by Liz Beavis
One thing I think that has really become more clear to me over the past few years is how removed we are from our food supply. Our food supply is driven by supermarkets and manufacturers with big budgets who can afford to tell us what we ‘should’ want, and tell us a few bits of ‘good’ information so we can feel good about what we buy, but conveniently forget to tell us the not so good stuff about our choice of product – important information that should also play a role in our decision making when we buy our food.
Fortunately we are just beginning to see this disconnect and starting to think a bit more about where our food comes from.
Over the next couple of newsletters we will discuss some issues to ponder on where our food comes from. We kick off this series with Salmon, following on from Kate’s article VitaminD- fish-iency last month
What do you know about the fish you eat? We have been fed lots of information about how good fish is for us to eat – the health benefits of omega-3 fish oils. And I am no exception – I could rant for hours on the awesomeness of these essential fatty acids. But at what price?
Do you know what impact our increased fish consumption has on our oceans? Once upon a time fishing activities were well within the capacity of our oceans, but as fishing boats (and nets) got bigger – and dare I say fishing companies got greedier!) and as our appetite for fish increases it is putting quite a strain on our fish stocks, particularly for some species.
One way to minimise that issue is fish farming, or aquaculture however that comes with its own subset of issues! Fortunately some aquaculture companies are making an effort to reduce environmental impact. I have found this information quite difficult to get hold of previously, but as more people start asking questions companies who fish sustainably are happy to share their story.
When I first started my research into salmon farming in 2011, Petuna was the only company I contacted who was willing to discuss their environmental practices. Aquafarming in pristine waterways on Tasmania’s West Coast has inspired sustainable practices from the start.
More recently, Tassal, Australia’s largest supplier of Atlantic salmon has also taken big steps towards improving sustainability, sealing their commitment by signing up to WWF Sustainable Seafood charter and working towards accreditation with Aquaculture Stewardship Council. Tassal was awarded Coles Sustainable Seafood Leadership Award in 2012, a stepping stone to Coles commitment to supplying only sustainable seafood by 2015 (I sincerely hope this is not a commitment with lots of asterisks and footnotes, like Coles commitment to Freerange pork which exempts overseas suppliers from the same standards!). Tassal shares their progress by publishing their sustainability report on their website.
One of the biggest criticism of aquaculture worldwide is overstocking of fish – the more fish in a small area, the more waste (fish faeces!). This often goes hand-in-hand with high use of antibiotics pumped into the water. Both of these factors don’t really matchup to the clean image I have in mind for how my food should be treated, but more importantly they also have a large impact on the ecosystem of surrounding waterways and local wildlife (plants, other fish and animals etc). Overfeeding of fish also add lots of extra nitrogens into the water so that algae thrive, often a little too well so as to upset the surrounding ecosystems – too much algal growth across the top of the water stops oxygen and light getting below the surface, starving out other plants and water-dwelling creatures.
Petuna which has one of the lowest rates of fish stocking of any aquaculture in the world, which minimises a number of environmental issues associated with overstocking. The unique area which is home to their fish farms in Macquarie Harbour on Tasmania’s West Coast has a high flow rate which minimises waste stagnation and disease harbouring. Thanks to the range of environmental measures Petuna does not require use of any antibiotics.
Many farms use chemicals to get rid of algal growth on the nets (cages) however Petuna pulls the nets out of the water to let the sun & wind kill the algae (I love such a simple solution!). Tassal are working to reduce the amount of antibiotics they use (currently down to 2% of previous use!) and plan to eliminate their use of treated nets by the end of the year. Tasmania is not home to particular parasites and lice that plague aquaculture elsewhere, so chemicals to treat these are not required.
Both fisheries also have a number of steps in place to avoid overfeeding and other factors which can alter the local ecosystem and they continually monitor water quality and take samples from the ‘floor’ of the waterway to monitor this.
Fish meal = Fishes meal?
Probably one of the most controversial issues with aquaculture of carnivorous fish such as salmon and trout is that their fish food (pellets) includes fish meal – which begs the question of how sustainable is this? In some systems, more fish is used in fish meal than the final amount of fish produced!
I have learnt quite a lot about sustainable fisheries recently and I’m pleased to say the story is not as bad as I expected (although I still have plenty more to learn on the subject!). The interesting thing is that fish consumption has increased (more than doubled) in a short space of time since 1970s, and most of this increase has been in aquaculture (wild fishing has reached its limits), and yet the use of fish meal has remained stable over this time (pretty impressive in a time when consumption of EVERYTHING from food to energy has increased many times over!!). This is because the use of fish as a food stock is now being used more efficiently – whereas once it was used predominantly as pig food now most of it goes to aquaculture. The companies producing fish pellets have also reduced the amount of fish that goes into the pellets, using other meal and vegetable products to make up the difference. This has the added benefit of reducing the nitrogenous waste into the water. And of course, not overfeeding reduces food waste too.
But still, that fish meal has got to come from somewhere. A reasonable amount of it seems to be bycatch from catching other fish – now in a perfect world there would be no bycatch in the first place, but while it exists if it wasn’t used as fish meal it would be tossed out as waste! Some of it is byproducts of fish industry eg fish heads & tails, which likewise would be otherwise waste. The company which provides the fish pellets to Petuna & Tassal make an effort to source fish meal from more sustainable sources, such as fast growing, smaller species of fish.
What makes salmon pink?
And finally some salmon mythbusting: do they add food colouring to salmon to make them pink? Well, yes but not the chemical artificial colours add to your red lollies or cordial. Wild fish are naturally pink due to carotenoids in their local diet. Carotenoids are the orange, red and pink colours that make our fruit & vegetables colourful. They are also powerful antioxidants supporting fish health. Aquaculture fish have carotenoids added to their feed to provide the colour we expect as well as nourishment for the fish. Different types or amount of carotenoids may alter the colour of the fish on your plate, but at no health risk to you.
It’s not quite the ideal of sitting by the side of a lazy stream with a single rod in hand, taking in the gorgeous tranquil Canadian vista ahead whilst you wait for the bite of a peaceful wild salmon, but lets face it that is a reality that most of us are never likely to achieve (and if we tried to it would no longer be a scene of tranquillity or plentiful in wild fish!). In the meantime it is great to know that some of our local salmon supplies are dedicated to improving their product as well as reducing their impact on the environment.
The taste test
So does farmed salmon taste any good? Top chefs seem to think so – Petuna salmon is favoured by well known restaurants such as Tetsuya’s and Flying Fish. But you can also enjoy it yourself at home. Locally Petunas, smoked salmon & trout are available at the fish markets and Tassal is available from most supermarkets in fresh, frozen, canned or smoked.
· Don’t believe everything you read on the internet: Australia’s aquaculture is experience is not necessarily plagued with the same issues as the Northern Hemisphere
· Some aquaculture companies are becoming more conscious of their health and environmental impact, and want to share their progress with consumers (us!)
· Now you know some key areas that are an issue in aquaculture you can ask the same questions of other companies
· Make an informed choice, and enjoy local Tasmanian Salmon that is healthy for you and healthy for the environment!