Development of crustacean plankton in a shallow, polyhumic reservoir in the first 20 years after impoundment (northeast Poland)

Multiannual changes of structure and biomass of crustacean zooplankton were studied in the shallow, lowland, polyhumic Siemianówka Reservoir on the upper Narew River in northeast Poland. High ammonium and soluble reactive phosphorus ion availability for phytoplankton, low water transparency, and high dissolved oxygen concentration resulted in humoeutrophication and caused an intensive development of summer cyanobacteria. We compiled and analyzed long-term (1993–2011) crustacean zooplankton community data and chlorophyll a concentrations. Zooplankton biomass and structure in the summer were related to the intensity of the cyanoprokaryota blooms. As chlorophyll a concentration increased, crustacean zooplankton biomass decreased and smaller crustacean species dominated the zooplankton structure. Large species of crustaceans (Daphnia longispina, D. magna, and Eudiaptomus graciloides) disappeared from the reservoir after filamentous cyanobacteria dominated the phytoplankton. Long-term studies suggest that phytoplankton with strong dominance of filamentous cyanobacteria shape the crustacean community but are probably an insignificant food source for the crustacean zooplankton in the Siemianówka Reservoir

Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.Peer reviewe

Local and regional factors influencing crustacean zooplankton communities in the Narew River

Liczba stron - 182, Liczba tabel - 10, Liczba rycin - 43, Bibliografia – 246 pozycjiCelem pracy była charakterystyka wybranych lokalnych i regionalnych czynników kształtujących strukturę zooplanktonu skorupiakowego siedlisk nizinnego systemu rzecznego. Obiektami badań były różne typy ekosystemów wodnych Doliny Górnej Narwi, w tym limniczny zbiornik Siemianówka. Łącznie przeanalizowano 610 prób zooplanktonu skorupiakowego Ogólnie w siedliskach Doliny Górnej Narwi stwierdzono występowanie 75 gatunków Crustacea, w tym 48 gatunków wioślarek (Cladocera) i 27 gatunków widłonogów (Copepoda). Zarejestrowano również dwa nowe gatunki dla fauny Polski - wioślarkę Camptocercus fennicus Stenroos 1898 i widłonoga Metacyclops planus (Gurney 1909). Największe bogactwo gatunkowe zooplanktonu skorupiakowego stwierdzano w starorzeczach, gdzie występowało ponad 80% wszystkich gatunków. Natomiast największym źródłem zooplanktonu skorupiakowego jest zbiornik Siemianówka, który znacząco wpływa na ilość i skład zooplanktonu rzeki Narew na odcinku 55 km poniżej zapory. Jednak gatunki ze zbiornika występowały nawet na stanowisku rzeki Narew oddalonym 130 km od zapory. Zbiornik Siemianówka może również zasilać zespoły zooplanktonu skorupiakowego starorzeczy w dolinie rzecznej. Przeprowadzone badania sugerują, iż odległość od źródła jest mniej istotnym czynnikiem kształtującym zbiorowiska zooplanktonu skorupiakowego starorzeczy, a większą rolę odgrywają lokalne warunki.The aim of the study was to describe the influence of local and regional processes on crustacean zooplankton in the habitats of lowland river system. The objects of the research were different types of aquatic ecosystems in the Upper Narew Valley, including limnic Siemianówka Reservoir. In total, 610 samples of crustacean zooplankton were analyzed. In total, in the Upper Narew Valley there were found 75 species of Crustacea, including 48 species of Cladocera and 27 species of Copepoda. Two species were recorded new for Polish fauna, i.e. Camptocercus fennicus Stenroos 1898 and Metacyclops planus (Gurney 1909). The highest species richness of crustacean zooplankton was found in oxbow lakes, where occurred more than 80% of all species described from the Upper Narew Valley. Siemianówka Reservoir is the largest source of crustacean zooplankton for the Upper Narew Valley and significantly affects the zooplankton composition and abundance in the Narew River on the distance of 55km below the dam. However, the species from the reservoir were noted even in the last Narew River station, i.e. 130 km below the dam. Siemianówka Reservoir may enrich crustacean zooplankton communities also in the oxbow lakes of the river valley. Performed studies suggest that the distance from the source is less important factor influencing crustacean zooplankton communities of oxbow lakes and more important are local conditions.Wydział Biologiczno-Chemiczny, Instytut Biologi

Biodiversity of microcrustaceans (Cladocera, Copepoda) in a lowland river ecosystem

