Volume 42 (2013): Issue 3 (September 2013)

Five green algal taxa rarely occurring in the world were found in subalpine lakes of the High Tatra Mountains in Poland. These are Actinastrum gracillimum G.M. Sm. var. elongatum (G.M. Sm.) Fott, Monoraphidium tatrae (Hindák) Hindák, Pediastrum braunii Wartm. in Wartm. et Schenk, Scotiella tuberculata Bourr. var. tuberculata and Thelesphaera olivacea (Beck-Mannag.) Fott. The taxa are described and illustrated with light micrographs and drawings. A review of their distribution in the world is presented.

In order to assess the ecological status of three lakes in a historical mining city (SE China), water metal concentrations and surface sedimentary diatoms and chrysophyte cysts were analyzed in 20 sampling sites. The significant correlations between the algal indices and the cumulative criterion unit (CCU) scores confirmed the importance of heavy metals in shaping algae communities. In the metal-polluted sites, diatom assemblages were dominated by metal-tolerant species, such as Nitzschia palea and Nitzschia perminuta. In the unpolluted samples, diatom assemblages were characterized by Cyclostephanos dubius, Discostella pseudostelligera and Aulacoseira species (mainly A. alpigena, A. granulata and A. ambigua). These dominant taxa in the unpolluted samples might be sensitive to metal contamination but tolerant of eutrophication. In addition, nonspherical cysts were much more abundant in the polluted sites, indicating that their presence should be indicative of metal contamination in this region. This study provides some clues for future metal pollution assessment through the use of siliceous algae in metal polluted lakes.

Anabaena poulseniana J. Boye Petersen Bot. Iceland 2, 1923 (Cyanobacteria), a cyanobacteria species new to Polish flora, was noted during a study of phytoplankton in one of Wrocław’s clay pits. The species was noted in plankton samples among Cylindrospermopsis raciborskii (Wołoszyńska) Seenayya et Subba Raju (Cyanobacteria) and Mougeotia sp. (Chlorophyta) filaments. The green algae created a bloom characterized by vegetation mats floating on the water.

The paper presents detailed characteristics for Anabaena poulseniana, and for the habitat and the ecological condition in the examined water reservoir during its presence. The paper also presents a comparison of morphological characteristics of A. poulseniana from Poland to the species from other geographical locations. The research will provide data on the morphology and ecology of the species. The species found during the study were documented in the form of original photos and illustrations.

The aim of this study was to estimate the residue of chlorinated pesticides in the edible fish caught in the Gulf of Gdańsk and in the Vistula Lagoon. The highest mean concentrations of total DDT were found in the muscles of salmon (331.45 ng g−1 lw.) and sabre carp (306.29 ng g−1 lw.) caught in the Vistula Lagoon, and in the muscles of cod (309.88 ng g−1 lw.) and herring (304.86 ng g−1 lw.) from the Gulf of Gdańsk. Moreover, it was discovered that the following were present in the muscles of fish: DDT metabolites (pp’-DDE and pp’-DDD isomers) as well as hexachlorobenzene and its metabolites and endrin, dieldrin, α-endosulfan isomers and methoxychlor. Pesticides concentrations were higher in the livers of fish than in the muscles, which proves that the removal of toxins from the fish systems dominates over their accumulation. Because no concentration limits for pesticides have been defined, consumer safety assessment of fish caught in the Southern Baltic and in the Vistula Lagoon is not possible. The authors, having observed an increase in heksachlorobenzen in fish tissues suggested the existence of contemporary sources of pesticides which introduce them into the coastal zone.

This study presents total mercury concentrations (HgT) in selected tissues and organs (blood, muscles, liver, kidneys, feathers and claws) of the herring gull (Larus argentatus) in order to assess the environmental pollution in the coastal zone of the southern Baltic. Dead, frozen birds were collected in the vicinity of Wladysławowo between December 2009 and March 2010, an exceptionally severe winter — a total of 13 specimens; 6 adults (>4 years old) and 7 immature birds (≤4 years old). Mercury concentrations in all analyzed samples exceeded the detection limit. The lowest average concentration, at a level of 0.4 μg Hg g−1 (d.w.) was observed in the muscles of adult and immature gulls while the highest, at a level of 3.3 μg Hg g−1 (d.w), was determined in the contour of immature gulls. A significant linear correlation was found between mercury concentration in the blood and the concentration in the kidneys and liver, with the coefficients of determination at R2 = 0.87 and 0.86, respectively. This indicates that blood of birds, as a mercury carrier, may reflects the concentration of mercury in tissues and internal organs of birds and, in the case of kidneys and liver, may express long-term exposure to mercury in nourishment.

