Migratory Cycle Research Articles

Migratory life cycle of Anguilla anguilla: a mirror symmetry with A. japonica.

The European and Japanese eel populations have declined significantly in recent decades. To effectively manage and conserve them, gaining a better understanding of their migratory life cycles is important. Previous research on the spawning ecology and larval dispersal of European and Japanese eels has led to many significant discoveries and advancements for their migratory life cycles. However, different scholars hold varying views on their migratory life cycles, especially concerning the European eel, therefore this article aims to provide a comprehensive review of research from multiple disciplines concerning the spawning ecology and larval dispersal of European and Japanese eels and to propose migratory life cycles of these two species. The migratory life cycle of the European eel is as follows: European silver eels undertake a year-long spawning migration from September to January to reach the Sargasso Sea for spawning before the next spawning season, typically between December and May. After hatching, European eel leptocephali are transported by the Gulf Stream, Frontal Countercurrents, North Atlantic Current, and Azores Current and return to Europe and North Africa for growth. Recruitment of European glass eels mainly occurs between October and June of the following year, and the recruiting season is more concentrated in countries closer to the spawning area and more dispersed in countries farther away. The consistent recruitment pattern and the growth rate of leptocephali suggest a larval transport period, also called larval duration, of around 1 year. Understanding the migratory life cycle of European eels can facilitate the evaluation or development of their conservation measures.

Predictive Model for Cell Positioning during Periodic Lateral Migration in Spiral Microchannels.

The periodic lateral migration of submicrometer cells is the primary factor leading to low precision in a spiral microchannel during cell isolation. In this study, a mathematical predictive model (PM) is derived for the lateral position of cells during the periodic lateral migration process. We analyze the relationship of migration period, migration width, and starting point of lateral migration with microchannel structure and flow conditions and determine the empirical coefficients in PM. Results indicate that the aspect ratio of the microchannel and the Reynolds number (Re) are key factors that influence the periodicity of the cell lateral migration. The lateral migration width is jointly affected by Re, the cell blockage ratio, and the microchannel curvature radius. The inlet structure of the microchannel and the ratio of the cell sample to the sheath flow rate are critical parameters for regulating the initial position. Moreover, the structure of the pressure field at the inlet constrains the distribution range of the starting point of the lateral migration. Regardless of whether the particles/cells undergo 0.5, 1, or multiple lateral migration cycles, the lateral positions predicted by PM align well with the experimental observations, thus verifying the accuracy of PM. This research helps to elucidate the characteristics of periodic lateral migration of cells in spiral microchannels and can provide practical guidance for the development and optimization of miniature spiral microchannel chips for precise cell isolation.

Seasonally flooded landscape connectivity and implications for fish in the Napo Moist Forest: A high-resolution mapping approach

The Amazon River Basin's fish diversity is shaped by its dynamic flood-pulse system, critical for hydrological and ecological connectivity. This study examines the Napo Moist Forest (NMF) ecoregion, mapping permanent and seasonally flooded areas from 2018 to 2021 using remote sensing and deep learning models. We aimed to map these areas at a high spatial resolution (10-m pixels) and analyse their role in maintaining lateral connectivity essential for fish diversity. Using synthetic aperture radar data from Sentinel-1 combined with deep learning algorithms, we produced high-accuracy flood maps to assess landscape connectivity between rivers and floodplains. Our methodology included creating a ground truth dataset with the Normalized Difference Water Index and integrating high-resolution optical data for model training, overcoming challenges of cloud coverage and dense vegetation. Our predictive model achieved high accuracy (mean pixel accuracy = 97 %) and consistently predicted 4801 km² of surface water, with only 3 % (130 km²) being seasonally flooded areas over four years. The Caquetá, Bajo Marañón, Napo, and Pastaza watersheds accounted for nearly 60 % of the flooded areas, highlighting their ecological importance. Connectivity analysis in three areas of interest within the NMF ecoregion revealed important seasonal and interannual fluctuations in hydrological connectivity due to changes in flooded patch characteristics. Reductions in the number and flooded patch area during low water seasons increased the distance between patches, leading to a disconnection between flooded areas, channels and rivers. Despite hydrological fluctuations, certain patches maintained consistent flooding, critical for lateral connectivity and sustaining aquatic biodiversity. These seasonally flooded areas act as connectors, influencing patch dynamics and connectivity with tributaries. Seasonal and interannual variations in hydrological connectivity are crucial for sustaining fish diversity. Conserving dynamic floodplains supports migratory fish life cycles and biodiversity. This study underscores the importance of high-resolution temporal and spatial data in conservation planning for aquatic ecosystems.

