ECOLOGICAL ROULETTE - THE GLOBAL TRANSPORT OF NONINDIGENOUS MARINE ORGANISMS

Ocean-going ships carry, as ballast, seawater that is taken on in port and released at subsequent ports of call. Plankton samples from Japan ese ballast water released in Oregon contained 367 taxa. Most taxa wit h a planktonic phase in their life cycle were found in ballast water, as were all major marine habitat and trophic groups. Transport of enti re coastal planktonic assemblages across oceanic barriers to similar h abitats renders bays, estuaries, and inland waters among the most thre atened ecosystems in the world. Presence of taxonomically difficult or inconspicuous taxa in these samples suggests that ballast water invas ions are already pervasive.