Used to fish more efficiently with grid Measures the grid’s angle, indicating the catch volume
Shows if the waterflow through the grid is blocked, resulting in loss of catch
Applicable for bottom and pelagic trawls
The aim was to fish for shrimp in fields with many small fish, but without taking the latter as a by-catch. In many countries there are regulations regarding trawling, and in some areas it is mandatory to use a grid in the cod end.
Use of GridSensor
The Scanmar GridSensor was developed to show the precise water flow through the grid, and also the grid’s angle. The angle will give you a good indication of the filling in the cod end, and if the trawl has twisted.
Water flow through the sorting grid is the most important observation. Not infrequently, the grid becomes blocked by skate, seals, shark, stones etc. In some seasons, big swarms of jellyfish seal the meshes in the cod-end, preventing water from flowing out. In these cases it is necessary to end the haul.
Changes to the angle give a good indication of the catch volume at any time, and the logging curve also shows where the influx was greatest.
With shrimp (and fish without a swim bladder), the cod-end sinks as it fills up. It is therefore usual to start with an angle above 50 degrees and to finish towing when the angle approaches 37 or 38 degrees.