Causes and consequences of a large-scale shift from sugar kelp (Saccharina latissima) to ephemeral algae and implications for management

The SACCHARINA project is based on the dramatic decline in the sugar kelp forest along the coast of Southern Norway. The sugar kelp normally dominates the sea-bed at 2 to 15 m depth in sheltered coastal areas of the Norwegian coast. Surveys have found tha t the sugar kelp forests have disappeared from large areas of the sheltered archipelago and are replaced by total dominance of a ?carpet? of silty turf algae. This event has been given great attention by scientists and environmental authorities and severa l possible hypotheses have been suggested, including eutrophication and climatic events. The SACCHARINA project aims to achieve new knowledge of the main processes that are likely to be involved in the observed large-scale shift in vegetation. It will be difficult to find or test what actually caused the reduction of the sugar kelp, but more important the project aim to study processes of importance for re-growth and restoration of the sugar kelp forests in order to support coastal zone management decisio ns and ecologically based technical actions to help restoration of the kelp forest. The objectives will be achieved by experimental studies of recruitment, growth and competition in the laboratory (aquarium), in the field and in mesocosms (large outdoor t anks) where the environmental conditions will be manipulated. The SACCHARINA project will be undertaken jointly by a team of participants from Norwegian Institute for Water Research, Institute of Marine Research, University of Bergen, University of Oslo t ogether with international participants from Åbo Akademi University of Finland and University of Stockholm.