Caspian Sea Coast Research Articles

Application of meta-heuristic hybrid models in estimating the average air temperature of Caspian sea coast of Iran

The rise of industrial societies leads to higher greenhouse gas emissions, profoundly affecting the climate in coastal regions. Consequently, air temperature readings from standard meteorological stations are key indicators of the Earth's environmental condition. Therefore, accurate estimation of daily temperature in each region is one of the important prerequisites for agricultural planning as well as water resources management and drought prevention, which can be done in different ways such as experimental, semi-experimental and intelligent models. In this research, WSVR, AIG-SVR, GWO-SVR and BAT-SVR hybrid models were investigated and evaluated in order to estimate the average daily air temperature on the shores of the Caspian Sea located in the north of Iran. For modeling, weather station data from Babolsar meteorological station located in Mazandaran province were used. During the water year from 2012 to 2022, daily parameters including relative humidity, maximum temperature, minimum temperature, wind speed, and evaporation were selected as network inputs, with the average daily air temperature as the network output. To assess and compare model performances, several criteria were employed including correlation coefficient, root mean square error (RMSE), mean absolute error (MAE), Nash-Sutcliffe efficiency (NSE), and percentage bias. Comparative analysis revealed that the WSVR model surpassed other models, demonstrating the highest correlation coefficient (0.992), lowest RMSE (0.096), and lowest MAE (0.042). The highest Nash Sutcliffe criterion (0.996) and bias percentage (0.001) were prioritized in the validation stage.

Risk assessment of heavy metals (Zn, Cu, Pb, and Ni) in the edible tissue of Oncorhynchus mykiss trout in the rivers of the southern Caspian Sea and the northern and southeast coast of Iran

The study aims to monitor and compare the concentration of heavy metals viz., zinc, copper, lead and nickel in the edible tissue of Oncorhynchus mykiss trout in the southern coast of Caspian Sea and the rivers of Khash city in the north-southeast coast of Iran. The average concentrations of zinc, copper, lead and nickel for the Stations in the north of Iran and the southeast of Iran were found 10.1, 8.1, 5.9, 4.7 and 6.5, 6.1, 3.5, 3.2 μg/g dry weight, respectively. Lead exceeded was the recommended standard limits by WHO, FAO, NHMRC, EC and UKMAFF. Based on the results, the average nickel metal was higher than the allowed concentration of international standards in all the studied stations, which indicates that more control should be done on the sources producing this metal around the target areas. furthermore, the daily intake (EDI) of the studied metals in all age groups were lower than the reference dose determined by the EPA organization and the tolerable intake (TI) provided by the FAO/WHO organization. The lowest frequency of daily consumption of Oncorhynchus mykiss was reported for the group of adult males and based on nickel metal (1.67 μg/g) and lead metal (1.14 μg/g) in the rivers located in the south of the Caspian Sea and the rivers of Khash city located in the southeast of Iran, respectively. The risk potential and risk index for non-cancerous diseases for all age groups in the muscle tissue of this fish was less than one, which shows that the consumption of this type of fish for human consumption will not cause a problem from the point of view of health and public health. However, management measures are necessary to prevent and control pollutants, especially in the southern shores of the Caspian Sea.

Unveiling nitrate contamination and health risks: Insights from groundwater quality assessment and Monte Carlo simulation along the Southern Caspian Sea Coasts

Groundwater resources are at great risk of contamination due to increased industrial and agricultural activities, population growth and urban expansion. This study investigated factors controlling spatio-temporal variability in groundwater quality and nitrate concentration at the southern coast of Caspian Sea, Iran to provide public health risk assessment. Na-Cl (44.8%) and Ca-HCO3 (58.6%) types water were the dominant hydrogeochemical facies in dry and wet seasons, respectively. Most of the examined groundwater samples were found unfit for drinking but appropriate for agricultural irrigation. The chemistry of groundwater predominantly influenced by combination of local lithology and ion exchange in aquifer as well as seawater intrsuin. Nitrate concentration varied from 0.05 to 200 mg/L with a mean value of 33.1 mg/L in which 13.7% and 27.5% of samples showed concentration higher than WHO's recommended value in dry and wet seasons, respectively. The highest nitrate concentrations were observed at locations in proximity to human settlements including cities, villages as well as agricultural lands. The identified pollution hotspots confirm nitrate contributions from un-treated wastewater effluents and agricultural practices with minimum contribution from industrial activities. The result of Monte Carlo simulation revealed that children were at highest risk from drinking of groundwater containing nitrate. This study highlights the urgent need for action to address the growing threat to groundwater quality and public health posed by contamination from various sources in the southern coasts of Caspian Sea.

