Frequency of algae along a transect at the island of Helgoland in 2005

A sublittoral transect (P3) in the North of Helgoland that had been investigated ~40 years earlier by Lüning (1970) was traversed again. Scuba dives were carried out between 24.06.2005 and 19.08.2005. For each sampling point, time, date and coordinates were given as well as the corrected depth in m mean low water spring tide. Along the transect, substrate and topography were recorded. Relative frequency and cover of 32 species grown attached to the seafloor and cover of 12 epiphytic species were obtained.