New research questions the sustainability of plant-based aquafeed
A new study called “The Sustainability Conundrum of Fishmeal Substitution by Plant Ingredients in Shrimp Feeds” questions the sustainability of a shift towards more crop-based ingredients to meet the increased demand for fish and shrimp feed. A shift that is driven largely by economic incentives.
The study is done by Wesley Malcorps from the University of Stirling in collaboration with a multidisciplinary team. You can find the study here.
In the study incremental fishmeal substitution by plant ingredients in shrimp feed was modeled and effects on marine and terrestrial resources such as fish, land, freshwater, nitrogen, and phosphorus were assessed. The study found that complete substitution of 20–30% fishmeal totals could lead to increasing demand for freshwater (up to 63%), land (up to 81%), and phosphorus (up to 83%), while other substitution rates lead to proportionally lower impacts. These findings suggest additional pressures on essential agricultural resources with associated socio-economic and environmental effects as a trade-off to pressures on finite marine resources.
Malcorps questions the sustainability of plant-based aquafeed and states that “a change in ingredients would shift resource demand from the oceans onto the land and could affect the nutritional value of shrimp.” He also said that: “While aquafeed consumes approximately 4 percent of global feed crops and therefore just a small share of available water and land, a move from fishmeal to plant ingredients should not be taken for granted as a sustainable solution, particularly in the shrimp sector.” Even though the study takes it starting point in shrimps, Malcorps stressed that the findings were also applicable to farmed freshwater and marine finfish.
Aquaculture is the fastest growing food producing sector. In 2016, Aquaculture was accountable for 80 million MT of production which makes up 46,8 % of the global fish supply. The researchers behind the study recommends that the topic is further examined, and they call for a more strategic use of fishmeal in aquafeed.