Potential invasions of phytoplankton in ship ballast water at South Korean ports

Abstract

We studied the phytoplankton communities in ballast water in ships that arrived at two South Korean ports. We determined the potential for phytoplankton in the ballast water to invade the South Korean marine environment, given the specific growth rates of the phytoplankton, the delay before the phytoplankton started growing, and the rate at which the phytoplankton would initially disperse in ports and bays. Most of the phytoplankton in the ballast water samples originated in countries such as China and Japan that are adjacent to South Korea, and diatoms dominated these phytoplankton communities. The abundance of phytoplankton in a sample did not appear to be related to any particular environmental parameter, including the voyage duration. However, the number of phytoplankton taxa in a sample decreased as the voyage duration increased. The survival and growth of phytoplankton communities in the South Korean marine environment were assessed, and we found that most invasions failed at the initial dispersal phase, especially when a community was introduced to pier-side seawater. However, some members of phytoplankton communities, if they were dispersed and where conditions were highly eutrophic, could grow fast enough to overcome the initial dispersal phase in South Korean ports and bays.