Onega Bay Research Articles

ХАРАКТЕРИСТИКА ПРИЛИВНЫХ ОСУШЕК В МЕЗОПРИЛИВНЫХ ЭСТУАРИЯХ РЕК БЕЛОГО МОРЯ НА ПРИМЕРЕ УСТЬЯ РЕКИ ПИЛЬЕМА В ОНЕЖСКОМ ЗАЛИВЕ

The biogeochemical characteristics of tidal drying in the estuary of the small Pilema River in the Onega Bay of the White Sea are considered based on observations made in October 2023. Here, mesotidal conditions are observed with a mean tidal range of 2.4 m at the entrance to the river mouth. Along the eastern shore of the estuary, anomalously high suspended sediment loads (356–692 mg/L) were observed due to stormy weather, but the estuarine section of the river, which is closed to developed wind disturbance, had relatively low suspended sediment loads (6–21 mg/L). The upper tidal drying zone was characterized by low values of benthic abundance, biomass and biodiversity, low projective cover of the bottom by algae, and insignificant concentrations of heavy metals such as cadmium, copper, lead and zinc. This situation is mainly due to active lithodynamic processes observed in this zone.

Characteristics of fucus algae cenopopulations near the Popov island of the White Sea

The aim: Determination of the biological characteristics of fucus algae cenopopulations for the development of recommendations for their rational exploitation. Method: The original data obtained in 2020–2022 according to the recommended methods of fisheries research were used. Novelty: The size, age and sex structures of cenopopulations and reproduction of three species of fucus algaeof the intertidal zone of the White Sea are analyzed. Result: Studies in 2020–2022 in the intertidal zone of Popov Island confirmed the stable state of cenopopulations of commercial fucus algae. Fucus algae settlements in the littoral is a fishing area with dense thickets, an estimated specific stock of 630.3 t/km. Extended sporulation of F. vesiculosus in the area of Popov Island from June to the end of October allows the formation of several age generations of seedlings. Together with vegetative reproduction, this significantly increases the survival of the cenopopulation and its resistance to climatic influences. The age of fertility in the studied areas is less than according to the literature data. In terms of resistance to environmental impact and survival, the dominant species can be put in the following order based on the characteristics of reproduction, area and density of juvenile settlements, and abundance in the intertidal zone: Fucus vesiculosus → Ascophyllum nodosum → Fucus distichus. Practical significance: Based on the data on the reproduction of commercial fucus algae near the Karelian coast of the Onega Bay, it is recommended to start harvesting algae in the littoral no earlier than July 1 after the end of the generative period in the most vulnerable species.

Spatial Variation in the Frequency of Left-Sided Morph in European Flounder Platichthys flesus (Linnaeus, 1758) from the Marginal Arctic (the White Sea)

The European flounder, Platichthys flesus, is a polymorphic flatfish, which has a large population variation in the proportion of left-sided and right-sided morphs across its geographic range. We compared the frequencies of these morphs in the White Sea (Kandalaksha, Onega, Dvina, and Mezen bays), the region in the northeastern part of species’ range adjacent to the Arctic. The proportion of the two morphs in the populations of White Sea flounders showed high variability and specific regional characteristics. The highest frequency of left-sided individuals was observed in the northwestern (Kandalaksha Bay) and southwestern (Onega Bay) parts of the White Sea. Flounders living in the eastern part of the White Sea (Dvina and Mezen bays) showed a much lower frequency of this trait. No consistent pattern of geographic variation in the proportion of the morphs was found in the geographic range of P. flesus. The lowest frequencies of left-sided individuals were recorded in the flounder populations living at the eastern and western margins of the geographic range. Geographic variation in the proportion of left-sided individuals in flounder populations is likely to be determined by a set of biotic and abiotic factors. Selective influence of the latter, acting through the trophic relationships of this species with other marine organisms, can differ in different parts of flounder’s geographic range.

