Demonstration of large scale seaweed cultivation at open sea and the positive effects thereof on the ocean

Agriculture has been developing for millennia, but on the oceans hunting and gathering is still the norm. The project consortium sees opportunities for sea agriculture (i.e. seagriculture or mariculture) - more specifically the cultivation of seaweed - as it is cheap, easy to harvest and extract, and readily accessible. A seaweed field the size of the Netherlands could provide enough proteins for the entire European population, and has additional potential as a source for biodegradable packaging materials, biofuels and sustainable fertilizers. This field could even be placed in the middle of the Atlantic Ocean, where agricultural production does not interfere with rich ecosystems.

AlgaeDemo aims to demonstrate the sustainable, large-scale (1.4 ha) industrial cultivation of select native bred seaweed species at open sea, more specific in the North Sea area. Along this route the right cultivar for the location will be selected, which we will mechanically seed and harvest on advanced large-scale textile cultivation substrates. By applying a state-of-the-art Autonomous Underwater Vehicle (AUV) for monitoring the growth of the macroalgae and the condition of the substrates and anchoring, a largely automated and highly reliable seaweed farm is built to both reduce costs, risk to people and property and global warming - by minimalizing ship movement.

Large scale seaweed cultivation in the sea will enhance water quality by feeding on nutrients and CO2, therefore mitigating ocean acidity. This way seaweed will absorb important lost nutrients, washed out from the agricultural activities on land and transported to the ocean by our rivers. Especially the mining of phosphates is considered to reduce or even end in next decades, having a major effect on our crop yields on land. Seaweed can “capture” the lost phosphates if cultivation areas are placed in the right locations (e.g. near delta areas). Furthermore, offshore seaweed cultivation has a positive effect on fish populations, because the cultivation areas function as nurseries for smaller fish in restricted areas for ships and fishermen.

Project partners

• SIOEN Industries NV, SIOEN (BE);
• Seaweed Harvest Holland BV, SHH (NL);
• Energieonderzoek Centrum Nederland, ECN (NL);
• Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek, TNO (NL).