Novel ingredients need to be used effectively alongside fishmeal and fish oil
FISHMEAL and fish oil have been the major constituents of feeds for modern aquaculture since its inception several decades ago. It is fair to say that the pace of modern aquaculture development would have been far slower if it hadn’t been for the fact that feeds based on these ingredients are a straightforward means of providing the required nutrition for farmed fish.
In the early days of aquaculture, feed formulations based predominantly on fishmeal and fish oil were comparatively uncomplicated; this freed up technological effort to concentrate on other important areas of aquaculture, such as systems technology, fish health and selective breeding, in order to create the viable industry that we have today.
A means of supplying nutrition to growing fish in a practical manner negated any requirement for early research effort on fish nutrition that could have delayed industry development. Fishmeal and fish oil are the foundation of modern fed aquaculture.
The reason why these earlier feeds were so successful in achieving the nutritional needs of farmed fish is self-evident: fishmeal and fish oil are the constituent parts of the prey items that farmed fish species such as Atlantic salmon would consume in their wild state.
For example, wild Atlantic salmon are documented as preying on blue whiting, sandeel and herring in the North east Atlantic (Haugland et al., 2006), and this is what the wild fish choose to eat from all the fish (and invertebrate) species available in the marine environment.
Blue whiting, sandeel and herring are all instantly recognisable raw material sources for fishmeal and fish oil.
The fish species that are chosen to be farmed generally are high value, because the economic model for production is optimised for fish holding superior market prices, and those higher market prices then increase the likelihood of aquaculture businesses being successful.
Those fish species in the sector of the aquaculture industry that has driven innovation have tended to be the higher trophic level, and therefore carnivorous fish species. They are obligate piscivores, and evolved to utilise dietary proteins and fats that are found in lower trophic level fish species.
Whether the raw material is whole fish, or by-product, all the manufacture of fishmeal and fish oil does is remove water following a cooking process, thereby providing more nutritionally concentrated materials that are first class ingredients for aquafeeds.
After several millennia of evolution, it should come as no surprise that the optimum nutrition available from whole fish and by-products via fishmeal and fish oil to farmed fish is exactly what they need, physiologically speaking.
With comparatively high protein levels (usually 68-72 per cent), high digestibility (often 90 per cent or more), perfectly profiled amino acid and fatty acid balances, and a range of micronutrients including vitamins and minerals that are essential for heath and growth, fishmeal and fish oil are benchmark aquafeed ingredients against which the performance of other ingredients are measured.
The real issue with fishmeal and fish oil is availability of supply. For the last 25 years or so, the production of these materials has been relatively stable, at approximately five million tonnes of fishmeal, and just under one million tonnes of fish oil.
A key point here is that supply has not increased alongside the increased need for aquafeed volume. There just isn’t enough of these materials to satisfy the demands of a continually growing aquaculture, hence aquafeed, sector as the materials are dependent on managed natural resources, that is, marine fisheries.
Disappointingly, the myth that a growing aquaculture sector puts additional pressure on capture fisheries for more fishmeal and fish oil continues to be perpetrated despite the data showing clearly that there is no additional supply of marine ingredients despite a rapidly growing aquaculture industry.
This is because, for the most part, these fisheries of small pelagic fish species are regulated, managed and comparatively productive, in contrast to some of the other food fish species fisheries.
Not all the annual supply of fishmeal and fish oil goes to aquaculture, of course (IFFO’s 2018 estimates indicate 74.6 per cent and 72.7 per cent respectively), and the market ultimately decides the destination of these high value ingredients.
Fishmeal and fish oil carry with them several decades of data and information about raw material supply, production, nutrient profile and other details. They are a known factor in the feed industry, and as such remain the most important contributor to nutritionally complete feeds, even if they no longer occupy the majority volume in the formulations.
Their performance is known and quantified to the degree that they form important ingredients for aquafeeds.
Interestingly, though, there are still discoveries
or new revelations of the importance of some compounds in both materials that may have further beneficial growth or health effects for fish stock in aquaculture production systems- for example, taurine in fishmeal and cetoleic acid in fish oil.
The materials’ full nutritional value remains to be discovered, which is a statement of truth that does not rest well alongside the numerous claims, appearing with increasing frequency in the media, for fishmeal and fish oil replacements.
How can true replacement be vaunted when we don’t yet know exactly how important fishmeal and fish oil are to fish growth and health?
A key facet of fishmeal and fish oil production that is well known to those in the industry is the success story that is the development of a recognisable certification standard, and the outstanding level of uptake that has been observed across the sector.
Regrettably, the importance of this work is not quite as familiar to those outside the sector, and especially to those who seek to criticise the use of fishmeal and fish oil in aquaculture, or even aquaculture itself.
It is, however, undeniable that the development of the IFFO Responsible Supply standard, and its implementation since 2009, has done a very great deal to improve product traceability, integrity and responsible sourcing in the supply chain.
With an uptake that represents in excess of 50 per cent of annually produced fishmeal and fish oil, the level of certification goes far beyond that of other feed ingredients.
The IFFO RS Standard has two parts: an assessment of the fishery from where the fishmeal plant sources its raw material. (This assessment consists of an independent desktop based review of fisheries management that follows the UN Fisheries and Agricultural Organisation’s (FAO) Code of Conduct for Responsible Fisheries.); and an independent audit of the fishmeal and fish oil producing plant where robust sourcing, traceability and manufacturing systems must be in place.
The IFFO RS standard has existed for more than a decade and although initially developed by IFFO, is a separate entity in its own right in order to ensure full separation of the certification standard from the trade association work.
The IFFO RS standard will grow further, both from full certification and also within the Improver Programme (IP). The IP is based on the concept of Fishery Improvement Projects (FIPs).
FIPs themselves are a way of initiating positive change in locations where regulation may not be entirely effective for a number of different reasons. On top of the target fishery, FIPs will also tend to have benefits for the broader marine environment as they are often organised on ecosystem based fishery management principles, as well as the long term sustainability of the fishing communities that provide the raw material.
In summary, fishmeal and fish oil continue to have a bright future in the aquafeed industry by virtue of their unique nutritional contributions, level of certification and environmental performance.
Although the need for more feed volume is clear with a continued growth of aquaculture, the novel ingredients that are being developed need to be used effectively alongside fishmeal and fish oil to provide optimal fish nutrition for many years to come.
It is important that the fundamental importance of fishmeal and fish oil is recognised in aquafeeds, and the feed producers themselves should not be shy about mentioning that they use responsibly sourced fishmeal in their product. It may yet in time be regarded as what it is – the natural diet of the farmed fish species.
“Fshmeal and fish oil are benchmark aquafeed ingredients against which the performance of other ingredients are measured”
From top: Blue whiting, sandeel, herring