Internal Solitary Waves in the White Sea: Hot-Spots, Structure, and Kinematics from Multi-Sensor Observations

A detailed picture of internal solitary waves (ISWs) in the White Sea is presented based on an analysis of historical spaceborne synthetic aperture radar (SAR) data and field measurements. The major hot-spot of ISW generation locates in the southwestern (SW) Gorlo Strait (GS), characterized by the presence of strong tides, complex topography, and two distinct fronts. Here, pronounced high-frequency isopycnal depressions of 5–8 m were regularly observed during flood and flood/ebb slackening. Other regions of pronounced ISW activity are found near Solovetsky Islands and in the northwestern Onega Bay. The spatial and kinematic properties of the observed ISWs are linked to water depth, with larger wave trains and higher propagation speeds being observed over the deep regions. Direct estimates of ISW propagation speeds from sequential and single SAR images agree well, while theoretical ones obtained using a two-layer model overestimate the observed values by 2–3 times. This is explained by the effective modulation of ISW propagation speed during the tidal cycle by background currents that are not accounted for in the model. Enhanced values of diapycnic diffusion coefficient in the pycnocline layer were registered near the frontal zones, where intense 14–17 m high ISWs were regularly observed.

Bird summer distribution patterns on islands in Onega Bay, White Sea

We studied avian populations and distribution patterns on 20 islands in Onega Bay, White Sea, with transect surveys completed to register selected biotic and abiotic factors in July 2020. Bird population densities proved to be the highest on small secluded islands rarely visited by humans and on treeless islands. We also found positive correlations between the species richness and the island size, presence of woody vegetation, and human visitation. It is noteworthy that although human interference can cause species diversity on the islands to increase, the relative abundance of birds declined. Furthermore, species diversity increased due to the arrival of species atypical of this region and, hence, lacking the complete set of requisite adaptations. Further human pressure on the islands can eventually destabilise their avifaunal complexes and aggravate the current transformation of northern communities in response to climate change.

PROMOTING THE KNOWLEDGE OF THE ENTOMOFAUNA OF THE ONEZHSKOYE POMORYE NATIONAL PARK

We report the first express study of the insect fauna carried out in the Onezhskoye Pomorye National Park, located in the northwest of the Arkhangelsk Region. Insects were collected along the eastern coast of Onega Bay of the White Sea, mainly at a distance up to 2–3 km from the coastline. In total, we revealed 616 species from 9 insect orders, most of which are reported for the first time for the territory of the national park. The local fauna mostly consists of widespread boreal species, but there are some peculiarities associated with the geographic location of the study area. There is a group of species, including inhabitants of both forest communities and coastal biotopes which, although known in some regions of Western Europe, have not been previously recorded on the western coast of the White Sea. In addition, the presence of elements of the eastern fauna that had not been previously known in the western Palaearctic was confirmed for the territory of the national park. The records of several species with more southern distributions in regions west of the White Sea are also noteworthy. Some species are generally quite rare, probably throughout the range. Two of them are listed in the regional Red Data Books of Karelia – Keroplatus tipuloides Bosc and Finland – Heterocheila buccata (Fallén). New distribution data were obtained for many species, which made it possible to extend their known ranges. Two species of parasitoid wasps – Endromopoda nigricoxis (Ulbricht), Platylabus pseudopumilio Riedel, and three species of Diptera – Mycetophila moravica Landrock, Lonchoptera nitidifrons Strobl, Lasiomma seminitidum (Zetterstedt) are new to the fauna of Russia. Our results provide a good starting point for further entomological research in this protected area.

Заметки о лихенобиоте некоторых островов в Онежской губе Белого моря (Республика Карелия)

Information about lichens on Kondostrov Island and five other islands situated nearby in Onega Bay of the White Sea is given for the first time. A distinctive feature of this archipelago is Russian larch (Larix archangelica) growing in an isolated position in the westernmost point. All in all, 145 lichen species have been recorded from six islands, with the highest richness (90 species) on the largest island Kondostrov. Bryoria fremontii and Lobaria pulmonaria are red-listed in the Russian Federation; six more species, viz. Chaenotheca gracilenta, Collema nigrescens, Pertusaria coronata, Ramalina obtusata, R. roesleri, and R. subfarinacea, are red-listed in the Republic of Karelia.

On the Role of Small Photosynthetic Flagellates in the Fall Phytoplankton Community of Onega Bay, White Sea

On the Role of Small Photosynthetic Flagellates in the Fall Phytoplankton Community of Onega Bay, White Sea

Long-term dynamics of the proportion of left-sided individuals in the populations of the European flounder Platichthys flesus (Linnaeus, 1758) in the White Sea

Interannual variation in proportion of left-sided individuals has been studied in the populations of the European flounder from Onega (2002–2019), Mezen (2010–2016), and Dvina (2005–2019) bays of the White Sea. It was found that the flounder populations show no statistically significant and consistent changes in this character. The frequency of left-sided individuals in the local populations and the character of interpopulation differences in different years of the observation period remain relatively constant. The comparison of the results of this study with those of earlier studies reveals a similarity in proportions of left-sided fish over the past 40–60 years in flounder populations of the Kandalaksha Bay and Onega Bay. These results highlight the importance of the proportion of left-sided morphs for the analysis of population differentiation of the European flounder in the White Sea.

