“In 2006, fish meal prices reached levels that were previously unimaginable and nearly double the high end of the normal range over the past several decades” – the opening statement by Prof. R. W. Hardy, Director Aquaculture Research Institute, of the University of Idaho makes frightening reading for koi keepers.

Fish meal has been found to have the closest amino acid profile as required by koi of any of the protein sources. Not only is the amino acid profile excellent but fish meals are rich in vitamins and minerals. Some researchers have stated that fish meal appears to have an ingredient – unidentified at this stage – the other protein sources do not have that produces better growth.

The price of fish meal has gone through the roof because of two reasons - the demand has increased and fish meal production is lower than the 15 year average.

7.05 million metric tons of fish meal are produced throughout the world every year. El Nino years negatively affect fish meal production and during these years production falls to about 5 million metric tons. Peruvian anchovies account for about 25% of the global fish meal production. This area is greatly affected by El Nino and as the ocean water warms up the Peruvian anchovies move to cooler water affecting the harvest.

Other countries have also experienced decreased fish meal production. EU production is down; sardine catches from Japan has not recovered since their collapse in 1998. Even recent events such as Hurricane Katrina has negatively affected the menhaden industry in the USA.

The demand for fish meal in China has had a dramatic effect on the price as their needs have increased to over 1 million metric tons per annum. Most of this is used to manufacture fish feeds.

In 2003 worldwide aqua feed production for all species of fish was around 19,500,000 metric tons per annum. Scientists calculate that before the end of the decade this will increase to 37,000,000 metric tons (Barlow, 2000). Interestingly much of this increase is expected to be utilised for pond fish. Pond fish are defined as fish grown in mud type ponds whereas fish grown in concrete ponds such as trout and salmon have water flowing through their systems. “Pond fish” have traditionally been fed feeds that are not nutritionally complete because they can access nutrients from natural sources in ponds. As production of fish such as carp switch more and more to concrete or formal type of ponds with fresh water flowing through them, a complete, balanced nutritional diet requirement becomes more important. The production of carp feeds is by far the highest of the different fish species.

In order to compensate for the ever increasing world fish meal price scientists have attempted to find alternative protein sources for the manufacture of fish feeds. If the alternative protein sources were equal to or superior in nutritional and economic value to fish meal they would be widely used in fish feed production.

As an amino acid source for koi / carp all easily accessible alternative protein sources are inferior to fish meal – this is a fact. Many protein sources have inferior amino acid profiles needed by fish for growth and health. Plant proteins have missing amino acids and after identification supplementary amino acids must (or should) be added. This adds to the cost of the end product.

It is a fact that many koi foods use alternative protein sources to fish meal. This is to reduce manufacturing costs. The alternative protein sources fall into three categories – animal protein (poultry by-product meal, meat and bone meal and feather meal) which have lower protein digestabities and higher ash levels – plant protein such as soya meal and “novel” proteins (single cell proteins, insect meals, seafood processing waste and products derived from ethanol production). These have been considered too expensive for inclusion. The animal protein sources have been used for many years in fish feeds but their quality can and does vary considerably. Limiting amino acids in plant proteins are methionine and lysine.

There is even protein produced from bacteria grown on methane that seems to be a good fish meal replacement. Despite the negatives associated with alternative protein sources these ingredients have been used in aquafeeds to reduce the amount of fish meal and therefore the higher cost.

Over the last decade about 30 - 32% or about 2.2 million metre tons of world fish meal production has been utilised in the manufacture of fish foods. This is predicted to increase dramatically over the next decade.

There is much effort being directed at finding successful alternatives to fish meal as the prime source of protein in aqua feeds. Soybean meal seems to be emerging as a very good substitution for part of the fish meal in aqua feeds. Interestingly it is the increase in available energy through the carbohydrate part of the diet as well as the inclusion of lipids that has resulted in dramatic increases in the efficiency of protein digestion and utilisation. This has resulted in the lowering of protein inclusion rates. It must be noted that there is a vast difference between koi and farmed carp. Koi keepers would do well to feed their collections on a high protein diet – above 35% protein (but not higher than about 42% protein). Lower protein levels mean an increase in carbohydrate being fed to the fish.

Carp farming is moving towards high-input systems. Therefore their diet will have to be balanced and accurately made. Carp feed production is expected to increase from about 7,000,000 metric tons to about 27,000,000 million tons by 2010. (just sitting here with a smile on my face trying to work out how many 2kg bags of Shogun Koi Nutrition 27,000,000 tons of carp food production would be? – I can just see the guys at the factory .... good morning I would like to place an order for 27,000,000 tons of aqua food please! ...... no problem sir, is delivery next week Friday Ok with you!!)

Soybean meal is likely to make up the bulk of the protein for the adult feed but the fry and fingerlings will continue to use fish meal.

Adding small amounts of fish meal to plant based protein sources in aqua feeds seems to restore some adequate levels and balance to the formulation. It also adds the palatability that is needed to encourage the fish to eat the food.

As the demand for fish meal increases the cost of quality fish meal – i.e. high-protein, low ash meal will increase. Synthetic amino acids are very expensive and not always a viable option. Proteins sources from grains such as wheat, corn (mealies) are deficient in several amino acids and must be blended in with other proteins. I do believe that not all koi foods which use concentrated protein from these sources are blended in with other proteins. The reading from the lab may show a good protein level but there may be an imbalance and deficiency in some amino acids.


Facts in this article have been reproduce with the kind permission of Prof W. Hardy, Director Aquaculture Research Institute, University of Idaho

References: Worldwide Fish Meal Production Outlook and the Use of Alternative Protein Meals for Aquaculture – R.W. Hardy



Chris Neaves