With the United Nations Food and Agriculture Organisation (FAO) reporting that 90% of our oceans are either overfished or fully fished, one would think that the best approach to conserving marine life while maintaining a constant supply of fish for consumption would be aquaculture.
Although an intuitive solution, it is unfortunately a commonly misunderstood belief. Today, the current aquaculture practice uses large amounts of aquafeed which are predominantly made up of fishmeal, a commodity made from wild-caught fish where 4-5 tonnes of fish are needed to produce a tonne of fishmeal. A counterproductive practice where foraged fish is used to feed aquaculture fish. At date, 25% of our fishes caught globally are processed into fishmeal. This upsets the balance of nature as it removes the major food source in the marine food chain. Despite counterarguments made by the wild-caught industry and claims of the sustainability measures put in place for forage fish, the environmental consequence over decades of commercial fishing speaks for itself.
Nevertheless, with the required protein content in the diets of reared fish, there is almost no other way to go about doing it. With the increasing prices of fishmeal and fish oil, more plant-based substitutes have been included in aquafeed. Although protein sources such as soy, corn or even poultry by-products have been used as alternatives in aquafeed, none can come close to the nutritional profile of fishmeal. Largely due to its imbalanced amino acid content and anti-nutritional factors. Experts have also advised against replacing large amounts of fishmeal and fish oil with plant-based material. Apart from the anti-nutritional components, plant-based aquafeed contains excessive fibre, non-starch polysaccharides and has poor palatability.
Contrarily, insect-based aquafeed has an amino and fatty acid profile that is more identical to fishmeal with highly digestible contents making it very suitable for juvenile fishes. Insects have also proven beneficial as a protein alternative in multiple feed trials. Further expanding the possibilities of insect protein, studies confirmed that the calcium and fatty acid composition of insects can be adjusted through modulating the content of their substrate. Allowing farmers to fine-tune the insect’s nutritional profile to meet the dietary requirements of a target species. A trait that other protein alternatives do not possess.
Compared to soy or corn that has a one-year turnover, insects can consistently reproduce rapidly throughout the year regardless of seasonality with considerably less water. Environmentally, insects leave a much smaller environmental footprint compared to fishmeal and have a high feed conversion efficiency. Ethically, as far as entomologists are concerned, it is believed that insects do not feel pain as vertebrates do, due to the absence of pain receptors.
All things considered, insect-based aquafeed proves to be preferable in the parameters of efficiency, nutrition, sustainability, and ethics.