Fishing and Gear Technology

Unit 11 - Trawl fishing gear and operation

11.7.Mid water Trawls
11.7.1.Rope trawl
Rope trawl was developed during 1970 in Poland, Germany, Norway, France and Netherland. In all designs rope can be found in three or four panels running from; head rope, foot rope or side rope down to approximately one quarter of the length of the net.The biggest concern in the design was what shape the leading ropes were going to take. Unlike normal netting, the ropes are independent of one another on the basis of equal tension in each of the ropes. Wings are narrow at the top and wider at the bottom, with a very small bosom resulting in a very noticeable reduction of drag. But this is not superior to conventional gears in the quantity of catch. The ropes do not have herding effect on fish that a normal net do. An explanation of this can be that these ropes which are stretched in the direction of towing seems to be static to fish. But the sound and the vibration that goes along with the movement of the ropes makes the fish to get away. Between the ropes, water does not move and it is safe and easy for fish to escape. As a comparison, these make a whole wall of vibrating water between the twines drive the fishes into the net.