The Salmon Story
Prized for its high Omega 3 content, salmon is Australia’s most popular table fish. However, the salmon that we find on our tables in Australia is not a native fish – it is Atlantic Salmon that is intensively farmed in open sea cages in Tasmania.
In recent years, the industry has come under increasing scrutiny, primarily as a result of an ABC Four Corners exposé aired in October 2016. Earlier this year, Atlantic Salmon was ‘red-listed’ under the Australian Marine Conservation Society’s ‘Sustainable Seafood Guide’. Many of the industry’s practices have been deliberately hidden from the public in order to retain its image as a ‘clean’ and ‘wild’ product sourced from Tasmania’s pristine coast. Here are some relatively unknown facts about farmed Tasmanian salmon.
Because of the high densities of fish being farmed in restricted seacages, resulting in extreme overcrowding, antibiotics and pesticides need to continually be added to the water column to maintain fish and water health. These chemicals not only end up polluting the surrounding marine ecosystem, but are also deposited and stored in the fatty tissues of the fish.
Biological conditions are so poor in the seacages that mass fish deaths frequently occur, the latest in May 2018 when 1.35 million fish died within six months at Macquarie Harbour.
Hundreds of tonnes of fish faeces descend every year upon the seafloor under the seacages. This de-oxygenates the water, creating ocean dead zones around the farms. Ocean currents are carrying these polluted waters across to Tasmania’s once pristine coastline, and are now environmentally threatening Tasmania’s World Heritage coastline and waterways.
Farmed salmon is naturally grey in colour, due to the absence of wild-foraged prey containing carotenoids. Artificial colouring is thus added to the feed to make them pink or orange in colour, depending on the manufacturer’s palette preference.
The growing awareness of overfishing, combined with the ethical, health and environmental concerns over salmon farming, is leading consumers to search for sustainable and wild-caught fish products, and this includes alternatives to smoked salmon, such as mullet and mackerel.