Volume 45 (2016): Issue 4 (December 2016)

The present study was performed to follow temporal variation of the soft-bottom molluscan fauna in north-western Iskenderun Bay. The benthic material was collected at a depth ranging from 3 to 37 m at 12 sampling locations by the van Veen grab sampler in the summer season of 2012, 2013 and 2014. A total of 133 species were identified in the study area through the examination of the collected material. Among the identified species, Corbula gibba (Olivi, 1792), Bittium reticulatum (da Costa, 1778), Nassarius pygmaeus (Lamarck, 1822), Cerithidium diplax (Watson, 1886) and Finella pupoides Adams, A., 1860 have the highest values of the frequency index. According to the Bray-Curtis similarity index, these species also have an important effect on the similarity between the stations. Furthermore, C. diplax and F. pupoides are alien species to the Mediterranean.

Both phytoplankton of the Kizilirmak River/Black Sea transition zone and their interactions with nutrients were investigated between July 2007 and December 2008. A total of 447 taxa belonging to the divisions: Cyanobacteria (24), Bacillariophyta (209), Bigyra (1), Cercozoa (1), Charophyta (11), Chlorophyta (32), Cryptophyta (11), Miozoa (119), Euglenozoa (14), Haptophyta (13), Ochrophyta (10) and Protozoa Incertae Sedis (2) were identified at 5 different sites in the study area. Seventy four taxa were recognized as new records for the Algal Flora of Turkey and 41 taxa were determined as HAB (Harmful Algal Bloom) organisms.

According to the hierarchical clustering and MDS analyses, surface phytoplankton were distributed along the salinity gradient from freshwater to saline waters, and the early spring samples were separated from the other samples. However, in addition to the agglomerative hierarchical cluster analysis, the samples were divided into four groups – “Fresh”, “Brackish”, “Marine” and “Early spring-Marine” – as a result of MDS analysis.

The results of this study revealed that the surface phytoplankton were influenced by the salinity and the Secchi Disc depth together with the seasonal water temperature dynamics and NO₃-N concentrations throughout the research period.

Cyanobacteria are natural components of many freshwater bodies worldwide. In Russian lakes, the presence of potentially toxic cyanobacteria was also frequently observed. Our study was conducted in Sestroretskij Razliv Lake (Razliv) and Lower Suzdal Lake (Suzdal) in Saint Petersburg region, Northwestern Russia, which differ from one another in eutrophic status and composition of the phytoplankton community. In large, shallow, artificial and hypertrophic Razliv, Aphanizomenon flos-aquae and Microcystis spp. dominated. Fourteen microcystin variants were identified in this lake. The maximum concentration of extracellular microcystins was 41.37 μg l⁻¹. In eutrophic and shallow Suzdal, dominated by Planktothrix agardhii, nine microcystin variants and anatoxin-a (<0.54 μg l⁻¹) were found. The maximum total concentration of extracellular MCs in this lake was 2.89 μg l⁻¹. Regular studies into the production of cyanotoxins in these water bodies were carried out for the first time. The analyses performed with the application of high-resolution tandem mass spectrometry revealed the presence of microcystins in 59% of the samples collected during a 3-year study. Since both lakes are used for recreational purposes, the regular monitoring program should be implemented to protect water users from a potential risk that was identified in our study.

Macrophytes play a major role in the structuring of aquatic environments, and create diverse microhabitats. Therefore, these plants represent an important factor regulating the zooplankton biomass, taxonomic composition, and distribution in freshwater ecosystems. In the current study, we examined the effects of the structural heterogeneity provided by various macrophytes. We identified four habitat types in this study: (1) open water (without macrophytes), (2) the helophyte zone, (3) the pleustophyte zone, and (4) the mixed vegetation zone (containing pleustophytes, nymphaeids, and elodeids). We tested the hypothesis that complex habitat structures support large zooplankton assemblages. Specifically, we collected zooplankton samples from a total of 119 sampling points in the Upo Wetlands, South Korea, during the spring and autumn of 2009. The largest zooplankton assemblage was found in the mixed macrophyte zone, followed by the helophyte and pleustophyte zones. The pleustophyte zone supported larger zooplankton assemblages during autumn compared to spring. Differences in zooplankton assemblages were considered to be strongly related to seasonal variation in the development and growth of pleustophytes. However, two-way ANOVA revealed that seasons had no significant influence on the zooplankton density and diversity. Instead, different habitat types substantially determined zooplankton characteristics. In conclusion, we demonstrated that wetland areas with high macrophyte species diversity contribute toward higher zooplankton diversity.