Unravelling the metabolomic signatures of migrant and non-migrant glass eels (Anguilla anguilla) and their response to diazepam exposure

Understanding the migratory cycle of the European eel is crucial for implementing effective conservation measures. The reasons why some glass eels settle in lower estuaries rather than migrating upriver remain unclear. This study aims to identify metabolomic signatures that distinguish active (migrant) from inactive (non-migrant) glass eels. Using a combination of target and non-target screening (NTS) approaches, the metabolite profile of glass eels was studied, and a PLS-DA classification model was applied to find differences between behavioural phenotypes. This model highlighted methionine, glutaryl-L-carnitine, and palmitoylcarnitine as key metabolites, with methionine being significantly different between groups. Glutaryl-L-carnitine strongly correlated with activity, suggesting it might be a more sensitive indicator of glass eel activity than previously studied parameters such as weight loss and oxygen consumption. The findings suggest that differences between active and inactive eels result from both swimming activity and intrinsic metabolic differences, with methionine linked to both factors. We also explored potential differences in how diazepam affects active and inactive glass eels. However, our metabolomic approach lacked the sensitivity to detect significant variations. Overall, this study provides valuable insights into the metabolomic distinctions between active and inactive glass eels, establishing a foundation for future research in this field.

Access to medicines among asylum seekers, refugees and undocumented migrants across the migratory cycle in Europe: a scoping review

IntroductionAccess to essential medicines is a critical element of health systems and an important measure of their performance. Migrants may face barriers in accessing healthcare, including essential medicines, throughout the...

Dendritic cell force-migration coupling on aligned fiber networks

Dendritic cells (DCs) are antigen-presenting cells that reside in peripheral tissues and are responsible for initiating adaptive immune responses. As gatekeepers of the immune system, DCs need to continuously explore their surroundings, for which they can rapidly move through various types of connective tissue and basement membranes. DC motility has been extensively studied on flat 2D surfaces, yet the influences of a contextual 3D fibrous environment still need to be described. Using ECM-mimicking suspended fiber networks, we show how immature DCs (iDCs) engage in migratory cycles that allow them to transition from persistent migration to slow migratory states. For a subset of iDCs with high migratory potential, we report the organization of protrusions at the front of the cell body, which reverses upon treatment with inflammation agent PGE2. We identify an unusual migratory response to aligned fiber networks, whereby iDCs use filamentous protrusions to attach laterally and exert forces on fibers to migrate independent of fiber alignment. Increasing the fiber diameter from 200 to 500 nm does not significantly affect the migratory response; however, iDCs respond by forming denser actin bundles around larger diameters. Overall, the correlation between force-coupling and random migration of iDCs in aligned fibrous topography offers new insights into how iDCs might move in fibrous environments in vivo.

