We are well acquainted with the efforts of aquaculture feed companies to use less fishmeal by substituting it with soy and grain proteins and oils. This is an economic strategy that is fine while grain and soy prices are stable and low and seafood prices are high, but it is also vulnerable to sudden rises in commodity prices. Questions are also asked about whether it is right to feed soy and grain meal to fish when humans can eat it themselves.
The extreme weather over the summer, together with widespread fires in the Russian grain belt, have led the country’s authorities to place a ban on wheat exports. This has caused a sharp rise in the world price of wheat, and it is certain that this will have a knock-on effect on other commodity grains, as substitution takes place and speculators move in to make a quick buck. As reported by SeafoodSource last week, the FAO warned that it is “highly unlikely that commodity prices will fall to pre-2000 levels in the foreseeable future.”
Such events bring home the reality that a large part of aquaculture is just another branch of agriculture and relies on much the same ingredients as poultry, pork, beef and dairy production. In some ways it can be seen that fed aquaculture is even less of a farming activity than some of these land based examples. After all, when did a salmon farmer rely on natural grazing to provide part of his livestock’s diet?
All this leads to speculation about just what is true aquaculture. At one end of the scale the culture of carnivorous fish requires that all food is supplied by the farmer, while at the other end there is culture of seaweeds and filter feeding molluscs that require no inputs of any kind. In between are a range of activities such as semi-intensive shrimp farming, pond culture of carp and tilapia, and tank culture of abalone and sea urchin. In all these systems the fish or shellfish feed on naturally available food, but also rely to some extent on an artificial diet being provided for them.
This range of activities is no different from those we find in land based agriculture, with the great majority of meat coming from animals that are entirely reliant on an artificial diet. At the other end of the scale is the harvest of free range meat and organic, zero input vegetables. Everything else in between requires either an artificial diet or a high input of fertilizers and energy. Why then, do the environmental organizations reserve special criticism for those who do their farming in the sea, rivers or lakes? Why is it OK to put half a continent under the plough to produce bread, beef, beer and biofuel, yet it is somehow immoral to feed soy protein to a salmon?
The world has a growing population, and it is widely accepted that people should eat more seafood to promote good health. However, if this is to happen, then the gap between supply and demand will continue to grow and can only be filled by aquaculture, given the static or declining nature of fish stocks.
For aquaculture to meet the demand in an economically and environmentally sustainable way, it needs to free itself from reliance on land-based agriculture products. This means finding ways of producing fish and shrimp diets from within the aquaculture industry itself by massive cultivation of organisms further down the food chain such as seaweeds, bivalves and other filter feeders. Only then will aquaculture truly distinguish itself as being something separate, different and perhaps better than agriculture. It will be interesting to see how and when this happens.