This report is a contribution to the Strategic Environmental Assessment (SEA5) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). The SEA5 review differs from previous assessments in that the zone includes a large coastal fringe, along the whole east coast of Scotland and the Northern Isles, and contains a diverse range of habitats, from inter-tidal rocky shores and sandy beaches, to the shallow sub-littoral and deepwater mud basins offshore. These habitats support a wide range of invertebrate resources, of which six species of crustacean, four species of bivalve mollusc and two species of gastropod mollusc form the basis of a thriving shellfish fishing industry in Scotland.
The landings are dominated by the Norway lobster, Nephrops norvegicus which occurs in four main areas, one of which, the Fladen ground, is in close proximity to mature oil fields. The fishery for this species in the North Sea is likely to increase, with diversion of effort from the demersal fisheries for cod and other whitefish.
Much of this expansion should take place at Fladen where the stock is at present under-exploited. It is likely, however, that trawl gear used in the Norway lobster (and pink shrimp) fisheries will be required to be more selective in order to reduce the by-catch of demersal fish, especially cod, and the wastage through discarding of under-sized fish.
Relevant aspects of the biology of each species are described, including habitat preference, distribution, feeding, life-cycle, reproduction and spawning. Details are given about the fishing methods used, assessments of the state of stocks, and the management regime and legislation currently used to control each fishery.
