In an open letter responding to the article the marine ingredients chief made a staunch defence of the use of fishmeal and fish oil in aquafeeds as “valuable, responsibly sourced and highly effective ingredients”. Equally, he pointed to the limitations of using insect-based ingredients – not least the scale of the fledgling industry being so small.
He wrote: “The article titled ‘Why Salmon Eating Insects Instead of Fish Is Better for Environment’, published on 5 February, discusses fishmeal and fish oil replacement in salmon feed by a Netherlands-based company but quotes information that is both out-of-date and incorrect. Although we agree with the need for additional feed options in aquaculture to ensure the growth of this vital industry, the total replacement of fishmeal and fish oil, as called for in this article, is unjustified and damaging to the fish farming industry.
“The practice of feeding fish to fish is labelled as both inefficient and unsustainable in the article, but I would argue that responsibly sourced and used strategically, fishmeal and fish oil are both an efficient and sustainable feed choice. The growing management of wild capture fisheries has ensured that in recent years stocks are in fact steady and not declining (UN FAO State of World Fisheries and Aquaculture 2016). While catches of some small pelagic species used to produce fishmeal and fish oil are volatile, this is due to environmental fluctuation with permitted catches being varied in line with biomass abundance to protect the stocks. These small pelagic species are often not as palatable, spoil quickly and are less popular compared to other local fish, but can be turned into highly nutritious feed. Further evidence of sustainability in the production of marine ingredients is that over 45% of the global production of fishmeal and fish oil is now independently certified as being safe and environmentally responsible, including in its sourcing of raw materials, a figure that far exceeds any other source of feed ingredient.
“Regarding the efficiency of the use of fishmeal and fish oil, our latest FIFOs (Fish In:Fish Out ratios), using 2015 data, show a conversion rate of 1kg of wild fish used in feed creates 1.22kg of farmed salmon, demonstrating that farmed salmon now produce globally more consumable protein than is used in feed. This ratio is significantly lower than the out-of-date figures quoted in the article and shows how fishmeal and fish oil are now being more strategically used at key points in aquaculture production cycles with a trend towards optimising their nutritional contributions. In fact, looking at the FIFO ratio misses the rationale for the inclusion of fishmeal and fish oil in feeds as their contribution to growth and health of farmed fish goes well beyond the supply of mere protein and energy.
“Many fed farmed fish species have evolved to digest fish protein and much of the modern fish farming industry has been built on feeds using fish based ingredients. An increasing amount (currently 35%) of fishmeal is produced from recycled by-product and waste from fish processing. Fishmeal and fish oil are rich in many of the micronutrients that are required for health, many of which are classed as essential. Even reducing levels of fishmeal in feeds has resulted in feed companies having to supplement with specific materials that are both costly produce, and carry their own environmental impacts. Removing fishmeal as an ingredient to feed could therefore compromise the health of the fish and close an environmentally friendly way of recycling waste products. Production of marine ingredients like fishmeal and fish oil do not require the same levels of fresh water for irrigation, treatment with agricultural chemicals such as fertilisers and pesticides, or use land needed to grow crops. While insect meal may be a theoretical alternative, the production of the millions of tonnes needed to replace fishmeal is currently not viable. When it is clear that the amount of fishmeal and fish oil is not sufficient to meet the growing demand for feed manufacture and, in the best interests of the fish farming industry, the raw material sources for feed should be maximised, it makes little sense to exclude these valuable, responsibly sourced and highly effective ingredients. Although not such a punchy selling message, the reality is that there is an opportunity for alternative ingredients like insect meal without needing to displace fishmeal.”