This GIS data represents the current core distribution area Rice's whale based on the best available data. The GIS data will be updated and could change as new data are collected. This Core Area polygon was created by drawing a convex hull polygon around all recorded Rice's whale sighting locations from NMFS SEFSC surveys and tag data collected between 1989 and 2018. The convex hull polygon was trimmed on the western-side to the 410 m. To incorporate the high degree of uncertainty in the whales’ distribution into a definition of core distribution, a 10 km buffer was applied to capture the uncertainty in position data and the 10km strip width of the visual surveys, followed by addition of a 20 km buffer to this "position uncertainty" to account for the possible movement whales could make in any one direction from an observed sighting.