This study compared selected methods of assessing the pollution in the littoral sediments by heavy metals (Zn, Cu, Pb, Ni and Cd) in 13 lakes of the Borecka Forest. For this purpose, the ecotoxicological criteria (PEL TEL), the geoaccumulation index (I_geo), the contamination factor (CF) and the contamination degree (C_d) were applied. Characteristic values for both Poland (GBP) and the Earth’s crust (GBE) were assumed as the geochemical background. In addition, the organic (TOC) and inorganic (TIC) carbon were determined in the analyzed sediments. Regardless of the method or adopted background value, the highest pollution level was in the littoral sediments of Lake Szwałk Mały and Lake Kacze. This was primarily associated with increased concentrations of Cd (1.25 and 0.64 mg kg⁻¹, respectively), which was considered as “likely to have toxic effects on organisms” (exceeding PEL). Several potential sources of this metal (fertilizers, herbicides, leaky septic tanks, bait fishing, drainage ditches, allochthonous organic matter) were identified. The content of heavy metals in the littoral sediments of other lakes was sufficiently low and they could be considered as basically uncontaminated.

The effect of climate variability on estuarine water environments was assessed in two systems of the Bay of Biscay, the estuaries of Bilbao and Urdaibai, with contrasting morphology, hydrodynamic features and anthropogenic influence. To that purpose, the main time scales of variability in relevant environmental factors were established along spatial salinity gradients and, using a combination of multivariate and regression analyses, the contribution of each factor to the total variability, as well as the influence of climate factors in the seasonal and inter-annual estuarine environment variations were assessed. The major seasonal modes of variability in the water environments of both estuaries were accounted for by water temperature together with salinity stratification and/or chlorophyll a. This seasonal variability was associated with climate variability, as shown by the relationship with air temperature and river flow. The major inter-annual modes of variability were also accounted for by water temperature, along with dissolved oxygen and/or chlorophyll a in Bilbao, and chlorophyll a and/or transparency in Urdaibai. These were also associated with climate variability, in this case summer air temperatures. Water quality variables, such as dissolved oxygen and transparency, were found to be sensitive to reveal the effect of long term anthropogenic activities.

This paper evaluates water quality and ecological status of lakes located in the Wielkopolska National Park and its buffer zone. Changes in water quality were analyzed from 1974 to 2012 in order to assess the effectiveness of the protection strategies implemented on the studied lakes since 1957, i.e. the date when the park was established. The ecological status of the lakes was assessed with the use of macrophytes as well as hydromorphological and physicochemical analyses performed in 2012. Changes in water quality of the studied lakes within the last 40 years were analyzed based on available published and unpublished data, as well as field studies. All water bodies are characterized by advanced eutrophication. However, evaluation of the ecological status showed good status of the charophyte-dominated lakes, i.e. Lake Wielkowiejskie and Lake Budzyńskie. Lack of significant differences in physicochemical water qualities between the park and its buffer zone indicated that measures implemented to protect the water, particularly in the park, are ineffective. This study shows that more radical conservation measures are necessary to protect and improve the water quality, not only in WPN and its buffer zone but also in the whole catchment area.

The present study focused on the determination of the baseline data and correlations between biological and physicochemical variables, including the assessment of trophic conditions in Lake Qarun. The concentrations of nutrients were high, with the maxima usually in the east subarea (total nitrogen 6.40 mg dm^-3, mineral nitrogen 2.34 mg dm^-3, orthophosphates 0.22 mg dm^-3). A total of 134 phytoplankton species were recorded. Bacillariophyceae and Dinophyceae co-dominated spatially and seasonally in phytoplankton assemblages. The highest phytoplankton density (935 × 10⁴ cells dm^-3) and chlorophyll a content (69.3 μg dm^-3) were recorded in the east subarea of the lake, whereas the largest total and dominant fish (Mugil cephalus and Solea spp.) were in the west. Tilapia zillii and Engraulis encrasicolus were most abundant in the east and in the middle part, respectively. When phytoplankton density decreased from the east toward the west subarea, the Secchi disk depth increased. The TLI-based assessment indicated hypereutrophic waters at most sites of Lake Qarun. Statistically significant positive or negative correlations were found between the dominant fish species: T. zillii and Solea spp., and the phytoplankton density, Dinophyceae density, concentrations of TP, chlorophyll a, ammonium, nitrite and nitrate. Such correlations may be helpful to better understand how to enhance the sustainable fish production.

