Summary
Stand reductions and disappearance of sugar kelp (Laminaria saccharina) has been observed along the south and southwest coast of Norway in recent years. The reductions has been most pronounced in wave protected and semisheltered areas, where dense forests of sugar kelp have been largely replaced by carpets of filamentous algae, covered by sediments. The causes and ecological consequences of these vegetational changes are still unknown. Kelp forests are highly productive and diverse communities, providing important feeding and nursery habitats for many species of fish, and their disappearance may thus have negative effects on coastal ecosystems.