Protozoan communities were studied in the coastal zone of the southern Baltic Sea. Stable environmental conditions and typical, bimodal seasonal changes in the protozoan biomass were observed at the sampling site in Sopot (2003–2004). At the sampling site in Ustka (2007–2008), strong benthic resuspension and irregular impacts of fresh water resulted in atypical seasonal changes in the protozoan biomass with a summer peak only. The mean annual biomass had similar values at both sites: 43.2 μg C dm−3 in Sopot and 38.6 μg C dm−3 in Ustka. The protozoan community in Sopot was dominated by ciliates (48% of the biomass), whereas in Ustka — by heterotrophic nanoflagellates (53%).

The paper presents modeling of egg production (Egg — no. of eggs female−1 d−1) by Temora longicornis in the changing environmental conditions of the southern Baltic Sea (Gdańsk Deep). It is hypothesized that the food-saturated rate of egg matter production is equivalent to the specific growth rate of copepods. Based on the findings from the south-western Baltic Sea, Egg of T. longicornis is evaluated as a function of food concentration, temperature and salinity over a wide range of these parameters. Subsequently, the rate of reproduction during the seasons in the Gulf of Gdańsk is determined. According to our calculations, values of Egg reach ca 11 eggs per day in April and decline strongly in June-July, while the second smaller peak in reproduction occurs in September, ca 8 eggs per day. Our results suggest that egg production rates of T. longicornis depend not only on food concentration and temperature, but also on salinity, which is a masking factor in the Baltic Sea.

Extensive sampling (450 grabs) was performed all over the inner part of Puck Bay (105 km2 area) in summers of 2007–2009. The GIS-based analysis of samples was performed to assess in detail the distribution of 32 benthic species. The minimum area of occurrence was less than 1 km2 for Lekanosphaera rugicauda and the maximum was 83 km2 for Cerastoderma glaucum. The material reveals that species with the pelagic larval stage were most widespread, with the least distance between individuals and the highest average density (e.g. Cerastoderma glaucum, Hydrobia ventrosa). The most isolated and the least dense species within the studied area were discretely mobile, non-larval crustaceans (e.g. Gammarus oceanicus and Lekanosphaera rugicauda), present at single sites with the largest distance from each other. We conclude that analysis of species distribution helps in understanding the threats to populations of marine invertebrates and marine spatial planning, through locating the isolated species and populations.

Laboratory-reproduced and bred asps were experimentally infected with Contracaecum rudolphii larvae, either directly or with previously infected copepods. In the fish exposed to larval infection, the intensity and prevalence of infection were noticeably higher than in the group exposed to copepods. The course of larvae development was similar in both groups. In the larvae measuring ca. 1000 μm in length, the gastrointestinal tract with a developed ventriculus, ventricular appendix and intestinal caecum was clearly visible. The mouth was surrounded by three lips. Over the 10-week experimental period, slightly-coiled larvae surrounded with a thin theca but no encysted larvae were found in the fish exposed to larvae. On the other hand, spirally-stranded and encysted larvae were observed after the 7th week in the fish exposed to infected copepods. The results demonstrated that in the experimentally infected asps, the intensity and prevalence of infection as well as the location of the larvae in a fish depended on the type of invasive material applied.

Lake Modre is a lobelia lake. Numerous typical plant species occur here, including Lobelia dortmanna, Littorella uniflora, Isoetes lacustris, and Sphagnum denticulatum. They develop the following associations: Lobelietum dortmannae (Oswald 1923) Tx. ap. Dierss. 1972, Isoetetum lacustris Szańkowski et Kłosowski 1996 n.n., and a community with Sphagnum denticulatum Brid.

