Isefjord and East Jutland Danish blue shell mussel
MSC status
Certified as sustainable in January 2012.
Summary
Species: Mussel, Mytilus edulis
Location: The fishery operates in the Isefjord and on the East Jutland Coast. These areas are located in the southern Kattegat and the Belt Sea and are part of ICES subarea IIIa and FAO statistical area 27, Baltic subdivision 22.
Fishing methods: Mussel dredge
Vessels: Isefjord fishery - 2 vessels.
East Jutland fishery - 5 vessels.
Number of fisheries: 1
More about mussel
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 size, draught, and power of the vessels operating in both fisheries are regulated by the legislation in order to control effort and dredging in shallow water depths. Vessels may be no more than 16m long and are limited to an engine power of 300hp. 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.
Fishery tonnage
In 2010 2,393 tonnes was landed from Isefjord and 2,344 tonnes from East Jutland.
Commercial market
Products are fresh and processed mussels (canned) with markets identified as mainland Europe.
Actual eligibility date
25 February 2011
