The Future of Fish Food?


Its no secret that the world is eating more farmed fish than ever before. According to the World Wide Institute nearly half the seafood the world eats today is farmed.

On average, each person on the planet is eating four times as much seafood as was consumed in 1950. Experts predict that farmed seafood will grow an additional 70 percent by 2030.

According to fisheries expert Brian Hallweil the world’s greatest growth in fish farming today is occurring with large fish farms raising high-value, predatory fish such as salmon, striped bass, tuna, and shrimp.

“Raising these species is an exercise in “reducing” fish to produce table fish” he says “That is, in turning certain fish, usually smaller species such as anchovy, herring, capelin, and whiting, into feed for other, typically larger, species. “Increasingly, we are fishing down the ocean chain so we can move up the fish-farming chain.” he said.

So Globally, consumer demand for fish continues to climb, especially in affluent and developed countries. Its a big business worth over US$61 billion in 2004 and growing.

The United Nations Food and Agriculture Organization (FAO) “estimates that an additional 40 million tonnes of aquatic food will be required by 2030 — just to maintain current levels of consumption.” Some researchers at the FAO are concerned that the planet will run out of fish meal by 2030 ending the dreams of farming fish from the by-catch of gradually depleted fish reserves.

Fish Pellets

It takes 5kg of wild fish to turn into 1 kg of fish meal

So if you are into Aquaponics, what do you feed your fish when stocks of fish pellets run out or get too expensive to buy?

Its a difficult question that has stumped scientists looking for alternative ways to feed fish. Critics say it takes 5kg of wild fish to turn into 1 kg of fish meal. Figures like that don’t look great. Thats a big waste of fish and in the end not sustainable. Can we get our fish to change their diet and eat something else?

At Stanford University researchers found that fish fed on fish meal and oil grow faster and tend to have more flavor than fish fed on an alternative diet, providing a profit incentive for fish farmers to buy more wild-caught fish. It’s finding an alternative to the long chain Omega 3 oils found in depleted fish stocks that seems to be the problem. What do we substitute these fish oils with and still be able to grow out our farmed fish and keep the consumers happy?

Reducing the Fish Oil

According to a recent newspaper report in The Australian, there seems to be light at the end of the tunnel, partly, or so it seems. The report states that – Australian fish farmers are using less and less fishmeal. Why? Duncan Leadbitter is a seafood sustainability specialist and director of the consultancy firm Fish Matter. “It’s declining because we’re learning a lot more about the dietary needs of these animals. In the past we would shovel in some fish and feed them the closest to what they would eat in the wild.”

“When barramundi were first fed pellets, they used to contain 50-60 per cent fishmeal. The latest generation of feeds now get down to as low as 15 per cent without impacting on the performance or health of the fish.”

So what is the fishmeal replaced with? “Part of my role is identifying all the micro and macro nutrients in the fish and shrimp diet,” says Glencross. “We look at what they eat naturally and what they eat when they have a compounded diet [a mixture of plant and fishmeal] and then make a comparison.”

It’s common practice in Australia to blend fish oils used in the diet with poultry or canola oils. “The fish do well with that but it does tend to dilute the long-chain Omega 3 oils [the ones that are good for us],” says Glencross. “That said, of all the fish you get at the supermarket, farmed salmon is still the highest in Omega 3.”

It’s not only environmental concerns that are driving research into using more plant material. Fishmeal is expensive. Blending it with poultry, lupin and canola meals makes financial as well as environmental sense. And, according to Glencross, “we can raise them on high levels of grain and they do just as well as on high levels of fish oil”.

According to a 2010 report on aquaculture nutrition, salmon farmers in Australia use, on average, the lowest amount of fishmeal in the world. Roy Palmer, president of the Asia-Pacific chapter of the World Aquaculture Society, says our level of sustainability is ranked in the highest category. “Clearly, other countries have got to work their way up to our level,” he says.


Canola, Genetically Modified Fish Feed and Marine Algae
Australian CSIRO scientists have been looking at alternative forms to fish oil and one of the them is the oil derived from Canola.

Brett Glencross is the CSIRO’s principal research scientist for aquaculture. He says that “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 (fish) 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.”

But how good is substituting fish oils with land animal proteins?

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.

If you’re not convinced that feeding fish a land animal diet is good for them, you are not alone. Many people are concerned about disease spreading or jumping from one species to another.

“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.” said Geoff Allen, “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.”


What about Genetically modified Canola?

Scientists have discovered that they can modify the genetic instructions of a Canola plant to simulate the genetic signature of long chain Omega 3 fish oils.

James Petrie, a scientist at the CSIRO says “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.”

The research into genetically modified canola is an arduous journey taking many years of testing before it is deemed safe for human consumption.

James Petrie says consumers have nothing to fear from the process. Scientists are also studying algae as an alternative to Canola as it’s genetic signature could also be modified to make a protein suitable to feed farmed fish.

If this all sounds like Frankenstein food then consider whats alternatives there are to depleted fish stocks, over population and the possible threat of world hunger. A scary proposition whichever way you look at it.