Growth of the Queen Scallop Chlamys Opercularis in Suspended Cages in the Firth of Clyde

Abstract

INTRODUCTIONEstimations of the growth of bivalves have traditionally been determined from measurements of animals collected on a regular basis from natural populations. Generally size frequency distributions have been analysed or growth rates estimated from measurements of the distances separating the annual rings (Hughes, 1970; Seed & Brown, 1978; Taylor & Venn, 1978). While both methods provide valuable information on shell growth, a more direct approach is to investigate experimentally the growth of individual animals held in cages and to follow the seasonal changes in the dimensions of their shells.The queen scallop Chlamys opercularis (L.) is found in large numbers in areas around Great Cumbrae Island in the Firth of Clyde where they form the basis for a small local fishery. In 1979 the British Steel Corporation started operating a deep-water terminal at Hunterston unloading and loading iron ore and coal. It was envisaged that accidental spillage of material during transfer from the vessels to the shore might affect the queen scallop populations in the area.