An assessment of scallops, Pecten maximus Linnaeus, 1758), in Scotland west of Kintyre

This paper describes an assessment of a fishery for Pecten maximus using virtual population analysis, a method much used in ICES fish stock assessments. Despite obvious differences between bivalves and fish in both biology and the natures of the fisheries, the method performed adequately on data aggregated over large areas. Long term trends in yield, stock biomass and recruitment calculated from annual VPA are described. Total stock biomass and recruitment are clearly related, high biomass following years of good recruitment. Recruitment appears more important than fishing mortality in determining stock biomass. It is tentatively suggested that recruitment a year ahead might be predicted; if so, prospects of forecasting catches would be good. The yield per recruit curve is flat-topped, indicating that the present realized values are near the maximum likely to be obtained. It is concluded that there is no special reason for concern about the present level of exploitation of the stock. -Authors