began in the 1940s, and reached its peak in the 1960s. It is still probably the most important local commercial fishery.

Side-scan sonar image of bottom marks left behind by a clam
dredge. The marks are on the order of one foot deep. Even the trails of much smaller scallop dredges are quite obvious to divers.

There must have been something especially good at this location to be worth dragging over it repeatedly in circles. In inshore areas and bays, dredging like this is extremely destructive of aquatic vegetation and shellfish beds, and is prohibited. It is estimated that the entire area of the Grand Banks is dragged-over like every year. This is a tremendous disturbance. New Jersey is probably similarly used.

Dredge dimensions are approximately 6-9 feet wide by 18-20 feetlong; each dredge is custom-made on-site as needed. Construction is welded steel. The dredge is raised and lowered on the steel cable, which is slackened when towing. The dredge is towed on a 3-4" nylon line; movement is in the direction of the arrow. The elasticity of the nylon prevents the whole towing apparatus from being destroyed should the dredge be hung-up on an obstruction. The steel cable also serves as a backup should the nylon line part.

Water is pumped down from the boat through the 8" water hose into a manifold at the front of the dredge. Nozzles in the manifold direct water jets into the sea floor to break it up and raise out the clams, which are scooped into the dredge by the cutting bar