A Resource from the Sea We’d Like to See More Of

Last June, the first offshore seaweed harvest in the Dutch Northsea yielded just 15 kilograms. But this little amount of fast-growing algae could be very promising for the European seaweed industry, which is preparing to scale up. What are the future prospects of seaweed farming and will they be sustainable?

Autor*in Maaike Reynaert, 10.08.15

Last June, the first offshore seaweed harvest in the Dutch Northsea yielded just 15 kilograms. But this little amount of fast-growing algae could be very promising for the European seaweed industry, which is preparing to scale up. What are the future prospects of seaweed farming and will they be sustainable?

Close to an unmanned island, a buoy called the ‘Spoetnik’ is the only visible sign of the first offshore Dutch- run seaweed farm. A year ago, Dutch foundation the ‘Noordzeeboerderij‘ (Northsea farm) put the platform down into sea with baby seaweed aboard, yielding the harvest mentioned above. Not much but enough for a test drive before cultivating it on a large scale. The brown seaweed was sent to research institutions where its nutritional composition will be further examined. Eventually, the Noordzeeboerderij hopes to be facilitator for companies to use the area for sustainable seaweed harvesting.

Although seaweed has been harvested for ages, it has not been cultivated on a large scale before. Studies show that seaweed farming is less demanding of its local environment in comparison to standard aquaculture, an industry that operates in a polluting way. But how does sustainable seaweed farming look? For this article I researched the potential of a sustainable seaweed farming and production and looked at how seaweed could be a resource to create bio-plastic, bio-fuel and be used as a meat supplement to boost protein levels among other uses.

The Nature of Sustainable Seaweed Farming

Seaweed farming initiatives aim for a clean break away from traditional harmful ways of farming, using methods that could be beneficial to the environment instead. This needs to be done on a large-scale though. Harvesting seaweed from its existing natural stocks – which is being done in various coastal areas around the globe – puts a lot of pressure on these ecosystems. As a major nutrient for the whole coastal environment, a reduction would directly impact fish, mammals and birds living in the area.

Farming seaweed will not solve the problem of how to feed the estimated 9 billion people in 2050. However, it does have some groundbreaking qualities that show that large-scale seaweed farming could be a sustainable form of agriculture.

  • By it’s very nature, seaweed farming does not exacerbate land use scarcity. The Dutch sea is already dense with windmills and the Noordzeeboerderij wants to cultivate seaweed within the windmill parks, minimising distress to the area.
  • Underwater farming systems could function in a closed loop using waste from fish. Instead of mono-aquaculture operations that damage the environment, seaweed-farms would be able to support marine biodiversity.
  • Seaweed has a negative carbon footprint. Some types can absorb up to five times more carbon dioxide than on-land plants can
  • no fresh water and fertilisers, nor deforestation are necessary for farming seaweed. A huge plus given how reliant land-based agriculture is upon these three things.

The Production of Seaweed

The worldwide seaweed industry has an estimated total value of US$10 billion per year of which about 83 percent is used for human consumption and the rest for fertilisers, animal feed additives or medical applications Seaweed is rich in protein, making it a sustainable substitute to meat, since it is at the bottom of the food chain and does not have the environmental impact that meat production has. Biologist Ronald Osinga from the Wageningen University in the Netherlands has calculated that an 180,000 square kilometre ‘marine-garden’ of seaweed would provide enough protein for the entire world population. So why don’t we all start eating seaweed burgers, as made by the Dutch Weed Burger, one of the many start-ups introducing seaweed on the menu today.

Seaweed could also be a viable substitute for many products. Made up of 50 percent oil, seaweed can be a resource for biodiesel. When processed, seaweed can be used as an ingredient for bio-plastics as well, which could open up a whole new world wherein even cars are made from algae. It is perhaps not surprising that this idea comes from Japan, where the ‘Toyota 1/X‘ was designed, a kelp car with a body made out of seaweed-oil.

However, food and bio-plastic make up a relatively small fraction of seaweed use. All these various destinations for seaweed make it worth considering not only to what extent seaweed is sustainable to farm and for what environmental unfriendly materials it could substitute, yet as well the production itself. Extracting water out of the plant is an energy-consuming process for instance, which might account for other production processes as well.

Future Prospects

On top of sustainability, seaweed farming and production can also give local economies a boost. Bert Groenendaal, project coordinator of textile manufacturer Sioen, partner of AT~SEA, believes cultivating seaweed on a large scale could create new jobs and attract investors.

Seaweed farming and production appears promising. But considering the fact that seaweed cultivation in Europe is still in its test phase, we have to keep an eye on where development steers. However, as long as test-farms like the Noordzeeboerderij as well as the seaweed production industry have sustainability high on their agendas, the future of sustainable aquaculture looks very interesting.

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