Validating the fishing locations reported in the logbooks using the positional data of vessel monitoring systems in the multi-day fishery of Sri Lanka

Abstract

As part of monitoring, control and surveillance of marine fisheries, a logbook monitoring and vessel monitoring system (VMS) were introduced for multi-day fishing. The present study investigates the possibility of using VMS data to validate logbook records of fishing locations of multi-day fishing vessels. The data from 1,424 multiday vessels were fitted with VMS, which was operated from May 2017 to April 2018. During the period, there were 17,626 fishing trips and 66,717 fishing occasions. In the VMS tracks where the locations were flooded, drift gillnet-operated vessels were seen as a condensed zig-zag pattern, while longline fishing vessels as curve-shaped tracks, and ring net fishing vessels as condensed locations had irregular-shaped clumps. The differences in coordinates of fishing locations in the logbook records matched with the tracks predicted by VMS in multi-day boats of three gear types indicating that almost all fishing operations were within ±10º of both latitudes and longitudes and further around 70% of fishing locations had less than 1 arcminute of a difference. Therefore, VMS track data can be used to verify and validate logbook records of fishing locations in multi-day vessels.