Successful seaweed harvest and test of submersible cultivation system
End April 2025, the seaweed cultivation experiments of the Belgian Pilot at the Bantry Marine Research Station (BMRS, IR) came to a successful end, marking an important milestone in the practical testing phase of the Belgian Pilot.
The submersible seaweed cultivation system (developed by Impact9) was installed at BMRS in November 2024, testing the durability and performance of the submersible cultivation system and the growth performance of two seaweed species – the kelps Alaria esculenta and Saccharina latissima. After an eventful storm season, the team consisting of researchers of Ghent University (Phycology Research Group and Artemia Reference Center), Impact9 and colleagues of the Bantry Marine Research Center (BMRS), were positively surprised by the excellent performance of the system and dense seaweed growth (Figure 1).
Figure 1 Successful seaweed growth at the end of the cultivation trials on the submersible cultivation system.
Since the installation in November, the system got repeatedly submersed before storm events to protect the juvenile seaweeds from excessive hydrodynamic forces that could have resulted in dislodgement and consequently low yields. The system was lowered to around 8 m immediately after the installation in November 2024 to escape the forces of storm ‘Bert’ and brought back up to the surface once conditions calmed down.
The observed growth of the seaweeds, with individuals of up to 3 m in length for Alaria esculenta, demonstrates the successful escape of high hydrodynamic forces through the submersible system. Following the harvest, the team assessed and quantified the growth and morphological characteristics of the seaweeds grown at different seeding densities to evaluate which species is more suitable for cultivation in high-energy and offshore locations (Figure 2).
Figure 2 Seaweed sample collection after the successful harvest to evaluate best performance.
