Inventory and Stock Assessment of Gracilaria Spp. in Ilocos Sur

Abstract

Sargassum, one ofthe country's seaweed exports, abounds in the coastal barangays of Ilocos Sur. Although dominant in most months of the year, no published report has been made in the area prior to this study. Taxonomic and standing crop studies were performed for a period of two years. Environmental parameters like temperature, salinity, and water movement were also monitored as they affect Sargassum biomass production. Four species were observed in the area: Sargassum crassifolium, S. cristaefolium, S. polycystum, and S. siliquosum. All four species showed different growth patterns and seasonal dominance. Data on biomass production show that Sargassum is abundant in the coastal towns of Ilocos Sur. The reefs which extend several meters seaward in most coastal municipalities support algal blooms anytime of the year. Temperature and water movement affect Sargassum biomass production. Greater production occurs during coldermonths andin areas with moderate water movement. Consideration of these two ecological factors are important for proper management of the resource.