Volume 45 (2016): Issue 2 (June 2016)

We investigated the distribution of several picophytoplankton groups (Prochlorococcus, Synechococcus, and picoeukaryotes) in relation to a warm eddy in the northern South China Sea in summer 2012. An anticyclonic eddy centered on 117°E longitude was identified during the sampling period using satellite data and hydrologic mapping. The layer of maximum Prochlorococcus and Synechococcus abundance within the eddy core dropped from 50 to 75 m, which was consistent with the subsurface chlorophyll a maximum. The water-column integrated abundance of Prochlorococcus, Synechococcus, and picoeukaryotes in the eddy core (9.67±0.23, 1.56±0.04, and 0.28±0.01 × 10³ cells ml^-1, respectively) was significantly lower (P<0.05) than that of the reference stations (25.10±2.32, 2.71±0.63, and 0.92±0.15 × 10³ cells ml^-1, respectively), and the abundance of Prochlorococcus in the core was also significantly lower than that at eddy edges (15.75±1.78 × 10³ cells ml^-1). However, there were no differences in the water-column integrated Chl a between the eddy core and edge. Our findings show that the warm eddy led to the reduced picophytoplankton abundance, especially of Prochlorococcus and picoeukaryotes, causing the layer of maximum picophytoplankton abundance to differ from that of the subsurface Chl a maximum.

The aim of this study was to describe the production biomass and abundance dynamics of the major Baltic calanoid copepods (Acartia spp., Temora longicornis and Pseudocalanus sp.) in the Gulf of Gdansk (the southern Baltic Sea) during a three-year period from March 2010 to December 2012. The data were collected at six stations located in the western part of the gulf. Acartia spp. was the most abundant taxon throughout the study period. The observed differences in the weighted mean depth for the investigated species were >2 m between nauplii and adults of Acartia spp., >5 m between nauplii and adults of Temora longicornis and 3 m between nauplii and younger copepodites of Pseudocalanus sp. The highest values of the secondary production rates were determined for Acartia spp. - almost 17.55 mg C m^-2 d^-1 (summer 2011), while Temora longicornis reached 3.80 mg C m^-2 d^-1 in spring 2010 and Pseudocalanus sp. had the highest secondary production values in summer 2011 - about 1.28 mg C m^-2 d^-1.

The Vistula River plays an important role in the supply of autochthonous and allochthonous material to the Gulf of Gdansk. The suspended particulate matter (SPM) of fluvial origin is considered to constitute a specific sorbent for halogenated organic compounds due to their lipophilic characteristics and relative solubility. Because there are many factors affecting the input of SPM into the estuarine environment of the Gulf of Gdansk, e.g. hydrological characteristics of the Vistula River, it became necessary to verify whether the same processes may affect a discharge of organic contaminants. The study presents an approach to the assessment of temporal trends in SPM concentration in the Vistula River discharged into the Gulf of Gdansk as well as the analysis of pentachlorophenol (PCP), a commonly used agricultural biocide, a precursor of dioxins in either dissolved or particulate phases in the river (the Vistula River) and sea waters (the Gulf of Gdansk). The study revealed that the hydrological characteristics appear to influence a load of SPM. However, the discharge of PCP is additionally related to the environmental conditions, physicochemical properties of the compound and the sorbent, affecting the partitioning of PCP into dissolved and particulate phases.

We investigated the frequency of antibiotic resistance of Enterobacteriaceae and the presence of vancomycin-resistance genes in samples taken from the Sea of Marmara, and the Istanbul and Canakkale Straits, Turkey. Different colony-forming bacteria were isolated and identified with the VITEK 2 Compact 30 system. The antibiotic resistance of the isolates was determined by the disc diffusion method. The isolates were tested against amoxicillin, ampicillin, aztreonam, ceftazidime, cefotaxime, cefuroxime, ofloxacin, vancomycin, tetracycline, kanamycin and gentamycin. The presence of vancomycin-resistance genes (vanA and vanB) was also investigated. The level of Enterobacteriaceae species was higher in the Sea of Marmara than in the Istanbul Strait and the Canakkale Strait. Isolates showing resistance to the greatest number of antibiotics were identified from E. coli isolates. The resistance of the selected bacterial isolates were as follows: kanamycin (82%), vancomycin (78%) and ampicillin (60%). Some intermediately vancomycin-resistant Enterobacteriaceae isolates had the vanA gene. This study provides evidence of widespread bacterial resistance to clinically relevant antibiotics in marine environments. It also contributes to the knowledge on the distribution of antibiotic resistance among Enterobacteriaceae and indicates the importance of control measures in domestic water treatment.

The objective of this work was to examine the water quality using three diatom indices SPI, GDI and TDI. The material for the study was collected during four seasons from autumn 2010 to summer 2011, from four sampling sites located on the Wisłoka River, in the town of Dębica and the surrounding area. The Wisłoka at all selected sites was characterized by alkaline or close to neutral pH (pH 6.5-7.7). Electrolytic conductivity ranged from 364 to 480 µS cm^-1. The Wisłoka at the selected sites in the urban area and in the surrounding areas was characterized by high diatom species richness. The total of 238 taxa from 53 genera were recorded, of which the most numerous were: Nitzschia (44), Navicula (33) and Gomphonema (12). Achnanthidium minutissimum var. minutissimum, Amphora pediculus, Navicula gregaria, N. lanceolata, and Nitzschia dissipata ssp. dissipata were usually the dominant species. Chemical parameters indicated very good quality of water. However, the diatom indices used to assess the water quality, classified the studied water into a group corresponding to quality class III or IV.

