The Tylihul Estuary is the largest and deepest estuary in the northwestern Black Sea region, which separated from the sea by a sandbar in the 18^th–19^th centuries. The large catchment area (5,420 km²), small width (up to 4.5 km) compared to its length (60 km), numerous long sandbars, and depth differences, ranging from 3–5 m in the northern part to 10–22 m in the southern part, complicate water exchange, and the degradation of river basins leads to a deficit in runoff. As a result, its hydrological regime is artificially regulated by a connecting channel, which has operational shortcomings that have repeatedly led to sharp changes in the salinity of the estuary (Tuchkovenko and Loboda 2014). Natural seasonal changes in salinity, which are mainly caused by river runoff, are limited, while sharp changes related to artificial hydrological conditions occur when, for example, access to seawater is closed or opened over a period of several years. During research conducted in the summer of 2023, the salinity of the estuary reached 29.7 PSU (practical salinity units).

The estuary is home to infrastructure related to an oyster farm as well as two small resort areas which attract tourists mainly with their oyster bars. One of these bars, located in the village of Kordon in the Odesa district (Fig. 1), have a wide tourist infrastructure with wooden boardwalks and piers extending into the water near the oyster bar. This allows visitors to eat oysters while standing on these structures and throw their shells directly into the estuary. As a result, a zone of discarded oyster shells with a radius of up to 5 m forms around the piers and wooden decks. This area is one of the research monitoring stations of the Institute of Marine Biology MAS of Ukraine (IMB), with observations taking place each season to ensure continuous monitoring of ecosystem changes, but it covers sublittoral mixed sediments and macrophytes, not the littoral zone directly adjacent to the resort infrastructure. The second resort area is in the village of Ukrainka in the Mykolaiv region. It has a different internal layout and the beach area preferred by tourists is more separated from the oyster bar.

Figure 1.

Photos of site: Tylihul Estuary oyster bar near an oyster farm in Kordon village.

The analysis included three sources of primary material, shown in Table 1 and in the text. All material was collected during the expedition on June 16, 17, 2023 in the village of Kordon in the Odessa region (46.8343°N, 31.1038°E).

The first included living epibionts on dead oyster shells collected in the littoral zone of the Tylihul Estuary near the oyster bar. Such epibionts also included both macroinvertebrates and spawning fish found inside the shells deposited at the bottom of the estuary. These specimens were extracted from the oysters and subjected to a thorough examination. The second source included live oysters from the oyster bar kitchen and epibionts (attached macroinvertebrates) found on their shells. The third source included macroinvertebrates found on hard substrates of wooden boardwalks and piers extending into the water near the oyster bar. The analysis also included the macrofauna present on live oysters sold on the beach.

The second resort area, in the village of Ukrainka in the Mykolaiv region (46.7474°N, 31.1680 °E) was studied during the expedition on August 16, 2023. In this area, we did not find any accumulations of discarded oyster shells or new alien species, and this area will not be discussed further in our paper.

Sampling underwater was conducted by snorkelling, allowing for direct access to the underwater environment. The identity of any invasive invertebrate species colonizing the oyster shells, and of the living oysters sold in the oyster bar were confirmed using molecular techniques.

All animals found on the shells, together with a small part of the oyster muscle tissue, were dissected and preserved in 96% ethanol for molecular study. The specimens were deposited in the collection of the IMB.

Genomic DNA was isolated at the Department of Ecology and Vertebrate Zoology at the University of Lodz (Poland) using the Chelex buffer method (details in Casquet et al. 2012). DNA barcoding was performed based on the mitochondrial cox1 gene (Hebert et al. 2004). The DNA was amplified using HCO2198 and LCO1490 primers (Folmer et al. 1994) under the following PCR protocol: 3 min – 94 °C; (30 s – 94 °C, 1:30 min – 45 °C and 1 min – 72 °C) × 5; (30 s – 94 °C, 1:30 min – 51 °C and 1 min – 72 °C) × 35; 5 min – 72 °C (Hou et al. 2007). The amplicons were purified with exonuclease I (20 U/μl; EURx) and Fast Polar-BAP alkaline phosphatase (1 U/μl, EURx).

