Developing Molecular Methods to Identify and Quantify Ballast Water Organisms: A Test Case with Cnidarians

摘要

The potential for organisms to be transported by ballast water is well documented. Furthermore, biological invasions mediated by ballast water transport have led to some rather severe economic and ecological consequences as seen in the examples of the zebra mussel and green crab. Unfortunately, this is not necessarily a new phenomenon. As long as ships have traveled so have these sorts of stow away organisms. However, what has changed is the rate of invasions. Bigger ships, with greater volumes of ballast water, are traveling faster which increases the abundance and survival of organisms in their ballast tanks. The growing recognition of the consequences of invasive species has led to much effort in improving our basic understanding of the role of ballast water. One key question is simply what species are being transported. Various studies have documented the presence of a tremendous diversity of non- indigenous species in ballast water. Importantly, the authors of these studies acknowledge that these numbers are underestimates since larval forms, as well as the adults, of species in many groups cannot be easily distinguished based on morphology. Thus, characterization of the taxa present in ballast water samples is often restricted to the taxonomic level of order, class or even phylum.