Lower Volga River Research Articles

Climate, Disease, and Upheaval in the Turkic World in the 14th-15th Centuries

This paper examines the role of climate and disease as a major factor resulting in disruption and upheaval in the Turkic world in the 14th-15th centuries. The first issue the paper addresses is the beginning of the climatic downturn in circa 1280, which will ultimately culminate in the Little Ice Age of the late 15th-18th centuries. The paper cites recent work on the role of climate in the history of Iran. While the author has explored this issue in detail for the history of the Golden Horde, the impact of climate change on Iran in the 14th-15th centuries is a topic which has yet to be investigated adequately by historians. More importantly, climate change is associated with the spread of the Black Death, both in the original point of its spread and especially in the lower Volga River delta. The paper addresses the role of the Black Death (1346- ) as a disruptive factor in the history of the Golden Horde and the Chağatay Khanate. Citing recent research, it also considers legacy of the Black Death in the political, socio-economic, and cultural history of the Il-Khanate and what it meant for the rise of the Aqqoyunlu state. In the Golden Horde, Central Asia, and the Ottoman Empire, the Black Death led to a decline or disappearance in the earlier Islamic Turkic literary language. The earlier archair literary language was replaced by a newer literary language closer to the vernacular or spoken language of the people. There is also evidence of cultural responses to plague written in the new language.

Bogdo–Baskunchak Nature Reserve as a geoheritage site

Abstract The Bogdo–Baskunchak Nature Reserve is a geoheritage site in the Caspian Depression, near the Lower Volga River. The Salt Lake Baskunchak and the Mount Big Bogdo with the gypsum field are the main objects of interest. Local legends about this place and the history of salt mining and trading, as well as geological exploration, make this geoheritage site special. This natural landscape is intact, as seen by the first scientific expeditions of the eighteenth century organized by the Imperial Academy of Sciences and Arts in St Petersburg. Reports and papers about this area are associated with Pallas, Humboldt, Murchison, Eichwald, Auerbach, Pravoslavlev, Efremov and other scientists and expeditions. Extensive research and important discoveries were made in this area, mostly in mineralogy, stratigraphy, palaeontology, sedimentology, salt tectonics, and mining. This area reflects its long history of exploration and could be a good example of organizing the protection of geological landmarks and monuments in arid regions. In 1916, a Russian law was passed giving the government rights to organize reserves ( zapovednik ) for scientific and cultural purposes in the most remarkable natural areas. Only in recent decades have geological monuments in Russia become specially protected sites.

PALEOLITHIC SITE SUKHAYA MECHETKA (VOLGOGRAD) IN THE CONTEXT OF STRATIGRAPHY AND PALEOGEOGRAPHY OF THE LOWER VOLGA RIVER AREA

The Sukhaya Mechetka is the most important Middle Paleolithic site in the Eastern Europe. The paper presents the analysis of the section, including its cultural layer, in the context of stratigraphy and paleogeography of the Lower Volga River region. The structure of the section represents 11 main stages of sedimentation and paleogeographic evolution of the site territory, which are closely related to global and regional changes in the climate and the level of the Caspian Sea. The base of the section reflects the stage of a river existence on the territory of the site that flowed into the Volga River estuary, formed by the Early Khazarian transgression of the Caspian Sea at the end of the Middle Pleistocene (MIS 6). A long continental period of evolution under multi-directional climate fluctuations of different amplitudes from the Mikulino interglacial (MIS 5e) till the Late Valdai glacial epoch (MIS 2) is reflected in the middle part of the section. The Late Khazarian and Hyrcanian transgressive basins (MIS 5), as well as the Paleo-Khvalynian stage (MIS 3) of the Caspian Sea did not reach the latitude of Sukhaya Mechetka. The stage of Early Khvalynian transgression (MIS 2, 16 190 ± 200 years ago) during the degradation of Ostashkovo glaciation is expressed in the upper part of the section. Three paleosoils have been found that reflect the warming periods of the MIS 5 stage and are related to its 5e, 5c and 5a sub-stages. The middle paleosoil contains a cultural layer assigned to the Micoquian/KMG community of Northern Eurasia. The climate was moderately warm during the Neanderthal settlement of the territory, steppe landscapes dominated the interfluve, and the forests grew in the balka. The Hyrcanian transgression of the Caspian Sea with an estuary in the Volga River valley predetermined a high erosion basis and the formation of a balka with a wide bottom and gentle banks. A permanent fresh watercourse attracted mammals which were an object of hunting for ancient men. All this, obviously, became a basis for the organization of settlement in the Sukhaya Mechetka balka. Correlation of the section with detailed studied loess-soil sections of the Lower Volga River region makes it possible to determine the age of its cultural horizon in between 97-110 thousand years ago.

