- Atlantic salmon, also known as salmon or Tasmanian salmon.
- Atlantic salmon is the most popular fish in Australia but it is not native to Australian waters and is entirely farmed.
- Most Atlantic salmon eaten in Australia is raised from eggs by farmers and then transferred to sea cages in Tasmania. It is also imported from New Zealand farms.
What’s the Catch?
- Salmon are farmed in concentrated numbers in open sea cages. The cages generate large amounts of waste, including fecal waste and uneaten feed, which seeps in to the surrounding waterways.
- The sea cages are moved around the area to minimise the effects of the waste. However, research and analysis into the ecological impact of these sea cages has only recently begun, so the long-term effects are not clear.
- Farmed Atlantic salmon are not self-sufficient as they are a carnivorous fish and must be fed pellets containing ground up wild fish and wild fish oil.
- At least 1.7 kilos of wild fish is required to make enough feed to produce 1kg of salmon.
- Innovations in salmon feed have meant that other, more sustainable sources of protein have been developed – protein from land animals (for example, byproducts of the poultry industry), as well as vegetable proteins. Also, the overall protein content in fish pellets has been reduced by about 50% over the past five years, making the salmon feed more environmentally friendly at the production end as well as at the waste end – a lower protein pellet produces less nitrogen-rich salmon waste.
- Salmon has a high concentrate of long-chain omega 3 fatty acids, which are very beneficial for humans. Omega 3 fatty acids promote healthy joints and skin and reduce the risk of heart disease.
- In the wild, salmon gets its long-chain omega 3 fatty acids, along with its pink colouring, by eating smaller fish, krill and shrimp.
- In order to retain the nutritional benefits of wild salmon, farmed salmon must be fed fish oil, which is extracted from wild fish (in Australia, it’s often anchovies caught in foreign fisheries).
- While farmed salmon’s reliance on wild fishmeal (protein) has been successfully reduced over the years, it is harder to find a replacement for fish oil, with its nutritious long-chain omega 3 fatty acids.
- The provenance of the wild fish used to supply this fish oil impacts on the sustainability of salmon farming.
- Environmental and economic sustainability are driving innovations in salmon feed. One promising development uses microalgae to generate long-chain omega 3 fatty acids, while another uses genes from microalgae to develop oil seeds like canola that will contain long-chain omega 3s for use in fish food. These options would provide an alternative to fish oil, making salmon feed cheaper for salmon farmers and better for our ocean environments.
- Tassal is Australia’s biggest salmon farmer, and all of its salmon farms are certified for responsible aquaculture by the Aquaculture Stewardship Council.
- By June 2017, all ASC-accredited salmon farms will be required to source their fish meal from Marine Conservation Society-approved sources.
- The Australian Marine Conservation Society says to eat less farmed Atlantic salmon.
What’s the Solution?
- Choose a more sustainable fish, like eastern school whiting or King George whiting. Both these fish have sustainable stocks and are fast growing species, quick to reproduce and replenish their numbers. The methods used to fish these species have a low environmental impact. The Australia Marine Conservation Society lists eastern school whiting and King George whiting as a better choice when choosing seafood.
Whats the recipe?
- The Australian Marine Conservation Society on atlantic salmon
- Good Fish Bad Fish on atlantic salmon
- Tassal Operations’ Macquarie Harbour Farm certified for responsible aquaculture by the Aquaculture Stewardship Council
- Learn about an Australian innovation that could reduce the aquaculture industry’s reliance on wild fish
- The Australian Marine Conservation Society on eastern school whiting
- The Australian Marine Conservation Society on king george whiting
What's the Catch premieres 8.30pm Thursday 30 October on SBS ONE.
Join in the conversation using #whatsthecatch