Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: ballast tank sediment

Sortuj według:

Ogranicz wyniki do:

Unintended “biological cargo” of ships entering the River Odra estuary: assemblages of organisms in ballast tanks

Gruszka P., Rokicka-Praxmajer J., Cupak J., Radziejewska T., Wolska M.

Zeszyty Naukowe / Akademia Morska w Szczecinie

2013

nr 33 (105)

22--29

Water and sediment in ships’ ballast tanks provide habitats for various organisms, and thus facilitate alien species introductions. Ballast tank water and sediment of 19 ships docked in the GRYFIA Szczecin Ship Repair Yard (Szczecin, Poland) located in an area connected with the River Odra estuary (Southern Baltic), were sampled in 2009–2011 to find out if the ships could be vectors of species introductions to the estuary, already known for the presence of non-indigenous taxa. This study showed the ballast water of the ships examined to house rotifers, copepods, cladocerans, and bivalve and cirriped larvae – common constituents of zooplankton assemblages in coastal waters. The ballast tank sediment supported meiobenthic foraminiferans, nematodes, harpacticoid copepods, turbellarians, bivalves, polychaetes, and chironomid and cirriped larvae. It is not possible at this stage to judge what meiofaunal taxa constitute an alien component in the estuary biota. Macrobenthos in the ships’ ballast tank sediment examined was represented mainly by nereid polychaetes. Although the unintended “biological cargo” examined proved quite diverse and abundant, it contained few identified alien taxa. It does not seem likely than any of them could pose a threat of a biological invasion in the River Odra estuary. However, numerous species remained unidentified, and therefore assessment of the risk of alien species introduction and invasion contains a large measure of uncertainty. On the other hand, the risk as such remains, since the density of ballast water-borne organisms in all ships exceeded the allowed limits.

A home away from home: a meiobenthic assemblage in a ship's ballast water tank sediment

Radziejewska T., Gruszka P., Rokicka-Praxmajer J.

Oceanologia

2006

No. 48 (S)

259-265

The world-wide research on ship-aided dispersal of marine organisms and invasions of non-indigenous species focuses primarily on the plankters, which show the greatest potential for invading new areas and establishing viable populations in them, either in the water column (holoplankton) or on the bottom (meroplanktonic larvae of benthic species settling on the sea floor). As meiobenthic animals usually lack a pelagic larval stage in their life cycle, no biological invasion study has, to our knowledge, ever specifically targeted marine transport as a means of meiofaunal dispersal. Here we present a set of data showing that the sediment deposited in a ship's ballast water tank does support a viable meiobenthic assemblage. We examined 0.015-dm3 aliquots of a 1 dm3 sample from a c. 1.5-cm thick layer of sediment residue in the ballast tank of MS Donnington, brought to the "Gryfia" Repair Shipyard in Szczecin (Poland). The samples were found to contain representatives of calcareous Foraminifera, hydrozoans, nematodes, turbellarians, harpacticoid copepods and their nauplii, and cladocerans, as well as meiobenthic-sized bivalves and gastropods. Nematodes proved to be the most constant and most numerous component of the assemblage. The sediment portions examined revealed the presence of 1-11 individuals representing 11 marine nematode genera. The viability of the meiobenthic assemblage was evidenced by the presence of ovigerous females of both nematodes and harpacticoids. Survival of the meiobenthos in shipborne ballast tank sediment residues may provide at least a partial explanation for the cosmopolitan distribution of meiobenthic taxa and may underlie the successful colonisation of new habitats by invasive meiofaunal species.