## 4 Discussion
In a recent study [41], [PERSON] and [PERSON] observed under high salinity an increase of ALA content in euhalophyte _Suaeda salsa_ playing an important role in regulating intracellular fatty acid unsaturation. In addition, the high content of ALA in chloroplast membranes acts as protection for plants against damage during cold spells, as a process for acclimation [42]. In general, the C18 FA in plants play an important role in the modulation of membrane properties to adapt to variation of growth conditions associated to biotic and abiotic stresses. Moreover, these biomolecules are a reserve of carbon and energy in triacylglycerlycerols and are precursors of bioactive compounds with multiple bioactivities [43]. LA content in three halophytes cultured in aquaponics is similar to conspecifics in the wild, being predominate in the roots. Linoleic acid FA and ARA are the most useful form of omega-6 FA for human nutrition, in human tissues, and LA is an essential FA that is converted mostly in ARA [18; 44; 45]. Results suggest that under the aquaponic conditions, halophytes were not nutrient limited. When calculating the PUFA/SFA ratio, an indicator of good nutritional quality and good health status [46; 47], our data show that both wild and cultured _H. portulacoides, S. ramossissima_, and S. _perennis_ displayed a ratio above the threshold value indicative of good nutritional quality (0.45). Moreover, the PUFA/SFA ratio was often higher in halophytes cultured in aquaponics than in wild conspecifics, evidencing a higher level of FA unsaturation. These findings support the suitability for human consumption of _H. portulacoides_, _S. ramossissima_, and _S. perennis_, cultured in aquaponics, namely in IMTA systems coupled to marine RAS system. A comparable finding was also previously reported by [PERSON] et al. [45], with the halophyte _Sarcocornia ambigua_ (Amaranthaceae) also exhibiting a PUFA/SFA ratio averaging 3.4 (higher than the indicator value of good nutritional quality), hence being considered suitable for human consumption. One major advantage of aquaponic systems is their resistance and resilience against threats from soil-borne pests and diseases [7]. Beyond this advantage, the following additional benefits from cultured halophytes coupled to marine IMTA systems for human consumption, can be highlighted: (i) in opposition to freshwater, saltwater is not a limited resource [48]; (ii) it enables the reduced dependency on wild specimens of halophytes, which is particularly relevant as most are classified under environmental regulations (e.g., EU Habitat Directive; Bern Convention on the Conservation of European Wildlife and Natural Habitats; RAMSAR convention on wetlands); (iii) it is a sustainable way to improve food production [5,8] in line with SDG2; (iv) RAS provides a continuous source of high quality nutrient-rich effluents for aquaponics [14] so no additional input is required [21]; (v) it promotes the recycling of nutrients, minimizing losses, and environmental impacts on water bodies receiving the effluent; (vi) it promotes water filtration, thus reducing the costs of wastewater treatment [8,14,49], being in line with SDG14; and (vii) it is in line with the framework for circular economy [50]. The production of halophytes in aquaponics coupled to a marine IMTA system can be regarded as an important way to create added value, through the retention of nutrients within the productive system and avoidance of their loss to the environment, thus achieving the objectives of the 2030 Agenda for Sustainable Development [50].