Browsing by Author "Ragaza, A. R."
Sargassum studies in Currimao, Ilocos Norte, Northern Philippines I. Seasonal variations in the biomass of Sargassum carpophyllum J. Agardh, Sargassum ilicifolium (Turner) C. Agardh and Sargassum siliquosum J. Agardh (Phaeophyta, Sargassaceae) Three species of Sargassum (S. carpophyllum, S. ilicifolium and S. siliquosum were collected each month for a period of one year from the inter- and subtidal zones of Pangil, Currimao, Ilocos Norte, The Philippines. Average monthly biomass was species-specific and significantly influenced by the effect of fertility states of the seaweed, collecting zone, and collecting months. A higher biomass of reproductive plants was accounted for in all species in both zones. Among the three species, S. siliquosum had the highest reproductive and vegetative biomass in both zones, followed by S. carpophyllum and S. ilicifolium. Maximum fertility was observed in October for S. carpophyllum and in November for S. ilicifolium and S. siliquosum. Minimum and maximum reproductive biomass was recorded in May and December, respectively in all species. Biomass of vegetative or non-fertile plants was highest in September in all species except for S. carpophyllum, while minimum biomass was recorded in March for S. carpophyllum and May for S. ilicifolium and S. siliquosum. Reproductive plants had more biomass than vegetative plants. The average monthly wet biomass (g m−2) of other Sargassum species was higher in the subtidal than in the intertidal zone. The biomass of seaweeds associated with Sargassum did not follow a definite pattern. Although water temperature, pH and salinity values were relatively constant, slight variations of temperature were positively correlated (P = 0.05) with subtidal biomass.
Sargassum Studies in Currimao, Ilocos Norte, Northern Philippines II. Seasonal Variations in Alginate Yield and Viscosity of Sargassum carpophyllum J. Agardh, Sargassum ilicifolium (Turner) C. Agardh and Sargassum siliquosum J. Agardh (Phaeophyta, Sargassaceae) The yield (%) and viscosity (cps) of alginate from Sargassum carpophyllum, S. ilicifolium and S. siliquosum collected along the inter- and subtidal zones of Currimao, Ilocos Norte were determined monthly for a period of one year. Results show that each species demonstrated an individual pattern of alginate characteristics which is significantly influenced by the collecting zone, fertility state, and collecting month (P < 0.05). Positive correlations were observed in alginate yield and viscosity with species and fertility states. Among the three species, S. ilicifolium is the best species for alginate production for the food industry based on viscosity characteristics, followed by S. siliquosum and S. carpophyllum.