ЗАРАЖЕННОСТЬ КАРПОВЫХ РЫБ ЛИЧИНКАМИ ПАТОГЕННЫХ ДЛЯ ЧЕЛОВЕКА ГЕЛЬМИНТОВ И БАКТЕРИЯМИ В НИЖНЕЙ ЗОНЕ ДЕЛЬТЫ РЕКИ ВОЛГИ В СОВРЕМЕННЫЙ ПЕРИОД

Recreational and artisanal fishing is very widespread in the Astrakhan Region; its primary targets are cyprinids, which are susceptible to epedemiological threats. Food products derived from the biological resources harvested during such fishing are not subjected to the processing in specialized facilities, and therefore, safety of the final product for its consumer cannot be ensured. In this region, the diseases, the agents of which are transmitted through fish and the products of its processing, are annually recorded among the population. Sanitary and parasitological control is one of the components in the set of measures for the prevention of these diseases. This work was aimed at evaluation of the infection level in some species of commercially valuable cyprinids in the Lower Volga River Delta with bacteria and larvae of pathogenic helminths capable of causing the development of diseases in humans. An incomplete helminthological survey of Caspian roach, common bream, white bream, crucian carp and rudd, as well as microbiological examination of their muscle tissue have been carried out in accordance with the requirements of the regulatory documents currently in force with application of methods described in State Standards. Larvae belonging to four species of human-pathogenic parasites have been recorded in the parasitic fauna of the Caspian roach, rudd, and white bream. Common bream was infected by larvae belonging to two species of such helminths. The identified larvae of pathogenic trematodes and nematodes were viable. The level of bacterial contamination of fish muscle tissues did not exceed the standard-prescribed limit, and the sanitary indicator microorganisms were absent. The results of the parasitological study indicated the need for mandatory disinfection of cyprinid fish from larvae of pathogenic helminths.

МАКРОФИТЫ РОДА POTAMOGETON — БИОИНДИКАТОРЫ НАКОПЛЕНИЯ ТЯЖЕЛЫХ МЕТАЛЛОВ

This work presents the investigation of the content of some heavy metals in the pondweeds of the Lower Volga River Delta within the area of Astrakhan State Biosphere Reserve. Higher aquatic plants extract chemical elements both from bottom sediments and water column. Moreover, the macrophytes, namely the representatives of Potamogeton genus, are capable of extraction and accumulation of the metals dissolved in the water, contained in the suspended colloidal particles, and present on the surface of leaves. This work is aimed at the identification of species-specific features of the typical hydatophytes—aquatic plants of Potamogeton genus—pertaining to the accumulation of heavy metals. The content of chemical elements in the investigated specimens has been identified using atomic absorption spectrometry; the results have been processed with statistical methods. It has been found that all investigated plant species accumulate iron and manganese in the highest quantities and cobalt and cadmium in the lowest. The investigated pondweed species have shown species-specific properties in the accumulation of chemical elements. Potamogeton crispus and Potamogeton lucens are found to be iron concentrating species. Potamogeton lucens also accumulates nickel, iron and manganese, and Potamogeton pectinatus accumulates chrome, cobalt and lead.

