Introduction
Fish meal is widely used in aqua feeds because of its high quality nutritional profile. However, the catch of wild fish is linked to substantial environmental concerns, notably pressure on wild fish stocks and marine ecosystems. Limiting reliance on fish meal while preserving zootechnical performance has therefore become a key lever for enhancing the environmental sustainability of aquaculture. Feed formulation approaches typically include reducing fishmeal inclusion levels, lowering the quality of marine-derived ingredients, or replacing marine proteins with alternative sources such as plant-based or functional ingredients. Although these strategies aim to mitigate the environmental impacts associated with fishmeal use, they must be evaluated using standardized assessment tools such as Life Cycle Assessment (LCA), which quantifies environmental impacts across multiple categories (e.g., climate change, eutrophication). This study evaluated through LCA the environmental impacts of two formulation strategies, by partially replacing fish meal or using a lower quality fish meal in the diet with a supplementation of a marine peptide concentrate (Pepsea F) in European seabass (Dicentrarchus labrax).
Material and Methods
Data from Bardera et al. 2026 (presented in a separate abstract for EAS 2026) were used for LCA, including fish performance, feed and some farm data. Experimental diets included Pepsea F (Adisseo) and consisted of two formulation strategies: (i) partial replacement of high-quality fish meal (with 68% crude protein), reducing inclusion from 20% to 10%, and (ii) substitution of fish meal quality, from 68% to 60% of crude protein, at a constant 20% inclusion level. All experimental feeds were formulated to be isoproteic, isolipidic and isoenergetic. Performance parameters, including feed intake, specific growth rate (SGR), and feed conversion ratio (FCR), were measured.
LCA for Pepsea F at plant gate was conducted following ISO 14040/44, PEFCR and FAO LEAP guidelines, where applicable. LCA from cradle to farm gate (per kg of fish) was performed using feed ingredient list, growth performance and feed efficiency outputs, and Turkish seabass farm data. GFLI v2.2 database (2024) was used, and LCA followed FAO LEAP (2020) and PEFCR guidelines, where applicable. Feed ingredient origins reflected Turkish, European or Global import values when no other data was available. Five impact categories were assessed: climate change, acidification, eutrophication freshwater and marine, and water use. In addition, the Environmental Return on Investment (EROI) was calculated as the ratio of the carbon footprint avoided at the animal product level to the impact generated by additive production at the plant level.
Results
At the cradle to farm gate level, formulation strategy (i) with partial replacement of fish meal combined with Pepsea F supplementation, led to a marginal reduction in climate change impacts, from 5.92 to 5.85 kg CO2eq/kg fish (-1%), compared to the basal diet. This strategy also resulted in reductions in marine eutrophication (-12%) and water use (-3%), while slightly increasing acidification (+1%) and freshwater eutrophication (+1%) per kg of fish.
In contrast, formulation strategy (ii), based on fish meal quality substitution at constant inclusion levels, yielded more pronounced LCA indicators improvements. Climate change decreased from 6.08 to 5.66���kg���CO2eq/kg fish (7%). In addition, there was an improvement in acidification (-1%), freshwater eutrophication (7%), and water use (3%) compared to the basal diet. However, marine eutrophication was slightly higher for the lowquality fish meal supplemented with Pepsea F (+4% per kg of fish) relative to basal diet.
The EROI calculated for the first strategy (i) resulted in 6, while it reached 38 from the second strategy (ii), indicating that for an investment of 1 kg CO2eq due to feed additive production, its use resulted in these studies in savings of 6 or 38 kg CO2eq on the value chain depending on the formulation strategy.
Discussion & Conclusion
These results show that, additionally to performance improvements obtained in Bardera et al. 2026 (EAS 2026), Pepsea F associated with different formulation strategies can reduce different LCA environmental impacts in European seabass, with magnitude depending on the strategy applied. The second strategy, having more significant effects on climate change, appears especially relevant for companies with carbon reduction objectives, as CO2 emissions represent one of the main indicators used to evaluate corporate sustainability performance.
In contrast, the first strategy relied on partial fish meal replacement with soy protein concentrate ingredient, which increased the climate change impact of the feed compared to the basal diet. Consequently, despite improved fish performance associated with Pepsea F supplementation, the final climate change reduction at the farm gate was limited and considered non-significant. This finding aligns with Kok et al. (2026), who emphasized that substituting marine ingredients with plantbased alternatives can modify the distribution of environmental pressures across ecosystems. In particular, the use of soy imported from South America is still associated with landuse change impacts, highlighting the importance of carefully evaluating tradeoffs between marine resource use and terrestrial environmental constraints when designing more sustainable aquafeeds.
Besides, the magnitude of the observed environmental benefits is influenced by methodological assumptions. In the second strategy (ii), identical fish meal proxies from the GFLI v2.2 database were applied to both high and lowquality fish meal, due to the lack of supplierspecific data and differentiated datasets. This conservative assumption likely underestimates the environmental gains, as lowerquality fish meal, potentially derived from byproducts, can reasonably be expected to have a lower environmental footprint under economic allocation. Consequently, the mitigation potential associated with Pepsea F marine peptide supplementation and fish meal quality decrease may be greater than reported here.
Taken together, these findings illustrate both the potential and the limitations of LCA for assessing fish meal reduction strategies. Further studies combining LCA with complementary indicators, such as Fish-In Fish-Out ratios (FIFO) and emerging biotic resource depletion or biodiversity metrics, would enable a more comprehensive evaluation of feed reformulation strategies and their implications for marine resource use and ecosystem integrity.
References