This logbook is maintained to track catch and effort of albacore using hook and line gear, particularly by trolling. Catches are expressed in number of fish. This logbook is generally maintained on a daily basis and sometimes even on a partial-day basis, and includes information pertinent to each day at sea over the course of an entire fishing trip. For example, a typical logbook contains daily records regarding where the vessel was (latitude and longitude) and for days when actually fishing, the number of albacore caught and discarded. For the most part, returned logbooks contain complete records regarding days spent fishing (say versus days spent transiting to fishing areas). Logbooks are mandatory, self-reported by the fishers and collected by the California Department of Fish and Wildlife (CDFW). The NOAA Fisheries Southwest Fisheries Science Center (SWFSC) receives these logbooks and then compiles the data into an in-house database. Comparisons of landings and logbooks collected indicate that some logbooks are missing in some years. The data are owned by CDFW and managed jointly by CDFW and SWFSC.
The logbook data records catch and effort at discrete latitude/longitude points for each set made. Using the discrete points, a raster layer was created using the Point Density tool in ArcGIS to create a map of where the points reported in logbooks are more and less dense.