Pollen metabarcoding reveals the origin and multigenerational migratory pathway of an intercontinental-scale butterfly outbreak

Migratory insects may move in large numbers, even surpassing migratory vertebrates in biomass. Long-distance migratory insects complete annual cycles through multiple generations, with each generation's reproductive success linked to the resources available at different breeding grounds. Climatic anomalies in these grounds are presumed to trigger rapid population outbreaks. Here, we infer the origin and track the multigenerational path of a remarkable outbreak of painted lady (Vanessa cardui) butterflies that took place at an intercontinental scale in Europe, the Middle East, and Africa from March 2019 to November 2019. Using metabarcoding, we identified pollen transported by 264 butterflies captured in 10 countries over 7months and modeled the distribution of the 398 plants detected. The analysis showed that swarms collected in Eastern Europe in early spring originated in Arabia and the Middle East, coinciding with a positive anomaly in vegetation growth in the region from November 2018 to April 2019. From there, the swarms advanced to Northern Europe during late spring, followed by an early reversal toward southwestern Europe in summer. The pollen-based evidence matched spatiotemporal abundance peaks revealed by citizen science, which also suggested an echo effect of the outbreak in West Africa during September-November. Our results show that population outbreaks in a part of species' migratory ranges may disseminate demographic effects across multiple generations in a wide geographic area. This study represents an unprecedented effort to track a continuous multigenerational insect migration on an intercontinental scale.

International migration, food insecurity, and mental health: A scoping review protocol.

Food insecurity is a global priority that has been found to negatively impact mental health, increasing the risk of mental disorders and severe mental illness. International migrants may face food insecurity throughout their migratory cycle due to a range of risk factors, such as poor transit conditions, precarious employment, financial pressure, discrimination, and lack of availability and access to culturally relevant food, among others. Although there are multiple reviews on migration, food insecurity, and health in general, no scoping review has been conducted on food insecurity among international migrants focusing on mental health. To investigate the available evidence on food insecurity and mental health among international migrants. A search of scientific literature in English, Spanish, French, Italian, and Portuguese published since 2013 will be performed in the Web of Science, PubMed, Medline, APA PsycArticles, Cinahl, and ASSIA databases, including grey literature available in Google Scholar. Two authors will independently review titles, abstracts, and full texts before extracting data from publications complying with the eligibility criteria. Extracted data will be descriptively mapped according to emerging thematic categories. The review will contribute to identifying what is known about international migration, food insecurity, and mental health, gaps in the literature, opportunities for specific research subtopics, and how food insecurity and mental health can be linked in the existing literature.

Order within chaos: potential migratory strategies and individual associations in fin whales feeding off Iceland

BackgroundThe life cycle of most baleen whales involves annual migrations from low-latitude breeding grounds to high latitude feeding grounds. In most species, these migrations are traditionally considered to be carried out according to information acquired through vertical social learning during the first months of life and made individually. However, some recent studies have suggested a more complex scenario, particularly for the species of the Balaenoptera genus.MethodsHere, we studied the variation of δ15N and δ13C values along the growth axis of the baleen plate from 24 fin whales feeding off western Iceland to delve into their pattern of movements and to identify potential associations between individuals. The segment of baleen plate analyzed informed about at least two complete migratory cycles. We performed cluster analyses through two different methodologies and, whenever possible, we genotyped 20 microsatellite loci to determine potential existence of kinship.ResultsResults of the of δ15N and δ13C values agree with a dispersion strategy in the winter breeding grounds. However, and despite the overall large variability, several pairs or groups of individuals with no kinship showed highly similar isotopic patterns for two consecutive years for both δ15N and δ13C values.ConclusionsOur results suggest that, notably, some whales without kinship share the same migratory regime and destinations. We hypothesize that this could reflect either: (i) the sharing of particularly beneficial migratory regimes, and/or (ii) long-term association between individuals.