From a large basin to a small lake: Siliceous microfossils stratigraphy of the isolation basins on Big Solovetskiy Island (the White Sea, NW Russia) and its implication for paleoreconstructions

This paper discusses the results of siliceous microfossils studies performed in a “staircase” of four isolation basins (33.7 m–2.9 m a.s.l.) on Big Solovetskiy Island (Solovki Archipelago, the White Sea). Diatoms were used as a primary group for paleoinferences, while chrysophyte cysts and sponge spicules also demonstrated high indicative potential. In all study lakes, the siliceous microfossils stratigraphy revealed three main stages of their evolution, i.e. large-basin, transitional and small-lake stages, each characterized by certain composition of the diatom assemblages and floristic diversity, relative abundances of chrysophyte cysts and sponge spicules, and siliceous microfossils concentrations. In the uppermost lake, glaciolacustrine environments unfavorable for aquatic biota existed during the large-basin stage. The proglacial lake stage terminated prior to ca. 10.4 cal ka BP, followed by a (semi)terrestrial episode before the transition to small-lake environments. In the other three lakes, marine environments were inferred at the earlier stage, characterized by the predominance of marine and brackish-marine diatoms, increased proportions of sponge spicules and low “cysts to diatoms” ratio. At the transitional marine-freshwater stage, mass growth of small fragilarioid diatoms and decreased abundances of spicules indicated unstable environments, while increased proportions of cysts pointed to progressive freshening of the basins. The duration of the marine-freshwater transition expectedly prolonged from ca. 200 yr in the upper basin (16.6 m a.s.l) to ca. 500 yr in the lowermost lake (2.9 m a.s.l.). The isolation from the sea took place between ca. 6.3 and 1.4 cal ka BP. At the small-lake stage, siliceous microfossils stratigraphies reflected local specifics of the basins and their catchments. We argue that besides traditionally used diatom data, relative and absolute abundances of siliceous microfossils also possess high indicative value for isolation basin studies. Our study demonstrated that marine waters on Big Solovetskiy Island never reached ca. 34 m a.s.l. during the Holocene, unlike the western coast of the Onega Bay where the Preboreal marine intrusion was recorded even at higher elevated localities. Different rates and amplitudes of shoreline displacement are thus suggested for the inner and outer parts of the Onega Bay. During the mid-Holocene Tapes transgression, before ca. 6.3 cal ka BP, the relative sea level on Big Solovetskiy Island exceeded 17 m a.s.l. The average estimated rates of the shoreline retreat during the second half of the Holocene gradually decreased from 0.28 cm year−1 to 0.2 cm year−1, indicating slowed isostatic uplift.

Functional Activity of Phytoplankton and Optical Properties of Suspended Particulate Matter in Onega Bay of the White Sea

Functional Activity of Phytoplankton and Optical Properties of Suspended Particulate Matter in Onega Bay of the White Sea

Modiolus modiolus Communities of Onega Bay, White Sea: How Stable Are They over Time and Space?

Macrozoobenthic communities of Onega Bay of the White Sea were studied in 2010 at ten stations, which repeated the survey sites performed in the 1950s and 1980s by the staff of the White Sea Biological Station, USSR Academy of Sciences. Benthic communities where bivalve mollusks dominated by biomass were observed at all sites investigated in 2010. The stations were divided into two main groups; Modiolus modiolus was the dominant species in the first one, Clinocardium ciliatum in combination with various bivalve species as subdominants dominated in the second. There were also communities in which Hiatella arctica and Macoma calcarea dominated; each community was recorded at only one station. Due to the inability to follow accurately the sampling methods and the peculiarities of primary processing used in the historical surveys, the comparison of the data was carried out using only bivalves, because this was the most reliably defined group that unquestionably dominated in all communities. No significant changes were found in bivalve dominance. The replacement of the blue mussel settlement with a Hiatella arctica community was observed at a shallow depth (13 m). Deeper than 40 m, the dominants changed: Clinocardium ciliatum by Mya truncata (1952), Elliptica elliptica by Macoma calcarea (1981), and Clinocardium ciliatum by Macoma calcarea (2010); these changes were most likely associated with the patchy distribution of these key forms. Modiolus modiolus communities, observed in Onega Bay in 1952 and 1981 at depths of less than 40 m, were found in the same places in 2010. The stability of macrobenthic communities, where large, long-lived bivalves dominated (in particular, Modiolus), was most likely due to the absence of significant changes in the environmental conditions and of an anthropogenic load in Onega Bay during at least the second half of the XX century and the early XXI century.