The material was subjected to Sanger sequencing (Macrogen Inc); the results were analysed in online GenBank repositories using BLAST (https://www.blast.ncbi.nlm.nih.gov) and BOLD identification to find similarities. The data were registered in BOLD under dataset DS-OYSTER. The sequences were assigned BINs (Barcode Index Numbers) based on the genetic distance to other similar sequences in the database (Ratnasingham and Hebert 2013). The algorithms used to assign BINs are described in Ratnasingham and Hebert (2013); for invertebrates, a genetic distance greater than 2% is assumed to indicate a different Barcode Index Number. A map of the geographic distribution data of the identified M. gigas and Monocorophium insidiosum (Crawford, 1937) sequences and those available in the BOLD System (www.barcodinglife.org, Suppl. material 1) was performed in QGIS v.3.0.8.

The risks associated with invasion by newly-discovered alien species were determined by three approaches: identification of invasion pathways, assessment of potential species-related risks (invasiveness) and the observed level of biological pollution.

Any pathways used for invasion were identified using the CBD Pathway Classification framework (Harrower et al. 2017; Tsiamis et al. 2017).

Invasiveness was assessed using the Species-specific Biopollution Risk (SBPR) index (Panov et al. 2009). This index is based on a general assessment of the degree of invasiveness of a specific alien species according to its potential for high risk for dispersal (HRD), high risk for establishment in a new environment (HRE), and high risk of causing ecological and negative socio-economic impacts (HRI). The HRD, HRE and HRI information of a particular alien species is widely available in any publications associated with its introduction; how to use these data to inform the SBPR index are provided within the original methodology.

Based on these three risk aspects, a species can be classified according to a five-point risk assessment scale in line with the Water Framework Directive (Directive 2000). This risk-based approach is used when formally including an alien species in the Grey, White, and Black Lists: the Grey List indicates that a species is a priority for research and status clarification, and the Black List for environmental management. The White List includes species that are not a priority for management.

The level of biological pollution of the Tylihul Estuary caused by each exotic species detected was assessed using the BioPollution Level (BPL) index; this estimates the biological pollution of a particular water body based on four expert judgements: abundance/distribution class, impact on native species and communities, impact on habitats, and impact on ecosystem functioning (Olenin et al. 2007).

For both SBPR and BPL indices, the term ‘experts’ hereinafter refers to the authors of the article who conducted the assessment procedures.

The Black Sea is home to considerable numbers of cultivated M. gigas and Crassostrea virginica (Gmelin, 1791), both of which have ranges expanding into natural habitats. Although the M. gigas found in the studied Tylihul oyster bar have commercial value, it is important to recognize that it also has invasive potential and can act as a vector for the spread of other species; as such, it could pose a significant threat to the local ecosystem, and measures should be taken to prevent its escape into the wild. The penetration of M. gigas into other parts of the Black Sea with the emergence of breeding or potentially breeding wild populations has already been recorded in several regions of the Black Sea outside the study area (Aydin and Gül 2021). Indeed, this commercial oyster species (Kim et al. 2015) has been repeatedly identified as an invasive species in natural environments in other parts of the world (Liu et al. 2011; Pejovic et al. 2016; Ren et al. 2016).

The communities present on the dead oyster shells were found to comprise alien species, probably introduced with the oysters as accidental hitchhikers. These were accompanied by large numbers of native invertebrate species, which are typical inhabitants of the Tylihul Estuary (Varigin 2023) and were also found on other hard substrates in the vicinity.

Two new alien species were identified on the discarded shells, S. balanoides and A. modestus, indicating that the shells represent a new introduction vector for the Black Sea. While these species have been reported elsewhere (Carlton et al. 2011), their association with oyster shells and subsequent introduction through discarded remains is a novel finding. The amphipod M. insidiosum has multiple introductions into the Black Sea: it was previously listed from Crimea (Shadrin and Anufriieva 2013; Grintsov 2018) and from the eastern Turkish coast (both genetic BINs: BOLD:AAE1628, BOLD:AAE9749) but without discussion of the vectors of introductions.

