This feature class contains summary spatial data summarizing historical bull kelp distribution in South Puget Sound. This data was developed as part of a research project described in the publication: Long-term changes in kelp forests in an inner basin of the Salish Sea (Berry et al, 2021 PLOS ONE).

These line features approximate the -6.1 m bathymetry contour, divided into 1 km segments. Includes attributes for the study findings. Line is derived from the line feature used by the SVMP and Marine Vegetation Atlas (minor edits include replacement of flats with 1 km sites, addition of shoals, minor adjustments.)