| The efficiency of the scallop dredge used in baie de St Brieuc (Britany) has been directly determined by divers swimming along the track marks left on the bottom. Results, concerning essentially year class two, show that efficiency and damage caused by the dredge on scallops are highly variable according to nature of the sea bed. On smooth grounds, the average efficiency is 67% and the average percentage for severely damged scallops is 2% ; on rough grounds, theses percentages are respectively 30% and 17%. These results associated with a dredge survey on a particular area of the baie de St Brieuc allow an assessment of scallops abundance. The statistical method used, relevant to the geostatistic theory, takes into account the scallop spatial distribution... |
