Oceanologia (Jun 2006)
A home away from home: a meiobenthic assemblage in a ship's ballast water tank sediment
Abstract
The world-wide research on ship-aided dispersal of marineorganisms and invasions of non-indigenous species focuses primarilyon the plankters, which show the greatest potential for invadingnew areas and establishing viable populations in them, eitherin the water column (holoplankton) or on the bottom (meroplanktoniclarvae of benthic species settling on the sea floor). As meiobenthicanimals usually lack a pelagic larval stage in their life cycle,no biological invasion study has, to our knowledge, ever specificallytargeted marine transport as a means of meiofaunal dispersal. Here we present a set of data showing that the sedimentdeposited in a ship's ballast water tank does support a viablemeiobenthic assemblage. We examined 0.015-dm3 aliquotsof a 1 dm3 sample from a c. 1.5-cm thick layerof sediment residue in the ballast tank of MS Donnington, broughtto the "Gryfia" Repair Shipyard in Szczecin (Poland). The sampleswere found to contain representatives of calcareous Foraminifera,hydrozoans, nematodes, turbellarians, harpacticoid copepods andtheir nauplii, and cladocerans, as well as meiobenthic-sizedbivalves and gastropods. Nematodes proved to be the most constantand most numerous component of the assemblage. The sediment portionsexamined revealed the presence of 1-11 individuals representing11 marine nematode genera. The viability of the meiobenthic assemblagewas evidenced by the presence of ovigerous females of both nematodesand harpacticoids. Survival of the meiobenthos in shipborne ballast tank sedimentresidues may provide at least a partial explanation for the cosmopolitandistribution of meiobenthic taxa and may underlie the successfulcolonisation of new habitats by invasive meiofaunal species.
