The first data on the freshwater microcrustaceans of Shokalsky Island (Russian Arctic).
ABSTRACT: Information on freshwater invertebrates of the Russian Arctic is very scarce, especially concerning insular biota. The species composition of microcrustaceans (Cladocera, Copepoda) of many arctic islands is still unknown and have never been explored. Here we report the results of the first investigation of the zooplankton of the Shokalsky Island (Yamalo-Nenets Autonomous Okrug, Russia). Information on freshwater invertebrates of the Russian Arctic is very scarce, especially concerning insular biota. The species composition of microcrustaceans (Cladocera, Copepoda) of many arctic islands is still unknown and have never been explored. Here we report the results of the first investigation of the zooplankton of the Shokalsky Island (Yamalo-Nenets Autonomous Okrug, Russia).The new records reported here are novel for the region and significantly expand the knowledge of the high--latitude aquatic biota. We studied the species composition of Cladocera and Copepoda of 21 freshwater habitats located on the south-western part of Shokalsky Island. We found 15 species of microcrustaceans in total and all of them are reported for the first time here. Also, the obtained data expand the existing ranges of distribution of some species and report several new taxa for the whole Yamalo-Nenets region of Russia.
Project description:Background:Sub-lakes are important for the maintenance of the ecosystem integrity of Lake Poyang, and zooplankton play an important role in its substance and energy flow. Methods:A seasonal investigation of zooplankton was conducted in spring (April), summer (July), autumn (October) and winter (January of the following year) from 2012 to 2016 in a sub-lake of Lake Poyang. The aim of the present study was to understand the seasonal dynamics and interannual variation of zooplankton communities and their relationship to environmental factors. Results:A total of 115 species were identified in all samples in the four years, which comprised of 87 Rotifera, 13 Cladocera and 15 Copepoda. Rotifera was the dominant group in terms of quantity, and its species richness and abundance were significantly higher when compared to Cladocera and Copepoda (P < 0.05), while Cladocera dominated in terms of biomass. The species richness of Rotifera exhibited a significant seasonal difference (P < 0.05). Both the density and biomass of zooplankton revealed significant seasonal differences (P < 0.05). In general, the density and biomass of zooplankton were higher in summer and autumn, when compared to winter and spring. Biodiversity indices were dramatically lower in spring than in the other seasons. The non-metric multidimensional scaling (NMDS) analysis suggested that these zooplankton communities can be divided into three groups: spring community, summer-autumn community, and winter community. The seasonal succession of zooplankton communities did not have interannual reproducibility. In high water level years, the dominant species of zooplankton (Cladocerans and Copepods) in the wet season had a lower density, and the result in low water level years was exactly the opposite. The redundancy analysis revealed that water temperature (WT), conductivity, pH and dissolved oxygen (DO) had significant effects on the zooplankton community. Conclusions:The community structure of zooplankton has a significant seasonal pattern, but has no interannual repeatability. In high water level years, the dominant species of zooplankton (Cladocerans and Copepods) in the wet season had a lower density, and the result in low water level years was exactly the opposite. The density, biomass and diversity indices of zooplankton were significantly different in different seasons. The present study was helpful in the further understanding of the ecosystem stability of lakes connected with rivers, providing scientific guidance for the protection of lake wetlands.
Project description:The present work aims to study the Zooplankton seasonal distribution and diversity in Karanja reservoir, Bidar district for the period of two years from October 2001 to September 2003. We have recorded 36 species of which, 15 species belongs to rotifera, 11 species belongs to cladocera, nine species belongs to copepoda and ostracoda three species. Among zooplankton, particularly rotifera was the dominant group throughout the study period and highest count was recorded in the month of March 2003. Cluster analysis was also revealed by dendrogram and Shannon diversity index is also presented. Zooplankton community is also correlated with physicochemical parameters.
