Lake Ilmen Research Articles

Industrial fishing on Lake Ilmen, Novgorod region: catch dynamics in the XX century and the current status

The long-term dynamics of commercial catches on Lake Ilmen in the Novgorod region for the period from 1912 to 2023 was traced. The structure of catches and the fishing base is described, taking into account the affecting factors. Specifics of organizing fishing at present stage are given.

Current state of bacterioplankton of Lake Ilmen

Objective: Determination of the quantitative level of the Lake Ilmen bacterial community in a retrospective. Assessment of lake water quality by microbiological indicators based on the results of seasonal microbiological studies in 2022Research material and methods used: The material was samples of bacterioplankton from the surface water layer of the Lake Ilmen, collected in May, August and September 2022. The total numbers of microorganisms was determined by the epifluorescence method using DAPI fluorochrome. Standard methods were used to determine the number of saprophytic microorganisms at two temperature regimes.Originality: For the first time in the last 25 years, the quantitative characteristics of the bacterial community of Lake Ilmen were determined. A quality assessment of lake waters has been carried out, and the values of self-purification coefficients were calculated.Results: The microbiological characteristic of the water masses of Lake Ilmen, as a habitat for bioresources, is presented. The maximum values of the total bacterial numbers (TBN) were observed in May (average 5.05±0.52×106 cells/ml) during the spring flood, the minimum — at the end of September (average 3.21±0.89×106 cells/ml) during the cooling period of the lake. Coccoid cells prevailed in the bacterioplankton, which indirectly indicates the absence of contamination of the lake waters with organic matter of various origins. According to the average for the observation period TBN (4.10±1.05×106 cells/ml), the trophic state of the lake corresponded to weakly eutrophic. The number of saprophytic bacteria growing at 22 °С always exceeded that at 37oC, which indicated active self-purification processes. According to the quantitative ratios of the TBN and the number of saprophytic bacteria growing at 22 °С (OMH 22 °С), the water masses of the lake, with rare exceptions, belonged to the conditional category of “pure” (oligosaprobic)

Parasites as biological indicators of fish of lake Ladoga amd lake Ilmen

It has been established that the parasitofauna of pike and roach caught from Lake Ladoga and Lake Ilmen differ, which is determined by the significant hydrological and environmental features of these reservoirs. Parasites such as Paracoenogonimus ovatus and Ergasilus sieboldi, which are numerous in the fish of Lake Ilmen and practically absent in Lake Ladoga, can be used as biological tags to determine the reservoir from which this fish was caught. No helminth larvae dangerous to humans and animals were detected in the studied fish.

An assessment of the state of the fish fauna in the lower course of rivers and floodplain water bodies in Lake Ilmen catchment based on the data from surveys with fine-mesh fishing gear in 2020–2021

Having analyzed fry seine catches from the lower reaches of the rivers flowing into Lake Ilmen and from floodplain lakes in the Msta and Lovat river deltas, we have updated information on the composition of the fish population of reservoirs and watercourses of the Lake Ilmen catchment. In total, 19 fish species belonging to six families were present in the catches in 2020–2021. The fish communities of the lower reaches of the rivers Volkhov, Lovat, Shelon, Veronda and floodplain lakes of the Lovat and Msta deltas featured high similarity, with the predominance of limnophilic species, in contrast to the riffle sections of the Msta, where rheophilic fish species dominated in abundance. At most survey sites, the catches were dominated by the main harvestable fish species of Lake Ilmen. The biomass of fish underyearlings in the autumn period of 2020 in floodplain lakes of the Lovat and Msta deltas was four to six times that of in the littoral zone of Lake Ilmen and comparable to the levels at survey sites in the lower reaches of the rivers Msta and Volkhov. Fry seining of river and lake areas within the Novgorod Region revealed fish species not previously reported for the Lake Ilmen catchment or formerly considered rare in the catchment. Lake Ilmen catchment being hydrologically isolated from the main invasion pathways as well as the absence of intentional acclimatization activities are factors promoting the stability of the native composition of the fish fauna and the reason why only one naturally dispersing species, the silver carp, has become naturalized in Lake Ilmen.

INHABITANTS OF THE HOLY RIVER OF NOVGOROD: THE VOLKHOV IN THE HISTORIC, CULTURAL AND MYTHOLOGICAL TRADITION OF MEDIEVAL NOVGOROD

The River Volkhov, connecting Lake Ilmen and Lake Ladoga, used to be atransportation line of utmost importance in northern Russia (Fig. 1). As earlyas the 8th–9th century AD, the water route along the Volkhov was masteredby the Slavs – migrants from the southern shores of the Baltic Sea. During theViking epoch, two major townships of northern Russia appeared at the headand the outfall of the Volkhov: they were Ladoga and the predecessor of Novgorod, Rurik’s Township. And in the second quarter of the 10th centuryNovgorod the Great was founded. For the city’s population, the River Volkhovwas not only the basis of their economic life, but also a sacred natural feature.