Harnessing eDNA metabarcoding to investigate fish community composition and its seasonal changes in the Oslo fjord

In the face of global ecosystem changes driven by anthropogenic activities, effective biomonitoring strategies are crucial for mitigating impacts on vulnerable aquatic habitats. Time series analysis underscores a great significance in understanding the dynamic nature of marine ecosystems, especially amidst climate change disrupting established seasonal patterns. Focusing on Norway's Oslo fjord, our research utilises eDNA-based monitoring for temporal analysis of aquatic biodiversity during a one year period, with bi-monthly sampling along a transect. To increase the robustness of the study, a taxonomic assignment comparing BLAST+ and SINTAX approaches was done. Utilising MiFish and Elas02 primer sets, our study detected 63 unique fish species, including several commercially important species. Our findings reveal a substantial increase in read abundance during specific migratory cycles, highlighting the efficacy of eDNA metabarcoding for fish composition characterization. Seasonal dynamics for certain species exhibit clear patterns, emphasising the method's utility in unravelling ecological complexities. eDNA metabarcoding emerges as a cost-effective tool with considerable potential for fish community monitoring for conservation purposes in dynamic marine environments like the Oslo fjord, contributing valuable insights for informed management strategies.

Study on formation mechanism of mud-inclusion-type underground debris flows using natural caving method

This study aimed to investigate the formation mechanism of the mud-inclusion-type underground debris flows of natural caving underground mines. The characteristics of fine moraine particles flowing through the coarse-grained ore bed were used to analyze the formation process of mud inclusions in the caving ore bed through a physical model test. Based on the movement behavior of the mud inclusions of moraine in the caving ore bed, a formation-mechanism generalized model of underground debris flows with mud inclusions was established. The model was used to examine the formation mechanism of mud-inclusion-type underground debris flows in natural caving. The results showed that the fine moraine particles had good cross-flow characteristics in the process of drawing coarse-grained ore. The accumulation of fine moraine in the ore bed was a prerequisite for the formation of mud inclusions, and the fluid inclusions were formed by a mixture of the particles with the infiltrated water. When mud inclusions in moraine are affected by many factors, such as ore-drawing vibrations, blasting vibrations, and groundwater, the inclusions undergo multiple migration–stop–migration cycles, resulting in separation or fusion. However, the inclusions are released along the optimal random pore path to the outlet, forming a certain scale of underground debris flows accidents. The accuracy and reliability of the formation mechanism were verified through geophysical explorations based on the equivalent inverse flux transient electromagnetic method. This study not only broadens the research on debris flow, but also provides theoretical guidance for the prevention and control of underground debris flows.

The Migratory Cycle of Images: Reactivation Strategies in Contemporary Artistic Productions

Since the 1990s, an increasing number of artists, curators, dancers, choreographers and other professionals of the cul-tural panorama have looked at reality with an extractive ap-proach: they have used objects already in circulation in the artistic context and re-proposed them in the present by ad-justing them on a formal and/or content level. With the aim of analysing the consequences of these reactivation strategies, the essay intends to outline the importance of the so-called “re-enactment studies” which have hitherto dealt with the subject, and it then discusses the utility of a novel analytical model called “migratory cycle of images”. The latter propos-es to approach a generic act of reactivation in operational terms, identifying the role that images play in the various phases of the process. Finding proper support in contempo-rary philosophical theories such as Object-Oriented Ontology and in the analysis of some exemplary artistic productions, this operation allows to: question the terminology currently used in the field, arrive at the formulation of new nomencla-tures, and, finally, outline the boundaries of the “enactment studies”, along with different prefixes to differentiate the mul-tiform methods of re-generating the existing.

Adaptability of Integrated Community Care models in Moldova to overcome compounded crisis, including supporting refugees. 

