title: Denaturing gradient gel electrophoresis shows that bacterial communities change with mid-ocean ballast water exchange.
abstract: Ships carry ballast water for better stability and to control trim. However, the discharge of ballast water near ports is known to transport invasive species from one coastal area to another. The exchange of ballast water on the high seas is supposed to reduce such invasions of exotic species. In this study, we used denaturing gradient gel electrophoresis (DGGE) to analyze the composition of the bacterial community in ballast water before and after such a mid-ocean exchange, and we also measured total bacterial counts. Our findings confirmed that the ballast water was replaced by the mid-ocean exchange, as indicated by the marked change in the composition of the bacterial community. There was also a significant decrease in bacterial abundance after the mid-ocean exchange. Finally, our findings support the incubation hypothesis, because the composition of the bacterial communities changed over time within the same ballast water.
authors.affiliation: Asian Natural Environmental Science Centre, University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. utomaru@mail.ecc.u-tokyo.ac.jp
authors.forename: Akiko
authors.initials: A
authors.lastname: Tomaru
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kawachi
authors.forename: Mikihide
authors.initials: M
authors.lastname: Demura
authors.forename: Yasuwo
authors.initials: Y
authors.lastname: Fukuyo
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000254:growth & development; D018407:Bacterial Physiological Phenomena; D015169:Colony Count, Microbial; D017753:Ecosystem; D004591:Electrophoresis, Polyacrylamide Gel; D009792:Oceans and Seas; D012623:Seawater / Q000382:microbiology*; D012767:Ships; D013997:Time Factors