Project Status - Complete
Start Year: 2002
End Year: 2005
Funding Body: BIM under National Development Plan 2000-2006

Geographic Area:
Local Study Area:

Project Co-Ordinator: Oliver Tully, BIM
CMRC Contact: Gerry Sutton

Abstract

Irish vessels fish for scallops in both inshore and offshore waters off the southeast coast of Ireland, in the Irish Sea and English Channel. Fishing effort potential peaked at 528 dredges in 2002. Landings peaked at 1891 tonnes in 2004. The fleet supports a number of processing plants in south Wexford. Fishing activity of the fleet is limited, by European legislation, to 525012 kilowatt days per annum.

The Scallop Advisory Group provides a co-operative forum within which management plans for the fishery are developed. Hydrodynamic and particle tracking models indicate that temperature and currents off the south east coast control the dispersal of scallop larvae and growth and accumulation of toxins by adult scallops. Seabed maps, developed using multibeam acoustic methods, and annual scallop surveys, indicate that scallop abundance is highly correlated, on broad and fine spatial scales, with the composition of the sediment.

Catch rates, derived from private diaries and official logbooks, and standardised for vessel and weather effects, declined in some areas by 20-50% between 1995-2004. Catch rates, however, were largely stable in deeper waters between 1999 and 2004. Fishing activity data needs to be collected at fine spatial scale, ideally using electronic logbook systems, to allow safe interpretation of trends in catch rates. Spatial management of effort is important in order to conserve spawning areas that act as sources of recruitment and to optimise yield per recruit, given that growth rate varies spatially. The seabed maps can be used to reduce dredge effort and increase catch rates and efficiency of the fleet but must be paralleled by additional or alternative management measures in order to give adequate protection to stocks.