Introduction: The Healthy Life Project in Moldova works and collaborates with local authorities across all sectors, including civil society organisations, community members and NCD patients to promote integrated, person-centered care. The aim is to ensure vulnerable people, including refugees, have access to health and social care. Overall, Moldova has received nearly 698,000 Ukrainian refugees, of which 96,646 currently remain in the country.
 Methods: Through intersectoral capacity building community teams developed local integrated care work plans, including joint assessments of people with NCDs and coordinated individual care across different sectors and community resources. The plans also involved a focus on responding to the needs of Ukrainian refugees. Within this continued implementation support, the project included questions of access to health and social care along the migratory cycle to maintain management of chronic conditions. Around 97% of refugees are residing in the host community, most of them require particular support in accessing their rights in practice, being women (59%), children (48%) and the elderly (21%).
 Results: Request for health care services from refugees (28,30%) is one of the forms of assistance expected in addition to cash handouts (76,84%) and in-kind support (35,79%). Therefore, in addition to building capacities for monitoring and management of NCDs, and the application of integrated care, the project considered specific actions for refugees. Training on managing NCDs within the refugee crisis was provided to Primary Health Care (PHC), hospital, Public Health, and emergency care management teams in 20 districts. To support and ensure mobility of PHC practitioners in responding to increased community needs due to hosted refugees, 835 medical kits were purchased and distributed, alongside protective equipment and disinfectants for both the health and social workers. A guide for community social workers on supporting refugees was developed in partnership with the National Social Assistance Agency and has since been embedded in the curricula of the social assistance faculty within the State Pedagogical University. 
 During 2022, 20 integrated community care centers have reached 8,464 persons with NCDs, with 77% having their wellbeing jointly assessed by a community nurse and social worker. As a result, most of them were included in preventive measures and supported to manage NCDs (7851 persons). The most vulnerable were identified and assisted, including 15% of NCD patients (675 persons) and supported to gain access to social benefits, while people with complex needs (663 persons) received access to home health and social care. Considerable progress has been made to promote integrated working locally, between health and social care. As everywhere, collaboration is reliant on personal motivation and local relationship building, and some teams take longer than others.
 Conclusions: Such community approaches are playing an important role in coordination of efforts to support the most vulnerable, as Moldova continues to face a refugee crisis. This continuous support to build capacity and ensure implementation of common approaches, facilitated by a jointly held normative framework supports a more integrated approach to service provision at community level, coordinated by local authorities thus making more efficient use of scarce resources.

Interactions between stoneworts (Charales) and waterbirds.

Stoneworts (Charales) are green algae that represent an important food resource for many waterbird species in Europe and elsewhere. Browsing avian herbivores (e.g. swan, goose, duck and coot species) consume Charales plant vegetative parts, by head-dipping, up-ending or diving. A lower fibre content and longer growing season may make Charales as attractive to such herbivores as sympatric submerged higher plant species in some circumstances. Charales respond to environmental stress (e.g. drought) by producing abundant diaspores, in the form of oospores (sexual) and bulbils (asexual), both rich in starch, generating abundant food for waterbirds at critical stages in their annual migratory cycles. Waterbirds feed on these by diving (e.g. common pochard Aythya ferina and red-crested pochard Netta rufina) or by filtering from the water column (e.g. dabbling duck species), ensuring dispersal of sexually produced and vegetative diaspores locally (because of predator swamping) and remotely (through endo- and ectozoochorous dispersal by long-distance migratory waterbirds). Greater invertebrate density and diversity associated with Charales canopies enhances their attractiveness over other submerged macrophyte beds to diving predators [e.g. tufted duck Aythya fuligula, common pochard and Eurasian coot Fulica atra (hereafter coot)]. Fish fry preying on these invertebrates use such vegetation as predator cover, in turn providing prey for avian piscivores such as grebes and cormorants. Abundant Charales contribute to maintaining a transparent water column due to canopy density, nutrient effects, dampening of sedimentation/remobilisation of suspended matter and nutrients and allelopathic effects on other plants (especially phytoplankton). Shallow, relatively eutrophic waters can flip between clear-water high-biodiversity (where Charales thrive) and turbid species-poor depauperate stable states (lacking Charales). Shifts between turbid conditions and rich submerged Charales beds have profound elevating effects on aquatic diversity, to which waterbirds show rapid aggregative responses, making them ideal indicator species of ecological change; in the case of Charales specialists (such as red-crested and common pochard), indicators of the presence and abundance of these plants. Large-bodied colonial nesting birds (e.g. cormorants, gulls, heron and egrets) aggregating along lake shores contribute high N and P loadings to water bodies sensitive to such external and internal inputs and can cause local eutrophication and potential loss of Charales. Despite variation from complete seasonal removal of Charales biomass to undetectable grazing effects by herbivorous birds, evidence suggests little effect of avian grazing on biomass accumulation or the stability of community composition (under otherwise stable conditions), but we urge more research on this under-researched topic. We also lack investigations of the relative foraging profitability of different Charales organs to waterbirds and the degree of viability of gyrogonites (fertilised and calcified oospores), vegetative bulbils and plant fragments after passage through the guts of waterbirds. We especially need to understand better how much the carbonate armour of these organs affects their viability/dispersal via waterbirds and urge more research on these neglected plants and their relationships and interactions with other organisms in the aquatic biota.

