Blue mussel

Blue mussel (Mytilus edulis) is a native species and is widely distributed in great numbers along the west, north and east coasts of Iceland. The mussel farming industry in Iceland is a relatively new one, and novel technology is continuously developing. The first experiment in farming blue mussel in Iceland was carried out in 1973 and 1985–1987 to investigate feasibility. In the past decade, blue mussel have been grown experimentally by private parties in some places along the coastline of Iceland.  Mussel are relatively easy to grow as they require no artificial food or hatcheries to produce seed. There are, however, several important biological factors that control, and effectively limit, potential production at a farm or in a particular region.   

Methods

In Iceland the larvae settle on collectors in late summer or early autumn and there has been high settlement intensity at all sites.  Many methods are used worldwide when growing mussel, but in Iceland only suspended long-lines have been used. The mussels are either grown from settlement to market size on the seed collectors or they are “socked”. Socking is the operation by which juvenile or seed mussel are loaded into mesh sleeves.  The seed is stripped from the collectors, declumped and graded into size classes. The sleeves are then attached to the long lines where the mussels grow until market size is reached.

At present, mussel farming in Iceland is based on a 2-3 year production cycle.  It typically requires about one year for seed to grow to a suitable size on collectors followed by 1-2 years in socks to reach market size, approximately 50 mm to 70 mm in shell length. This growth period varies among sites, shortest along the west coast with a production cycle of about two years and longest along the east coast, about three years.  

Fouling and predators

The attachment to the product of unwanted organisms from the algal and faunal community, called fouling, can cause problems. Levels and types of fouling agents can vary greatly over short distances and between years.  The most common fouling organisms in mussel culture in Iceland are epiphytic algae and barnacles. Predators can also cause problems and the main pests are eider ducks and sea-stars. Many different methods are used to try to prevent damage from these organisms. 

Monitoring of mussel production

Mussel live on natural populations of algae in the sea. Some of these algae contain substances that are toxic to human beings. If this happens, harvesting is postponed until the mussels have eaten themselves “clean” again. To ensure that the mussels are of good quality, they are regularly sampled for testing. 

Production

The annual production of blue mussel has been a few tonnes per annum. Bout fifteen blue mussel farms are in operation in 2009, mostly experimentally. Norðurskel, located in Eyjafjörður, grows mussel on an industrial basis. It is forecasted that production of blue mussel in Iceland will be less than 300 tonnes 2010.   

References and further reading

Thorarinsdottir et al 2007

Valdimar Ingi Gunnarsson