Volume 43 (2014): Issue 3 (September 2014)

The presented results provide the first comprehensive description of the C. pengoi population and document new records of its expansion to the west in the Polish coastal zone of the Baltic Sea. In June–August 2006, C. pengoi was observed for the first time continuously for nine successive weeks in a broad range of the water temperature and salinity. Its abundance fluctuated from some to several hundred specimens per cubic meter. In July the species was much more abundant in the water far from the coast, whereas in August its maximum density was observed at the most shallow station. The population of C. pengoi occupied the whole water column, from the surface water to 80 m depth, its vertical distribution was not uniform. C. pengoi was represented by specimens from all age-specific morphological stages (BS I–III). The largest part of the population (up to 81.53%) was composed of juvenile specimens (BS I and II). Parthenogenetic females in the second instar constituted the majority of BS II specimens.

The study was conducted in Lake Długie located in Olsztyn, the Masurian Lake District. In the 1950s and in the 1960s, Lake Długie was used for 20 years as a collector of raw domestic and storm sewage. This has led to complete degradation of the lake. After preliminary protection measures implemented in the catchment, the lake was restored by artificial aeration and phosphorus inactivation methods. Long-term recultivation of the reservoir resulted in a significant and long-lasting improvement of the water quality. Before restoration, the average concentration of organic phosphorus in the surface water layer amounted to 0.166 mg Porg l−1 and of organic nitrogen — to 3.0 mg Norg l−1. After restoration, these values decreased to 0.058 mg Porg l−1 and 2.0 mg Norg l−1. The results obtained eight years after the recultivation of Lake Długie are extremely interesting. The amounts of chlorophyll a did not exceed 7 μg l−1, water transparency remained at a depth of 2.9 m, and BOD5 did not exceed 2 mg O2 l−1. These observations show that during implementation of recultivation treatments, only chemical parameters of the water significantly changed, while biological elements reacted to the treatments with some delay.

Rates of physiological processes and bioenergetics of the Harris mud crab Rhithropanopeus harrisii were determined during a 7-day experiment on adult males (mean wet weight 0.83 ± 0.16 g) exposed to temperatures of 15°C and 20°C (S = 7). The results show that the change in temperature by 5°C caused detectable changes in locomotor activity, food consumption and faeces production and significant (p < 0.05) changes in metabolic rates. Food assimilation efficiency and the ammonia excretion rate did not change significantly (p > 0.05). The energy expended on metabolic processes was similar at both temperatures (15°C and 20°C) and amounted to 17.7 ± 6.4% and 16.7 ± 4.3% of the assimilated energy, respectively. Similar values were obtained for net production efficiency K2 (P/A) at 15°C and 20°C, i.e. 80.4 ± 22.4% and 82.9 ± 9.7%, respectively. The amount of energy available for production was 2-fold higher at a temperature of 20°C than at 15°C and amounted to 103.69 ± 25.61 and 206.40 ± 20.76 J d−1g−1 wet wt, respectively. The results show that from the bioenergetic point of view, higher experimental temperature is more “profitable” for adult R. harrisii specimens because it provides better conditions for the growth and reproduction.

The ecological state of the Kiev Reservoir affected by intensive contamination as a result of the accident at the Chernobyl Nuclear Power Station in 1986 was assessed in terms of the species-indicators of epiphytic algae occurring in the fouling of higher aquatic plants. It has been found that inhabitants of slowly flowing and moderately warm waters, alkaliphiles, indifferent organisms in relation to water salinity, nitrogen-autotrophic taxa tolerating elevated concentrations of organically bound nitrogen, β-mesosaprobionts and eurysaprobes (in relation to organic contamination) and eutraphentic organisms (indicators of the trophic state) prevailed in phytoepiphyton of the Kiev Reservoir. As a result of comparison of the original results with literature data obtained prior to the accident, it has been found that over a span of about 30 years (from the 1970s–1980s to 2010–2013), the taxonomic structure of phytoepiphyton remained almost unchanged. At the same time, the intensity of eutrophication, alkalization, and thermofication processes increased.

