Can reduction fisheries be sustainable?

What is a reduction fishery?

A reduction fishery is one that uses its catch to provide bait for other fisheries, or to produce fishmeal or fish oil. Fishmeal produced is used to supplement feed for agricultural livestock and farmed fish. Fish oil is used in human nutritional supplements as it is rich in omega-3 fatty acids and the antioxidant astaxanthin. 

Reduction fisheries typically target small pelagic (midwater) species, also known as 'forage fish', like menhaden, anchoveta, herrings, blue whiting and capelin. Other species lower down the food chain, like Antarctic krill are also caught by reduction fisheries.

Do reduction fisheries impact ecosystems?

Reduction fisheries, like any other fishery, can impact the ecosystem and therefore must be managed sustainably.

The small pelagic fish targeted by reduction fisheries are mainly 'low trophic level' species. A trophic level describes an organism's position in the food chain, indicating what it eats and what eats it.

Species at lower trophic levels are usually herbivores that eat plankton, algae and seaweeds. In turn these low trophic level species are the food of everything above them in the food chain. As the main food of larger predatory fish, seabirds and marine mammals, the ecosystem is dependent on low trophic level species.

Because of this dependency, some low trophic level fish are also designated as 'keystone' species. This means they hold the ecosystem together through the role they play – like a keystone in an arch. And if, like a keystone, an unsustainable amount of the species is removed, it can lead to dramatic changes or even the collapse of the ecosystem.

Consequently, the MSC takes the sustainable management of reduction fisheries and those targeting low trophic level and keystone species very seriously.

Does the MSC promote reduction fishing?

The MSC's mission is to end overfishing, and our vision is one of oceans teeming with life. We do not make broad generalisations regarding the sustainability of one type of fishing over another but want all fishing activity, whatever its context, to be sustainable.

To maintain healthy oceans and abundant fish stocks, we believe sustainable fisheries should be recognised for their efforts as this encourages more responsible fishing practices worldwide.

To ensure this, fisheries aiming to become certified as sustainable to the MSC Fisheries Standard must demonstrate through an  independent and scientifically-led process that they are targeting fish stocks in a way that does not cause long-term harm to the environment.

What is the MSC doing to ensure reduction fisheries are sustainable?

The MSC Fisheries Standard is widely regarded as the gold-standard for marine environmental sustainability. It takes an extremely cautious approach to the management of fisheries that target low trophic level and keystone species.

A fishery cannot be certified to the MSC's standard unless it can show, with independently verified evidence, that it

• only targets abundant stocks
• is minimising its impacts on the ecosystem, habitats and dependent species
• is under effective management and observant of all laws pertaining to fishing practices

Due to the importance of low trophic level and keystone species to the ecosystem, the MSC has extra requirements for reduction fisheries.

Catch limits for reduction fisheries are set at a much lower level than is considered sustainable for other species. This ensures fish populations remain abundant and can continue to sustain predator populations and the wider ecosystem.

Certified fisheries must also demonstrate that their catch is used as fully as possible, minimising waste and deriving economic, nutritional and practical value from a catch.

For example, trimmings of species caught for food, such as haddock, pollock, herring and mackerel, are also used to produce fishmeal and fish oil. These products do not come from reduction fisheries but do ensure effective use of a byproduct that would otherwise be thrown away.

Can sustainable reduction fisheries support aquaculture?

Since the publication of the Blue Food Assessment (BFA) in 2021 followed by the United Nations Food and Agriculture Organization’s (UN FAO) Blue Transformation Strategy in 2022, there has been increasing awareness of the importance of 'blue foods' - seafood and seaweed sourced from oceans, rivers and lakes - in delivering global food security.

Much of future blue food production will come from aquaculture, yet farmed fish are often fed fishmeal and fish oil from reduction fisheries catching wild fish. The MSC believes these farms should use only sustainable feed, including fishmeal from certified reduction fisheries or from seafood byproducts.

Since 2012, the Aquaculture Stewardship Council (ASC) Standards has recognised MSC certification as the gold standard for sustainable wild seafood. The ASC Feed Standard 2023 requires most marine raw materials, used in all ASC compliant feeds, to come from reduction fisheries that are certified to the MSC Fisheries Standard.

In October 2024, the MSC and MarinTrust, a program for responsible marine ingredient sourcing, signed an MoU to improve understanding of their programs, reduce duplication, and create efficiencies for marine-ingredient producers.

Reduction fisheries and human consumption

Given the challenges around food security and the fact that seafood is an essential source of protein for millions worldwide, there is genuine concern around the use of fish in animal feed instead of for human consumption.

However, global tastes in seafood mean that smaller, bony species that are mainly used for reduction are disliked by many people. Antarctic krill are not fit for human consumption in their unprocessed state.

According to the UN's State of the World Fisheries (SOFIA) report 2024, of the 185.4 million tonnes (live weight equivalent) of aquatic animals harvested globally in 2022, about 89% (164.6 million tonnes) was used for direct human consumption.

The remaining 11% (20.8 million tonnes) was destined for non-food purposes, of which about 83% (17 million tonnes) was reduced to fishmeal and fish oil for which there is demand, without wasting important resources.

Nevertheless, it is essential that all marine resources are sustainably harvested especially those species destined for reduction processes and that play a major role in the ecosystem. The MSC program ensures long term sustainability of fisheries irrespective of the market destination of the products they deliver.