Planktonic fauna of small salmon rivers in the Kola Peninsula

The zooplankton of 23 small salmon rivers of the White Sea and Barents Sea basins in the Kola Peninsula were studied. The species composition and quantitative indices in juvenile salmonids habitats are characterized. The maximum species diversity and abundance of planktonic fauna were recorded in lake-regulated rivers and places with large quantities of water. The quantitative development of zooplankton in rivers is low, which testifies to its minor role as a food resource for salmonid juveniles. The assessment of the ecological state of the river water is presented.     

The fauna and ecology of butterflies (Lepidoptera,Rhopalocera) of the Kanin Peninsula and Kolguev Island

A total of 29 butterfly species in the forest-tundra and 14 species in the hypoarctic tundra were recorded on the Kanin Peninsula. Six species of butterflies were identified on Kolguev Island. The data on the fauna and distribution of species in the forest-tundra of the Kanin Peninsula are generally typical of this natural zone (Chernov and Tatarinov, 2006). The faunas of the northern part of the Kanin Peninsula and the southern part of Kolguev Island comprise fewer species, including those of the Arctic complex. This phenomenon is related to the coastal position of the regions, the cool summer and strong winds. On Kolguev Island, seasonal migrants appear simultaneously with the local species or considerably later. The most abundant species in the forest-tundra of the Kanin Peninsula are Erebia disa, Oeneis norna, Clossiana freija, Pieris napi, and Vacciniina optilete. The dominant species in southern tundra localities are Erebia euryale, E. pandrose, and Boloria aquilonaris, which coincides with the result of the 1903 research (Poppius, 1906). Only the dewy ringlet Erebia pandrose was recorded regularly in the south of Kolguev Island in 2009. In spite of the impoverished fauna of Rhopalocera some butterfly species clearly prevail in abundance and inhabit a wide range of biotopes, which agrees with the concept of compensatory mechanisms (Chernov, 2005). A high abundance of E. pandrose is a specific feature of the northern part of the Kanin Peninsula and Kolguev Island, pointing to the connection of the biota of these territories with the Subarctic regions of Fennoscandia.     

The bottom invertebrates of small rivers in an area where pesticides were buried

The effect of Kilmezskii pesticide burial on the condition of zoobenthos of Osinovka and Loban’ rivers (the Vyatka River basin, Kirovskaya oblast) is reviewed. A faunistic list of water invertebrates in these rivers is published for the first time, qualitative and quantitative indices of zoobenthos development are given, and the condition of watercourses is assessed using bioindicative methods. The peculiarities of benthic communities of the Osinovka River and its tribute, i.e., a significant impoverishment of species composition, the simplification of structural organization, and low bioindicative indices, allow us to assume that the burial has a negative effect on zoobenthos condition.     

Comparison of zoobenthos and zooperiphyton of large and medium rivers

The results of a study of zoobenthos and zooperiphyton of two rivers of the Ob’ River middle reaches are shown. A comparative analysis of the composition and abundance values of two ecological groups of zoobenthos and zooperiphyton hydrobionts has revealed the difference in their taxonomic compositions and dominant complexes. The similarity in total number and biomass of zoobenthos and zooperiphyton in the large river and the higher values of zooperiphyton quantitative development in a medium river have been identified.     

Dynamics of the abundance and conditions of reproduction of mass species of pacific salmons (<Emphasis Type="Italic">Oncorhynchus</Emphasis>) on the northwestern coast of Sakhalin

The efficiency of reproduction of Pacific salmons of the genus Oncorhynchus in the rivers of the northwestern coast of Sakhalin Island is characterized on the basis of long-term data (1989?2014). Differences between the rivers in the northern and southern parts of the region under study have been revealed with respect to the channel type, faunistic composition of the aquatic biota, and prevailing species of salmons. A high spawning efficiency of pink salmon O. gorbuscha, high densities of filling of spawning grounds, and a relatively poor composition of the freshwater ichthyofauna have been recorded in the rivers of the northern part with the mountain–piedmont type of channel. Varied fish population and the high spawning efficiency of chum salmon O. keta have been recorded in the rivers of the southern part with the mainly lowland channel. The salmon spawning area in the rivers of the northern and southern parts has been estimated. The data on the dynamics of the abundance of salmons on the northwestern coast of Sakhalin are given. The total value of the passage of spawners to the rivers of northwestern Sakhalin that is required for effective reproduction has been estimated, ranging from 0.672 to 1.639 million specimens for pink salmon and approximately 0.43 million specimens for chum salmon.     

