Seasonal changes in biomass and net production of Ecklonia kurome Okamura community off Gounoura, Iki Island, northern Kyushu, Japan

Abstract

Annual net production of Ecklonia kurome Okamura growing off Gounoura, Iki Island, northern Kyushu, was investigated from December 2011 to December 2013. Densities of adult E. kurome ranged from 17.6 to 40.8 inds. m^-2 and their biomass was 302 to 1,532 g dw m^-2. The number of newly produced bladelets ranged from 0.01 to 0.23 day^-1, being lower in summer and higher in winter. Annual net production of E. kurome was estimated at 2,785 to 2,880 g dw m^-2 year^-1. Compared with the congeneric species Ecklonia cava Kjellman, E. kurome in northern Kyushu had a lower weight of maximal biomass whereas they shared an equivalent level of annual net production.