The Long-Term Effects of Contamination by Fuel Oil on the Coastal Ecosystem in the Onega Bay of the White Sea

A comparative analysis of the current content of petroleum hydrocarbons in various components of the ecosystem was performed to assess the ecological state of the southeastern part of the Onega Bay (White Sea) that suffered from a spill of fuel oil in 2003. The analysis showed relatively low levels of petroleum hydrocarbon concentrations: from 0.34 to 4.55 mg/kg, with a median of 1.41 mg/kg in bottom sediments; from 9.41 to 14.25 mg/kg, with a median of 12.30 mg/kg in tissues of benthic organisms; and below 1 MPCfishery (the maximum permissible concentration) in water. The records of low concentrations of bacteria that use petroleum hydrocarbons (fuel oil) allow us to conclude that the state of the examined ecosystem is close to the natural condition.

Size-Age Structure of Navaga Eleginus nawaga in the White, Barents, and Kara Seas

Based on long-term data (1959−2017), a comparative analysis of the size–age structure of eight navaga Eleginus nawaga populations in the White, Barents, and Kara seas was carried out. The relationship between the growth rate of the navaga and the duration of the period with the optimum water temperature for feeding (0−12°C) was revealed. Individuals of the same age groups have the largest sizes in the central part of the range (Mezen Bay and the White Sea Voronka, Cheshskaya Bay of the Barents Sea), and the smallest ones in Pechora Bay of the Barents Sea. The higher growth rate of navaga in the northern part of the range (Kara Bay of the Kara Sea) compared with the southern (Onega Bay of the White Sea) is explained by the absence of heating of coastal waters above the limit favorable for feeding. The increase in the average size of the navaga of the populations under consideration in 1991–2017 relative to those in 1960−1990 is due to the lengthening of the period with a temperature >0°C for almost 1 month. In Mezen Bay and the White Sea Voronka and in the Barents Sea bays, the average length and weight increased only in the younger age groups, and they hardly changed or even decreased in the older ones. This was the result of an increase in the number of fish of older age groups in these areas as a result of a reduction in catch.

Hydrological and hydrochemical research of the mouths of the small rivers flowing to the White sea in the winter low water season of 2019

In the winter low water season in March and the first week of April 2019, complex hydrological and hydrochemical studies were carried out at the mouths of two small rivers of the White Sea catchment basin (the Mudyuga river, which flows into the Dvina Bay, and the Tamitsa river, which flows into the Onega Bay). The results indicate significant differences in the short-period variability of hydrological and hydrochemical parameters in the winter in the studied river mouths compared with the characteristics observed in the tidal estuaries of large and medium rivers, as well as in the mouths of small rivers of the southern seas.

Assessment of accumulation of petroleum hydrocarbons by the hydrobionts of the south-eastern part of the Onega bay of the White sea

In order to assess the current state of the ecosystem of the southeast of the Onega Bay of the White Sea affected by fuel oil spill in 2003, the accumulation of petroleum hydrocarbons was analyzed by the dominant species of aquatic organisms collected on the littoral of the most polluted coast in the areas of Purnem and Lyamts villages. In 2012, samples of aquatic organisms were taken in an area where all the species discussed in this work are represented on a small area: bivalved mollusks, attached molluscs, gastropods, polychaetes. In 2013 and 2018, samples of hydrobionts were additionally selected, in the three-kilometer strip of the coast on either sides of the givin point. In 2012 and 2013, high concentrations of HC in the tissues of bivalves were recorded. In 2018, the concentrations of hydrocarbons in the tissues of the studied hydrobionts were comparable to background values. A non-parametric test of Mann-Whitney showed a significant decrease in НС in mussel tissue from 2013 to 2018, at a significance level of 0.05. Taking into account the low levels of HC in the aqueous medium (less than 1 MPC of fishfarm) and in bottom sediments (from 0.34 to 9.03 mg/kg, the median of 1.41 mg/kg) in 2018, and is comparable with the background contents of hydrocarbons in tissues of aquatic organisms. We can conclude that after 15 years of the fuel oil spill, the condition of the Cape Deep ecosystem in terms of the content of hydrocarbons returns to the baseline state, continuing emissions of oil-sand lumps do not adversely affect the ecosystem. Based on the work done, it can also be concluded that ecotoxocological methods are priority in assessing the prolonged (or delayed) accidental impact of heavy petroleum products on aquatic ecosystems. The conclusion about the presence or absence of a negative impact on the aquatic ecosystem of hydrocarbons, based solely on the analysis of abiotic components, may not be sufficiently informative because it does not take into account the accumulative and deferred effects, especially manifested in the cold Arctic waters.

