Seafood Romo East Jutland and Isefjord blue shell mussel dredge
MSC status
Certified as sustainable in March 2012.
Summary
Species: Mussel, Mytilus edulis
Location: East coast of Jutland, Denmark and Isefjord, Denmark
Fishing methods: Mussel dredge
Vessels: 5
Number of fisheries: 1
More about mussels
Mussels can withstand wide variation in salinity, desiccation, temperature and oxygen concentration, resulting in the ability to occupy a large variety of microhabitats. Mussels can be found on any substratum providing a secure anchorage such as rocks, stones, gravel, shingle, dead shells, and even mud and sand. In soft bottom areas as the Limfjord, the mussels form stabilised mussel beds of interconnected mussels and dead shells. The blue mussel Mytilus edulis is a filter-feeding bivalve filtering primary on micro-algae and debris, but at lower rates also on zooplankton. The planktonic life of Mytilus edulis varies from 2-4 weeks depending on temperature, food supply and availability of suitable settlement substratum; hence it can take 10 and more weeks between the fertilisation and the settlement of the mussel. The maximum settlement period is in June – July, although a cohort of larvae and settlement are often observed in September. The growth rate of mussels varies greatly and is dependent largely on the availability of food. Suspended mussels suspended are reported to grow 9% daily, whereas the rate of those in mussel beds is much lower due to food competition and limitations of the transport rates of food to the bottom.
More about the fishing methods
The mussels are fished by one or two dredges on each vessel. Traditionally, the “Dutch” type of mussel dredge has been used in this fishery. The 2 metre wide steel dredge has to have a maximum weight of 100 kg. On the frame is attached a 2-3 metre long bag. The bottom part of the bag is a made up of a chain link matrix and the upper part of the bag is made of nylon mesh. The mouth of the dredge must be equipped with bars or a grille with a spacing of no more than 25cm to prevent any large substratum material such as boulders from entering the dredge. The dredges have a total weight of around 120kg, and a frame weight of 50kg (half the weight of the “traditional” dredge). As before, the dredges are fitted with bars across their mouth to minimise the ingress of boulders.
Fishery tonnage
East Jutland: 685 tonnes (2010)
Isefjord: 825 tonnes (2010)
Commercial market
Products are fresh and processed mussels (canned) with markets identified as mainland Europe.
Actual eligibility date
17 May 2011
