Studies on the recruitment of Sargassum spp. (Fucales: Phaeophyta) in Balibago,Calatagan, Philippines

Two separate 1?m² plots were cleared of algal cover every 3 or 4 wk for 1 yr and each time, one was filled with cleaned, sun-dried coralline rocks. These plots were closely monitored in subsequent months for any sign of Sargassum regrowth. Control plots were also monitored during the same period. New growth was first detected in December in cleared and control plots, 3 months after the start of the reproductive season for Sargassum spp. in the area. New growth was observed in the plots with coralline rocks in January, and only on rocks placed at least 3 months earlier. No new growth was observed in cleared and control plots after June, nor throughout the rest of the experimental period on rocks placed after October. Pre-conditioning of the coralline rocks appeared to be a prerequisite for settling of Sargassum germlings and the importance of timing in laying these rocks for successful colonization of Sargassum spp. is discussed.