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Cultivating Seaweed

The Scottish Government (SG) recognises that the seaweed cultivation sector offers significant commercial potential, both through the cultivation of a single species and as part of Integrated Multi-Trophic Aquaculture (IMTA) developments (where species which are fed or farmed, for example Atlantic salmon, are grown alongside species whose culture results in nutrient or energy extraction for example, mussels or seaweeds).   

The sector is in its very early stages: most trial farms and IMTAs have fewer than 10 lines but there is the possibility of this developing on the small-medium scale of up to 50 x 200m lines. In order to support that some guidelines (Policies) have been written for potential developers to consider before applying for permission to cultivate.

The policies cover commercial seaweed cultivation either grown on its own or as part of an Integrated Multi Trophic Aquaculture (IMTA) system:

  • Policy 1: in principle, the SG is supportive of small-medium farm seaweed cultivation, subject to regulatory consideration; the General Policies set out in Chapter 4 of Scotland's' National Marine Plan; and any other relevant policies within that Plan. Applications for such seaweed farms should demonstrate that mitigation measures have been considered to prevent adverse environmental effects, and set out how these will be delivered.

  • Policy 2: only species native to the area where seaweed cultivation will take place should be cultivated, to minimise the risk from non-native species

  • Policy 3: where seaweed is grown for human consumption, cultivators should site farms away from sewage outfalls and other potential sources of pollution

  • Policy 4: equipment used in seaweed cultivation should be fit-for-purpose to withstand damage from adverse weather conditions

  • Policy 5: other marine users and activities should be considered in the siting of farms

  • Policy 6: small-medium size farming is unlikely to be spatially limited, and may be located anywhere in Scotland, subject to agreement and appropriate local conditions

  • Policy 7: the SG is supportive of IMTA

The Seaweed Cultivation Policy Statement identifies two development scales, small-medium (0-50 x 200m lines) and large (>50 x 200m lines).

These policies do not apply to wild harvesting of seaweed.