Project description:<b>Background: </b>The European North-East of Russia is the territory which includes the Nenets Autonomous District, represented by the East European tundra (from Kanin Peninsula to Vaigach Island), Komi Republic with its taiga ecosystems and the Urals (Northern, SubPolar and Polar). Over 20 years of systematic studies of soil fauna in the studied region has resulted in a huge amount of data being accumulated that can be analysed from different positions. Considering that the representation of Russian soil biota data, especially from European North-East of Russia in the GBIF database is not large, our data are of great interest to the scientific world community. The accumulation of such data will solve questions on national and global scales using large arrays.This study produced a dataset containing information on occurrences on soil invertebrates (Lumbricidae, Chilopoda, Diplopda, Collembola, Elateridae and Staphylinidae) in the European North-East of Russia. The dataset summarises occurrences noted in natural and disturbed forests, tundra and mountain ecosystems.<br><br><b>New information: </b>Data from 196 geo-referenced localities of European North-East of Russia (tundra, taiga and mountains ecosystems) have been collated. A total of 5412 occurrences are included in the resource. The current project surveys 13 species of earthworms, 20 species of millipedes, 246 species of springtails, 446 species of rove beetles and 60 species of click beetles. The diversity of soil invertebrates in the European North-East of Russia has not been fully explored and further exploration will lead to more taxa.
Project description:The magnitude of community-wide dispersal is central to metacommunity models, yet dispersal is notoriously difficult to quantify in passive and cryptic dispersers such as many freshwater invertebrates. By overcoming the problem of quantifying dispersal rates, colonization rates into new habitats can provide a useful estimate of the magnitude of effective dispersal. Here we study the influence of spatial and local processes on colonization rates into new ponds that indicate differential dispersal limitation of major zooplankton taxa, with important implications for metacommunity dynamics. We identify regional and local factors that affect zooplankton colonization rates and spatial patterns in a large-scale experimental system. Our study differs from others in the unique setup of the experimental pond area by which we were able to test spatial and environmental variables at a large spatial scale. We quantified colonization rates separately for the Copepoda, Cladocera and Rotifera from samples collected over a period of 21 months in 48 newly constructed temporary ponds of 0.18-2.95 ha distributed in a restored wetland area of 2,700 ha in Doñana National Park, Southern Spain. Species richness upon initial sampling of new ponds was about one third of that in reference ponds, although the rate of detection of new species from thereon were not significantly different, probably owing to high turnover in the dynamic, temporary reference ponds. Environmental heterogeneity had no detectable effect on colonization rates in new ponds. In contrast, connectivity, space (based on latitude and longitude) and surface area were key determinants of colonization rates for copepods and cladocerans. This suggests dispersal limitation in cladocerans and copepods, but not in rotifers, possibly due to differences in propagule size and abundance.
Project description:The studies on marine copepods of Costa Rica started in the 1990's and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species), which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic). By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific) and 45 from the Caribbean coast (8% of species known from the Caribbean Basin). Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the biogeographic relevance of the inland copepod fauna of Costa Rica requires more detailed surveys.
Project description:Vitamin D status in groups of northern indigenous people of Russia leading close to traditional (seminomadic reindeer herding), post-traditional (in settlements) or "modernized" (in towns) way of life was analysed.The survey study groups consisted of 178 Nenets and Komi aged 18-60 living in the Arctic (66-67°N). Urban Komi, Udmurts and Komi-Permiaks (n=150) living in a non-Arctic area (57-61°N) formed a control group. The concentration of serum 25-hydroxyvitamin D (25OHD), as a transport form of vitamin D, was assessed by enzyme immunoassay analysis.The group average 25OHD levels in both rural and urban Arctic residents are within the range of values seen in the non-Arctic urban subjects adjusted for season: 39.7-47.7 nmol/l. Abandoning traditional lifestyle associates with lower vitamin D levels in indigenous Arctic people. Mean±standard deviation 25OHD values among Nenets were lower in those living in the administrative centre (a big settlement) with a population of 1,460 (32.2±12.90 nmol/l) than in the residents of small settlements (39.6±14.08 nmol/l), and in reindeer herders (42.4±13.45 nmol/l; p<0.05 in both cases). Komi townspeople had lower 25OHD concentrations (47.7±12.00 nmol/l) than Komi reindeer herders (68.7±25.20; p<0.01).The transition from seminomadic to post-traditional and "modernized" way of life has led to a decrease in the consumption of traditional foods among the indigenous people of the Russian Arctic. Our data support the notion that the traditional northern diet promotes healthy vitamin D levels, while adherence to the "western" type of diet correlates with a lower 25OHD concentration.
