Interview to Australian Fish Industry: Sustainable alternatives for farmed fish nutrition

ANNE KRUGER, PRESENTER: Aquaculture might seem like a simple solution to the global decline in wild fish stocks. But the problem is the most popular farmed fish species need to eat fish or at least fish oil to get the healthy ingredients which make them such an important part of the human diet.

Right now there's a global search for new sustainable alternatives and some of the most promising research is being done right here in Australia.

SEAN MURPHY, REPORTER: It's harvest time at the Taylor Made Fish Farm near Nelson Bay on the NSW mid north coast. Each week about 1,200 kilograms of live Barramundi is transferred by road to restaurants in Sydney. And this year the company will expand into the retail market.

NICK ARENA, TAYLOR MADE FISH FARM: There's going to need to be a lot more land-based farming done. In general, I think we're moving towards a more value-added processed fish so that people are wanting more fillets rather than the whole fish.

SEAN MURPHY: At fish markets across Australia there's been a surge in demand for and supply of farmed fish.

WAYNE HULME, CHRISTIE'S SEAFOOD: There's been a definite increase in the amount of farmed fish available and in many cases it's become some of our most popular species. If you look at our sashimi bar we now stock New Zealand king salmon, which has no antibiotics, no growth hormone, it's a fantastic fish, very high oil content.

We stock the Tasmanian farmed salmon, the Hiramasa king fish, all of these products are in our sushi bar because the cold chain has been managed so well. You know when the fish were taken from the water, when they were processed. when they get to me - I can serve that to someone and say "you can eat that raw without any problems."

So that's an area where it's so well handled now you've got that confidence in it. Fresh water fish, you've got Rainbow Trouts, you've got your Silver Perches, you've got all of these fish.

SEAN MURPHY: Aquaculture is feeding a booming worldwide market.

BRETT GLENCROSS, CSIRO: Aquaculture's been the fastest growing primary industry or meat production sector in the world for clearly over the last 10 to 20 years. In Australia it's an industry worth close to a billion dollars a year and we're very small by world standards.

On the world scale now one in every two fish in the world eaten now is actually farmed and that's grown from a base of 10, 20 years ago where it was probably only 10 per cent.

GEOFF ALLAN, NSW DEPT. INDUSTRY AND INVESTMENT: That demand is increasing so rapidly and if we look at projected global population expected to reach about nine billion into not too far into the future and our increasing per capital consumption - we're going to need another 70 million tonnes above existing production just to meet our projected consumer demand.

SEAN MURPHY: With wild caught fisheries collapsing or endangered across the planet, aquaculture is seen as the key to a sustainable supply of fish into the future. But the problem with farming popular carnivorous species, such as salmon or Barramundi, is that they too rely on a limited supply of fish.

DOUG TOCHER, UNI OF STIRLING, SCOTLAND: Their traditional diets have been made using fish meal and fish oil and that's been a very sensible approach because that's what the fish are eating in nature and the public have accepted that. Unfortunately, the paradox with fish farming is that the very same reasons that we have to farm the fish in the first place are the same reasons that we can no longer use fish meal and fish oil because they also, of course, come from the marine environment and it's not sustainable.

Now I'm going to be talking about the developments on oil usage within aquaculture in Europe.

SEAN MURPHY: Professor Doug Tocker is one of Europe's top scientists on fish nutrition. At a world oils conference in Sydney late last year he told an international audience that the European Union was investing about $100 million in the search for alternatives to fish oil.

Australian researchers are also at the cutting edge of research into fish nutrition.

BRETT GLENCROSS: Fish have generally evolved without the mechanism to get significant energy from carbohydrate sources like starch, like we do. If I put wheat in a fish diet it really doesn't add much energy value.

Fat, on the other hand, is a really energy dense nutrient. It actually has about twice the energy of the next most energy dense nutrient, which is protein. Therefore the amount of energy I can get into a fish diet if I add a lot of oil to it, goes up significantly. And it's the amount of energy in a diet which actually affects the efficiency of the production process.

SEAN MURPHY: Brett Glencross is the CSIRO's principal research scientist for aquaculture. As part of the organisation's Food Futures Flagship, he's been investigating a range of alternative oils, which can still provide enough nutrition for fish to grow in a commercially viable way.

BRETT GLENCROSS: There's a range of alternatives you can use. We've done work already looking at alternatives like poultry oil, soy bean oil, canola oils and these all offer a really good nutrient source in terms of giving that energy. However, unlike fish oils, none of these oils have the long chain omega 3, which is so important for our own human health.

But what we've learnt to do is be able to blend some of these oils, like poultry oil or canola oil with fish oil to make sure we can still guarantee that there is a critical level of long chain omega 3 in the fish, so the fish that you go to buy that's farmed still is always going to give you that omega-3.

SEAN MURPHY: At the NSW Department of Industry and Investments Fisheries Centre at Port Stephens on the mid north coast, researchers are also part of the global search for alternatives.

GEOFF ALAN: We've concentrated on Australian agricultural ingredients an they include some of the terrestrial animal meals - poultry meals, meat meals and also the vegetable proteins, grains, wheats, cereals and we've looked at how we can maximise the use of those for our diets and we've been very successful.