The detected species in Tylihul Estuary exhibit considerable divergence with regard to their origin, for example, the Australasian A. modestus compared to the boreal circumpolar S. balanoides and M. insidiosum. This diversity has various implications for their distribution dynamics and prognoses in the context of climate change (Jones et al. 2012; Crickenberger and Wethey 2018; Herrera et al. 2019; Glenner et al. 2021). The cold-water habitat of the Black Sea, which in its most desalinated northwestern part was traditionally accompanied by periodic icing, historically prevented invasions by warm-water tropical and subtropical alien species such as A. modestus. On the contrary, arctic-boreal species, which often do not survive in the Mediterranean Sea, have historically been present in the Black Sea fauna as a permanent element (Zaitsev and Mamaev 1997). However, climate change over the last two decades has dramatically altered the situation, and warm-water alien species, previously found only sporadically in the Black Sea, are beginning to form stable populations, as shown, for example, for the Blue Crab Callinectes sapidus Rathbun, 1896 (Kvach et al. 2025a). Interestingly, among the other alien species previously recorded in the Tylihul Estuary, those which are characteristic of hard substrate communities were absent on the oysters. In particular, Arcuatula senhousia (Benson, 1842), a recent invader actively colonizing the region (Zhulidov et al. 2021; Son et al. 2023; Varigin 2023), was only identified in clusters of filamentous algae and was present at a greater depth than oyster shell clusters. In addition, the crab Rhithropanopeus harrisii (Gould, 1841), characteristic of estuaries of the region (Makarov 2004; Son et al. 2013), was not observed; the species may have disappeared from the Tylihul Estuary, or become extremely rare, following a sharp increase in salinity.

An interesting feature is that oyster valves were actively exploited as refuges by native fish species. Bivalve shellfish aquaculture is a ready source of shells as settlement substrate, which has a significant impact on the value of habitats for fish and mobile invertebrates (Theuerkauf et al. 2022). It is a typical spawning substrate used by demersal fish such as gobiids and blenniids (Inui et al. 2010; Tiralongo et al. 2016; Prakash and Kumar 2025). Gobiids are one of the most numerous fish components in the Tylihul Estuary (Kvach 2004; Snigirov et al. 2017). Both fishes that occurred in the locality (Gobius niger, Parablennius tentacularis) are native for the Black Sea (see Movchan 2011; Snigirov et al. 2020). The Black Goby was registered in the estuary in the last decade as a common species (Snigirov et al. 2017), while the Tentacled Blenny is common in adjacent sites of the Black Sea (Khutornoy and Kvach 2019; Snigirov et al. 2020) but registered in the Tylihul Estuary for the first time. Overall, the observed pattern is consistent with similar scenarios noted in various other regions: the large, textured shells provide hard substrate and refuges for a variety of benthic species, both attached fouling and mobile fish and crustaceans, which can support a diverse biological community (Kingsley-Smith et al. 2012; Walles et al. 2015; Png-Gonzalez et al. 2021). In the Tylihul Estuary, where natural hard substrates are scarce and no shipping ports or other large-scale hydraulic structures are present, even small amounts of such hard substrates attract invasive species and affect biodiversity. However, at their current level of distribution, new species only present weak and localized levels of biological pollution.

Current aquaculture risk assessments often overlook marine food residues as a potential vector. However, oyster bars merit particular consideration, whether they are separated from farming locations or not. If they are present in areas near farms, the accumulation of discarded shells can drive the spread of invasive species, while if they are located away from the farms, discharges can create distinct target biotopes for invasive species. A similar risk may come from consuming oysters at beach parties or cocktail bars that do not specialize in seafood but just sell it.

There is hence a need to reassess the current system of pathway classification by incorporating food tasting sites (bars) and their proximity to farms. Until now, the “3.3 Food contaminant (including of live food)” pathway has been a well-known route for terrestrial organisms (Montagnani et al. 2022) but was not considered relevant for aquatic invertebrates: in over 200 cases of invasion by target species or associated companion species following escape from aquaculture/mariculture, or by transport to breeding and rearing sites, not a single case in Europe has been identified based on the CBD Pathway Classification (Pergl et al. 2020).

In an inventory of biological invasions taking place in the seas of Europe, more than 150 identified taxa (genera or species) of animals, plants and microorganisms were associated with edible farmed molluscs, mainly oysters (Di Blasio et al. 2023).

In the Tylihul estuary, several exotic barnacles were observed, but these were not associated with oyster cultivation (Di Blasio et al. 2023). Such species are often actively dispersed by shipping. Other pathways for invasion are possible, but these are usually only discussed when shipping is unlikely or when direct evidence of another route is available. This bias in assessing pathways of introduction is a recognised source of difficulty in invasion science (Katsanevakis et al. 2013; Katsanevakis and Moustakas 2018).

