Aller Aqua, the industry partner from Denmark in LOCALITY, has reached a significant milestone in the project: they have successfully produced an aquafeed prototype on an industrial scale. These prototypes are now ready to be tested in a farm scale fish-feeding trial, which will take place in sea cages in Norway from August to October 2026.
From screening to prototypes: how we selected the effective candidates
The prototypes were developed based on earlier work within LOCALITY’s work package 5, which focused on identifying algae-based functional additives for aquafeeds. Sparos and GreenCoLab screened nearly 70 ingredients as first step to identify promising algal strains. From among them, the better performing microalgae (Chaetoceros sp., Thalassiosira sp., Phaeodactylum sp.) and macroalgae (Ascophylum sp., Saccharina sp.) were evaluated as whole biomass, broken-cell biomass, soluble fractions, and residual fractions to ensure a thorough understanding of their effectiveness. All ingredients were tested ex vivo using intestinal explants from Atlantic salmon, rainbow trout, and gilthead seabream, representing both cold- and warm-water species. The intestinal mucosal response was assessed by measuring the expression of genes related to immune response, antioxidant activity, and epithelial integrity. The algal biomass and extracts that significantly enhance immune responses, boost antioxidant activity, and strengthen epithelial integrity were selected for the next round of evaluation (refer to report D5.1).
Based on the results obtained at Sparos and GreenCoLab, the three top-performing microalgal extracts or biomass were selected for the laboratory trials. Using these selected algal biomass or extracts, Nord University conducted three studies:
i) an in vitro study using the gill epithelial cell line,
ii) an ex vivo study using gills from salmon that were administered the additives, and
iii) a wound-healing monitoring study conducted over 8 weeks with fish fed the algal additives.
In addition, Sparos with Riasearch and GreenCoLab performed two in vivo trials to understand the effect of these algae products on skin response to sea lice insult, and their potential as therapeutical agents for salmon skin damage. The preliminary results from the feeding trials indicate that the tested algal products have no adverse effects on growth and welfare, and can support stronger responses to insults in skin, promote tissue repair and enhance wound healing, whether used alone or in combination.
Upscaling the process: from laboratory trial to field trial
Aller Aqua will conduct a feeding trial in sea cages in Norway to assess the effectiveness of the selected algal additives under farming conditions. In this trial, two groups of fish will be offered feed containing the additives, and their effectiveness in combating sea lice infestation in a natural environment will be assessed.
Based on the laboratory results from the in vitro study and the feeding studies (refer to D5.2), two ingredients, alone or in combination, were selected for the field trial. For this, the feed type was selected, and a prototype was produced. The algal additives will be top coated onto Aller Aqua’s commercial salmon feed and used in the feeding trial.
Why this matters
The production of a consistent prototype at an industrial scale represents a critical milestone in the journey toward real-world implementation. The successful upscaling indicates that the process can be reliably reproduced outside of a laboratory setting, thereby supporting LOCALITY’s objective of developing nature-positive, algae-based products for the aquaculture industry.
Next steps
The field feeding trial will take place August-October 2026.
The Aller Atlantic 6 mm feed prototype to be used in the field trial.
