Using Vessel Monitoring System (VMS) Data to Identify and Characterize Trips Made By Bering Sea Fishing Vessels

Changes in marine environments, fishing regulations, and the timing of physical and biological processes may require fishers to redistribute their effort in time and space, or even to different target species. By examining fishing patterns and deliveries, we can model how changing fishing locations impact the ports and processors where fish are delivered and how longer trips may affect fishers’ stress and profitability. Vessel monitoring systems (VMS) are increasingly required in fisheries worldwide to monitor the locations of vessels in real-time. These electronically collected data facilitate resolution of vessel behaviors, regardless of whether the vessel has a fishery observer on-board. We used VMS data to identify the starts and ends of observed and unobserved trips made by catcher vessels in the United States Bering Sea fishery for Walleye Pollock (Gadus chalcogrammus) from 2003 – 2013. Integrating a series of spatial, speed, and time filters, we characterized trip durations and distances traveled for >50,000 fishing and non-fishing trips. Our algorithm was tested against more than 10,000 trips for which fishery observer data were available. With only slight modifications, our algorithmic approach has been successfully adapted to other trawl and longline fisheries in the Gulf of Alaska and the Gulf of Mexico.