Project description:The European Marine Strategy Framework Directive requires the EU Member States to estimate the level of anthropogenic impacts on their marine systems using 11 Descriptors. Assessing food web response to altered habitats is addressed by Descriptor 4 and its indicators, which are being developed for regional seas. However, the development of simple foodweb indicators able to assess the health of ecologically diverse, spatially variable and complex interactions is challenging. Zooplankton is a key element in marine foodwebs and thus comprise an important part of overall ecosystem health. Here, we review work on zooplankton indicator development using long-term data sets across the Baltic Sea and report the main findings. A suite of zooplankton community metrics were evaluated as putative ecological indicators that track community state in relation to Good Environmental Status (GES) criteria with regard to eutrophication and fish feeding conditions in the Baltic Sea. On the basis of an operational definition of GES, we propose mean body mass of zooplankton in the community in combination with zooplankton stock measured as either abundance or biomass to be applicable as an integrated indicator that could be used within the Descriptor 4 in the Baltic Sea. These metrics performed best in predicting zooplankton being in-GES when considering all datasets evaluated. However, some other metrics, such as copepod biomass, the contribution of copepods to the total zooplankton biomass or biomass-based Cladocera: Copepoda ratio, were equally reliable or even superior in certain basin-specific assessments. Our evaluation suggests that in several basins of the Baltic Sea, zooplankton communities currently appear to be out-of-GES, being comprised by smaller zooplankters and having lower total abundance or biomass compared to the communities during the reference conditions; however, the changes in the taxonomic structure underlying these trends vary widely across the sea basins due to the estuarine character of the Baltic Sea.
Project description:Directional dispersal by wind and other dispersal agents may generate spatial patterns in passively dispersing metacommunities which cannot be detected by classical eigenvector methods based on Euclidean distances. We analysed zooplankton communities (Rotifera, Cladocera, Copepoda) in a cluster of soda pans distributed over a short spatial scale of 18 km and tested explicitly for directional signals in their spatial configuration. The study area is exposed to a prevailing northwestern wind direction. By applying asymmetric eigenvector maps (AEM), we were able to identify corresponding directionality in the spatial structure of communities. Furthermore, the match between community composition and environmental conditions exhibited a spatial pattern consistent with the prevailing wind corridor, with best match found downwind the dominant wind direction. We also found that classical eigenvector methods based on Euclidean distances underestimated the role of spatial processes in our data. Our study furthermore shows that dispersal limitation may constrain community assembly in highly mobile organisms even at spatial scales below 5 km.
Project description:Mercury (Hg) is a contaminant of major concern in Arctic marine ecosystems. Decades of Hg observations in marine biota from across the Canadian Arctic show generally higher concentrations in the west than in the east. Various hypotheses have attributed this longitudinal biotic Hg gradient to regional differences in atmospheric or terrestrial inputs of inorganic Hg, but it is methylmercury (MeHg) that accumulates and biomagnifies in marine biota. Here, we present high-resolution vertical profiles of total Hg and MeHg in seawater along a transect from the Canada Basin, across the Canadian Arctic Archipelago (CAA) and Baffin Bay, and into the Labrador Sea. Total Hg concentrations are lower in the western Arctic, opposing the biotic Hg distributions. In contrast, MeHg exhibits a distinctive subsurface maximum at shallow depths of 100-300?m, with its peak concentration decreasing eastwards. As this subsurface MeHg maximum lies within the habitat of zooplankton and other lower trophic-level biota, biological uptake of subsurface MeHg and subsequent biomagnification readily explains the biotic Hg concentration gradient. Understanding the risk of MeHg to the Arctic marine ecosystem and Indigenous Peoples will thus require an elucidation of the processes that generate and maintain this subsurface MeHg maximum.
Project description:Sea ice loss is accelerating in the Barents and Kara Seas (BKS). Assessing potential linkages between sea ice retreat/thinning and the region's ancient and unique social-ecological systems is a pressing task. Tundra nomadism remains a vitally important livelihood for indigenous Nenets and their large reindeer herds. Warming summer air temperatures have been linked to more frequent and sustained summer high-pressure systems over West Siberia, Russia, but not to sea ice retreat. At the same time, autumn/winter rain-on-snow (ROS) events have become more frequent and intense. Here, we review evidence for autumn atmospheric warming and precipitation increases over Arctic coastal lands in proximity to BKS ice loss. Two major ROS events during November 2006 and 2013 led to massive winter reindeer mortality episodes on the Yamal Peninsula. Fieldwork with migratory herders has revealed that the ecological and socio-economic impacts from the catastrophic 2013 event will unfold for years to come. The suggested link between sea ice loss, more frequent and intense ROS events and high reindeer mortality has serious implications for the future of tundra Nenets nomadism.