Potential factors affecting the occurrence of filamentous algae include the morphometry of water bodies, the type of substrate and physicochemical conditions of the habitat. This study attempts to describe the individual filamentous algae species recorded in Poland, taking into account the trophic and ecological characteristics based on our own research and available literature data. Filamentous algae attached to the substrate as well as those forming free-floating patches (loose or dense mats) and crusts occur in all types of water bodies. Among the representatives of filamentous algae species, Cladophora have the greatest time-spatial range for they grow abundantly in all types of water bodies. In other parts of Poland, Cladophora species are most common in rivers and shallow lakes. In the typical filamentous algae community, Cladophora, Spirogyra and Oedogonium occur with the highest frequency; Zygnema, Mougeotia, Microspora and Rhizoclonium are also present, but with smaller frequency. According to our studies, distribution of filamentous algae species is correlated with the eutrophic index (PO4_{3 -}, N-NO_{3 -}, Chl a), chlorides of anthropogenic origin and TDS.

The growth rates of ciliates estimated under natural conditions with the widely used size fractionation method are much lower than those observed in cultures. However, recent studies performed with a modified dilution method demonstrated that the size fractionation method underestimates the ciliate growth, because it does not remove predators of the same size as the organisms studied. Thus, it is still unresolved whether ciliates are food-limited in different systems and whether their growth rates are indeed lower than those in cultures. This study was conducted in highly eutrophic Lake Gardno using a modified dilution method. Each time, two dilution experiments were performed (around noon and around midnight). Four small, common ciliates from the genera Rimostrombidium, Tintinnidium, Cyclidium, and Urotricha were studied. The first three ciliates demonstrated very high mean diel growth rates exceeding 0.1 h^-1, which corresponded well to the highest values reported in the literature for the ciliate growth in cultures at similar temperatures. Tintinnidium sp. demonstrated a diel growth rhythm. Urotricha sp. was sensitive to the experimental procedure, and measurements of its growth were unsuccessful. Concentrations of food particles were analyzed to check whether organisms studied were food satiated.

The removal of oil spill pollution is an important issue of water environment protection. A hydrodynamic model for the determination of oil spill removal area is proposed based on the Euler-Lagrangian particle tracking method. After the results of flow field simulation are validated by the measured data, the trajectory of oil particles is calculated. The optimal location of oil spill removal area is obtained by comparing the oil removal rate of different removal areas. The current method presents a useful way of locating the optimal oil spill removal area to clean the surface waters.

This paper presents examples of application of a common reference datum, such as NAP, within the elevation EVRS reference system for the Baltic Sea. A common reference datum allowed for setting the geographical pattern of occurrence of extreme sea levels in the Baltic Sea. The eastern Baltic coasts exposed to western air masses are vulnerable to extreme hydrological events (the Gulf of Finland, the Gulf of Riga and the Gulf of Bothnia). On the contrary, the Swedish coasts of the central and northern Baltic are the least threatened by extreme sea levels. The south-western coasts of the Baltic Sea (the Bay of Mecklenburg and the Bay of Kiel) cover the basins with the most frequent and the most severe storm falls and extremely low sea levels. Demonstration of the Baltic surface deformation magnitude during a storm event is another example of NAP application. The instantaneous height difference between the north-eastern and southwestern coasts was 356 cm, which resulted from the negative impact of pressure (water cushion) induced by a dynamic and deep low-pressure system moving through the Baltic Sea. The common reference datum allowed for visualization of the so-called “theoretical water” distribution which has a wide application in the hydraulic engineering within the coastal zone. In addition, the study provides examples of differences that may be observed during storm events between the real sea-level data and the hydrodynamic model forecast. This is of great practical significance in terms of forecasting storm surges in the Baltic Sea.

Although marine research on anthozoans began at the end of the 1800s with some reports on the occurrence in Turkey, comprehensive knowledge about their biotic features remains limited. This study is the first detailed diversity assessment of scleractinian corals inhabiting the Turkish waters. The surveys conducted on rocky habitats between 2011 and 2014 around the Dardanelles and Marmara Sea provided the distributional data of nine corals, five of which (Caryophyllia inornata, Paracyathus pulchellus, Polycyathus muellerae, Phyllangia mouchezii, Leptopsammia pruvoti) were recorded for the first time from the above-mentioned regions. During the surveys carried out at 200 stations down to 50 m depth, a total of 1072 scuba dives were made and the ecological features of habitats, physical characteristics of coral species and an updated list of corals as a contribution to the scleractinian fauna of Turkey were provided. The abundance rate of Polycyathus muellerae and Cladocora caespitosa in Eceabat and Dardanos regions was higher than at the other stations.

This study shows the macrozoobenthic biodiversity and the quality status of the Zostera marina meadow in the Gulf of Gdansk. To our knowledge, this is the first study focused on the assessment of environmental quality based on macrofauna occurring on such a small and specific habitat as a seagrass meadow.

The meadow is dominated by Zostera marina, but also Zanichellia palustris and Potamogeton pectinatus are present. Compared to the soft bottom macrofauna in the southern Baltic, the biodiversity of macrozoobenthos is very high, which is reflected in 33 taxa observed during the whole research, while the mean number of taxa was 12. There were also some taxa found only on the bottom overgrown with vegetation, e.g. Idotea balthica or even taxa that are currently rarely observed in the Gulf of Gdansk, e.g. Gammarus locusta or Gammarus ineaquicauda. Nineteen percent of the stations were classified into the very good quality status and 50% into the good quality status, so the environmental status of this meadow based on the BQI index is assessed as good. Given these results, this is probably one of the best preserved meadows in the southern Baltic.