Trials onboard the FV Favonius out of Peterhead showed Echo can successfully detect where you are catching prawns. The technology solves one of the major issues in the prawn industry: where are prawns being caught throughout a tow? Currently, Captains are fishing blind. Prawns cannot be detected with any shipboard or trawl mounted sounders or sonars. 1000’s of hours are wasted towing in areas with no prawns.
A pickup device (pictured below) is installed in the tunnel of the trawl. As prawns hit this pickup device, the Echo sensor listens for the sound and transmits the data back to the vessel in real time. Seafield Navigation of Fraserburgh worked very closely with the Favonius to fine tune the technology. The pickup device went through various versions. Fish can still easily enter and the pickup wraps around the drum. This is NOT a grid.
The Echo consists of a sensor in the trawl communicating wirelessly to a hydrophone mounted in the vessel. Echo listens for prawns hitting the pickup device. The data suggests prawns congregate in “hives.” You are catching when going through the hives and the rest of the tow, you are probably only catching water! Analysis of Echo data has indicted on a 5 hour tow, the vessel was can only catching prawns for 40 mins.
In the wheelhouse, the information is graphed. The aside prawn shows the “hot spot” was at the beginning of the tow with catches dropping off dramatically as the tow went on.
Captain Andrew on the Favonius says, “We were surprised how well the Echo worked. We have made preliminary tows with Echo. Echo showed me where the prawns were.”
The technology has also been evaluated by BIM. In their report, BIM noted, “A review of underwater camera footage after this haul showed a relatively high number of Nephrops…..suggesting that the Echo system was working well.”