Trophic status of Lake Ilmen (2003– 2020)

Lake Ilmen is one of the most productive lakes in the northwestern part of European Russia. The purpose of the study was to assess the trophic status of the Ilmen in the period 2003–2020 based on two different indicators. The trophic status index (ITS) is calculated from two hydrochemical indicators: the pH value and the percentage of water saturation with oxygen. The other indicator of the trophic status is the average annual concentration of total phosphorus. Interannual ITS values for the period from 2003 to 2020 were determined. The input for the calculations was data from lake monitoring regularly conducted by the North-Western Department of Hydrometeorology and Environmental Monitoring. It has been established that the trophic status of Lake Ilmen in the specified period was mainly characterized as eutrophic except for years 2006, 2008, 2017, and 2019, when it was mesotrophic. According to the concentration of total phosphorus in 2003, the trophic status of the lake was characterized as hypertrophic, in 2018 as mesotrophic, while in other years it was eutrophic. It is advisable to apply the results of the study in decision-making for reducing the anthropogenic phosphorus loading on the lake.

New data on the rise of Lake Ilmen (NW, Russia) in the Holocene

Abstract. This paper discusses a rise of Lake Ilmen in the Holocene, its origin, and consequences for the Neolithic culture of the region. We assume that in the second half of the Holocene there was a long-lasting level rise of Lake Ilmen. The level rise was associated with the Holocene Ladoga transgression into the Ilmen-Volkhov basin.

Biodiversity of the Ilmen Klint

The Ilmen Klint is a geologically formed landmark located in the Shimsky and Starorussky districts of the Novgorod region. Its location area is the western part of the southern shore of Lake Ilmen and covers the delta of the Lovat and Shelon rivers. A characteristic feature of the soils of the banks of the Psizha river is the presence of laminated dense crystalline yellowish-brown limestones. In the upper part of the Ilmen Klint, near Buregi village, brown limestones have formed. The modern vegetation cover of the Ilmen Klint has resulted from a long historical process and now continues to undergo changes. The main role in this is played by the human, their economic activities. In 2001, the Ilmen Klint was accorded the status of a Specially Protected Natural Area (SPNA) of the Novgorod region in order to preserve and study its natural diversity and maintain its ecological balance. The carried out floristic studies made it possible to describe natural habitats with a rich floristic composition and equity participation of Lathyrus pratensis L., Medicago falcata L.: Medicago lupulina L., and Anthyllis macrocephala L. species. The meadows and outcrop areas of the Ilmen Klint are characterized by a high diversity of rare species with certain patterns of meadow community development. At a high coastal slope level, there is a dry meadow with a herb-foxtail community. In addition, the participation of crop wild relatives (CWR) in natural plant communities of the Ilmen Klint territory is considered. Species of the Fabaceae L family are the main source of CWR here. Human well-being depends on the conservation of biodiversity and biological resources, particularly plant resources.

Finds of West-European coins of the 11th — early 12th century at Novgorod (Rurik’s) Gorodishche

This paper is a publication of West-European denarii of the 11th — early 12th century and their imita- tions provenient from the territory of Novgorod Gorodishche (Rurik’s Hillfort). All the known coins are discussed — both those yielded by archaeological excavations (8 items) and single finds by private persons (13 items). The new numismatic materials expand and supplement the available information on the earliest and very important trade-handicraft and military-administrative centre of the Lake Ilmen region.

Novgorod musical-epic tradition - the possibilities of reconstruction

The author is the first to raise the problem of reconstruction of the musical-epic traditions of Novgorod region. The research object is chant-declamation forms of folklore, typologically related to the bylina tradition. The research subject is their structural and stylistic peculiarities. For the first time, all facts of existence of musical epos, recorded in Novgorod region by various collectors, are gathered in one source - from the auditory notations of A.K. Lyadov (1890) to the latest evidence of existence of the musical-epic tradition (the recordings of Leningrad - St.Petersburg conservatory of the 1980s - 1990s). As the materials for comparison, the author uses the folklore images from Vologda, Arkhangelsk and Tver regions. Some musical texts are published for the first time. The author defines the genre composition of the musical-epic area of Novgorod folklore (buffoonery and takes, ballads, spiritual poems and memorial songs), describes the forms of composition of the main samples (one-line verses, long speeches and strophical). The research material gives reasons to assume that in Novgorod folklore traditions of the late 19th - the 20th centuries, the forms of recitation of music were widespread, typologically related to two North-Russian styles - the symbolic brief-chant and rhapsodical. The author concludes that the lake Ilmen basin and the adjacent territories was one of the places where these styles had been forming. On the one hand, the discovery of the typological relation of Novgorod and the North-Russian forms of musical narration helps define the structure and evaluate the style of single facts of Novgorod folklore. On the other hand, the parallels found are of key importance for the confirmation of Novgorod origins of the North-Russian bylina traditions.   

