History and process

The ascophyllum covered shores
The ascophyllum covered shores

Thorverk hf.

Since 1976 Thorverk ltd. has been carefully harvesting Ascophyllum nodosum (rockweed) and Laminaria digitata (kelp). The seaweed grows on the shore and around the numerous islands in Breiðafjörður, West Iceland -as well as on other rocky shores in subarctic waters. According to Icelandic law the shore belongs to the adjacent farms. Therefore a resource rent is due to land owners. The Thorverk industrial plant operates therefore with the full consent of the regional farmers as well as national regulation and allowed annual quota. The rule of thumb (based on research and experience) is not to return for a new harvest until 4-6 years a-later. The Icelandic Marine Research Institute estimates the biomass and recommends annual allowance of harvest.

Seaweed Meal Processing

The Asco rockweed is brought ashore and dried gently with geothermal heat (hot water from volcanic bedrock) to make aIsland landscape few thousand tons of dried algal meal annually. The geothermal heat comes from local wells. The product has been certified as organic since 1999 and sustainably harvested since 2007 by certified annual auditing. 

The A. nodosum is collected between April and October using specially designed floating harvesting machines. They cut the plants well obove the growth point (It is similar to trimming buses). The harvested grounds are then left for regrowth for at least four years. 


 Freshly cut is green, uncut is black

Harvesting schemes are deployed for the seaweed,  based on five decades of experience and in accordance with surveys and consultancy from Icelandic and international research and expert consultancy.

Once landed, the crop is chopped and dried using a band dryer. Clean, dry air is pre-heated to a max. of 85°C using hot geothermal water that is fed through heat exchangers. This gentle drying procedure ensures that all minerals and organic substances are preserved in the raw material. The drying heat also prevents surface oxidation and browning or burning. Its colour is therefore delightfully bright. The use of the geothermal water also means the production process is environmentally benign. The geothermal hot water flows freely from the wells and emits next to zero of CO2

Laminaria digitata is harvested from deeper common waters. It is harvested using a specially equipped coaster in late autumn and winter that selects the crop according to size. In this way the oldest and the youngest are sconed..