Uppermost Turonian bryozoans from the Lower Volga River region: scanning electron microscopy and micro-computed tomography studies

Uppermost Turonian bryozoans from the Lower Volga River region: scanning electron microscopy and micro-computed tomography studies

Analysis of the Relationship between the Phylogenetic Diversity of Benthic Communities and Degree of Mineralization of Plain Rivers of the Lower Volga River Basin

Analysis of the Relationship between the Phylogenetic Diversity of Benthic Communities and Degree of Mineralization of Plain Rivers of the Lower Volga River Basin

Cascade of reservoirs and its role in solids flow regulation and water quality management in the Lower Volga River

Cascade of reservoirs and its role in solids flow regulation and water quality management in the Lower Volga River

The Middle Palaeolithic of the lower Volga River (Volograd Region, Russia)

The Middle Palaeolithic of the lower Volga River (Volograd Region, Russia)

First reliable chronology for the Early Khvalynian Caspian Sea transgression in the Lower Volga River valley

During the late Quaternary, dramatic changes in relative sea level (~170 m) are known to have occurred in the Caspian Sea. However, all previous attempts at resolving the uncertainty associated with the timing of these transgressive/regressive events, primarily using radiocarbon, have produced inconclusive or controversial results. Here we present the first reliable chronology for the largest known transgression (Early Khvalynian). This was derived using optically stimulated luminescence (OSL) analysis of sand‐sized quartz, with support from infrared stimulated luminescence (IRSL) from K‐rich feldspar grains, all extracted from 16 sediment samples collected along the Lower Volga River. These samples were taken from loessic sediments, marine clays (known as Chocolate Clays) and the overlying modern soils exposed at three sections (Srednyaya Akhtuba, Raygorod, Leninsk) ~200 km upstream of the present‐day estuary. The differential bleaching rates of the quartz OSL and feldspar IRSL signals were used to evaluate the degree of resetting of quartz (and feldspar) signals; it was possible to conclude that all signals, and particularly quartz OSL, were sufficiently reset at deposition to allow accurate age estimation. Our results show unambiguously that the Early Khvalynian marine Chocolate Clays present at all three sections were deposited post‐LGM, between ~17 and ~13.1 ka ago. These age estimates are further constrained by those from the overlying Kastanozem soils (9.6–0.7 ka) and underlying loess‐soil series (32–19 ka), confirming a young (17–13 ka) age of the transgressive stage of the Early Khvalynian. Relative sea level during this period must have been well above the sampling altitudes of 11.7 m a.s.l. (Srednyaya Akhtuba), 11.3 m a.s.l. (Raygorod) and 4.7 m a.s.l. (Leninsk) to explain the absence of significant alluvial sand and to allow the deposition of the fine Chocolate Clays marker horizon.

Genetic monitoring of progeny derived from natural spawning of Acipenser ruthenus Linnaeus, 1758 and Acipenser stellatus Pallas, 1771 as well as their hybrids in the Lower Volga river during the period 2017 to 2019

The state of natural spawning of sturgeons in the Lower Volga River was investigated through genetic monitoring of juveniles (larvae, fingerlings, subadults) captured at seven traditionally used monitoring locations. Sampling was performed during the period 2017–2019. In total, 460 individuals were caught and genotyped using a set of six microsatellite loci (Afug41, Afug51, Afug135, An20, AoxD161, AoxD165) and mtDNA control region sequencing. The observed species-specific microsatellite alleles revealed the presence of juvenile sturgeons originating from natural spawning also included some hybrids between Acipenser stellatus and A. ruthenus. Thus, the majority of sterlet breeding takes place in natural spawning grounds but also sterlet hybridizes with a small number of stellate sturgeons. Juveniles of other sturgeon species were not identified, and it is concluded that natural spawning activities of Russian sturgeon, beluga and ship sturgeon were insignificant or even absent in the Lower Volga during the observation period.

THE BRONZE CAULDRON OF PIATRA ȘOIMULUI (CALU) (NEAMȚ COUNTY, ROMANIA). NOTES ON THE DISTRIBUTION, DATING AND USE OF SUCH TYPE CAULDRONS IN THE SARMATIAN ENVIRONMENT