Alongshore variability in berm and sandbar migration patterns on a highly dynamic beach

Sediment exchange between the shoreface and the foreshore is investigated through the analysis of sandbar and berm migration cycles at La Misión beach in Baja California, Mexico. In general, nearshore sandbars migrate onshore during low-energy wave conditions merging with the shoreline to become intertidal sandbars that later contribute to berm rebuilding. However, significant alongshore differences were observed in the sandbar welding and berm rebuilding process, which can be attributed to alongshore wave skewness and near-surfzone flow variations. The analysis of topographic and bathymetric surveys collected monthly over a 5-year period revealed larger shoreline retreat and longer recovery times in the southern beach compared to the north. This was related to the inability of sandbars to weld to the intertidal beach during spring and summer, occurring only during extended periods of low-energy waves. In the southern beach, the berm formation process exhibited less dependence on incoming wave energy, persisting during mild-energy winters, and reforming in the presence of sandbars. Hydrodynamic measurements indicated that the southern part of the beach experienced relatively more intense net offshore flows (up to −0.2 ms−1) due to undertow, and possibly related to the presence of persistent rip currents. In contrast, the berm in the northern beach followed a seasonal erosion and rebuilding process associated with sandbar migrations driven by variations in incoming wave energy and cross-shore sediment transport. This was characterized by larger near-bed wave velocity skewness compared to the south. Net flows in the north were predominantly onshore, reaching up to 0.1 ms−1 during lower-energy periods with oblique wave incidence. This study reveals the presence of considerably distinct sandbar and berm migration cycles along a relatively short beach of 2.2 km long. It also highlights how such variability can be related to the morphodynamic feedback with sandbars affecting hydrodynamics, particularly near-bed wave skewness and near-surfzone flow variations, which in turn influence sediment transport and morphological evolution.

Interannual variability in otolith biogeochemical signatures of Japanese Spanish mackerel in the Yellow Sea

Fishes often use multiple habitats to complete their life cycles, leading to their unique otolith biogeochemical signatures. Interannual variability in otolith biogeochemical signatures is expected as fish respond to annual environmental variations in their distribution areas. In this study, we focus on Japanese Spanish mackerel Scomberomorus niphonius, an abundant commercial species in the Yellow Sea. As highly migratory fish that undergo their entire migratory cycle in a year, S. niphonius is susceptible to environmental variations. Consequently, they are believed to exhibit discernibly distinct migration patterns and varying timings of ontogenetic events across different years. Otolith biogeochemical signatures of 1-year-old spawning adults S. niphonius caught in the Yellow Sea from 2016 to 2018 were measured from core to edge using laser ablation inductively coupled plasma mass spectrometry (LAICP-MS). We hypothesized that the year-specific chemical signature could be found in 2016 as a strong El Niño Southern Oscillation event happened. From 2016 to 2018, converse ontogenetic changing patterns was observed for Sr/Ca and Ba/Ca, with Sr/Ca being positively correlated with sea surface salinity while Ba/Ca being negatively. As expected, the year-specific effect was identified for 2016 cohort but it was only significant on Ba/Ca. During this year, a stronger variation of elemental concentration and an earlier downward shift of Ba/Ca were found. These results provide evidence that otolith biogeochemical signatures have useful applications as natural tags, helping understand the interannual variability in migration of marine fish species.