Mercury in the water of small rivers of the Onega Bay basin of the White Sea

The results of the expeditionary studies of the mercury behavior in the water of small rivers of the Onega Bay basin of the White Sea are presented. Priority forms of mercury migration have been identified and the forms of its location along the trunk of the Kyanda River have been calculated. The relationship between the content of various forms of mercury on the one hand and salinity, pH, Eh waters on the other has been analyzed. The influence of hydrological phases on the transformation of inorganic forms of mercury has been revealed. Differences in the levels of content of dissolved mercury and its connection with the salinity in the extuar areas of the marginal filters of the Subarctic rivers in natural conditions and the environment of anthropogenic impact were established.

Characteristics and microgeographic variation of whistles from the vocal repertoire of beluga whales (Delphinapterus leucas) from the White Sea.

The beluga whale (Delphinapterus leucas) produces a variety of sounds, including whistles as well as pulsed, noisy, and biphonic vocalizations. This study presents the fine-scale, microgeographic characteristics of beluga whistles from data collected in four locations across Onega Bay and Dvina Bay in the White Sea, Russia. Ten parameters were measured from 1232 whistles. The whistles had a fundamental frequency from 0.4 to 25.0 kHz and duration from 0.04 to 3.93 s. Although two distinct types could be recognized in the White Sea beluga's whistle repertoire, other whistles formed a graded continuum. Among them, "flat" whistle contours with no inflection points appear to be the most common (39.7%), to be followed by frequency-modulated whistles: ascending (27.1%) and descending (15.6%). Non-linear phenomena detected in the whistles included frequency jumps (23.1%), biphonations (13.2%), sidebands (5.2%), and subharmonics (0.5%). The whistles varied in frequency parameters and duration across the locations, while those recorded in the same location in different years showed minimal difference. Beluga whistles appear to be an extremely diverse class of vocalizations. This, together with the lack of clear correlations between the behavior of whales and whistle production suggests whistles may perform multiple functions within the beluga whale communication system.

Mercury in the Water of Small Rivers of the Onega Bay Basin of the White Sea

The results of the expeditionary studies of the mercury behavior in the water of small rivers of the Onega Bay basin of the White Sea are presented. Priority forms of mercury migration have been identified and the forms of its location along the trunk of the Kyanda River have been calculated. The relationship between the content of various forms of mercury on the one hand and salinity, pH, Eh waters on the other has been analyzed. The influence of hydrological phases on the transformation of inorganic forms of mercury has been revealed. Differences in the levels of content of dissolved mercury and its connection with the salinity in the extuar areas of the marginal filters of the Subarctic rivers in natural conditions and the environment of anthropogenic impact were established.

Spatial distribution of phytoplankton in the subarctic estuary (Kem’ river, the White Sea)

The species composition and biomass of the phytoplankton (Ph) as well as hydrological characteristics were estimated in 4 spatial surveys in the subarctic tidal estuary of the Kem’ River and adjacent area of Onega Bay (White Sea, Russia) in June–July 2008–2011. The study area was divided into 3 zones (the river zone, the gradient zone and the marine zone), based on the salinity variation of the surface layer. In total, 318 species of Ph were registered, 143 species are found in the river zone, 225 — in the gradient zone, 106 — in the marine zone. The greatest number of species in all zones was represented by diatoms. The highest biodiversity of Ph in the surface layer was detected in the gradient zone. The averages of total biomass of the Ph in the surface layer (Bo) at different years varied in range 2.8–16.9 mg C/m3. Although Bo did not differ significantly between zones, with the exception of 2011, when Bo was the highest in the river zone, dissimilarity in the structure of the Ph in the river, gradient and marine zones were 61–95%. The similarity of the Ph at the stations of each zone was poor (22–53%) with the lowest values in the gradient zone. It is postulated that the tidal cycles determine the spatial and temporal heterogeneity of the composition, structure and abundance of Ph in the Kem’ river estuary in summer.