In contrast, M. insidiosum invasions appear to be potentially associated with cultivated molluscs. Such invasions have been associated with oyster mariculture in various regions including Irish lagoons and along the Pacific coast of North America (Wasson et al. 2001; Oliver et al. 2007). Its precise invasion history in the Black Sea remains unclear, but for the first few years after its discovery (1999-2001), it was only observed on mussel collectors (Grintsov 2018).

Oyster shell recycling, i.e. the use of empty shells collected by restaurants or consumers to replenish substrate in the sea, is a widespread practice in North America, where there are many such environmental programs ranging from localized small-scale returns of shells to the sea to the construction of huge oyster reefs from empty shells acting as breakwaters (Chowdhury et al. 2019; Kimbro et al. 2020; Birney et al. 2021; Petrolia and Mohrman 2024). However, it is important to note that attempts to imitate the oyster reefs natural to the region, i.e. those formed by Crassostrea sensu lato, may use many shells from other cultivated species.

Generally, shell recycling is not a common practice in Europe; however, as part of initiatives by local activists and NGOs, oyster shells from oyster bars on the Tylihul Estuary were used to create experimental artificial reefs, which in 2020 were installed in the Black Sea near the Kinburn Spit (TSN 2020).

In situ evidence of species transfers taking place in this way, and the associated recommendations for quarantine of empty shells, concern mainly pathogens harmful to live oysters (Bushek et al. 2004; Brumbaugh and Coen 2009). However, studies also highlight the possibility of the transfer of toxic unicellular algae present on the shells (Brumbaugh and Coen 2009), which has been confirmed experimentally by Hégaret et al. (2008).

Such transfers can be classified as pathway “3.10 Transportation of habitat material (soil, vegetation, wood…)” (Harrower et al. 2017), although the shells were probably not previously used as an underwater building material. This differs from the pathway described before (i.e. 3.3 Food contaminant, incl. live food) in that the shells are transported as building material, during which they are subjected to temporary drying that kills most aquatic invertebrates present. Nevertheless, it seems that this pathway takes place in the studied region and may become an additional route in the Black Sea basin, which is dependent on the transportation of oysters as live food. Potentially, if found, harmful algae and bacteria that are introduced can also be classified under other categories, such as ‘Transport – Contaminant’. Harmful algal outbreaks can directly impact health and profitability by poisoning.

The potential use of discarded clamshells in building projects like artificial reefs may hence pose a risk of species invasion. Although the used shells were left for a long time at high temperatures, killing any macrozoobenthos, it is possible that any microalgae present may well survive. Additionally, clamshells can serve as stepping stones for the secondary spread of invasive species, even though they start completely clean.

The lower salinity of the Black Sea typically acts as a barrier against certain oceanic species (Gomoiu et al. 2002). However, the Tylihul Estuary has undergone repeated changes in salinity which have destroyed the original communities (Gogaladze et al. 2021) and may have created a unique opportunity for new species to thrive.

This issue has been exacerbated by the closure of the Black Sea for recreation purposes due to the Russian-Ukrainian war (Kvach et al. 2025b). As a result, estuary-based activities have experienced increased demand and higher numbers of recreational visitors and tasting sites have purchased additional oysters from diverse import sources to meet the demand.

Hence, an effective management strategy is required. Experiments increasingly show that localised strategies for countering biological invasions are failing and efforts need to be redirected towards large-scale preventive approaches, in particular, the formation of a common European management area (Kurtul and Haubrock 2024). Analyses of invasion pathways in European marine ecosystems have found aquaculture-related invasions to be managed most effectively via strict national regulations (Katsanevakis et al. 2013). It is important to note that the live food-related pathway of invasion is not driven by production, a part of national economic activity, but by international and domestic trade, separate spheres of control and management (Hulme 2021).

Until recently, Ukrainian legislation included very few direct regulations for the management of invasive species, with the exception of the phytosanitary control system. Some commitments that relate to monitoring, research, or general management strategies are included in various signed international agreements. Among these, the following agreements may affect marine and estuarine species associated with mariculture: the Convention on Biological Diversity (1995), ratified in 1995, the Convention on the Conservation of European Wildlife and Natural Habitats or the Bern Convention (Council of Europe 1996), ratified in 1996, and the Convention on the Protection of the Black Sea against Pollution (United Nations Environment Programme 1994), ratified in 1994.

In addition, explicit standards for preventing biological invasions by controlling relevant pathways are given in 2004 in the International Convention for the Control and Management of Ship Ballast Water and Sediments (International Marine Organization 2004) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (ratified in 1999).

