Shellfish fisheries form an important aspect of the Scottish fishing industry, with recent annual values of over £90 million. Shellfish comprise crustaceans (including lobsters, crabs) and molluscs (such as scallops, cockles and mussels).
The most important of the shellfish species is the Norway lobster, (Nephrops norvegicus), which is one of the most valuable of all species landed into Scotland. A number of other crustacean and mollusc species are also valuable to the Scottish fishing industry, while others have a significant potential, or are important locally. Norway lobster is the only shellfish species managed through the Common Fisheries Policy, but a range of UK and Scottish legislation exists for other species, covering landing restrictions and fishing gear.
While Norway lobster can be caught by both trawling or in baited traps (creels), the fisheries for the other important crustaceans, lobsters (Homarus gamarus), edible crabs (Cancer pagurus) and velvet swimming crab (Necora puber), use only creels. These fisheries mainly take place in inshore waters, although an important offshore fishery for edible crabs has developed off the north coast of Scotland. Other species, including the shore crab (Carcinus maenas), the squat lobster (Munida rugosa and others) and crayfish (Palunirus elegans), are also fished in some areas.
Molluscs - Bivalves
The king scallop (Pecten maximus) is the second most valuable of the shellfish species, and is fished mainly with scallop dredges. A smaller fishery takes place for the queen scallop (Aequipecten opercularis), using dredges or trawls. In recent years hydraulic dredge fisheries have also developed for razorfish (Ensis spp.) and a range of other bivalve species (including those described as surf clams). Both scallops and razorfish are also fished commercially by divers in some areas. Cockle (Cerastoderma edule) fisheries also exist in a number of areas around Scotland, and can be exploited by vessels using suction dredges or in shore-based operations using either tractor dredges or hand gathering.
Molluscs - Gastropods
The gastropods are the least exploited of the shellfish families, with active fisheries for whelks
(Buccinum undatum) and periwinkles (Littorina littorea). Whelks are fished with baited traps (of a different design to those for crabs and lobsters), while periwinkles are collected by hand from the shore.