Four sediment cores from the southern part of the Arkona Basin were analyzed in terms of their geochemical composition, age and stratigraphy. The main stages of the Baltic Sea: the Baltic Ice Lake, the Ancylus Lake and the Littorina Sea were identified in all the analyzed cores. The data confirmed the high water fluctuation and significant environmental changes during the Baltic Sea evolution in the Late-Glacial and the Holocene. The signs of the second regression of the Baltic Ice Lake, dated at around 11 000 cal BP, were identified at a depth of 24 m b.s.l. Regression of the Ancylus Lake, dated at 9300 cal BP, was identified at a depth of 23 m b.s.l. The most pronounced period was the transition stage between the Ancylus Lake and the Littorina Sea. The record of the Littorina Sea onset in the sediments of the Arkona Basin is marked as a sudden increase in loss on ignition, biogenic silica, magnesium, calcium, iron and strontium. The age of the Littorina Sea in the Arkona Basin was estimated as younger than 8200 cal BP.

Toxicity assessment of environmental compartments, in particular sediments as a highly complex matrix, provides a more direct way to assess potential adverse effects of pollutants present in a sample in contrast to chemical analysis estimating only a quantitative level of xenobiotics. Interactions between chemicals, formations of derivatives and the influence of chemical properties of sediments such as the organic matter content causing the intensified sorption of hydrophobic pollutants suggest that a traditional approach to the sediment quality, based only on chemical analysis may be insufficient. The presented study describes the vertical and horizontal variability of toxicity of Gdańsk Basin sediments. Based on 128 surface sediments samples and using geostatistical methods, a prediction map for the EC50 parameter was created. This allowed the evaluation of the toxicity of the surface sediment layer at any selected point of the study area. The applied analysis can be functional for many other locations worldwide. In the present study, the hypothesis about the location of toxic sediments in the vicinity of Gdańsk Deep, outer Puck Bay and close to Vistula River mouth was further confirmed.

The research was conducted on the parasite fauna and food composition of Eutrigla gurnardus caught as by-catch in commercial catches of the Atlantic cod Gadus morhua near the Shetland Islands. Thirteen species and two genera of pathogens were identified, including six species and one genus recorded for the first time in this host. Copepoda — Euphausiacea dominated in the stomach contents (they are also the intermediate hosts for most of the parasites found), while Gadidae dominated among the fish. A checklist of E. gurnardus parasites is included.

The aim of the study was to compare the biological analyzes of the Linda River (Central Poland), which were based on three diatom indices: IO, GDI and IPS in order to select the best diatom index for the biological assessment of the lotic water quality. Additionally, the summary of the selected results of the biological and chemical analyzes was presented to show how precise the biological analyzes are as a basic tool in the assessment of the ecological status of the lotic waters. The results showed that each of the indices assessed the water in the Linda River to a specific but different quality class. The IO index showed class II of the water quality, while the IPS and GDI — class III. Statistical analysis conducted with the nonparametric Kruskal-Wallis test for independent samples (Kruskal, Wallis 1952) showed that differences in the values of individual indices at different sites were not statistically significant. It should be noticed that the IPS and GDI indices gave values that classify the water in the Linda River at least one class below. The obtained results confirmed that the biological methods are most reliable in the assessment of the water quality. These methods are less sensitive to a single impact of the environmental factors, therefore they permit accurate determination of the ecological status of the water ecosystems.

Peat bogs are unique and important habitats for biodiversity at the species and ecosystem level where low pH of water plays a major role. The main objective of the present study was to compare the benthic diatom assemblage structure of the selected part of the Fenn’s and Whixall Mosses complex in order to verify whether selected sampling sites differ from each other. The complex is a cut-over, lowland raised mire, which is a National Nature Reserve (NNR) and a Site of Special Scientific Interest (SSSI).

Altogether 92 diatom species were identified in 72 benthic samples collected between September 2008 and August 2009 from six selected sampling sites. Statistical cluster analysis was used to classify diatom samples and to observe the structure of diatom assemblages. The results of this analysis grouped the data set into 3 clusters with 24 samples from each of the two sampling sites in one cluster. Such a clear division shows that pH of water has an impact on the species composition, the richness and diversity of benthic diatom assemblages.

Coastal upwelling occurred along the west coast of Guangdong in the northern South China Sea during the summer of 2006. The effects of upwelling on the vertical and horizontal distributions of Prochlorococcus and Synechococcus were investigated. A distinct vertical temperature difference between the surface water and water at a depth of 30 m was observed in the coastal upwelling region. There was a clear spatial variability of temperature, and an increasingly obvious horizontal gradient was created from the coast to offshore waters. Picophytoplankton communities observed from the coast to offshore waters were significantly different. In the coastal upwelling waters, the picophytoplankton community was dominated by Synechococcus within the euphotic zone. Prochlorococcus dominated the picophytoplankton community in the euphotic zone in the non-upwelling region. This difference in the picophytoplankton community structure was due to different hydrodynamics. The results of canonical correspondence analysis demonstrate that temperature, salinity, and phosphate concentration may be important factors affecting the distribution of Prochlorococcus and Synechococcus.

