Infralittoral: A subzone of the sublittoral in which upward-facing rocks are dominated by erect algae, typically kelps; it can be further subdivided into the upper and lower infralittoral (based on Hiscock, 1985). The term is also used by Glémarec (1973) to refer to areas (étages) with a eurythermal environment of great seasonal and also daily and tidal amplitude. 1) lower The part of the infralittoral subzone which, on hard substrata, supports scattered kelp plants (a kelp park) or from which kelps are absent altogether and the seabed is dominated by foliose red and brown algae. It may be difficult to distinguish the lower infralittoralwhere grazing pressure prevents the establishment of foliose algae. 2) upper The part of the infralittoral subzone which, on hardsubstrata, is dominated by Laminariales forming a dense canopy, or kelp forest (based on Hiscock, 1985).