This piece authored by Dr Brett Glencross was originally published in International Aquafeed, February 2025 edition

Last month I wrote on the limitations of metrics like the fish-in:fish-out (FIFO) ratio and the forage fish dependency ratio (FFDR) on the assessment of sustainability of marine ingredients. Fundamentally, neither of these simplistic measures provides any discrimination between a well managed and/or sustainable fishery over a poorly managed or unsustainable one. Their only merit is that they give a single and simple number (when calculated properly) for those who don’t want to think too deeply on the broader issues. So, clearly neither FIFO or FFDR are useful metrics for sustainability and all reality we should just move on from them to something that does provide some objectivity to decision making, and importantly the ability to make comparisons between choices. Afterall, simply scapegoating something without considering what the impact of any alternative options might be, is a not a wise way to progress anything.

What is a far more constructive system is the use of life cycle assessment (LCA) methodologies. What is useful about the LCA approach is that can be equally applied against marine ingredients and any alternative options. In doing so, this enables a comparable approach amongst all ingredients so the information from can be cross compared and decisions made based on what footprint you need to manage. That is the other beauty of LCA, is that is not a one-horse-race. The system enables you to compare things on a wide range of sustainability issues like carbon footprint, water use footprint, land use footprint among others. Like all systems though, there are rules that need to be followed for it to work. So that is why groups like the global feed life cycle assessment institute (GFLI.org) are there to set things straight and maintain a global database on LCA data for the global feed industry. So far, there are over 1500 different ingredient sources in that database, including about 50 marine ingredient options. The majority though is data on grain ingredients, and not without reason.

Almost four billion tonnes of grain are produced globally each year. I was recently checking out the 2022 global grain statistics [https://openknowledge.fao.org/server/api/core/bitstreams/4039b22f-597f-4176-85da-cfd54160347c/content] only to find out that over 40% of global grain production is fed to an animal. Close to 1.5 billion tonnes of grain each year is fed to an animal, like pigs, chickens and fish. Total global fish production (wild fisheries + aquaculture) in 2022 of 192 million metric tonnes (MMT) is only 5% of that volume of grain production. And of that 192 MMT less than 9% is used as feed. Indeed, that total production of fish (192 MMT) is only about 12% of the volume of grain just used as feed. So why is this an issue? Well one of the contentions about marine ingredients is that the fish they are produced from would be better used as food. I don’t think anyone in the fishing sector would disagree with this, as food use significantly out pays feed use. But we could also make the same claim against grains. Surely, they too would better fed to humans than pigs or cattle? Unfortunately, what gets lost in such simplistic arguments is the reality of supply/demand and logistics and the issue of resource quality. Much of the grain used as feed is downgraded product that fails to meet certain food requirements. But rather than waste that production, the better option is to feed it to our future food (i.e. an animal). And a similar case can be made for some fishery resources as well. A good example of this is the growing use of using fishery and aquaculture by-products are the raw material base for global fishmeal and fish oil production. As of 2023 [https://www.iffo.com/marine-ingredients-production], about 16 million tonnes of whole wild fish is used, compared with about 12 million tonnes of by-products. From that raw material input, the differences in sources result in fishmeal production from by-products of around 39% of global production, while with fish oil from by-products represents 54% of production. Compared to the former practices of burning or burying this waste, clearly this is a positive way of upgrading the downgraded.