In the last few years, Ukraine has undergone a large-scale modernization of legislation related to alien species as part of the integration of the legislative norms and principles of the European Union. A number of changes have already been implemented, including mandatory monitoring of invasive species in inland, transitional, coastal, and marine waters, the integration of regulations and lists of dangerous alien species adopted into legislation by the European Commission (Katsanevakis et al. 2023), and the adoption of several national conservation strategies.

This has been accompanied by the comprehensive integration of European regulations regarding the management of invasive species directly into Ukrainian legislation concerning aquaculture, fishery, Industrial Fishing and Water Conservation, protection of flora and fauna, and the management of protected areas. The Institute of Marine Biology (NAS) is an expert organization coordinating bills and official documents in these areas.

The planned legislation fundamentally tightens border control over the movement of invasive species and the possibility of their use in aquaculture. It also establishes obligations for fishery reclamation, which includes the removal or destruction of invasive species that threaten aquaculture. Bulgaria and Romania have already performed similar procedures as part of the EU entry procedures (Băncilă et al. 2022), as are many other countries in the Black Sea region.

The new Ukrainian legislation will not be retroactive, and a complete ban on the use of invasive species in aquaculture will not apply to previously-introduced species. As such, M. gigas, which has traditionally been used in local mariculture (Massa et al. 2021), will not be completely banned, despite the fact that in the last decade, it has clearly exhibited the characteristics of an invasive species in the Black Sea, as well as in Europe as a whole (Anglès d’Auriac et al. 2017; Krapal et al. 2019; Aydin et al. 2021; Băncilă et al. 2022).

However, other Crassostreinae may be prohibited for import into Ukraine if they are included in the lists of controlled species. It should be kept in mind, however, that alien species that are valuable bioresources, especially in the context of food security, can be subject to inclusive management approaches in the form of various relaxations in control and eradication (Kourantidou et al. 2022; Gozlan et al. 2024).

Invasion could also be prevented by including potential hitchhikers in the lists of controlled invasive species. This is a feasible approach that requires research on oysters from various commercial lots present on the local market, although a pan-European project covering both importing and exporting countries would be desirable. Preliminary visual inspections indicate that different commercial brands of Pacific Oysters originating from various growing regions exhibit significant variation in their fouling organisms (Fig. 6). These fouling organisms primarily include barnacles, bryozoans, polychaetes, sponges, ascidians, and hydrozoans.

Figure 6.

Visual inspections of fouling organisms on Pacific Oysters from various commercial brands and growing regions. A. Clean shell with scarper marks from Fin de Clair Cancale France, and B. Shell from Atlantic Yerzeke, the Netherlands with C. Polychaete tubes (shown by arrow) and D. Drilling sponges (shown by arrow).

Recent studies of the Pacific Oyster industry have primarily focused on growth (Alunno-Bruscia et al. 2011; Devos et al. 2015), mortality (Kochmann and Crowe 2014; Schmitt et al. 2013), and viral infections (Dundon et al. 2011; Roque et al. 2012; Degremont et al. 2013; Mortensen et al. 2016); however, few genetic metabarcoding studies have examined biofouling in oyster farms. Studies based on eDNA may be useful for marine fishery management and ecosystem monitoring (Gilbey et al. 2021). Indeed, eDNA tools have been developed to detect the most harmful invasive non-native marine species for Ostrea edulis Linnaeus, 1758, and support its population restoration (Markus et al. 2021), or to detect wild oysters themselves (e.g. Coutts et al. 2022; Dugal et al. 2024;). Yet, there is lack of data on covering biofouling species on cultivated populations.

After inventory, any identified hitchhikers must undergo a Species-related Risk Assessment. In Ukraine, it is recommended that such aquatic invasive species should be subjected to the Institute of Marine Biology (NAS) risk assessment scheme, which is based on a Species-specific Biopollution Risk index. The inclusion of such species in pan-European or national lists of controlled species will provide legislative obligations for local administrations, business owners or other natural resource users to prevent invasions, remove or destroy introduced organisms, or develop management programs (Katsanevakis et al. 2023).

It should be noted that controlling oyster epibionts is unlike managing non-native species. The presence of epibionts influences both the marketability of the oyster at the time of sale (Mizuta and Wikfors 2019) and can cause problems with aquaculture, such as affecting population size, health and productivity, impacting economic costs, and causing general technical difficulties (Adams et al. 2011).

