The use of fish as feed for aquaculture is not uncontroversial. Some say that the practice should be reduced, if not stopped. They argue that the practice is not in the interest of those consumers who otherwise would have eaten the fish used. The amount of fish available is reduced as more than one kg of fish – in the form of feed – is needed to grow one kg in captivity. Also, the ever expanding demand for fish as feed is thought to endanger the long-term sustainability of targeted fish stocks.

Capture fisheries produces some 90 to 95 million tonnes of fish and other aquatic species per year. Of these somewhere between 20 and 25 million tonnes are regularly processed into fishmeal and oil. During the last two decades, a growing portion of the world’s fishmeal and oil has been bought by the fish/shrimp feed industries and converted into fish and shrimp feed. Most of the 25 to 30 million tonnes are obtained by industrial fisheries in the North Atlantic and in the Pacific Ocean off the west coast of South America.

In China, Southeast and South Asia, by-catch, particularly from trawl fisheries for shrimps, are used as fish feed. There are no precise estimates of the quantities involved, but it is believed that they may be of the order of 6 million tonnes of fish per year. Also, whole or chopped fish is used in growing quantities to feed captured juveniles of bluefin tuna.

It is an undisputable fact that modern farming of carnivorous fish and shrimp uses more fish as feed than is produced as finfish or shrimps; that is, the ratio between fish used and fish obtained is higher than one. However, if the fish used as feed is not consumed as food (for whatever reason: not appetising, too bony, too small or because it is not economically viable to preserve it for later consumption), then in the end, might not its use as feed lead to more foodfish?

The author shows that industrial fishing for forage species in the North Atlantic and in the Pacific, off the coast of South America, via manufacture of fishmeal and fish/shrimp feeds, brings about a net contribution of foodfish supplies, without causing a systematic collapse of the exploited forage species. However, the practice of using bycatch as fish/shrimp feed has apparently led to a decrease in the availability of fish as food for the very poor in some regions of South, Southeast and East Asia although this affirmation needs to be substantiated with hard data.

Also, it should be recognised that, a large part of the “forage fish” used to produce fishmeal is edible fish. If this fish could be made available as low-cost food to the poor, no doubt their food security would improve. The obstacles for such a development are economic and legal. On one hand, a global agreement under the WTO would be needed authorising the sale of “food grade” subsidised food-quality forage fish and, secondly, an internal fund would have to be created to finance (at the rate of billions of US$ per year) the production, storage and transport of cheap fish products based on “food forage fisheries” in the North Atlantic and Southeastern Pacific.

True, the practice of feeding fish to fish/shrimps leads to more foodfish being available for human consumption, but who will be able to afford the additional supplies? Most of the species that are fed with feeds that include substantial portions of fishmeal and fish oil are not low-cost items. It can be safely argued that these species will not be become a regular component in the diet of the poor, and particularly not of the poor in developing countries.

On the other hand, aquaculture today contributes about half of all the seafood eaten in the world. Doubtlessly the real price of all fish would have been substantially higher today, had not aquaculture existed. This will have benefited also the very poor. Naturally all the merit of this development does not lie with the use of fish as feed, as not all aquaculture systems use feed or fish, in one form or another, as feed.

The author ends by considering an aspect that is often neglected in the discussion of the use of fish as feed for fish: employment. Most governments see unemployment as a problem. They work to support the creation of employment. Thus, employment in feed fisheries, fishmeal/fish oil industries, fish/shrimp feed industries and aquaculture is a positive contribution.

The author identifies shrimp farming as a labour-intensive activity that provides employment to millions of unskilled workers in developing economies. In the absence of fishmeal/fish oil, most of those employment opportunities most likely would cease to exist.