The current state and long-term changes of zoobenthos in the Novosibirsk reservoir

The composition, structure, and spatial distribution of zoobenthos in the Novosibirsk reservoir have been analyzed. A decrease in species richness an increase in invertebrates abundance from upper to low sites of the reservoir, caused by changes in bottom sediment types, have been observed. A comparative analysis of the benthos community structure for a 50-year period (1959–2008) clearly demonstrates that, with an increase in the biomass of invasive species in the reservoir, the biomass of large bivalve mollusks decreases.     

Diurnal butterflies (Lepidoptera, Rhopalocera) of the Solovetskie Islands (Northwestern Russia, the White Sea)

The species composition and diversity of Lepidoptera Rhopalocera were studied on the Solovetskie Islands during five years (2001–2005). Twenty-nine species of five families were recorded. The most abundant species are Leptidea sinapis, Boloria aquilonaris, Heodes virgaureae, Plebejus argus, Arcia eumedon, and Cyaniris semiargus. The fauna of these islands is poorer than local faunas of the continental northern taiga, forest-tundra, and southern tundra of Europe. The species diversity of insular assemblages of diurnal lepidopterans is lower in comparison with analogous continental assemblages. They are characterized by the mixed species composition, when species with different ecological preference occur within the same habitat.     

The biogeochemistry and zoogeography of lakes and rivers in arctic Alaska

Water samples from 45 lakes and 8 rivers in arctic Alaska were analyzed for major anions, cations, nutrients, chlorophyll, zooplankton, and benthos. The waters were dilute (conductivities of 30 to 843 μS cm⁻¹), and their composition varied from Na-Ca-Cl waters near the Arctic Ocean to Ca-Mg-HCO₃ waters further inland. Sea salt input in precipitation was important in determining the chemistry of coastal lakes, partly because of low groundwater flow and less time for water to react with shallow unfrozen soils. Further inland, variations in water chemistry among sites were related mainly to differences in bedrock, the age of associated glacial drift, and the input of wind blown sediment. Variations in zooplankton species composition among the lakes were related more to latitude, lake morphometery, and biotic interactions than to water chemistry. The presence of fish as predators mostly determined the overall size structure of the zooplankton community. The chironomid taxa identified have been previously reported from the Neararctic, except for Corynocera oliveri which is a new record. The abundance of the widely distributed chironomid Procladius appears to be controlled by sculpin predation.     

Diatom bloom in the tidal freshwater zone of a turbid and shallow estuary,Rupert Bay (James Bay,Canada)

Phytoplankton biomass and species composition were studied from June to September 1991 at the mouth of four major rivers and in the freshwater (sal. 0 %), the estuarine (sal. 2–10%) and the coastal (sal. 10–12%) zones of Rupert Bay, located at the southeast tip of James Bay, Canada.A chlorophyll a maximum (5–14 µg 1^–1) was observed in the freshwater zone from July to September. Chlorophyll values were low at the mouth of the rivers and in the estuarine and coastal zones (chl a < 1.00 µg 1^–1). Diatoms were dominant in the freshwater zone (30–80 % abundance), with flagellates dominating in the estuarine and coastal zones (60–95% abundance). Diversity was low (H: 1.5–2.5) in the freshwater zone and decreased seaward (H: 0.5–1.5).The diatom bloom was composed almost exclusively of the autochthonous planktonic diatom Cyclotella meneghiniana Kütz., which contributed 25–85% of the species composition, and of the subdominant benthic species Diploneis smithii, Navicula lanceolata and Surirella robusta. Peak abundance occurred upstream of the turbidity maximum, in the tidal freshwater zone. In this zone the mean photic depth was 1 m and residence time was from 7 to 8 days during the bloom. Residence time is considered to be the dominant factor controlling the phytoplankton bloom, with light not acting as a limiting factor. The high turbidity due to resuspension and shallow depth of the bay controlled the species composition.     

放牧对滩涂底栖动物的影响

于2005年5月（春季）和10月（秋季）,调查了放牧对上海市崇明东滩大型底栖动物的影响.调查采样设置3个样区,其中Ⅰ、Ⅱ样区在放牧区,Ⅲ样区在非放牧区,3个样区均在潮间带的中潮带,共计90个样方.采集到底栖动物13种,其中节肢动物7种,软体动物4种,环节动物2种.Ⅰ、Ⅱ和Ⅲ样区春季分别有6、8和10种,秋季6、8和12种.各样区秋季底栖动物的平均密度均高于春季,春、秋季各样区的平均密度又均以Ⅲ样区最高.生物量与密度变化大体相似,以Ⅲ样区最高.与Ⅰ、Ⅱ样区相比,Ⅲ样区的多样性指数、均匀度和丰富度均最高,说明放牧改变了底栖动物种类分布的格局,使底栖动物的密度、生物量均有不同程度的改变,且放牧对崇明东滩底栖动物的生物多样性产生了一定的负面影响.     

