Wyniki wyszukiwania - BazTech

1

Linia wody – szczególne miejsce arenalu południowego Bałtyku dla wolnożyjących nicieni

Taberska A., Rokicka-Praxmajer J.

Inżynieria Ekologiczna

|

2018

|

Vol. 19, nr 1

9--18

PL

Praca przedstawia charakterystykę strukturalną i funkcjonalną zespołów nematofauny, zasiedlających osady na linii wody w południowym Bałtyku. Wolnożyjące nicienie oznaczono do rodzaju oraz określono ich strukturę troficzną. Zagęszczenie nematofauny na badanych stanowiskach wahało się od 10,52 ± 9,82 osob./10 cm2 do 124,49 ± 76,39 osob./10 cm2. Najliczniej występowały nicienie z rodzaju Ascolaimus, stanowiąc od ok. 45% do 74% całkowitej liczebności nematofauny. Łącznie w okresie badań stwierdzono nematofaunę należącą do 7 rodzajów. Za zasadniczy element nematofauny zasiedlającej osady na linii wody uznano nicienie z rodzajów: Ascolaimus, Axonolaimus, Enoplolaimus i Daptonema. Pod względem funkcjonalnym dominowali nieselektywni osadożercy, osobniki z nieuzbrojoną torebką gębową, reprezentowane przez nicienie z rodzajów: Ascolaimus, Axonolaimus, Theristus i Daptonema.

EN

This paper presents the structural and functional characteristics of nematofauna assemblages inhabiting the sediments along the water line in the southern Baltic Sea. The nematodes were identified to the genus level and assigned to appropriate trophic group. The density of free-living nematoda varied from 10.52 ± 9.82 ind./10 cm2 to 124.49 ± 76.39 ind./10 cm2. Ascolaimus was the most abundantly represented genus, accounting for from 45% to 74% of the total number of nematofauna. A total of 7 nematode genera were identified. Ascolaimus, Axonolaimus, Enoplolaimus and Daptonema were considered essential elements of nematofauna. In terms of functionality, non-selective deposit feeders were predominant, individuals with unarmed buccal cavity, represented by nematodes of the genera Ascolaimus, Axonolaimus, Theristus and Daptonema.

2

First record of brown colouration of Atlantic cod (Gadus morhua, L.) from the North Sea [commun.]

Rybczyk A., Czerniejewski P., Rokicka-Praxmajer J.

Oceanologia

|

2014

|

No. 56 (1)

159--163

EN

This paper reports the biological characterisation of a specimen of Atlantic cod (Gadus morhua L.) with a unique brown colour, which is the first fish of this species with such a colouration recorded from European waters. It was caught in the coastal zone of the North Sea in June 2011. This "brown" cod fish weighed 1074.3 g and had an overall length of 422 mm.

3

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

EN

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.

4

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

EN

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.

5

Meiobenthic communities of the Pomeranian Bay (southern Baltic): effects of proximity to river discharge

Rokicka-Praxmajer J., Radziejewska T., Dworczak H.

Oceanologia

|

1998

|

No. 40 (3)

243-260

EN

The Pomeranian Bay (southern Baltic Sea) is a component of the river Oder (Odra) estuarine system. It receives the Oder's discharge once it has passed through the Szczecin Lagoon, a eutrophic and polluted water body. The discharge has been documented as affecting the hydrography of the pelagic domain as well as the sedimentary environments and the macrozoobenthos of the Bay. This study focused on the distribution of meiobenthic communities in the Bay as investigated with the use of a suite of uni- and multivariate analyses applied to data collected at 14 stations in September 1993. Meiobenthic community characteristics (composition and abundance) are presented in relation to sediment properties (grain size, silt/clay and organic matter content), changing with distance from the major riverine discharge site. The communities studied showed a clear distinction between those associated with organic matter-enriched sediments close to the discharge site and the assemblages living in clean sands, away from the discharge. We conclude that the meiobenthos can be regarded as another compartment of the Pomeranian Bay system responding to the River Oder discharge.