The density of giant kelp > 1 m tall is recorded in four contiguous
20 m x 1m swaths that run parallel and adjacent to each 40 m transect.
Each transect has 2 sides. Kelp data is recorded on both sides of the
transect tape (inshore and offshore) in two twenty-meter-long sections
(0-20 meters and 21-40 meters) for each transect, resulting in
selected sections for each transect.