based farming systems.

Scientific evidence shows that fish feel pain, and so this affects how we should think about animal welfare in fish farming, including issues familiar to us from land-based farming systems like space allowance and how animals are handled, transported and slaughtered.

But with salmon, being in an aquatic environment also brings with it additional challenges. Aquaculture (farming animals in an aquatic environment) is like land-based farming in some ways, and in other ways, it’s of course quite different – bringing with it additional challenges. Read on to find out more about some of the unique challenges aquaculture poses for the welfare of farmed Atlantic salmon.

Water quality

Water quality is one of the most fundamental factors affecting fish welfare. Good water quality is crucial to promoting good health and reducing vulnerability to stress, disease and even death.

Fish breathe oxygen that’s dissolved in water, and low oxygen levels, e.g. when water temperature is higher than normal, can cause increased stress and susceptibility to disease. In a farming environment, appropriate oxygen levels at all stages of the process are critical for fish welfare.

Other water quality factors that can impact fish welfare include pH (acidity), as well as the levels of ammonia, carbon dioxide, nitrite and nitrate in the water. These are all naturally occurring chemicals (for example, ammonia is a component of fish waste, carbon dioxide is released when fish breathe, and nitrites and nitrates are essential parts of the nitrogen cycle which is vital for sustaining life) – but in too low or too high a quantity, they can be detrimental to fish welfare.

Water flow

Water flow is also important for fish welfare, at all stages of the farming process. Poor water flow can mean that less oxygen is available to fish or waste accumulating, including fish waste and waste from feed.

Salmon need to be able to swim freely and good water flow and current helps them to do this, in addition to sufficient space and the ability to choose to swim around, across, and up and down in the water column.

Environmental impact

As an animal welfare organisation, RSPCA is focused on the welfare of the fish being farmed. However, aquaculture activities and their impact on the environment should also be considered. Routine aquaculture activities and waste (such as fish waste, wastewater from hatcheries, processing and net maintenance) can impact water quality. Feed waste can also create bacterial mats in the sediment underneath marine pens.

Addressing environmental impact is an important consideration for the welfare of both the farmed fish as well as other animals who inhabit or are affected by the waters around fish farms.

The RSPCA continues to call for transparent, robust and effective regulation of the planning process; effective monitoring of environmental impact; effective enforcement to ensure ongoing compliance with regulations; more comprehensive and regular (including real-time) online publication of independently verified information relevant to environment and fish care; and assessment and approval of marine farming development plans to also consider fish welfare implications in the allocation of new leases for fish farming.

Where to next?

We continue to advocate to the Tasmanian government and to the salmon industry for measures to protect the welfare of animals, including those mentioned above that specifically relate to the marine environment.

As we mentioned in part one of this series, we also need better legislation to protect farmed fish as currently there is no legislation specific to the welfare of farmed Atlantic salmon. Regulation is focused on managing and monitoring the environmental impact of salmon farming, but not welfare. There’s also no national Australian Animal Welfare Standards and Guidelines for farmed Atlantic salmon, like there are for many other farmed animals – and so we continue to advocate for this to be created.

The RSPCA Approved Farming Scheme is one way we work to improve the welfare of farmed Atlantic salmon. Many of the requirements in the publicly available Standard which underpins the Scheme, and which producers have to meet and be assessed against if they want RSPCA Approved certification, go directly to water quality and other issues discussed here. The Standard isn’t yet perfect and doesn’t fully address every issue – but it challenges existing practices and provides a pathway for continuous improvement in the welfare of farmed Atlantic salmon.

In the final part of this series, we look at the challenges of managing wildlife incursions and interactions on salmon farms – an issue for a lot of farming systems but a uniquely challenging one when it comes to salmon farming in marine environments.

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Diving into farmed Atlantic salmon welfare, part 2

Water quality

Water flow

Environmental impact

Where to next?

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