TrawlCam is a headline mounted camera which, by enabling skippers to visually identify the type of whitefish entering a trawl, will be invaluable in the predominantly mixed fishery Scottish vessels engage in, says Seatronics.
The system has just completed successful commercial fishing trials, after 18 months development, on Peterhead skipper John Buchan’s 30m single rig whitefish trawler, Ocean Venture II.
The company started with the initial idea of devising a camera system capable of mounting on single or twin rig trawls nearly two years ago. Seatronics had the hardware in place with other projects related to the oil and gas survey industry. While the operating principle and technique are virtually the same, the electronics used had to be fitted into much smaller housings suitable for mounting on a trawl headline and handling onboard a vessel at sea. These requirements created some interesting challenges that have been overcome.
Seatronics will release the TrawlCam onto the market during Fishing 2009 in Glasgow.
“Our initial thought was to design a system that could be interfaced into any vessel's existing cable winch system. Seatronics has many customers that use a cable winch with a side scan tow fish; a system that when deployed, has the capability to look directly across the mouth of the trawl. The skipper can easily unplug the side scan tow fish and replace it with TrawlCam which uses the same standard 2-core net sonde cable supplied on most vessels with sub-conn connectors as standard," said a Seatronics' spokesperson.
The TrawlCam is a full working system that enables the skipper to constantly monitor:
• The footrope (up to 10m from the seabed during trials)
• The belly of the net
• The size and species of fish entering the net
John Buchan jnr, skipper of Ocean Venture supplied some very interesting data during the last sea trial of Trawlcam.
“The data recorded is quite outstanding," said John Buchan. "On one occasion, we can clearly see the footrope, the ground gear and the net coming into contact with a very large boulder. The ground hoppers on Ocean Venture's trawl are 22 inches in diameter and we can clearly see the net coming fast, and the ground gear struggling to climb over the top of quite a large boulder. In normal circumstances, the tension of the wire increases, the skipper then watches patiently to see if the tension falls back to commence towing, but to 'see' why the tension on the wires has increased is a real eye opener. Half way through the trip, we saw that the trawl had part of the belly torn out, and to know this kind of information instantly is a clear indication that fishing effort has been saved."