MiR-1284 suppresses the proliferation and migration of thyroid cancer.

To elucidate the role of microRNA-1284 (miR-1284) in the onset of thyroid cancer (TC) and its underlying mechanism. Differential expressions of miR-1284 in TC and thyroid tissues were detected. Regulatory effects of miR-1284 on proliferative, migratory, apoptotic potentials and cell cycle progression were assessed. In addition, miR-1284 levels in TC tissues and peripheral blood of TC patients were determined as well. Through collecting culture medium and exosomes of PTC cells, changes in miR-1284 levels were examined. MiR-1284 was downregulated in TC than normal thyroid tissues. Overexpression of miR-1284 attenuated proliferative and migratory potentials, but induced apoptosis in TPC-1 and FTC-133 cells. Moreover, overexpression of miR-1284 upregulated E-cadherin and downregulated N-cadherin in papillary TC (PTC) cells. MiR-1284 was downregulated in TC tissues, while its level in the peripheral blood of TC patients was upregulated. Besides, miR-1284 was upregulated in the culture medium and exosomes of PTC cells, which was reversed by Brefeldin A treatment. Overexpression of miR-1284 suppresses proliferative and migratory potentials and induces apoptosis in TC. Upregulated miR-1284 in the peripheral blood of TC patients may be derived from exosomes secreted by PTC cells.

ECOTOXICOLOGICAL ASSESSMENT OF THE INFLUENCE OF FUEL STATIONS ON THE POLLUTION OF URBAN SOILS WITH HEAVY METALS

Problem Statement and Purpose. In modern cities, there is a rapid increase in the number of gas stations (gas stations), which are also located in residential areas of cities, causing a high level of local pollution. The growing demand for gas station services leads to the expansion of their network and maximum proximity to consumers. Among the specific features of environmental pollution near gas stations are: a high concentration of pollutants in the surface layer of the atmosphere with subsequent deposition on the soil cover and the surface of plants, the absence of dispersion of pollutants by wind currents, the presence of a significant traffic load and toxic emissions from motor vehicles during refueling, etc. Among pollutants, heavy metals have a particularly negative impact, which, due to participation in various migration cycles, pollute all vital spheres: atmosphere, hydrosphere, pedosphere. The high content of heavy metals negatively affects the main functions of living organisms and human health. Soluble forms of HM are especially toxic. The purpose of this study is to assess the ecological state of urban soils in relation to their contamination by soluble forms of heavy metals within the influence of gas stations in the city of Odessa. Data & Methods. As a methodological basis, the developments presented in the scientific works of A. Antropchenko, I. Rabosh, O. Chaika and others regarding the assessment of the ecological state of the territories in the zone of influence of gas stations were used. When determining the impact of gas stations on soil pollution, the HM used both general scientific methods of research (systemic, analysis, observation) and special ones (laboratory-analytical, comparative-geographical, statistical, cartographic). Results. The conducted studies showed that urban soils within the influence of all gas stations have a significantly higher content of movable forms of HM compared to background values. Thus, the manganese content is 1.3–1.7 levels of the background content; zinc – 7–51; cobalt – 0.6–4; copper – 4–24; cadmium – 0–4; lead – 1.5–14. It was established that by the concentration factor, the most polluted are the soils with the content of zinc, copper, and lead, which is from 100% to 50% of the studied territory. 55% of the studied territory has a dangerous level of soil pollution according to the indicator of total pollution. The priority polluting elements that have the highest level of pollution intensity are zinc (Рj = 121.64) and copper (Рj = 51.01), which according to the scale of assessment of ecological danger of soil pollution belong to the fourth – very dangerous category of pollution, which can significantly influence the increase of the total morbidity of children and adults of the city. The average intensity of contamination of the investigated soils with lead (Рj = 24.92) corresponds to the second level (safe); manganese (Рj = 3.63), cobalt (Рj = 8.22) and cadmium (Рj = 9.46) – the first (permissible level of intensity of soil pollution). The correlation between the intensity of urban soil pollution and the total pollution index is 0.99, which confirms the negative impact of gas station operations on the ecological state of the city’s soil cover. Therefore, the conducted studies indicate a high probability of technogenic influence of gas stations on the soils of the studied territory and a high degree of their contamination with heavy metals, which can cause a negative impact on the health of the urban population. The danger of environmental pollution during gas station operation is currently, in our opinion, underestimated, and the issue of environmental safety of gas station operation requires further study. We believe that in order to increase the ecotoxicological safety of gas stations, it is necessary to conduct constant monitoring studies of the urban environment in order to assess the man-made load on the «soil-plant-human » system.

