University of Gothenburg
Maria Bodin håller upp brunalgen sockertare vid brygga.
Photo: Susanne Liljenström

Blue community gardens – cultivation below the surface

Imagine growing your own mussels, oysters and algae. At a test facility at Tjärnö marine laboratory, a concept for marine blue gardens is now being developed.

What is a blue community garden?

In a blue community garden seafood are grown and stored. Unlike crops on land, you do not need to add nutrients or water to the crops. There are enough nutrients in the sea in the form of nitrogen and phosphorus. The blue community gardens can be built either at sea or near the coast.

Suger kelp
The brown algae sugar kelp is one of the species found in test cultivation. Sugar kelp can be used, for example, to make seaweed chips.
Photo: Johan Wingborg

Which species are suitable for cultivation and storage?

It's important to only grow and store the species that already exist in the local environment so that new species are not introduced to the area. This needs to be investigated at each location before a blue community garden is placed.

Species tested at the test facility:

  • European oyster, Ostrea edulis
  • Blue mussel, Mytilus edulis
  • Sugar kelp, Saccharina latissima
  • Sea lettuce, Ulva spp.
  • European shore crab, Carninus maenas
  • Baltic shrimp, Palaemon adspersus
  • Rockpool shrimp, Palaemon elegans
  • Sand shrimp, Crangon crangon
  • Tunicates, Ciona sp.

Visit the test facility

At Tjärnö marine laboratory outside Strömstad on the Swedish west coast, it is possible to visit the test facility. On information boards you can read more about how the blue community garden works and the species in it. 

About the project

The test facilty at Tjärnö marine laboratory is part of the Interreg project Marint Gränsforum Skagerrak, which is an EU-funded collaboration between Sweden and Norway. The Svinesund Committee brings together actors on both sides of the border and works, among other things, to test blue community gardens in Norwegian Hvaler.

Inspiration from Denmark

Joachim Hjerl, founder of the organization Havhøst, shares his experiences of starting a movement that grows mussels, oysters and algae.

Video (32:21)
Blue community gardens – experiences from Denmark