AK Groundfish Fisheries text here
FMP Species text here
This dataset depicts a combination of observed and unobserved vessel tracks in a single dataset. Vessel lines are meant to be a representation of where a vessel was fishing during that time. This data is calculated as follows:
Observer data is combined with VMS data and cleaned for outliers. Lines are created from this combination of observer and VMS data. Catch and vessel data from observer database is joined to the lines.
An unobserved vessel’s VMS ‘fishing’ points are captured when the state statistical match what is reported, the vessel’s calculated VMS speed is between .9 and 4.1 knots, and the time period is correct (a trip for a catcher vessel or day for an unobserved catcher processor). VMS data is sorted on date-time and a line is created from the points. Line segments longer than 12km without a VMS points are removed, as line segments longer than 12km are often found when the vessel is transiting rather than fishing.