Thorverk hf.
Since 1976 Thorverk ltd. has been carefully harvesting Ascophyllum nodosum (rockweed) and Laminaria digitata (oar-kelp). These macro algae grow on the submerged shore and around the numerous islands in Breiðafjörður, West Iceland, similar to other coasts at the North Atlantic Ocean. According to Icelandic law the shore belongs to the adjacent farms. Therefore a resource rent is due to land owners for the Asco. The Thorverk industrial plant operates with the full consent of the regional farmers and according to 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 later on each lot. The Icelandic Marine Research Institute estimates the biomass and recommends annual allowance of harvest.
Seaweed Meal Processing
The Asco rockweed is harvested by mechanical cutters that trim about 1/3 off the top of each plant. This is only possible between the lowest and highest tide each day. The seaweed is kept on the harvesters until it is put in bags and left to float for a day or two in the sea. The sea temperature ranges in Breiðafjorður between 0°C-14°C approximately. Then the harvest is brought to harbour on a ship operated by Thorverk and dried gently with geothermal heat (hot water from volcanic bedrock) to make a few thousand tons of dried algal meal annually. The geothermal heat comes from local wells. The A. nodosum is collected between April and October using specially designed floating harvesting cutting 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. The processing plant and the products have been certified as organic since 1999 and its products sustainably harvested since 2007 by authorized external inspectors.
Harvesting schemes are based on five decades of experience and in accordance with surveys and consultancy from Icelandic and international research and expert consultancies. Measurements in 2015-2018 indicate that the biomass of Asco in the fjord has rather grown than decreased. This may be due to better influx of light because of harvesting, milder winters (frosen shores and drift-ice may rip Asco off their holdfast) and warmer seas.
When harvesters have trimmed the top of the seaweed there is a visible difference between cut and uncut plants (see photo).
Once landed, the crop is chopped and dried using a band dryer. Clean, dry air is pre-heated to a max. of 80°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 that 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. For Laminaria harvest a resource rent is paid to the Icelanedic state. It is harvested using a specially equipped coaster/comb in late autumn and winter. The comb is set to select the crop according to size which is often relative to the age. In this way the oldest and the youngest thalli are sconed. Since 2018 the Icelandic Marine Research Institute has been engaged in measuring the biomass of Laminari digitata in Breiðafjorður. Thorverk has supported the effort by lending ships and staff.
