ESG Tasmanian Salmon Producer Tour

Author: Natalia Tsurkova
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ESG Tasmanian Salmon Producer Tour

We visited Tasmania in June to tour Tassal’s hatchery, farming, and processing sites, and met with Salmon Tasmania, scientists from the Institute for Marine and Antarctic Studies (IMAS), certification bodies, and community and environmental groups to better understand farmed salmon production in Tasmania and the associated challenges in the region.

Our key findings centred on:

Maugean Skate and Oxygen Levels

IMAS scientists shared that salmon farming is one of the contributors to low oxygen levels in Macquarie Harbour, which has led to almost no recruitment of the endangered Maugean skate for the past eight years. Tassal acknowledged at the meeting that farming contributes to oxygen stress. Reducing biomass and using oxygenation in the harbour are helping, but not enough for the species to recover and rebound yet. Ongoing efforts are needed for the industry to coexist sustainably with the skate.

Picture of a Maugean skate at IMAS, where researchers run a breeding program to help protect the species.

Community Perspectives 

Community pressure around salmon farming is increasing, with growing numbers involved in protests, petitions, and shareholder resolutions for retailers. Concerns include antibiotic use, algae build-up, animal welfare concerns, vessel noise and lights, plastic pollution, farm waste, the near-extinction of the Maugean skate, the inconsistent strength of certifications like BAP and GLOBALG.A.P., and the blanket use of the term “responsibly sourced” by retailers. Community groups called for more transparency, as many questions remain unanswered. In some areas, local salmon sales are low, and local restaurants are anecdotally avoiding serving salmon.

However, support for aquaculture is strong in other regions like Tasmania’s West Coast, where many families rely on salmon farming. According to Blue Economy estimates shared during the visit, around 20% of the public in Tasmania oppose salmon farming, while 35% support it. On the mainland, awareness remains low, and national sales have, reportedly, not been affected by protests.

Offshore Farming Trials

Blue Economy Cooperative Research Centre (CRC) is trialling offshore salmon farming 12 km into Bass Strait. Offshore farming offers environmental benefits – cooler, deeper water and stronger currents can reduce disease, algae, and waste, while moving farms away from sensitive coastal areas. It may also reduce impacts on nearby communities. However, offshore farming is complex, expensive, and vulnerable to rough weather and predators. Industry participants are optimistic but say the infrastructure must be at a completely different level. The project is also looking at reducing antibiotic use and improving feed efficiency to lower emissions. Some community groups remain opposed to any form of offshore salmon farming.

Land-Based Farming

Some community members support a transition plan to land-based farming and the phasing out of inshore sites. However, businesses say this isn’t viable due to cost and technical challenges.

Fish Welfare in Sea Cycle

Tasmanian salmon farmed at sea are subject to a parasitic amoeba that attaches to their gills, causing a condition known as amoebic gill disease (AGD). Freshwater bathing of the fish is required to detach the amoeba. The transfer from freshwater to seawater is stressful for salmon and, unlike in the wild, farmed salmon in Tasmania are exposed to up to eight freshwater treatments to manage AGD. This contributes to mortality and raises welfare concerns. Fish in Macquarie Harbour do not need to be washed, as the harbour has a natural freshwater layer caused by tannins (which give the water a tea-like appearance). Current fish density is about 2% biomass to water.

Tassal’s sea pens, where salmon live for 18–24 months after spending about 18 months in freshwater hatcheries. Each pen holds around 60,000-70,000 fish.

Certifications 

Aquaculture Stewardship Council (ASC) is considered the strongest certification used in Tasmania and is one of the few aligned with the UN’s Convention on Biological Diversity. ASC stopped certifying salmon farms in Macquarie harbour in 2018. However, even ASC does not fully reflect local conditions. For example, ASC monitors oxygen only to a 5m depth, while impacts on the Maugean skate occur deeper (10-25m). In relation to water temperature (which can reach 20-21 degrees in summer and become too warm for salmon), ASC clarified that climate risks and site approvals are outside its scope, though its new standard includes more localised monitoring.

We will continue to monitor developments in Tasmania’s salmon industry, engage with stakeholders, and contribute to constructive dialogue where we can add value. Please contact us if you would like more information from the trip.

Maugean skate in the wild. Photo sourced from the internet.