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What is a reduction fishery?

A reduction fishery is one that uses, or ‘reduces’, its catch to produce fishmeal or fish oil rather than for direct human consumption. The reduction process occurs through cycling of cooking, pressing, extraction and drying to separate out the fishmeal and oil, leaving steam as a byproduct (IFFO). These fisheries typically target small pelagic (midwater) species like anchovies, herring and menhaden as they are rich in essential and fatty acids, amino acids, vitamins and minerals. Other species lower in the food chain, like krill are also caught for reduction purposes. Produced fish meal is often used as feed for livestock and fin fish in aquaculture as well as in pet food. Whereas, fish oils are often for human consumption, usually in the form of supplements.

It’s worth noting that trimmings of species caught for food, such as haddock, pollock, herring and mackerel, are also used to produce fishmeal and fish oil. These products, therefore, ensure effective use of a by-product that would otherwise be thrown away. However, these fisheries are not referred to as ‘reduction fisheries’.

Do reduction fisheries impact ecosystems?

Reduction fisheries often target species lower in the marine food chain, earning them the moniker ‘low trophic level species.’ These species can play an important role in sustaining marine ecosystems as many predatory fish, seabirds and marine mammals rely on them as their main food source. Therefore, overfishing low trophic level species can have significant impacts higher up the food chain. As such, the MSC Fisheries Standard has specific requirements that must be met for certification of fisheries targeting low trophic level stocks that play a ‘key’ role in the ecosystem.

MSC certified fisheries take an extremely cautious approach in setting catches for these key low trophic species, fishing at a much lower rate than is sustainable for other species. This ensures stocks remain abundant and can sustain healthy predator populations. These fisheries must provide evidence that their catches are not having detrimental impacts further up the food chain.

Should fish be prioritized for human consumption?

Seafood is an essential source of protein for millions of people. Concerns have been raised about the use of fish in animal and fish feed instead of for human consumption. However, it is important to remember that there are fisheries targeting small pelagic species such as mackerel, herring, sardines and anchovies which result in end products for human consumption. Additionally, the production of supplements from reduction fisheries is intended for human consumption. What also needs to be considered is that due to market demand and consumer preferences, many of these small pelagic species are viewed as less appetizing and in turn do not end up being consumed anyways.  The MSC doesn’t seek to influence demand or consumption of any particular species of fish. We want all fishing activity, whatever its context, to be sustainable.

Are there certified reduction fisheries?

In 2017, it was determined that one-sixth of the landings from marine capture fisheries were for reduction purposes (Cashion et al., 2017). A small proportion of the global raw materials used in fishmeal and fish oil is certified to the MSC Fisheries Standard. Within the MSC program, there are certified reduction fisheries targeting species such as krill, herring, sardine and menhaden. In addition, most MSC certified fishmeal and fish oil is made from the trimmings and by-products of species caught for human consumption. All these fisheries have undergone rigorous, independent assessment.

Within the United States in particular, menhaden caught on the East coast and in the Gulf of Mexico and trimmings from the processing of Alaskan seafood are the first and second largest production sources of fish meal and oil respectively (NOAA). Both Atlantic and Gulf menhaden are currently being assessed for MSC certification and several Alaskan fisheries are currently certified. Further information on fisheries in the MSC program can be found on our Track a Fishery website.

Final thoughts…

While there are certainly legitimate concerns about the practices of some reduction fisheries, it’s important to recognize there is a market for fishmeal and oils. We should also remember that some fish species will never be sold for human consumption. To maintain healthy oceans and abundant fish stocks, we believe sustainable fisheries should be recognized for their efforts as this encourages more responsible fishing practices worldwide.


Written and submitted by Emily McGregor and Philippa Kohn


Cashion, T., Tyedmers, P., and Parker, RWR. 2017. Global reduction fisheries and their products in the context of sustainable limits. Fish and Fisheries 18(6):1026-1037.