Diets for silver perch, for example, we can produce diets that perform just as well as fish meal based diets with zero fish meal in them. And diets for carnivorous species, like snapper for example, and some of the other marine carnivores, we can reduce fish meal levels own to 15, 20 per cent of the diet. So, substitution is certainly possible.

SEAN MURPHY: Research leader, Jeff Alan, says fish show no ill effects from eating these animal products, which are not part of their natural diet. And there's no risk to human health, such as mad cow disease, which he says was caused by feeding sheep protein to cattle.

GEOFF ALAN: There's absolutely no evidence anywhere that fish are vulnerable to any of those proteins, or prions, which were thought to be responsible for mad cow disease. No chance that they can cross species barriers, like fish, and infect people. So I think we're completely safe with feeding any of our animal meals to fish or any of our other grains.

SEAN MURPHY: It's not just fish that contain long chain fatty acids but also marine algae. Harvesting that on the sort of scale needed for a global industry is problematic, but Australian researchers believe they have a simple solution.

These canola plants have been genetically modified to contain the sort of long chain fatty acids that make fish part of a healthy human diet. They've been bred at the CSIRO's plant sciences laboratory in Canberra as part of the Food Futures program.

JAMES PETRIE, CSIRO: We've got proof of concept - so what that means is that we've proven that a canola plant or flax plant or an oil seed plant is actually capable of making these long chain omega-3 oils in the seed and building them up to relatively good levels. What we've got to do now is take it out of the lab and get it on to the farm.

SEAN MURPHY: So how far away are you from it becoming a commercial reality?

JAMES PETRIE: Well, because Australia has a very strong regulatory component to this sort of research, we estimate it will take around five to seven years, somewhere between 2015, 2020 - around about there and the reason is that we've still got a little bit of research to finish off, but most of that sort of time scale is actually taken up by deregulation or making sure that the plan and the product is safe for human consumption.

SEAN MURPHY: James Petrie says consumers have nothing to fear from the process.

JAMES PETRIE: The algae and the canola are very, very similar. What we find is that the plant is able to make use of those genes without any difficulty at all. It's just a fairly natural extension of what the plant already does, just taking it a few further steps. What we focus on with a project like this is looking at the product that we're going to produce.

Now something like a canola oil which has got a lot of DHA in it is just going to be fantastic not only for the industry and the farmer but it's going to be really good for the people who are actually eating it in the long run because the more DHA and EPA we can get into people the lower the heart complications get and the better it is for people's neural networks.

SEAN MURPHY: The omega-3 project has huge potential for the food processing sector, where the health giving benefits of fish oil could be added to products such as bread and milk. But its impact on aqua culture is likely to be even greater.

RICHARD SMULLEN, RIDLEYS AQUAFEEDS: For us it's really exciting because, you know, the thing with fish oil and fish meal it is a finite resource, it's very heavily managed stocks and so there's a finite resource and so the cost of those raw materials is only going to go up and up.

And since the onset of the health benefits - when people realised the health benefit of fish oil - the price has been pushed up further by the human food market as well. So the work that CSIRO are doing and other groups on getting those fatty acids to be derived from canola oil is fantastic.

SEAN MURPHY: Ridley's is one of two aquaculture feed manufacturers in Australia. It produces about 40,000 tonnes of feed a year, specifically tailored to different fish species.

RICHARD SMULLEN: Basically the fish - the diets are specific to the species of fish so we'll make a Barramundi feed for Barramundi and we'll make a king fish feed for king fish, salmon food for salmon. Within that it's baby fish - as with baby humans - require something completely different to an adult fish. So the diets are developed for each stage of the life cycle. So not just in the size.

Obviously, we have very small pellets going up to large pellets for bigger fish but also with raw materials that are actually included and how much protein and fat are in those diets.

SEAN MURPHY: Ridley's has its own research department and it's investigated how best to use the limited stocks of fish meal and fish oil, blending higher concentrations at important times in the life cycle of different fish species and depending on seasonal conditions.

RICHARD SMULLEN: It gets too cold and they don't grow so we've developed seasonal diets.

So what we're able to do is change the diet so that although they're not eating very much of the feed it's actually making a significant improvement in the growth rate and we've seen growth rates, for example in King Fish and Salmon of 30 per cent over that period where they used to grow maybe one per cent or two per cent and, in fact in the winter period sometimes they would go backwards, get sick and have to be treated by a vet. So when you get the nutrition right you're not only improving the growth but we're also improving the welfare of the animal and we're seeing that now in all species. We're seeing it in prawns and salmon and king fish and it's really making huge steps to the Australian industry.

SEAN MURPHY: The benefits of that research can be seen at operations, such as the Gold Coast Aquaculture Farm on the banks of the Logan River in Queensland. It's 50 hectares of ponds produce more than 500 tonnes of prawns each season, more than double the Queensland average.

And manager, Nick Moore, believes improved nutrition can bring even greater benefits.

NICK MOORE, GOLD COAST AQUACULTURE FARM: I'd like to do it by 10 per cent. I mean it's growing your prawns quicker, getting to market size faster, having a more effective and efficient feed, that's the Holy Grail of all prawn farm and aquaculture farmers in general, because feed is so much of a high percentage of your cost and as long as your prawn or fish or whatever else is in the water they're exposed to - you want to get them to market. You want to get them out and to market as fast as you can generally.