We shall discuss here the bronze cauldron discovered in 1932 in the perimeter of the Daco-Getae settlement of Piatra Șoimului (Calu). The vessel was dated by R. Vulpe to the 3rd century AD and the 1st century BC by Gh. Bichir. According to its features, the Piatra Șoimului (Calu) cauldron belongs to type VI, variation 1, subvariation A in S. I. Demidenko’s typology. Although the earliest cauldrons of type VI.1.A come from a series of features of the second half of the 2nd century – end of the 1st century BC, they are mainly specific to the mid Sarmatian period, the majority originating in graves dated to the second half of the 1st century – early 2nd century AD. The Piatra Șoimului (Calu) cauldron is the single vessel of the type from the space between the Dnieper and the Carpathians, while the closest parallel is the vessel of Boguslav, a place located to the left of the Dnieper. The remaining cauldrons in type VI (over 60 specimens), come from territories in the Don river basin, the Kuban region and the area of the lower Volga river course. Upon the analysis of the Sarmatian date cauldron finds from Ukraine and the R. of Moldova, the author notes their small number and the fact they belong to types specific to the mid Sarmatian period, representing, together with other item classes, one of the innovations of this period (1st century – mid 2nd century AD). Furthermore, it is mentioned that most come from features and contexts with a marked eastern nature of the period between the second half of the 1st century – first half of the 2nd century AD. Considering that most cauldrons in type Demidenko VI were discovered in territories inhabited by the Alani Aorsi and Siraces and based on the dating of features containing identical cauldrons and the Sarmatians’ entry and settlement of the north and north-west Pontic area, the author concludes that the Piatra Şoimului (Calu) vessel, beside the other cauldrons specific to the mid Sarmatian period from the north and north-west of the Black Sea, reached the east Carpathian area sometime in the second half of the 1st century AD and by no means later than the events by early 2nd century AD.

Caspian Anadromous Shad Alosa kessleri kessleri (Grimm, 1887) from the Akhtuba River, Lower Volga River Basin: Biological and Morphological Features

Data on the dynamics of anadromous migration, age composition, body length, body weight, and morphometric characteristics of Caspian anadromous shad from the Akhtuba River are presented. Currently, Caspian anadromous shad from the Akhtuba River is monomorphic; no temporal groups have been identified. The population is represented by medium-sized young early-maturing (age of 2–3 years) fish with life longevity less than 5 years. Generally, according to the most important diagnostic signs, first and foremost, to the number of gill stamens and some plastic signs, Caspian anadromous shad from the Akhtuba River falls within the range of the diversity that is typical for the form.

Reduction in the Numbers of Blood-Sucking Blackflies in Volgograd during the 2018 World Cup as Special Task of Complex Water Resource Management of the Cascade Reservoir System

A mass emergence of blood-sucking blackflies in the Volgograd and Astrakhan oblasts is annually observed in May to July. The blackflies are distinct in their annoying behavior. Their bite are very painful, causing discomfort to humans and animals. The matches of the 2018 World Cup in Volgograd were scheduled for the second half of June. The threat of mass flight activity of blackflies in that period could negatively affect environmental sanitation and hygiene, which would inevitably be followed by breaches of the guarantees given by the government to the International Federation of Football Associations. The development of a schedule of water releases from the Volgograd water-storage reservoir was proposed as a measures to reduce the risk of blackfly occurrence in the period of championship matches. It was based on the available information on the dependence of the blackfly number and the occurrence calendar on the parameters of spring high water in the Lower Volga River (water release volumes, their maximum levels, and the characteristics of their declines). Implementation of the project of scheduled water releases was a complicated and integrated task, since it required alignment with the operating of the upstream water-storage reservoirs with satisfaction of the demands of the users of the integrated water resource management on the Lower Volga River itself and the water storage reservoirs of the Volga–Kama River Cascade. In addition, the available water resources and the insufficient accuracy of water-inflow forecasting should be taken into consideration.

Estimation of the Zonal Distribution of Species of Bottom Communities in Lowland Rivers of the Middle and Lower Volga River Basin

Abstract—A comparative analysis of the variability of the species structure of macrozoobenthos communities in small and medium rivers of the Middle and Lower Volga river basin has been carried out. The statistically significant influence of the natural climatic zone, where the watercourse is located, and manifestation of the latitudinal gradient of biodiversity are shown. A list of indicator species has been made for each geographical zone identified using different criteria of biotopical distribution. Based on the analysis, the indicator value (IndVal) index, which takes into account the zonal distribution of both the occurrence frequencies of a species and its abundance ratios, was recognized as the most adequate. Association rules that contain combinations of species that most frequently occur together in hydrobiological tests have been formulated using the Apriory algorithm.

