Seasonal variations in the fucoidan content of brown algae from Peter the Great Bay, Sea of Japan

The seasonal dynamics in the level of fucose-containing sulfated polysaccharides (fucoidans) have been studied in three brown alga species from Peter the Great Bay, Sea of Japan: Saccharina japonica, Sargassum pallidum, and Stephanocystis crassipes. In the latter two species, seasonal variations in the fucoidan content have been analyzed for the first time. During the year, the level of fucoidan in S. japonica varied from 0.98 to 4.19% dry weight; in S. crassipes, from 2.50 to 5.23%; in S. pallidum, from 1.86 to 6.31%. The maximum amount of this polysaccharide is accumulated in algae during reproduction: in August-October for S. japonica; in June and July for S. crassipes; and in July for S. pallidum. No significant correlation has been found between the level of fucoidan in algal tissues and the annual dynamics in sea water temperature, salinity, and concentration of biogenic elements. The obtained data can be helpful in determining the time to harvest algae for fucoidan extraction.