For years, much of the sustainability debate in aquaculture has rested on a seemingly straightforward assumption: reducing the inclusion of fishmeal and fish oil means producing more sustainably. Lower reliance on marine resources has often been treated as a direct indicator of improved environmental performance. However, a recent study published in the Journal of Cleaner Production suggests this view is too simplistic, and argues that feed sustainability needs to be assessed through a broader, genuinely multidimensional lens.
The paper examines how the environmental impact associated with feed used by Europe’s main farmed species evolved between 2000 and 2020. Over that period, production rose from 1.15 to 2.17 million tonnes-almost doubling. Growth was largely driven by Atlantic salmon, whose expansion and changes in diet consumption had a structural effect on the sector’s average footprint.
Alongside this production increase, the total amount of wild fish used to manufacture feed feel by 13%. At first glance, that might look like a clear environmental improvement. Yet the analysis shows that while direct pressure on fisheries decreased, other impacts increased substantially. Feed-related global warming potential rose by 314%, land use by 594%, and water consumption by 236%, with notable increases also recorded in marine and freshwater eutrophication.
According to the authors, the main driver of these shifts was not so much higher production volumes or changes in feed efficiency, but the transformation of feed composition itself. Replacing marine ingredients with agricultural raw materials – such as soy protein concentrate and rapeseed oil – shifted part of the environmental burden from marine ecosystems to terrestrial ones. In other words, the impact did not disappear; it moved.
This does not mean that reducing marine ingredients was a mistake, nor that the trend should be reversed. In fact, the study highlights that greater use of fishery by-products to produce fishmeal and fish oil helped reduce dependence on wild fish without generating significant additional impacts in other categories. What is challenges is the idea that a single indicator can define the sustainability of a complex system.
For Mediterranean species such as gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax), even though their production share is smaller than salmon’s, feed formulation has followed a similar trajectory of gradually reducing marine ingredients. This makes it essential to broaden the focus beyond the traditional “fish-in fish-out” metric and to incorporate, rigorously, variables such as the agricultural origin of raw materials, land use, water consumption, and crop traceability.
The debate opened by this study is not about pitching marine ingredients against plant-based ones. It points to something more fundamental: feed sustainability is multidimensional and requires comprehensive assessments that avoid simply displacing impacts between ecosystems. Reducing pressure on the sea should not automatically translate into increased pressure on land.
In a European context increasingly geared towards harmonised measurement of the environmental footprint of foods, this reflection becomes strategically important. Decisions on formulation, sourcing, and sector policies will need to be grounded in coherent, transparent multi-criteria evaluations.
The real question is no longer whether an ingredient is “good” or “bad”, but how to optimise the production system as a whole while minimising negative trade-off between marine and terrestrial resources. The study is a reminder that, in sustainability, partial analysis can lead to incomplete conclusions. As the authors note, the real challenge lies in understanding the details.
Reference:
Björn Kok, Wesley Malcorps, Maria J. Santos, Richard W. Newton, Robert Harmsen, David C. Little,
Sustainable aquafeed? The devil is in the detail. Journal of Cleaner Production, Volume 546, 2026, 147666,
ISSN 0959-6526, https://doi.org/10.1016/j.jclepro.2026.147666
Latest news
-
-
Governance, not just budget: defence of the EMFAF aligns with European auditor’s warnings
Brussels, 25 February 2026 |
-