Great White Egret Casmerodius albus in Novgorod Region in 2016–2018

Ninety-six registrations of great white egret from ten districts of Novgorod Region in 2016–2018 were analyzed. The birds were seen from single individuals up to 170 birds in one flock. The main areas of registrations of this species are the surroundings of the city of Novgorod and Lake Ilmen. The birds were seen on the territory from February 25 to October 31. We did not get any documented evidence of this species breeding, but breeding is possible. At present, the great white egret has to be considered as a summering, possibly breeding, and occasionally wintering species of Novgorod Region.

The correlation of the environmental dynamics of the southeastern periphery of the Poo zer ye (Valdai) glaciation in the Late Glacial and Holocene

The landscape-climatic reconstruction in the southeastern sector of the last Scandinavian (Poozerye (Valdai)) glaciation was carried out within transect in the direction from Lake Naroch (Belarus) to the Lake Ilmen (Russia) based on palynological, isotopic and radiocarbon data. The first stage of deglaciation of the territory located between the maximum Orsha (Ostashkov) stage and the Vepsian-Krestetskiy marginal formations lasted from 20.0 to 15.5 cal. ka BP. The onset of lake sedimentogenesis in this region dates from the final stages of the Pleniglacial (16.5–15.5 cal. ka BP). The vegetation cover about 14.7 cal. ka BP represented by grass-shrub tundra. At the beginning of the Belling-Allered interstadial, there was an active expansion of tree species (birch, pine) to the north, following the retreating glacier. At the end of the Allered (13.3 cal. ka BP), open pine forests with birch dominated in the north of Belarus, and birch and pine-birch in the neighboring regions of Russia. The beginning of the expansion of spruce, both in Belarus and in the northwestern regions of Russia, dates from 13.2 cal. ka BP, which is comparable with the oscillation of Herzensee (GI-1b). Late Dryas cooling characterized by the spread of herb-forest-tundra landscapes, in which, apart from pine and birch, spruce played a significant role. The boundary Late Glacial ‒ Holocene (about 11.5 cal. ka BP) is marked by a decrease in the content of spruce pollen, shrubs of tundra and grass. According to isotopic and palynological data during the Holocene, revealed episodes of cooling. Changes in vegetation occurred in the following sequence: birch and pine-birch forests (11.5‒10.0 cal. ka BP), mixed birch-pine with the participation of broadleaved species (10.0 ‒8.0 cal. ka BP), coniferous-broadleaved (8.0 ‒5.8 cal. ka BP), broadleaved ‒ dark coniferous (5.8‒2.7 cal. ka BP), dark coniferous and oak ‒ dark coniferous with birch forests (2.7 cal. ka BP ‒ modern stage).

РОЛЬ ТОКСИКОЗОВ В ПРИСПОСОБЛЕНИИ ЭКОСИСТЕМ К АНТРОПОГЕННОМУ ЗАГРЯЗНЕНИЮ СРЕДЫ (НА ПРИМЕРЕ ТОКСИКОЗОВ ВОДНЫХ ЖИВОТНЫХ)

In the past geological eras in the bio-sphere, species extinction was accompanied by speciation. Ecosystems adapted to a greater or lesser extent to coexist with a species whose activity had become a plane-tary factor and had a global impact on bio-spheric processes. One of it is the massive pollution of the main components of the biosphere - geobiosphere, hydrobooster and air. Its consequence is the development in living organisms of various pathological processes associated with the impact of tox-icants-toxicoses. The work was carried out in various re-gions of the USSR and Russia on reservoirs of various types and different objects of aquaculture. Various species and age groups of fish were studied. They were caught with trawls, nets, lifts, and sport fishing gear. Fish larvae were caught with a plankton net. A pathoanatomic method was used to assess the condition of fish. In some cases, histo-logical methods were used. Clams of the family Unionidae were surveyed in 1990-2011. They were collected by dredging in the reservoirs of the Volga, in the lake Ilmen, in the red sea of the Ka-relian isthmus of the Leningrad region and in the Gulf of Finland of the Baltic sea. The liver of 399 individuals was examined us-ing histological methods. Also Perlovitz. Unio pictorum, 474 copies of U. tumidus and 298 copies. the mussels Anodonta sp. Branched crustaceans were examined in 1989-2016. They were collected in a plank-ton grid in the reservoirs of the Volga, in the Nyvchimsky reservoir (the basin of the Volga river). Vychegda Komi Republic, in the Finnish and Kursk bays of the Baltic sea, in lake Ladoga, in the lake of Sevan (Armenia) and in lakes of the Karelian isth-mus of Leningrad region, in the mountain lakes of West Sayan (Krasnoyarsk region), the lakes in Darwin reserve (Vologda re-gion) and in the pools of Garbacki lakes Bolshezemelskaya tundra (Vorkuta district, Komi Republic). Fixation in 4% formalin by Rachkov method was examined in Bo-gorov's cell under the MBS-9 microscope.

