Spatial mapping of fishing by Trawl fleet along the northeastern Arabian Sea: A Passive Geo-referencing technique in spatial data-sparse fishery

Trawlers are the key fishing fleet, which is contributing significantly to the global marine fish catches because of the harvest efficiency and mechanization techniques. The trawl fleet comprises multi-day trawlers, MDTN, and mechanized trawlers, MTN in the region. The passive georeferencing technique (using haversine function) was attempted to locate possible fishing grounds using distance and bearing data. The mean distance traveled by MDTN and MTN fleets was 97.41 ± 77.33 km and 17.65 ± 9.64 km, respectively. Distinct variations in depth of operation were observed for MDTN and MTN at 71.56 ± 41.04 m and 26.48 ± 9.96 m, respectively. The depth and distance of fishing by MDTN were much greater than the MTN fleet in the region because of the duration of fishing, target resources, and fishing craft durability. The catch rates were higher in the case of MTN (Mean ± SD, 62.77 ± 39.82 kg/hr) than the MDTN (Mean ± SD, 32.57 ± 16.95 kg/hr). The research deliverable from the current work gives a comprehensive understanding of trawl fishery, range of operation, abundance and fishing intensity zones, and temporal preferences, etc. The results could be taken as decision tools in fishery management plans, inter-sector conflicts, declaration of MPA’s, and Marine Spatial Planning (MSP) in the region.