Support for Making Strategic Decisions on the Water Supply of the Lower Volga River Based on the Pareto Frontier Visualization

This paper describes the application of visualization of the optimal Pareto frontier in supporting decision making within the framework of a technique for integrated assessment of environmental problems. Integrated assessment is used in supporting the choice of strategic decisions on Volga River water management. The main attention is given to the problems of environmental conservation and economic development of the Volga–Akhtuba floodplain. The technique is outlined, the decision problem is formulated, and an integrated mathematical model is described, which makes it possible to estimate the reliability of meeting mutually contradictory requirements for river-water management. It is shown that application of the Pareto frontier visualization is an effective tool for supporting decisions on choosing a feasible long-term strategic goal for controlling the Volga–Kama Reservoir cascade.

Hydrological Regime of the Lower Volga River under Modern Conditions

The regularities of changes in the parameters of the hydrological regime of the Lower Volga are considered using data of routine observations at gaging stations and data of field studies carried out by the specialists of Zubov State Oceanographic Institute in 2006–2017. The main modern trends are revealed for runoff and water level, water temperature, and ice phenomena as well as for the duration of flooding of the Volga-Akhtuba floodplain during the spring flood. The parameters are compared for natural and regulated Volga River runoff conditions. It is shown that considerable variation in the duration of flooding of floodplains, in water temperature, and heat flow during the spring flood under modern conditions is caused both by runoff operation and by increase in the anthropogenic load on the area of the Volga-Akhtuba floodplain in the recent decades.

Initial stages of two Neolithisation models in the Lower Volga basin

In this paper, two groups of ancient sites located in the Lower Volga River basin are analysed. The first group is linked to the emergence of the oldest pottery in this region, which is one of the most ancient in Europe. The presence of this feature of the ‘Neolithic package’ can be dated to the middle of the 7th millenium BC. A production economy is a particular feature of the second group of sites, which can be dated to the end of the 6th millenium BC. This is one of the earliest pieces of evidence of the existence of domesticated species in Eastern Europe. These two groups of sites show the initial stages of two Neolithisation models in the Lower Volga basin.

Gibel carp Carassius auratus (Cyprinidae, Actinopterygii) in flowing water bodies of the Don River basin and the Lower Volga River basin

Data on the occurrence of Gibel carp in flowing water bodies of the Don River basin and the Lower Volga River basin are given. It is shown that gibel carp actively seeks for habitats with flowing water and can persist for a long time in streams with a current velocity from 1.0 to 1.3 m/s and overcome chutes with a current velocity of 2.6 m/s and streams with a depth of less than the body depth of the fish. Therefore, gibel carp is proposed to be considered as a lake–river fish. The outbreak of this species in streams is associated with its spawning period, when it moves in search of spawning grounds. It is assumed that these movements may contribute to its settling in rivers.

The parasite community of gobiid fishes (Actinopterygii: Gobiidae) from the Lower Volga River region

AbstractThe parasitic fauna in the lower Volga River basin was investigated for four gobiid species: the nonindigenous monkey goby Neogobius fluviatilis (Pallas, 1814), the round goby N. melanostomus (Pallas, 1814), the Caspian bighead goby Ponticola gorlap (Iljin, 1949), and the tubenose goby Proterorhinus cf. semipellucidus (Kessler, 1877). In total, 19 species of goby parasites were identified, of which two - Bothriocephalus opsariichthydis Yamaguti, 1934 and Nicolla skrjabini (Iwanitzki, 1928) - appeared to have been introduced from other geographic regions. The monkey goby had significantly fewer parasitic species (6), but relatively high levels of infection, in comparison to the native species. Parasitism of the Caspian bighead goby, which is the only predatory fish among the studied gobies, differed from the others according to the results of discriminant analysis. The parasitic fauna of the tubenose goby more closely resembled those of Caspian Sea gobiids, rather than the Black Sea monkey goby.