Верхнедевонские отложения (франский ярус) северо-запада Русской платформы: палеомагнитные данные

Paleomagnetic determinations for the Devonian strata of the Main Devonian Field, available in the international paleomagnetic data base, do not make it possible to construct both detailed magnetostratigraphic scales and reliable trajectories of the apparent polar wander path of the paleomagnetic pole. This is primarily due to the insufficient amount of data that determine modern reliability criteria. Obtaining more complete series of reliable paleomagnetic determinations is one of the important tasks of paleomagnetic studies. The paper presents new paleomagnetic determinations from a collection of rocks of the Frasnian stage of the Upper Devonian (Ilmen and Bureg Beds of the Semiluky Formation), sampled on the southern shore of Lake Ilmen, east of the village. Korostyn in 2009. Magnetomineralogical studies were carried out to determine the magnetic minerals of carriers of natural remanent magnetization. Three characteristic components of natural remanent magnetization have been identified. Two components correspond to the Late Paleozoic magnetization reversal (in the Carboniferous and Permian times). The third, bipolar component of the Frasnian age passes the reverse polarity test of the geomagnetic field.. The obtained position of the paleomagnetic pole by the bipolar component of the natural remanent magnetization is consistent with the available data on the section of the Late Upper Devonian of the Main Devonian Field.

Старая Ладога, СЭМ-исследования растительных остатков из палеопочв, разделенных отложениями Ладожской трансгрессии. Новые материалы и старые проблемы

This paper presents the results of SEM-examination of palynological complexes of two paleosols at the base of the Staraya Ladoga section. There was obtained evidence of the floodplain genesis of the paleosol directly under- lying the cultural layer of Zemlyanoye hillfort. A new palynological marker has been identified here which enables us to ground the synchronous character of the end of the Ladoga Transgression (in the southern Ladoga region) and the regression of Lake Ilmen (in the northwestern region).

THE WATER LEVEL REGIME OF LAKE ILMEN

Researches of changes in the water level of Lake Ilmen are important for studying the development of the river network in its basin, since it is the basis of erosion for them. The purpose of the work was to assess the level regime of Lake Ilmen during the Holocene, including the modern period. The level regime of the lake is determined not only by the inflow of waters from the catchment, but is also regulated by the runoff of the Volkhov River flowing out of it, which, which prior to the construction of the Volkhov Hydroelectric Power Station in 1926, depended on the marks of the Pchevsky and Veletsky rapids in the downstream. During the Holocene, the marks of the Pchevsky and Veletsky rapids were decreasing, because they been eroded by the Volkhov River. An approximate reconstruction of the change in rapids marks has been carried out, depending on the humidity of the climate in previous centuries. Evaluation of a varying degree humidification over a century / millennium is rather arbitrary and was taken as the ratio of the number of rainy years to years with droughts based on annals data. By the beginning of our era, the minimum water level of the lake was not less than 19.5 m. The maximum water level most likely did not exceeding the mark of 24.5 m, considering the similarity of climate to the last centuries, that is, the amplitude of the water levels was less than modern. Only climatic features determined the water level regime of the lake starting from the second half of the first millennium to the present day. On the grounds of the fact that the minimum bottom marks of some rivers, flowing into lake Ilmen (in particular Lovat’, Msta and Shelon’), are lower not only than the minimum water level of the lake, but also than the minimum marks of its bottom, we can do a preliminary conclusion that the water level of Lake Ilmen in the past was rather lower than at present and was at modern mark of 16-17 m Baltic system.

