Cultivation of Laminaria hyperborea in situ and in continuous darkness under laboratory conditions

Abstract

1. Two and three year old specimens of Laminaria hyperborea were transplanted to sub-tidal growth stations at 2 and 6 m water depth, respectively. 2. Maximum growth rate occurred in early May in specimens growing at 2 m depth, and in early June at 2 m depth. 3. Frond area size, attained by the specimens growing at 6 m depth in July, was at least 75 % of frond area size attained at 2 m depth. Stipe length of plants at 6 m depth, as recorded in July, was only about 1/3 of the stipe length attained at 2 m depth. 4. Growth rates of new phylloids of Laminaria hyperborea specimens kept in darkness from February until May are considerably reduced, if the old frond is amputated. © 1970 Biologischen Anstalt Helgoland.