Brygida Wawrzyniak-Wydrowska

Population dynamics of alien gammarid species in the River Odra estuary

During the period of 1988–2000, three alien gammarid species, i.e. Gammarus tigrinus Sexton, 1939, Pontogammarus robustoides G. O. Sars, 1894, and Dikerogammarus haemobaphes (Eichwald, 1841) were recorded in the Odra estuary. This study, the first record of G. tigrinus and P. robustoides in Poland, focuses on the distribution, abundance, and biomass as well as on population structure of the three new species found in the coastal zone of the estuary. G. tigrinus and P. robustoides were first sampled in the Szczecin Lagoon (mid-part of the estuary) in 1988. The densities of both species were high from the time they were first recorded and exceeded 10 000 ind. m−2, while the biomass was 25 and 140 g m−2, respectively. G.␣tigrinus occurred at higher densities in northern and eastern parts of the Lagoon, while P. robustoides was particularly abundant in the south-eastern part, most heavily affected by River Odra discharge. In 1999, the third gammarid, D. haemobaphes, was recorded in the southern part of the estuary. Both in 1999 and 2000, the species was found in qualitative samples (dredge collections of Dreissena polymorpha) taken from the western branch of the river. As estimated from quantitative samples, densities and biomass in the eastern branch were rather low and did not exceed 150 ind. m−2 and 2.7 g m−2, respectively. The Szczecin Lagoon population of G. tigrinus produces at least two generations within a year: a summer one and an overwintering one. The latter is dominated by older and larger specimens. The species may reproduce in the Lagoon from April until November.

Transfer of organic contaminants to the Baltic in the Odra Estuary

This paper describes the transfer of organic contaminants to the sea, using PAHs (12 compounds) and PCBs (11 congeners) as examples, through a eutrophicated coastal lagoon (Szczecin Lagoon, on the Polish-German border). The transfer of contaminants study was based on their concentration in recent sediments (0-10 cm), in relation to different environmental conditions such as temperature, salinity, turbidity, oxygen and nutrients in water, hydrological conditions, organic carbon and biomarkers (pigments and their derivatives) in sediments. Results include the data obtained between 1994 and 2000, also those on before and afterwards the great flood in July 1997, at different stations in the Lagoon and the adjacent Pomeranian Bay. The results indicated that the eutrophic estuary of the shape of lagoon acts as an effective trap for the hydrophobic organic pollutants. The abundance and taxonomy of plankton as well as detritus derived from it play an important role in bonding the studied compounds. The salinity gradient in the lagoon has a significant influence upon deposition of the pollutants from the water column to the sediments and the residence time of the compounds there depends strongly on oxic-anoxic status of the sediments and the strength of interaction with sediments resulting from polarity, the type and stability of associates formed, as well as on hydrological conditions. We conclude that eutrophication in this area prevents pollution of the sea to some extent.

Four new species of Nitzschia sect. Tryblionella (Bacillariophyceae) resembling N. parvula

Abstract In the course of research on the diatoms from surface sediments sampled in the marine littoral and sublittoral worldwide, and in some freshwater localities in central Europe, several problematic taxa were encountered resembling Nitzschia parvula. We therefore undertook a light and scanning electron microscopical study of five species of Nitzschia belonging to the section Tryblionella. After a period of misidentification, one of the taxa studied, N. parvula, is now known from the type preparation. The remaining taxa are either new to science or have previously lacked formal descriptions. The first of them is found in freshwater habitats and is described here as N. beyeri Lange-Bertalot, whereas the second, from the tropical marine littoral, is described as N. schweikertii Witkowski, Lange-Bertalot, Ruppel & Kociolek. The third species is known in the literature by the manuscript name ‘Nitzschia subconstricta Grunow’. However, this name was not validly published and subconstricta has recently been used for another species, described by Desikachary & Prema (1987). Grunows species is validly described here as N. ligowskii Witkowski, Lange-Bertalot, Kociolek & Brzezinska. It inhabits the marine littoral and is characterized by a very wide geographical distribution. The fourth new taxon, described here as N. buschbeckii Witkowski, Lange-Bertalot & Ruppel is known so far only from the Antarctic.

Living on the pH Edge: Diatom Assemblages of Low-pH Lakes in Western Pomerania (NW Poland)

Diatom communities were studied in 2003 in three low-pH peatbog lakes in Western Pomerania (NW Poland); two of the lakes (LK and ZB) represented natural acid water bodies (NAWB), the third lake (LP) being least acid stressed. The three lakes differed markedly in their abiotic regimes, mainly on account of water pH in the two NAWBs being consistently below 5.0, while the pH range in the non-NAWB extended well into the alkaline part of the pH scale. In terms of all the important environmental variables studied (pH, conductivity, dissolved organic C, dissolved Si, dissolved P, nitrate and ammonia N), the three lakes followed an environmental gradient with LP on one end and ZB, a fully natural peatbog reservoir with high acidity, lower conductivity, higher upper limit of dissolved organic C and higher dissolved P contents and much lower dissolved Si contents, on the other. The study confirmed the general pattern of a low taxonomic richness in waterborne and bryophyte-associated diatom assemblages inhabiting low-pH habitats. The diatom assemblages differed between the three lakes and conformed to the environmental gradient. The LP assemblage (216 taxa), dominated by the common neutrophile Achnanthidium minutissimum, showed a preponderance of circumneutral and alkaliphilous taxa; the LK diatoms (15 taxa) represented mostly acidobiontic and acidophilous taxa, while the ZB assemblage (11 taxa) consisted predominantly of acidobionts. The study supplied information on the distribution of taxa having a high conservation value on the European scale. Important in the NAWBs were rare and endangered diatoms, primarily members of Eunotia, as well as Frustulia crassinervia. Their occurrence, coupled with other environmental and biotic characteristics of the lakes studied, makes the latter ideal candidates for conservation and protection.

Organotins in fish muscle and liver from the Polish coast of the Baltic Sea: Is the total ban successful?

Muscle and liver tissues of nine fish species were analyzed to assess butyltin and phenyltin contamination. The samples were collected from three basins located in the Southern Baltic Sea coastal zone that each represent different potential for organotin pollution. Maximum total concentrations of butyltin compounds (BTs) in the fish muscles and livers were 715 and 1132ng Sn g(-1) d.w., respectively, whereas triphenyltin (TPhT) was not detected. In the muscle samples, the predominant compound in the sum of butyltins was tributyltin (TBT), while in the liver samples, tributyltin degradation products were found in the majority. The results demonstrate that 6-7years after the implementation of the total ban on harmful organotin use in antifouling paints, butyltins remain present in fishes from the Polish coast of the Baltic Sea. According to the HELCOM recommendation, eight samples exceeded the good environmental status boundary for tributyltin in seafood.