Staraya Russa and the southern coast of Lake Ilmen in the context of contacts with Northern Europe in the 10th–12th centuries AD

Staraya Russa and the southern coast of Lake Ilmen in the context of contacts with Northern Europe in the 10th–12th centuries AD

Morphometric analyses of Staurosira inflata comb. nov. (Bacillariophyceae) and the morphologically related Staurosira tabellaria from north-western Russia

ABSTRACTThe morphology and ontogenetic allometric trends of a rare diatom Fragilaria heidenii Østrup and the morphologically related Staurosira tabellaria (W. Smith) Leuduger-Fortmorel were compared using conventional and semilandmark-based geometric morphometric analyses. Fragilaria heidenii was studied in detail by light and electron microscopy using type material and recent samples from Lake Ladoga and Lake Ilmen (north-western Russia). The taxon is transferred into the genus Staurosira Ehrenberg as Staurosira inflata comb. nov. on the basis of its valve morphology. This taxon is characterized by the absence of rimoportulae, lack of perforated copulae, spines located on the interstriae, internal vola occlusion in the areolae and the features of the areolae and apical pore fields. Conventional morphometric analysis showed considerable overlapping of S. inflata and S. tabellaria in their frustule characteristics such as length, width, length-to-width ratio and striae density. Moreover, at later stages of the vegetative life cycle, S. inflata has a tendency to resemble S. tabellaria by its valve outline that makes it difficult to separate these two taxa. The geometric morphometric analysis revealed two shape groups corresponding to S. inflata and S. tabellaria that were separated by a clear gap. Semilandmarks representing shape of the middle part of the valve were primarily responsible for discrimination between species. Apart from differences in valve shapes, S. inflata and S. tabellaria also differed significantly in their ontogenetic allometric trajectories. Overall, our results demonstrate that the semilandmark-based geometric morphometrics is sensitive enough to distinguish species by their outlines, when traditional morphometric parameters are not able to discriminate them with confidence.

Evaluation of the Variability of the Shoreline of the Tsimlyansk Reservoir and Lake Ilmen according to Space Sounding Data

This article presents the results of a study of the dynamics of the shorelines of Lake Ilmen and the Tsimlyansk Reservoir to indicate the location of the boundaries of the water protection zone. The study uses the method of processing information from Terra/MODIS, Landsat-7 and -8, and WorldView-1 space systems. The analysis of remote-sensing data reveal the off-season and yearly variability in the area of the surface and shoreline, which is characteristic of water bodies under flat relief conditions. On the basis of the results of the research, the issue of the necessity of allocating a water protection zone, taking into account the morphometric features of water bodies and the characteristics of their hydrological regime, followed by amendments to the Water Code of the Russian Federation, is posed.

Fish, feather, fur and forest: Exploitation of wild animals in medieval Novgorod and its territory

The city of Novgorod the Great in north-west Russia has been subjected to extensive excavation of its superbly preserved medieval anaerobic deposits for many decades. Situated on the River Volkhov near Lake Ilmen and surrounded by mixed boreal and deciduous woodland and seasonally flooded meadowlands, Novgorod was well-placed for the exploitation of local wild fauna and flora. It was also the focus for international trade in furs obtained from a much broader catchment area. Although its inhabitants relied heavily on domestic animals and crops for their food, evidence for the acquisition of wild resources is also provided by animal bones, plant macrofossils, birch-bark documents and other archaeological finds. Pollen analysis has also provided information about landscape history of its hinterland. Even from a limited programme of sieved sampling, it is clear that a very large number of fish bones were present in the deposits. The main taxa are cyprinids, pike and zander, whereas birch-bark documents, largely concerned with tribute, mention salmonids and sturgeon, rare amongst the excavated remains. The wild bird assemblage is dominated by various species of ducks. Other waterfowl were utilised as well as large game birds such as capercaillie. Birds of prey are also present and other remains such as jackdaws reveal the local bird life in town. Wild mammals contributed little to the Novgorodian diet: bones of hare, beaver and elk being the most frequently found. Very few bones of fur-bearing mammals were recovered. The few remains include bear claws and bones of squirrel, marten, otter, and fox, in addition to beaver. Their paucity can be explained by the fact that most would have arrived from the hunting grounds to the north as prepared pelts without bones. Evidence for the hunting for these species is provided on sites deep within the forest zone such as Minino. Most of the wild animals eaten in Novgorod itself were obtained from the land and waters of its near hinterland. The paper discusses the character of the local forest based on pollen and other evidence. Models are being developed to provide a more detailed understanding of the changes in the composition of the forest during the medieval period and the consequences this had for wildlife. The paper demonstrates the benefits of developing a multi-disciplinary approach comparing urban assemblages with contemporary sites in its hinterland and further afield, to understand more fully how wild species were exploited in complex societies.