Skipper Ben Downs operates the west coast trawler FV Jamie Marie. Earlier in 2009, Ben installed a Notus Trawlmaster net monitoring system. A 30% increase in catch was reported as the skipper could fine tune the gear for optimal fishing.
Ben installed a Notus system to monitor: trawl wire lengths, door spread, door angle, trawl depth, headline height and footgear clearance. He has used Notus for mid water and bottom trawling. All sensors transmit information back to the vessel wirelessly and a 3D graphic is display in the wheelhouse.
Ben says “right away we could see the spread vary on the mid water gear from 30 to 70 fa. We immediately started to work the equipment to constantly keep 70 fa of spread.” After the spread was sorted, Ben started to discover additional ways to fine tune the gear. For example, he says “It was a waste of time to try and fish while turning as one door would go so much higher than the other. It was a lot better just to turn quickly and start fishing again.”
Mid water trawling is a fast pace fishery. Ben says “one of the biggest advantages of Notus is that you could constantly fine tune the gear.” Notus measure the trawl warps (wirelessly) and also indicates the adjustment when the trawl is off to one side. With this feature Ben was able to see “with a 5-7 m difference on the door distances, I could lose 20 fa of spread.”
Notus was just as important when bottom trawling. On the first tow, Ben says “we found our door spread had a max of 80′ instead of the 190′ we needed to properly spread”.
Ben also found the door angle sensor to be very important. He says “as soon as the doors break free from the bottom, we would see the door stand straight up.” As well, when the doors were falling over “we could throttle up to get the doors up again.” Another important adjustment based on the door angle was the trawl wire out.
Ben says “With too much warp out, the door would fall over and you would have to haul in wire to make it stand up again.” Surprisingly, Ben also learned that when bottom trawling, “the amount of wire out makes little difference to the door spread.” This gives the option to fish with less wire which does result in fuel savings.
