Underwater observations on escallop (Pecten maximus L.) beds

Abstract

In an age-frequency distribution plot of a biological population, it is axiomatic that there should be, in general, a preponderance of young. This expected distribution is not found when sampling some marine animals, notably lobsters and escallops. Many workers, including Priol (1930), Tang (1941), Elmhirst (1945), Baird (1952), Fairbridge (1953), and Mason have noted the absence ofyoung escallops (Pecten sp.) in the expected numbers in dredge hauls.A dredge without teeth, lined with sprat netting, was used at Brixham in an attempt to catch the young escallops, but this dredge filled so quickly with sand, gravel and shell that very few escallops were caught, although those taken did have a generally lower size-range than the escallops caught with a standard toothed dredge. At Castletownbere (Co. Cork) a naturalist's dredge similarly failed to catch many escallops.