Control methods can also be divided into two groups. The first, biofouling removal or punishment, involves directly cleaning the oysters by various methods, such as mechanical scraping, scrubbing, brushing, pressure washing, drying and ultraviolet irradiation, dipping into fresh, high-salt or chlorinated water, and manual removal of the most unattractive specimens (Adams et al. 2011; Mizuta and Wikfors 2019). In addition, the cultivation process can be controlled by decisions regarding engineering, equipment and procedures, cleaning and waste behaviour, and a choice of cultivation regime (Adams et al. 2011).

Punishment by mechanical scraping and pressure washing should ensure that ‘elite’ specimens sold in restaurants or shops meet local shape and size standards and are free of sediments and fouling such as barnacles, hydroids, other bivalve molluscs, and macroalgae (Adams et al. 2011). The shell is also home to boring polychaetes and sponges which, in addition to their aesthetic impact on the shell, form blisters and erosions that reduce its strength during transport (Mizuta and Wikfors 2019). These can only be removed during the aquaculture process (e.g. by ‘dipping’ methods and the culture regime itself) or by manual culling of non-merchantable individuals (Adams et al. 2011; Mizuta and Wikfors 2019).

The Ukrainian oyster market is still underdeveloped and has not led to the emergence of a discerning consumer. Inspection of live oysters available for sale, in both the studied tasting point and large supermarkets, showed that while prices for different batches differ considerably according to international quality standards, they are practically the same for a retail buyer. The same shop was found to sell oysters almost completely free of epibionts (with small barnacles inside the shell hollows inaccessible for brushing) with a regular drop-shape and standardised sizes at the same price as multi-sized long and skinny oysters, known as bunny rabbits (Fig. 6), which are densely covered with polychaete houses and drilled with numerous sponges. The second group are clearly intended for the frozen meat trade or the preparation of soups, which would be excluded from the live food trade for restaurants or parties in a more developed market.

Such poor oyster consumption traditions increase the risk of transferring live oysters with shells that have not been cleared of epibionts. Hence, another way of reducing the risk of the spread of alien species could be to raise consumer awareness of live food standards. Key aspects on the implementation of public awareness include creating informative posters and other educational materials. As well, local authorities can inform tourists and recreational visitors about the risks posed by invasive species and the importance of proper disposal of oyster shells (Fitzsimons et al. 2020). This can help reduce the unintentional transfer of live hitchhikers on dead shells.

Within specific invasion sites, the risks of invasion can be significantly reduced by periodic manual removal of discarded shells from the bottom of waterways by divers. In the case of the Tylihul estuary, where there is a shortage of solid substrates, it has been observed that introduced organisms take time to spread throughout the water body, and they concentrate directly on discarded shells.

Furthermore, in cases where oysters or their shells are used for construction purposes, such as the creation of artificial reefs, it is crucial to implement decontamination protocols such as treating the oysters or shells to remove any attached organisms or larvae (Cohen and Zabin 2009; Ruesink et al. 2005), developing quarantine and handling procedures, and researching the survival rates of microalgae and other biofilms.

The authors have declared that no competing interests exist.

No ethical statement was reported.

No use of AI was reported.

This study was carried out within the framework of the projects “Integrated Observation, Mapping Monitoring and Prediction for Functional BioDiversity of Coastal SEAs (DiverSea)” (Grant #101082004, HORIZON-CL6-2022-BIODIV-01-01). The molecular analysis was funded by the University of Lodz internal funds.

Halyna Gabrielczak: conceptualization, data curation, formal analysis, funding acquisition, investigation, methodology, visualization, writing – original draft, writing – review and editing. Mikhail O. Son: conceptualization, funding acquisition, supervision, writing – original draft, writing – review and editing. Yuriy Kvach: funding acquisition, investigation, validation, writing – review and editing.

Halyna Gabrielczak https://orcid.org/0000-0002-7888-477X

Yuriy Kvach https://orcid.org/0000-0002-6122-4150

Mikhail O. Son https://orcid.org/0000-0001-9794-4734

All data that support the findings of this study are available in the main text and supplementary materials, as well as in the BOLD System repository, http://www.boldsystems.org. Relevant voucher information is accessible through the public dataset DS-OYSTER (DOI: http://dx.doi.org/10.5883/DS-OYSTER).