Mechanised fishing vessel owners on Monday picketed the Fisheries and fishermen Development Department to press their demands. The fishermen could not venture into the sea since September 10 since, the estuary became shallow due to sand accumulation affecting the movement of fishing vessels. In spite of several requests, the Puducherry administration failed to take steps to dredge the estuary to ensure the movement of vessels. The fishermen resorted to a series of agitation including dharna after hoisting black flags on their vessels. As part of the agitation,they resorted to a picketing at the Thengaithittu fishing harbour.