As marine space becomes increasingly limited and inland food systems face sustainability challenges, land-based seaweed cultivation in closed recirculating aquaculture systems (RAS) offers a promising alternative. Within the EU project NOVAFOODIES, we evaluate the feasibility of a closed, land-based Ulva spp. cultivation system (Fig. 1) using artificial seawater. The land- based RAS design (Fig. 1) allows for precise control of growth conditions, minimal water exchange, and potential integration with renewable energy sources , making it a model for sustainable production.
The objective of this study is to evaluate the physiological and biochemical performance of two Ulva spp. strains with different reproductive traits, cultivated under identical conditions across multiple 14-day cultivation cycles . The cultivation setup consists of two vertical shelving RAS units (~300 liter each) , each containing six transparent 60-liter culture tanks (Fig. 1). Sampling is conducted at regular intervals (Day 0, 4, 7, 11, 14) within each cycle to monitor physiological development over time . Key data collected include growth rate, biomass (Fig. 2), yield, photosynthetic efficiency dissolved inorganic nutrient uptake (phosphate, ammonium, nitrate, nitrite), carbon and nitrogen content, total protein content, pigment composition, and specific leaf area . In addition, 24-hour nutrient uptake studies at early and late cultivation stages provide high-resolution data on nutrient dynamics and can be linked to physiological performance.
Preliminary results suggest characteristic changes in growth efficiency and nutrient assimilation across the harvest cycle, providing insight into optimal harvest timing , biomass quality and system efficiency . The findings contribute to the development of scalable and sustainable inland seaweed production systems and highlight the potential of land-based RAS as a viable component for the future of seaweed aquaculture.