Bacterial density variations of the coastal waters from three marine aquaculture centers in Bali, Indonesia

Abstract

Abstract The highly dynamic nature of marine waters can create unique characteristics for bacterial communities. The purpose of this study was to quantify the number of bacteria present in the beach sand and coastal waters of three marine aquaculture centers in Bali, Indonesia. Two locations that have developed were selected (Patas Village and Candikusuma Village). While an advance centre was located in Sumberkima Village Bay. Sampling was done in March-April 2021. Seawater and beach sand from the three locations were collected and analyzed for total plate count bacteria, Vibrio sp., halotolerant bacteria, rod-shaped gram-negative bacteria and anaerobic facultative bacteria. Sampling of sea water was carried out at 4-5 points around floating net cages and beach sand around the location. The sampling results showed that the total plate count bacteria and halotolerant bacteria in coastal waters from the three locations were less varied. While number of Vibrio sp. in Candikusuma Village lower than the Vibrio sp. in two centre. Rod-shaped gram-negative bacteria were found in advance centre (Sumberkima Village). Sand beach bacteria from Sumberkima Village and Patas Village have similar number of total plate count bacteria, Vibrio sp., halotolerant bacteria and rod-shaped gram-negative bacteria. However, the number of these bacteria were significant different with the same bacterial on the beach sand of Candikusuma Village, except anaerobic facultative bacteria. These results indicate that the bacterial population is influenced by development of aquaculture activities in coastal waters.