Enrichment of nutritional compounds in seaweeds via abiotic stressors in integrated aquaculture

Abstract

Seaweeds may contain significant amounts of essential proteins, carbohydrates, and minerals, offering an alternative, sustainable, healthy food source from the sea. However, there are yet challenges impending their full exploitation. Our study presents an innovative, two-step aquaculture approach integrating seaweeds and finfish, dedicated to enrich seaweeds with nutritional compounds. The approach involves diverting fish effluents rich in nutrients into a series of seaweed cultivation tanks. Then, the seaweeds were exposed to short-term abiotic stressors (namely, high irradiance, nutrient starvation, and high salinity) to stimulate synthesis of desired ingredients in their tissues. Our methodology enabled high growth rates of up to 25% seaweed biomass increase per day, with significant enhancements in the amount of protein, starch, and minerals within days. Moreover, the seaweeds presented elevated bioremediation capabilities assimilating the ammonia nitrogen, NO3 and PO4 with high uptake rates, and with 50–75% removal efficiencies. Industrial relevanceThe rising public awareness to quality of healthier food products has stimulated growing demand for seaweed supply. Our new approach suggests a promising direction toward the transition from seaweed production of raw, commodity seaweed biomass, to a tailored production of functional seaweeds, enriched with valued compounds that can be utilized in the emerging food and health industries.