With the current resource problems facing the fishing industry, fishermen are often seeking way to improve their efficiency. One method that is gaining popularity among trawl fishermen is the use of acoustic gear sensors. Typically, fishermen rely on their knowledge of how their boat works and feels to know how their net is behaving under water. With the use of acoustic sensors placed on the trawl gear fishermen can have a much better understanding of what is happening under water to maximize their productivity and increase overall efficiency.
Captain Jim Ford is a fisherman out of Newburyport, MA and has been using sensors on his trawl gears for the past four years. He has sensors on the doors of his trawl gear, which are used to spread the net. While fishermen generally know by feel how much they are spreading their net, Ford’s sensors provide him with real time information, displayed on a computer screen, of how his doors are passing through the water column. Ford also has a catch sensor, sometimes two, in the codend of his net, the section of the net that holds the fish that are caught. The idea behind the catch sensor is to notify Ford when his codend is filled with fish so that he can haul in the net, empty out the fish, and start a new tow. Depending on what species of fish Ford is fishing for, he sets the catch sensor to a maximum weight, say 2,000 lbs. When the codend is filled with 2,000 lbs of fish, a light goes off on his computer screen notifying Ford that his net is full and that he can haul it in.
Sensors provide fishermen with a better viewpoint of what is happening under water. Without a sensor a fishermen will pick a tow time, say two hours, and only deviate from that time if they feel a large change in the feel of their boat. Besides feel, they have no way of knowing how full their net truly is. They may catch all of their fish in the first thirty minutes of their tow yet they will keep going for another hour and a half to complete the two hours. During this time they are decreasing fuel efficiency, reducing the amount of fish they can catch, and decreasing their fishing efficiency. By having a sensor that notifies the fishermen that their net is full they can know exactly where they caught the fish so they can stay in that area and reach their desired total catch in a shorter period of time. Fishermen already know the ocean; sensors just give them a little added information that improves the way they fish.