Distribution characteristics of culturable bacteria in surface water of Daya Bay and their correlation with environment factors

Based on the culturable bacteria populations (CBP), temperature, salinity, pH, nutrients, chlorophyll a (Chl a), and other parameters obtained in surface water of Daya Bay in August 2020, this study focused on the distribution characteristics of CBP and their correlation with environmental factors mentioned above. The results showed that the cultivable bacterial abundance ranged from 100 to 1700 CFU/mL, with an average of 518 CFU/mL. The CBP in the surface water of the Daya Bay showed a decreasing trend from the inner bay to the outer bay. The CBP in the surface water presented significant negative correlation with salinity and pH (P<0.01, n=16), while significant positive correlation with phosphate (PO₄-P), silicate (SiO₃-Si), nitrite (NO₂-N), ammonium (NH₄-N) and chl a (P<0.01, n=16), indicating that the CBP were probably related to terrigenous input, and the growth and reproduction of bacteria were promoted by high nutrients near shore.