Taxonomic composition and abundance of macrozoobenthos in the Rybinsk Reservoir at the beginning of the 21st century

The structure of macrozoobenthos has been studied in the deep-water part of the Rybinsk Reservoir. A total of 73 species of bottom macroinvertebrates have been recorded, the majority of which are mollusks, oligochaetes, and chironomids. The macrozoobenthos on gray silts of channel parts of the reservoir was the richest in taxonomic composition and quantitative abundance. The maximum number of species has been recorded in the former mouth of the Mologa River, and the highest abundance of macrozoobenthos has been recorded near the village of Breitovo in June. Most of the macrozoobenthos is made up of oligochaetes and chironomid larvae; midge larvae dominate by biomass. Compared to the end of the 20th century, changes in the taxonomic composition and in dominating species of macrozoobenthos are observed.     

长江下游南京至江阴江段底栖动物的种群密度与分布状况

本文报道了1979年10—11月在长江下游南京至江阴江段53个采集点上共采到寡毛类8种,多毛类2种,水生昆虫14种,软体动物10种。干流中种类最多,支流次之,支流的河口地带最少。在种群密度方面,支流>干流>支流的河口地带;生物量支流>支流的河口地带>干流。关于长江下游的环境因子对底栖动物种类组成及数量分布的影响,作者也进行了扼要的分析。     

Comparative characteristics of the ichthyoplankton of lagoon lakes of the south-eastern part of Sakhalin

Ichthyoplankton surveys are made in lagoon water bodies of the south-eastern part of Sakhalin (the Vavai-Chibisan system of lakes, Lake Tunaicha, Lake Izmenchivoe) from April until November 2002–2007. Comparative characteristics of ichthyoplankton complexes in the ice-free period is given. In the investigated lagoon lakes, differences in the species composition of the ichthyoplankton by the number and time of appearance of the maxima of abundance of eggs and larvae are noted, and also related to morphological structure and hydrological conditions of water bodies. In lagoon lake Izmenchivoe with a salinity not less than 26‰, the eggs and larvae of marine fishes only takes place while, in Vavai-Chibisan lakes, that of freshwater fishes only takes place. In brackish lake Tunaicha, the lowest number of fish species reproduce. In the Vavai-Chibisan system and in Lake Izmenchivoe, one maximum of abundance of ichthyoplankton in June is recorded and, in Lake Tunaicha, two maxima (the highest in June and less expressed in August) are recorded. Irrespective of the species composition, the ichthyoplankton complexes of lagoon lakes have general traits determined by hydrological conditions of water bodies and by their general origin and geographic situation: prevalence of eggs and larvae of low boreal fish species, the maximum species diversity in the late spring-early summer, and decrease of abundance in cooler years.     

Distribution of soil-inhabiting testate amoebae along a mountain slope (Baikal Lake region, Khamar-Daban ridge, Cherskii peak)

The specific composition and distribution of soil-inhabiting testate amoebae along the Cherskii peak slope (Khamar-Daban mountain ridge, Lake Baikal region) were studied within the altitude range from 1000 to 1570 m above sea level according to the changes in biogeocenoses from birch-aspen to cedar-fir forests to cedar-fir-bush forest-tundra. One-hundred-four taxa were identified. The most common species are ubiquits with a wide geographical distribution: Trinema lineare, Euglypha levis, Euglypha rotunda, Trinema enchelys, Phryganella acropodia, Tracheleuglypha dentata, Assulina muscorum, Trinema complanatum, and Centropyxis aerophila. The species richness varies from 12 to 40 species per sample, and the abundance varies from 500 to 120000 ind. per gram of absolutely dry soil. The spatial heterogeneity of the specific composition grows with altitude, and the community composition changes. The absence of a common pattern in the cenotic changes in the communities of testate amoebae in Western Europe and the Lake Baikal region is discussed.     