Wetland management practices and secretive marsh bird habitat in the Mississippi Flyway: a review

AbstractManagement regimes on publicly owned freshwater wetlands in the Mississippi Flyway of North America (i.e., Flyway) have historically emphasized waterfowl, but there is limited information on how waterfowl‐focused wetland management affects other wetland‐dependent wildlife. Secretive marsh birds (SMBs) depend on wetlands with emergent vegetation throughout their migratory life cycle and often encounter vegetation and water conditions resulting from waterfowl‐focused management regimes. Thus, there is a need for better understanding of how SMBs are affected by wetland management and the extent to which waterfowl‐focused management regimes provide habitat for SMBs. In this review, we identify the vegetation and water conditions resulting from typical management objectives on freshwater emergent wetlands in the Flyway, review and qualitatively synthesize results from studies that directly evaluate how wetland management practices affect SMBs or their habitat, and assess how the vegetation and water conditions being produced for target species (mainly waterfowl) align with SMB habitat requirements. We searched online databases and used Google Scholar to locate peer‐reviewed literature, technical reports, and graduate theses that pertained to responses of SMBs or their habitat to water‐level manipulation, herbicide application, prescribed fire, disking, mowing, and planting crops. There are several management strategies that complement SMBs and waterfowl, such as reducing cover of woody species and providing flooded emergent vegetation. We also highlight management strategies that may not currently align with SMB life‐cycle needs and suggest adjustments that might promote habitat for SMBs while still achieving waterfowl population objectives. For example, adjusting the dates and duration of spring water‐level drawdowns on a portion of wetlands within a larger complex can provide for spring migrating waterfowl and ensure habitat for migrating and nesting SMBs. Ideally, future studies would address how modifications to management practices affect SMBs and monitor potential effects on waterfowl, resulting in a more holistic approach to wetland management.

The Afrotropical breeding grounds of the Palearctic-African migratory painted lady butterflies (Vanessa cardui)

Migratory insects are key players in ecosystem functioning and services, but their spatiotemporal distributions are typically poorly known. Ecological niche modeling (ENM) may be used to predict species seasonal distributions, but the resulting hypotheses should eventually be validated by field data. The painted lady butterfly (Vanessa cardui) performs multigenerational migrations between Europe and Africa and has become a model species for insect movement ecology. While the annual migration cycle of this species is well understood for Europe and northernmost Africa, it is still unknown where most individuals spend the winter. Through ENM, we previously predicted suitable breeding grounds in the subhumid regions near the tropics between November and February. In this work, we assess the suitability of these predictions through i) extensive field surveys and ii) two-year monitoring in six countries: a large-scale monitoring scheme to study butterfly migration in Africa. We document new breeding locations, year-round phenological information, and hostplant use. Field observations were nearly always predicted with high probability by the previous ENM, and monitoring demonstrated the influence of the precipitation seasonality regime on migratory phenology. Using the updated dataset, we built a refined ENM for the Palearctic-African range of V. cardui. We confirm the relevance of the Afrotropical region and document the missing natural history pieces of the longest migratory cycle described in butterflies.