Seafarms for large-scale protein production

Large-scale cultivation of seaweed at sea can double worldwide plant production. Such seafarms help feeding the growing world population. Researchers of Plant Research International are working on a sustainable cultivation at sea in which the proteins from seaweed can be utilised as raw material for various products.

Picture: Hortimare, Heerhugowaard
Picture: Hortimare, Heerhugowaard
Seaweed contains high-quality protein at high concentrations, appr. 25 per cent of dry matter. These proteins show a better digestibility than common plant proteins and are hardly allergic. This protein can directly serve as food for humans but also as sustainable source of protein for animal feed. Seaweed can also be conceived as renewable resource for biofuel, chemicals and several other products.

Phosphate utilisation

Seaweed production offers more advantages. The annual worldwide flow of phosphorous from land to sea amounts to 30 million tonnes of phosphorous. This is caused by excessive fertilisation of crops and the amount is larger than the annual amount mined in phosphate mines. Phosphate is essential for plant growth but it is now already clear that the vphosphate supply of the mines will be exhausted in the foreseeable future. Part of the phosphate that ends up in the sea can be recovered by cultivating seaweed, resulting in a better closed phosphate cycle.
Seaweed cultivation is already possible but does not yet take place at a large scale and often with negative effects in the sea. The challenge now is to set up a cultivation system that provides plants with sufficient nutrients without polluting the sea.

Small-scale tests

Zeeland has a seaweed test location in the Oosterschelde (Schelphoek) where our scientists are testing which seaweed species can best be cultivated and which have the best potential of supplying raw materials. They are also investigating possible cultivation systems. These include wires from which the seaweed is hanging or basins. For the time being, the scientists are focusing on the cultivation of seaweed as source of protein for fish feed. After mastering this, they will be searching for other possibilities to utilise seaweed.