Species composition and structure of macrozoobenthos in Lake Sevan during the period of its increased water level

A list of macroinvertebrate species recorded in the zoobenthos in Lake Sevan in 2007 and 2010 is presented. The list includes 38 species, 14 of which have been found in the lake for the first time. Chironomid larvae and pupae are the most diverse (27 species) in the macrozoobenthos of the lake. In Bolshoi Sevan, the maximum biomass of macrozoobenthos (24.82 g/m²) was recorded in the sublittoral; in Malyi Sevan the maximum biomass (14.31 g/m²) was recorded in the profundal. In 2010 chironomids dominated by biomass in the sublittoral (48.9 and 60.3%, respectively). The benthos in the littoral was dominated by oligochaetes (50.2%).     

Dynamics of food resources for beavers in settlements colonized and abandoned several times

The state of food resources for Eurasian beavers (Castor fiber Linnaeus, 1758) after several cycles of habitat colonization and abandonment has been analyzed in three beaver settlements on small rivers of Novgorod oblast. It has been shown that tree stands surrounding the settlements differ in composition and degree of damage but are similar in that they contain no forage for beavers: aspen is absent, and birch trees are large and require great efforts to cut them down and utilize. The undergrowth and understory also contain no aspen, while abundant willows and birch are represented by young, thin-stemmed plants unevenly distributed over the area. Tree species prevailing in abandoned settlements are not favored by beavers, implying that the animals must have expended extra energy for foraging. Supposedly, populations of beavers on small rivers in the southern taiga subzone, in habitats modified by their activities, will maintain their abundance far below the maximum possible level, depending on the rate of forage plant regrowth against the background of deteriorating habitat quality.     

Current status of the Russian desman habitats in small rivers of the Don River Basin in Saratov oblast and the abundance of this species

The Don Basin rivers confined to Saratov oblast were searched for the Russian desman in 2009–2011. The suitability of habitats for this species was assessed. Potentially negative factors for the Russian desman (Desmana moschata) in various types of habitats were detected, and their intensities were assessed. The small tributaries of the Khopyor and Medveditsa rivers have turned out to be suitable for the Russian desman; however, neither animals nor any sign of their life activities have been found using different techniques. Nonetheless, we cannot state that this species is absent in the small rivers of the Saratov oblast; however, if this species is present in the examined area, its abundance is extremely low. A drastic decrease in the Russian desman population and even its disappearance are most likely associated with intraspecific processes, factors of a global scale, and immigration of new species previously not found in the river ecosystems in the examined areas.     

Ichthyoplankton in the plankton community of the Crimean Peninsula shelf zone (Black Sea) in July 2010

Data on the species composition and quantitative distribution of ichthyoplankton, zooplankton, and jelly fish macroplankton from different areas of the Crimean Peninsula shelf zone in July 2010 are presented. It has been shown that the structure of species composition and the maximum abundance of ichthyoplankton are comparable to those in July 1988, i.e., until negative changes in the ecosystem of the Black Sea shelf, which took place in the 1990s. The average abundance of ichthyoplankton in July 2010 corresponds to the lowest long-term data obtained in July 1950s and 1960s. The effect produced by organochlorine contaminants and by the abundance of jelly fish macroplankton on the survival of pelagic fish eggs and fish larvae is studied. The prevalence of juvenile copepods in the guts of fish larvae, as well as the low proportion of fish larvae with empty stomachs (<10%), if compared to the data obtained in the 1990s (50–90%), point to the favorable trophical conditions for fish larvae in the area of investigation.     

Materials on the flora of Bacillariophyta in rivers of the white sea basin in the Republic of Karelia

A total of 290 species and varieties of Bacillariophyta including 32 that were new for the flora of Karelia and 18 that were new for the flora of Russia, have been recorded in phytoplankton in nine rivers of the White Sea basin. The genera Aulacoseira, Pinnularia, Eunotia, and Navicula s. l. are the richest in taxonomy. The maximum species diversity was recorded in the Suma (73), Kolezhma (91), and Chirko-Kem (146) rivers. The following species are the most widespread in the rivers that were under study here: A. ambigua, A. subarctica, A. subborealis, {tiA. tenella}, Asterionella formosa, and Tabellaria flocculosa.     

Taxonomic composition and trophic structure of benthic fauna in rocky rapids and riffles in rivers of the Republic of Karelia and Murmansk Oblast

The composition of bottom invertebrates in rocky rapids and riffles in rivers of the White, Barents, and Baltic seas in the territory of Eastern Fennoscandia is presented and analyzed. A total of 114 species (137 taxa of different ranks) have been identified. Most of them have Euro-Siberian (44%) and Palaearctic (36%) distribution. Regarding the feeding mode, collector–gatherers (32%) and collector–filterers (25%) dominate among trophic groups. Differences in the composition of zoobenthos between the southern and northern parts of the region can be explained not by the fauna genesis, but by latitudinal zoning.