Abundance of filamentous algae on Kappahycus alvarezii and Eucheuma denticulatum cultivated by vertical net

Abstract

Filament algae that attach to the Kapapphycus alvarezii thallus are mainly Chaetomorpha crassa, Cladophora sp. and Elachista flaccida. Algae fillament attached to the thallus K. alvarezii affect several factors including nutrient absorption and competition for sunlight. The purpose of this study was to determine the comparison of the number of algal filament attached to the thallus Kapapphycus alvarezii and Eucheuma denticulatum. The results showed that the most dominant filament attached to the thallus E. denticulatum was C. crassa with the highest number of filaments was 155.6 filaments/cm 2 with a wet weight of 2.98 g. the number of filaments of Cladophora sp is 13.8 filaments/cm 2.E. flaccida was found to be widely attached to the talus K. alvarezii. The number of filaments attached to the K. alvarezii thallus is 17.8 filaments/cm2 and was found on the 20th day. The average specific growth rate of K. alvarezii and E. denticulatum is 2% / day. this growth rate is not affected by the presence of algal filaments attached to the thallus. Physical-chemical parameters of the waters during the study showed that the temperature of the waters ranged from 29-30 °C, the brightness at study site was 9.1-9.35 m, the current speed ranged from 0.092 to 0.49 m / s. Salinity ranges from 30-33 ppt, nitrate ranges from 0.0237 to 0.0416 mg/L, Phosphate ranges from 0.0015 to 0.0036 mg/L and DO ranges from 5.7 to 6.4 mg/L. Pearson correlation analysis results confirm that seaweed growth has a positive correlation with current velocity and nitrate.