Although innovative tech company Marelec has expanded in recent years into sophisticated weighing and processing systems, the company’s roots lie in deck and winch systems for fishing vessels – and it hasn’t forgotten where it started out.
At the end of last year, Marelec trialled AI Catch, a system of filtering catches as they enter the cod-end of a trawl, sorting fish to be released from those to be retained during a tow.
Trials were carried out in collaboration with research body ILVO OOstende over three days onboard research vessel Simon Steven, with five tows on the Westhinder and Middelkerke banks in the North Sea, to depths of around 35 metres, and with the gear deployed for approximately 36 hours.
The system includes a sonar scanner ring in the net and a gateway that closes in the event of undersized fish or by-catch making their way down the tunnel, and returning them to open water. This ensures the survival of undersized fish and fauna by automatically redirecting them back to safety. The system is linked to the vessel via a cable through a specially controlled winch. The skipper can monitor the operation of the system in real time on a screen in the bridge.
“Following the implementation of some practical improvements, further field trials are now anticipated,” a Marelec representative commented. “This system could prove to be a milestone in efforts to reduce the by-catch of undersized fish and increase the sustainability of the fishing industry.”
Marelec set out to develop an innovative solution to release bycatch directly and alive, which resulted in AI Catch, which employs advanced technologies to scan fish swimming in the net and then sort them underwater based on commercial value.
One of the challenges in beam trawling is limited visibility underwater, making traditional camera systems ineffective. Marelec has overcome this by using internally developed ultrasonic sonar sensors to detect fish in the net. Through advanced imaging technology, the length of the fish is accurately determined, after which intelligent software decides whether the fish should be captured or directed to an escape route via a valve just before the cod end.
Marelec developed all aspects of this internally, including sensors, mechanical valves, motors, electronics and software. This includes imaging, interpretation of sensor data, valve control, and real-time information provision for the skipper.
