Deep Vision successful trial for commercial bottom trawling
A downsized version of the Deep Vision system has been trialled on a demersal trawl cruise in Scotland as part of the Smartfish project. – The results showed that a simplified deployment section can be used to collect images of sufficient quality for species identification and length measurements, says Dr Shale Rosen at Institute of marine Research (IMR).
The aim of the cruise with R/V “Alba na Mara” was to test a simplified, compact, deployment setup of the Deep Vision in-trawl stereo camera system that will be appropriate for the Scottish demersal trawl fleet and similar fisheries. The Deep Vision stereo cameras, lights and battery were housed in a smaller frame weighing only 41 kg, with a solid, light coloured background provided by lining the trawl with a white tarpaulin.
– I think the results were positive both in terms of the visibility of the images in demersal trawling conditions (Ed. note: See image) and the testing of a more flexible imaging chamber rather than the rigid frame we usually employ. Visibility was compromised in only a small percentage of the images to the point where passing fish could not be counted or identified by a human analyst and the flexible chamber was very promising, says Dr Rosen who attended the cruise from IMR.
The work was conducted as part of the project “SMARTFISH: Selective management and retention of target fish” with partners and support from Marine Science Scotland, IMR and CRISP Centre for Research-based Innovation in Sustainable fish capture and Processing technology, and funded by the Research Council of Norway.
– The version tested was just a trial, but provided very good direction on how an improved follow-up model should be constructed, says Dr Rosen.