Seasonal sampling was carried out between spring 2005 and winter 2007, always choosing days with calm sea conditions. Every samping day, three sporophytes were collected by the same scientific SCUBA diver from each of three replicated transects. Kelp pants were individually analyzed for maximal holdfast diameter, stipe number, number of dichotomies per stipe, total plant length, frond width, total drained wet mass, phylloid length, sori number, sporophylls number and phylloid length in the laboratory.