Ballast water from ships berthed at major ports of Malaysia

With the adoption of the Ballast Water Management Convention in 2004, research attention has been conducted on the development of ballast water treatment technology, but few studies focuses on the contents of ballast water discharge at ports. In this study, we collected ballast water samples from ships berthed at major ports in Malaysia to determine the types of organisms present, mainly plankton and microbes. We also formulated a ballast water quantifying method using the “bucket” system. Throughout the study period from November 2012 to May 2014, ballast water samples were collected from 36 ships, of which 28 ships were container ships. The ballast water samples were mostly collected manually through manholes and by means of overflow through airvents. The phytoplankton and zooplankton densities in ballast water were in the range of 25 -77600 cells/L and 0.26 – 450 individuals/L respectively. We identified a total of 119 phytoplankton taxa, of which 7 taxa belonged to the dinoflagellates group. This group of phytoplankton has the potential to form harmful algae bloom. For zooplankton, a total of 53 taxa were found in ballast water samples. This included a number of potentially invasive taxa that we were unable to identify to genus and species level such as zoea, fish eggs, ophiopluteus, larvae of polychaete, barnacle, actinula, starfish, bivalve and gastropod. As for E. coli, the colony count ranged from 0 – 256 CFU/100mL, while both Vibrio spp. and Enterococcus had colony count ranging from 0 to TNTC (too numerous to count: >300 CFU/100mL). Ballast water sampling using the bucket method had proven to be able to quantify plankton and microbes present in ballast tank. Therefore, the proposed sampling method could serve as an alternative for authorities in ballast water compliance monitoring.