Alternative supplies of fish meal and oil
There is an urgent need to find ways of relieving the growing pressure on industrial feed fisheries as the predominant sources of fish meal and oil.
Globally, research is underway to seek alternatives.
The drive behind this quest is threefold.
- There are concerns about the sustainability of these fisheries.
- The populations of many small feed fish species are highly influenced by environmental conditions. El Niño events correspond with a dramatic reduction in the Peruvian anchovy fishery, for example. Climate change may have a longer-term impact on feed fish stocks. It is thought that sea temperature rise may be fundamentally changing the North Sea ecosystem. Recent research indicates that rising temperatures in the southern North Sea are adversely affecting sandeel recruitment.
- It is predicted that within a decade demand will exceed the capacity of feed fisheries to supply the aquaculture industry, particularly with fish oil.
A number of alternatives to fish meal and oil from industrial fisheries do exist, such as plant proteins, small marine crustaceans and biotechnology products.
However, their cost, nutritional value and waste production considerations continue to restrain their commercial adoption. While adequate, favourably priced fish meal and oil products exist, the uptake of alternatives will continue to be slow over the medium term.
Environmental safeguards will also need to be applied to ensure the production and use of substitutes have minimal environmental impacts.
Substitution by plant material
Plant-based alternatives (eg soya based) to animal feed produced from fish meal and fish oils have been developed but their use is limited and their success has been mixed.
Substitution of fish meal with other protein sources is difficult as fishmeal provides an excellent balance of amino acids, but the major factor is the cost of the replacement meal ingredients.
Higher plant protein diets may also increase organic wastes from fish farms. Substitution with plant oils can lead to problems of reduced disease resistance.
Consequently, other sources of fish protein/oil are being investigated.
Use of fisheries by-catch and discards
The use of discards (or 'trash' fish) to produce fish meal and oils is a common practice in many fish meal producing nations in South America and the USA.
It has been estimated that between 17.9 and 39.5 million tonnes of fish are discarded globally each year by the commercial fisheries.
The use of discards and by-catch from commercial fisheries may provide more raw materials for the fish meal and fish oil industry. This should not be a reason not to introduce management measures to reduce by-catch and discarding however.
Instead, given that there will never be zero discards, this could be a beneficial use for material which is currently wasted.
Use of trimmings and processing wastes
It is better to recover waste in preference to exploiting another resource.
Further use of fish trimmings and offal could be used to increase the supply of raw material to fish meal and fish oil industries, especially if wastes currently disposed of at sea were returned to land for disposal.
Use of marine crustaceans
Small marine crustaceans, eg krill and copepods, may be a possible source.
However, there are concerns about the ecosystem effects of harvesting organisms such as krill that are even lower down the marine food chain than feed fish – environmental assessment must precede any such exploitation.
Biotechnology (bio-fermentation products using bacteria and algae to grow the relevant fatty acids)
Further research and development is needed before such products become a viable large-scale alternative to fish meal and oil from feed fisheries.