In 1991, the water of the lake was characterised by low concentrations of nutrients and calcium, acid reaction (pH<5), and Secchi depth visibility of 12 m. Following fry stocking in the lake in 1993 fish farming took place until approximately 1996. During this period the water quality in the lake changed radically in physiochemical terms. Water transparency decreased. Thermal and oxygen stratification developed, with oxygen deficits in the near-bottom layer. Concentrations of nutrient elements increased.

Drastic long-term changes were observed in the spatial and quantitative features of the lake vegetation. These particularly related to the instability of Lobelia dortmanna, and the diminishment of the phytocoenosis of Lobelietum dortmannae. Consequently, the phytocoenosis occurred only in the shallowest part of the phytolittoral. L. uniflora expanded, increasing its occurrence annually. Significant fluctuations in quantities of S. denticulatum occurred, correlated with changes in physiochemical water parameters, but shifted in time.

In this paper we examine the stomach contents of the omnivorous rotifer, Asplanchna priodonta, to evaluate possible trophic interactions between this rotifer and its potential prey in two large northeastern European lakes: moderately eutrophic Lake Peipsi and strongly eutrophic Lake Võrtsjärv. Our results show that the A. priodonta diet consisted of Bacillariophyta, Chlorophyta, Cyanobacteria, and Dinoflagellata. Ciliata were detected on rare occasion. Bacillariophyta were the most frequent food items in stomachs. There were no between-lake differences in the consumption of Chlorophyta and Cyanobacteria, whereas Bacillariophyta were consumed more in Lake Peipsi. However, neither Dinoflagellata nor Ciliata were found in stomach samples in Lake Võrtsjärv. We conclude that A. priodonta is an opportunistic feeder that is capable of influencing the phytoplankton community structure in large lakes.

The abundance of actinomycetes, filamentous fungi and yeasts in the marine epipsammon habitat and their spatial distribution were studied with conventional plating techniques in two marine beaches (Ustka and Czołpino, southern Baltic Sea) which are characterized by different anthropic pressure levels. Actinomycetes constituted the predominant group of studied microorganisms, while the least numerous were yeasts in the sand of both studied beaches. On both of the beaches researched in this study, the amounts of accumulated actinomycetales, fungi and yeasts were similar. When analyzing the distribution of the microflora along the horizontal beach profiles we found significant differences. In the sand collected along the profile perpendicular to the shoreline in Ustka and Czołpino beaches, the highest numbers of actinomycetes, filamentous fungi and yeasts were noted in the samples from the dune and the lowest in those from the subtidal zone and waterline. Generally, higher numbers of studied microorganisms were observed in the surface than in the subsurface sand layer. The occurrence of actinomycetes, filamentous fungi and yeasts showed considerable seasonal variation.

Straightnose pipefish (Nerophis ophidion), covered with hydroid Gonothyraea loveni, were caught in August 2010 near Gdynia while fishing with fyke nets. The hydroid colonies were spaced around the fish, from the head to the anus. These colonies seemed to cause serious problems with the balance and swimming ability of the fish. It appears that there are no symbiotic or parasitic relationships between the hydroid and the fish. The fish was probably just another substrate for G. loveni and became colonized by fouling on the skin surface. It should also be taken into consideration that hydroid colonies can move from place to place with their fish host. It is possible that the hydroid benefits from the fish active search for planktonic food.

The paper presents the history of diatom studies carried out in the Gulf of Gdańsk and the Vistula Lagoon since the beginning of the 20th century. One aspect of the research focuses on describing the structure of planktonic and benthic communities living in different parts of the area or occurring in their surface sediments as taphocoenoses. Other investigations concentrate on the fossil diatom flora, which is widely used in the research on the Late Glacial and Holocene to resolve paleogeographic, sedimentological and paleoecological problems.

An updated inventory of the cnidarian species living as epibionts on Crustacea was conducted. Cnidarian species that attach themselves to gastropod shells of hermit crabs were also considered. One hundred and forty-eight species of cnidaria were included, with similar numbers of hydrozoans and anthozoans. There were 163 basibiont species that were mostly decapod species. The presence of these epibionts on different crustacean species and their taxonomic positions were indicated. This review is intended to serve as a useful tool for future studies of this type of epibiosis.