In this study, the spatial distribution and seasonal variation of large tintinnids (>76 μm) were investigated in Shenhu Bay during three seasons of 2012. Of the 36 species identified, 9 were dominant (i.e. Tintinnopsis radix, Leprotintinnus simplex, Tintinnopsis japonica, Tintinnopsis tubulosoides, Leprotintinnus nordqvisti, Tintinnopsis beroidea, Stenosemella parvicollis, Tintinnidium primitivum, Tintinnopsis nana). A clear seasonal shift of the taxonomic composition as well as the lorica size of the dominant species was observed. The highest numbers of tintinnid species occurred in spring, while the highest abundance and biomass occurred in summer. Clustering indicated that the seasonal variations of the community structure were more obvious than spatial variations. Spearman correlation analysis revealed that density of phytoplankton prey had a significant impact on the tintinnid abundance. Redundancy analysis (RDA) illustrated that temperature, salinity and the nutrient level were the most important abiotic factors affecting the spatial and seasonal pattern of tintinnid communities in Shenhu Bay.

Seasonal variations of environmental factors, such as temperature and salinity, require metabolic acclimatization in sedentary benthic fauna distributed over a wide geographical range. The soft-shell clam Mya arenaria inhabits the coastal waters of the North Atlantic including North America and Europe. In Europe, M. arenaria populations are distributed from Iceland to the Mediterranean Sea, including the North Sea, the Baltic Sea and the Black Sea. Seasonal changes in physiological parameters (gonad index, condition index, biochemical composition and respiration rate) of M. arenaria from the Baltic Sea (the Gulf of Gdańsk, Poland), and the North Sea (Versee Meer, the Netherlands) were studied. The sex ratio of both populations did not differ from 1:1 and the seasonal gonad index was higher in the Baltic population. The average condition index changed seasonally at both studied sites, and was also higher in the Baltic population (except the autumn) compared to the North Sea. In both studied populations, the content of proteins, lipids and carbohydrates in the soft tissue followed the seasonal variations, and it was higher in the Baltic population. The respiration rate was lower in the Baltic population, and seasonal changes in the respiration rate seem to be correlated with changes in the water temperature. Based on the results obtained in the present study, we suggest that Mya arenaria is characterized by a large phenotypic plasticity and differences in the observed physiological traits are due to acclimatization to ambient environmental conditions.

Combustion processes are considered to be the main source of the dioxin emission in the Baltic region. Pentachlorophenol (PCP) and its derivatives, pentachlorophenyl laurate (PCPL) and sodium pentachlorophenate (NaPCP) are known as precursors of dioxins. The research was conducted to obtain the first data on the concentration of PCDD/Fs and PCP in the bottom sediments of the Port of Gdansk. Toxicity (the Microtox® test) as well as several sediment parameters have been examined.

In the surface layer of bottom sediments from the Port of Gdansk, all congeners of PCDD/Fs have been detected using GC-MS/MS. The highest concentration was obtained for OCDD (224.0–271.0 pg g−1 d.w.) and HpCDD (51.0–36.0 pg g−1 d.w.). The content of ΣPCDDs prevailed over ΣPCDFs. This may indicate that anthropogenic pollution from the land-based thermal sources has the strongest impact on the concentration of dioxins in the port sediments. The concentration of 17 dioxin congeners (WHO-TEQ) did not exceed the probable effect level (PEL) of 21.5 pg TEQ g−1 d.w. The concentration of PCP ranged from bellow the LOD (< 0.85 ng g−1 d.w.) to 12.4 ng g−1 d.w.

The positive correlation between toxicity and physico-chemical properties of the analyzed bottom sediments confirms that these parameters are important in terms of environment contamination.

Specimens of Piscicola pojmanskae were identified in the macrozoobenthos community in Zostera meadows in Puck Bay. The presented paper is the first report on the observation of this species in the Gulf of Gdańsk (the southern Baltic Sea). Leeches are a rare component of the benthic fauna in this brackish water area.