This study presents comprehensive research on microcrustacean diversity in different types of aquatic environments in the Upper Narew Valley over five years. A total of 559 samples were analyzed, and 74 species of crustacean zooplankton were identified. Metacyclops planus (Gurney, 1909) is a new species for the fauna of Poland and was found in oxbow lakes and tributary streams. The results of the study suggest that oxbow lakes, with more than 80% of all recorded species, may significantly contribute to the regional biodiversity of floodplain rivers. The highest crustacean community diversity was observed in the semi-lotic oxbow lakes, which emphasizes the role of intermediate disturbance in enhancing biodiversity of water bodies in river valleys. Generally, more “heterogeneous” habitats, such as small oxbow lakes and tributary streams, had higher crustacean species richness. However, a sampling station that was quite “homogeneous”, the Narew River upstream the Siemianówka Reservoir, had high crustacean species richness. The species accumulation curves revealed that approximately 50 - 100 zooplankton samples taken from different environments of river valley are required to establish crustacean species richness. These data could be important for river catchment management and could act as pilot survey data for monitoring plans.</p

Assessment Potential of Zooplankton to Establish Reference Conditions in Lowland Temperate Lakes

Zooplankton community data from 45 dimictic lakes, representing homogenous abiotic conditions, were used to distinguish indicator taxa of near-pristine, reference lakes with low anthropopression. Reference conditions were selected based on natural land use in the catchment, lack of or low human activity, and the absence of point sources of pollution, as well as good water quality. According to these criteria, six lakes were designated references and all represent mesotrophic conditions. Reference lakes had a low abundance of Cyclopoida and Rotifera, and significantly lower biomass compared to non-reference lakes. We have found that species characteristic of the reference lake were: Bosmina (Eubosmina) coregoni, Ascomorpha ecaudis, Collotheca pelagica, and Gastropus stylifer. The species responsible for differences among reference and non-reference lakes were Keratella tecta, Pompholyx sulcata, and Ascomorpha saltans, which are considered typical for eutrophic waters

Diversity and Structure of Pelagic Zooplankton (Crustacea, Rotifera) in NE Poland

This study presents the diversity and structure of pelagic zooplankton in north-eastern Poland. The research was conducted in 47 lakes with different trophic conditions in the middle of summer. Samples were collected close to the deepest part of the lakes to avoid the diverse benthic and littoral zones. We found 119 zooplankton species of which 32 were Cladocera, 16 were Cyclopoida, 4 were Calanoida, and 67 were Rotifera. We determined which species occurred most frequently in the region, as well as the species that were characteristic of different trophic conditions. We also recorded the presence of eight cold-adapted species which some of them are considered as glacial relicts (e.g., Eurytemora lacustris, Heterocope appendiculata, Cyclops lacustris). Our research revealed potential glacial refugia for planktonic species in 14 lakes of NE Poland. Our study suggests that the presence of stenotherm species may be an excellent indicator of the ecological status of deep lakes and could be considered in lake monitoring programs. Furthermore, we did not find Bythotrephes longimanus which has been reported from Poland. Instead, we found that B. brevimanus was the most common representative of the genus in the study area

Influence of environmental factors on vertical distribution of zooplankton communities in humic lakes

The influence of vertical environmental gradients on zooplankton communities was studied in five humic lakes with the high availability of food resources (phytoplankton and bacterioplankton) and low fish pressure. The factors that inhibit the development of large zooplankton in humic lakes are currently widely debated. We have found that relatively productive humic lakes do not offer many niches for zooplankton because of the sharp thermal gradient which results in a shallow layer of oxygenated waters. The results of this study indicated that different taxonomic groups of zooplankton are determined by a different set of environmental variables. This phenomenon explains very low species richness of zooplankton and a possibility of their coexistence in the narrow oxygenated layer. We concluded that due to sharp thermal gradient in humic lakes biomass of herbivores may be reduced which could promote development of phytoplankton.Studies in five productive humic lakes of low fish pressure indicated that taxonomic groups of zooplankton are determined by a different set of environmental variables, which explains very low species richness of zooplankton. Due to sharp thermal gradient in the lakes biomass of herbivores is reduced which promotes development of phytoplankton

Diversity of rotifer communities in lakes of the Suwalki Landscape Park

Studies of summer rotifer fauna of 11 shallow and 6 deep lakes of the Suwałki Landscape Park were conducted in an aim to assess the role of lake depth and biotic and abiotic factors in determining the diversity of rotifer communities in lakes undergoing a natural rate of eutrophication not accelerated by anthropopression. Some differences were observed when the group of shallow lakes was compared with that of deep lakes. The former were more differentiated as regards a list of rotifer species, partly due to the high proportion of species with low frequency. Consequently, their faunal originality was markedly higher and values of the percentage similarity of rotifer communities were much lower than in deep lakes. Species richness of rotifer fauna was also dependent on the trophic state of the studied lakes, the character of a nutrient limiting primary production, as well as biomass of diatoms and green algae