Identification and characterization of cyanobacteria population in organic milkfish farm during wet and dry season

Abstract

This study was conducted to identify and characterize the cyanobacterial population in organic milkfish farm during the wet and dry season; and assess water quality parameters in three milkfish ponds in Brgy. Tiwi, Barotac Nuevo, Iloilo. Four (4) species were identified using partial 16s rDNA sequencing, namely: Synechococcus sp. MMG-15, Synechococcus sp. NB0720, Nostoc sp. NTK29, and Haematococcus lacustris. Seasonal variations showed Haematococcus lacustris (0.447 cells/mL) dominance during the dry season, and Nostoc sp. (1.00 cells/mL) thrived during the wet season. The highest cyanobacterial densities during wet and dry seasons were found in Nostoc sp. (W=1.00 cells/mL, D=0.212 cells/mL), followed by Synechococcus sp. (W=0.722 cells/mL, D=0.271) and Haematococcus lacustris (W=0.586 cells/mL, D=0.447 cells/mL). It is found out that dissolved oxygen and nitrate levels varied significantly between the wet and dry season. Furthermore, results of this study indicate higher cyanobacterial abundance during the wet season. Finally, proactive water quality monitoring and cyanobacterial control measures are recommended for sustainable fish production.