Comparative performance of Sarcocornia fruticosa ecotypes in two systems: Traditional hydroponic versus integrated multi‐trophic aquaculture

Abstract

Halophytes like Sarcocornia fruticosa offer a sustainable solution for managing nutrient‐rich aquaculture effluents. This study compared the performance of three S. fruticosa ecotypes (BGU, Eilat, Acre) cultivated for 115 days under two nutrient‐supply regimes: a fertilizer‐based hydroponic system and an integrated multi‐trophic aquaculture (IMTA) system supplied with fish effluent. Among ecotypes, the Eilat ecotype consistently exhibited the highest protein content in apical tops (14.0% ± 1.8% DW under IMTA‐aquaponic; 11.9% ± 1.2% DW under hydroponic conditions) and the highest polyphenol concentrations (up to 3823.8 ± 26.7 mg GAE kg ⁻¹ FW in IMTA‐aquaponic apical tops), while BGU showed comparatively lower values across both systems. At the system level, plants grown under IMTA conditions exhibited higher specific growth rates (0.71 ± 0.19% d ⁻¹ ) and annualized biomass yields (11.1 kg m ⁻² y ⁻¹ ) than those grown in the hydroponic system (0.50 ± 0.12% d ⁻¹ ; 9.4 kg m ⁻² y ⁻¹ ). Nitrogen assimilation by plants was higher in the IMTA‐aquaponic system, with S. fruticosa assimilating 44.80 g N, representing 16.8% of the dissolved nitrogen (DN) delivered to the plant tanks, equivalent to an areal removal rate of 122 mg N m ⁻² d ⁻¹ , whereas plants in the hydroponic system assimilated 34.56 g N (11.1%; 94 mg N m ⁻² d ⁻¹ ). Fish biomass retained 21.5% of feed nitrogen; when combined with plant uptake (10.0% of feed nitrogen), total biological nitrogen retention reached 31.5%. Plants cultivated in the IMTA‐aquaponic system exhibited higher levels of protein, polyphenols, and carotenoids, particularly in the apical tops, and exhibited enhanced antioxidant activities (DPPH, ICA, and CCA) in selected organs and ecotypes. These findings highlight the dual role of S. fruticosa as both a biofilter and a high‐value crop and demonstrate ecotype‐specific differences in agronomic performance and bioactive composition.