title: Population attenuation in zooplankton communities during transoceanic transfer in ballast water.
abstract: Successful biological invasion requires introduction of a viable population of a nonindigenous species (NIS). Rarely have ecologists assessed changes in populations while entrained in invasion pathways. Here, we investigate how zooplankton communities resident in ballast water change during transoceanic voyages. We used next-generation sequencing technology to sequence a nuclear small subunit ribosomal DNA fragment of zooplankton from ballast water during initial, middle, and final segments as a vessel transited between Canada and Brazil. Operational taxonomic unit (OTU) diversity decreased as voyage duration increased, indicating loss of community-based genetic diversity and development of bottlenecks for zooplankton taxa prior to discharge of ballast water. On average, we observed 47, 26, and 24 OTUs in initial, middle, and final samples, respectively. Moreover, a comparison of genetic diversity within taxa indicated likely attenuation of OTUs in final relative to initial samples. Abundance of the most common taxa (copepods) declined in all final relative to initial samples. Some taxa (e.g., Copepoda) were represented by a high number of OTUs throughout the voyage, and thus had a high level of intraspecific genetic variation. It is not clear whether genotypes that were most successful in surviving transit in ballast water will be the most successful upon introduction to novel environments. This study highlights that population bottlenecks may be common prior to introduction of NIS to new ecosystems.
authors.affiliation: Great Lakes Institute for Environmental Research University of Windsor Windsor Ontario N9B 3P4 Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: Ghabooli
authors.affiliation: Research Center for Eco-Environmental Sciences Chinese Academy of Sciences 18 Shuangqing Road Haidian District Beijing 100085 China.
authors.forename: Aibin
authors.initials: A
authors.lastname: Zhan
authors.affiliation: Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" and Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires Argentina.
authors.forename: Esteban
authors.initials: E
authors.lastname: Paolucci
authors.affiliation: Great Lakes Institute for Environmental Research University of Windsor Windsor Ontario N9B 3P4 Canada.
authors.forename: Marco R
authors.initials: MR
authors.lastname: Hernandez
authors.affiliation: GEOMAR Helmholtz Centre for Ocean Research Kiel Düsternbrooker Weg 20 D-24105 Kiel Germany.
authors.forename: Elizabeta
authors.initials: E
authors.lastname: Briski
authors.affiliation: Biology Department McGill University Montreal Quebec H3A 1B1 Canada.
authors.forename: Melania E
authors.initials: ME
authors.lastname: Cristescu
authors.affiliation: Great Lakes Institute for Environmental Research University of Windsor Windsor Ontario N9B 3P4 Canada.
authors.forename: Hugh J
authors.initials: HJ
authors.lastname: MacIsaac
keywords: Ion torrent PGM; ballast water; biological invasion; genetic diversity; invasive species; next‐generation sequencing; nonindigenous species; zooplankton