The composition of water bug communities from 32 springs located in the central part of Montenegro was investigated. Twenty five species were identified, including 13 reported as new to Montenegro. The most common species were Hydrometra stagnorum and Velia sp. (Gerromorpha). Our study in the central part of Montenegro revealed that environmental and faunistic classification of karstic springs based on water bug communities may not correspond with each other. According to environmental characteristics, springs were divided into three groups indicating anthropogenic impact on the spring habitats. Water bug communities divided springs into four groups. There are differences in species richness between these four types of water bug assemblages and among the studied spring types. Results of CCA analysis revealed spring size as the main driver of biotic diversity of aquatic bugs in springs. Our study showed that community groups of water bugs specified in the biotic classification of spring habitats are much better defined than assemblages distinguished in the environmental site classification.

Diatoms are one of the key organisms used in biomonitoring studies and they occur in a wide variety of environments, exhibiting a broad range of tolerance to abiotic factors. Historically, the first freshwater diatom study in Turkey was conducted in 1844 by Ehrenberg based on the material collected from the Murat and Aras Rivers. Situated between large continents (Eurasia and Africa), Turkey comprises areas of very diverse geological, climatic and environmental conditions, so we should expect that organisms such as diatoms show high diversity in this region. The aim of this study is to present new sites of rare and new records in Turkey from different genera along with morphological and ecological characteristics. As a result, a total of 73 species (24 rare and 49 new records) are presented in this study.

The three spine stickleback Gasterosteus aculeatus is a small omnivorous, wildly distributed fish. In this study, food uptake and body condition of three spine stickleback, from the Gulf of Gdansk eulitoral was investigated. Samples were taken from three locations of the Gulf of Gdańsk: in vicinities of Sopot, Chałupy and Hel. Copepods were the most quantitive food components in the three spine stickleback stomachs. In spring, at Hel station -Harpacticoida and in Sopot, crustacean and fish eggs, were dominating as a fish prey. During summer, Calanoida were most abundant in stomachs collected from fish caught in Chałupy, fish eggs and Calanoida in those from Hel station. In stomachs of fish from Sopot location most common prey were Cladocera. Comparison of stomach content to food base and Fulton’s body condition index revealed that the three spine stickleback uses available food base in efficient way.

This study deals with the presence of Mytilus galloprovincialis on the Mediterranean green crab, Carcinus aestuarii Nardo, 1847 as an epibiont. Crab samples were collected by means of single-entry fyke nets at 6 different locations selected in the Çardak Lagoon. A total of 22 specimens of M. galloprovincialis (1-9 ind. per crab) on different body parts of 4 crabs were recorded. This is the first report about the occurrence of M. galloprovincialis on C. aestuarii.

Pharmaceuticals are commonly found in water collected from wastewater treatment plants, fresh water and saline water. Their presence in water may result in constant accumulation in living organisms, and consequently a negative impact on those organisms. Abiotic samples collected from the Gulf of Gdańsk were already proven to be polluted by several classes of pharmaceuticals, but the bioaccumulation was not investigated as far. This study presents the first results on the accumulation of pharmaceuticals in Mytilus edulis trossulus (Gould 1890) mussels collected from the Gulf of Gdańsk. The content of target 6 non-steroidal anti-inflammatory pharmaceuticals (ibuprofen, flurbiprofen, diclofenac, paracetamol, naproxen, ketoprofen) and 17α-ethynylestradiol in water and tissue samples was determined. The selected pharmaceuticals (paracetamol, flurbiprofen, 17α-ethynylestradiol) were found only in the largest individuals. The in situ BAFs calculated for paracetamol and flurbiprofen were 2850 and 16154 l kg^-1 (dry weight), respectively, suggesting a high potential for the bioaccumulation of these compounds. The synthetic hormone 17α-ethynylestradiol was also found in the collected mussels at the concentration of 310 ng g^-1 of dry weight. Generally, the examined mussels showed poor condition and it is highly likely that the accumulated pharmaceuticals are one of the important factors contributing to this.

Sporocysts with cercariae of Prosorhynchus squamatus Odhner, 1905 (Digenea, Bucephalidae) have been found for the first time in mussels Mytilus trossulus Gould, 1850 from the Gulf of Gdańsk (the southern Baltic Sea). The presented work provides a description and morphometry of larvae of this parasite.