Load–displacement behavior of helical pile using Frustum Confining vessel (FCV) and full-scale testing in Babolsar sand

Nowadays, the use of deep foundations in various civil engineering projects, especially in marine and coastal structures, has been increasing. One type of deep foundations are helical pile foundations, which have gained significant attention in recent decades. This research investigates the load–displacement behavior of different helical pile configurations regarding geometry, i.e., helix diameter and spacing ratio (S/D) in two different soil densities under pullout and compressive loading conditions via the FCV-AUT device. Babolsar sand from the southern coast of the Caspian Sea was utilized for advancing this study. Additionally, four full-scale pile tests were conducted on the Caspian Sea coast under both grouted and non-grouted conditions for pullout and compressive loading. The results indicate that increasing the helix diameter, soil density, and S/D ratio enhances the compressive load-bearing capacity. However, in tensile loading, the ultimate load decreases with an increase in the spacing ratio. Furthermore, the grouting process in the three-helix pile exhibits better performance compared to the two-helix pile, potentially increasing the pile capacity up to 30%. In conclusion, the results obtained from the FCV device, utilizing scale theory, have been generalized to the large-scale pile test results in the field, are representative of in agreement and compatible.

Avian Influenza Virus and Avian Paramyxoviruses in Wild Waterfowl of the Western Coast of the Caspian Sea (2017-2020).

The flyways of many different wild waterfowl pass through the Caspian Sea region. The western coast of the middle Caspian Sea is an area with many wetlands, where wintering grounds with large concentrations of birds are located. It is known that wild waterfowl are a natural reservoir of the influenza A virus. In the mid-2000s, in the north of this region, the mass deaths of swans, gulls, and pelicans from high pathogenicity avian influenza virus (HPAIV) were noted. At present, there is still little known about the presence of avian influenza virus (AIVs) and different avian paramyxoviruses (APMVs) in the region's waterfowl bird populations. Here, we report the results of monitoring these viruses in the wild waterfowl of the western coast of the middle Caspian Sea from 2017 to 2020. Samples from 1438 individuals of 26 bird species of 7 orders were collected, from which 21 strains of AIV were isolated, amounting to a 1.46% isolation rate of the total number of samples analyzed (none of these birds exhibited external signs of disease). The following subtypes were determined and whole-genome nucleotide sequences of the isolated strains were obtained: H1N1 (n = 2), H3N8 (n = 8), H4N6 (n = 2), H7N3 (n = 2), H8N4 (n = 1), H10N5 (n = 1), and H12N5 (n = 1). No high pathogenicity influenza virus H5 subtype was detected. Phylogenetic analysis of AIV genomes did not reveal any specific pattern for viruses in the Caspian Sea region, showing that all segments belong to the Eurasian clades of classic avian-like influenza viruses. We also did not find the amino acid substitutions in the polymerase complex (PA, PB1, and PB2) that are critical for the increase in virulence or adaptation to mammals. In total, 23 hemagglutinating viruses not related to influenza A virus were also isolated, of which 15 belonged to avian paramyxoviruses. We were able to sequence 12 avian paramyxoviruses of three species, as follows: Newcastle disease virus (n = 4); Avian paramyxovirus 4 (n = 5); and Avian paramyxovirus 6 (n = 3). In the Russian Federation, the Newcastle disease virus of the VII.1.1 sub-genotype was first isolated from a wild bird (common pheasant) in the Caspian Sea region. The five avian paramyxovirus 4 isolates obtained belonged to the common clade in Genotype I, whereas phylogenetic analysis of three isolates of Avian paramyxovirus 6 showed that two isolates, isolated in 2017, belonged to Genotype I and that an isolate identified in 2020 belonged to Genotype II. The continued regular monitoring of AIVs and APMVs, the obtaining of data on the biological properties of isolated strains, and the accumulation of information on virus host species will allow for the adequate planning of epidemiological measures, suggest the most likely routes of spread of the virus, and assist in the prediction of the introduction of the viruses in the western coastal region of the middle Caspian Sea.

Optimization of Targeted Differential Interferometric Measurements for Wellpads Detected by Mask Region-Based Convolutional Neural Network in the Tengiz Oilfield of the Caspian Sea Coast

Many previous studies have primarily focused on the use of deep learning for interferometric processing or separate recognition purposes rather than targeted measurements of detected wellpads. The present study centered around the integration of deep learning recognition and interferometric measurements for Tengiz oilfield wellpads. This study proposes the optimization, automation, and acceleration of targeted ground deformation wellpad monitoring. Mask Region-based Convolutional Neural Network (R-CNN)-based deep learning wellpad recognition and consequent Small Baseline Subset Synthetic Aperture Radar Interferometry (SBAS-InSAR) analyses were used for the assessment of ground deformation in the wellpads. The Mask R-CNN technique allowed us to detect 159 wells with a confidence level of more than 95%. The Mask R-CNN model achieved a precision value of 0.71 and a recall value of 0.91. SBAS-InSAR interferometric measurements identified 13 wells for Sentinel-1 (SNT1), 8 wells for COSMO-SkyMed (CSK), and 20 wells for TerraSAR-X (TSX) located within the −54–−40 mm/y class of vertical displacement (VD) velocity. Regression analyses for the annual deformation velocities and cumulative displacements (CD) of wells derived from SNT1, CSK, and TSX satellite missions showed a good agreement with R2 > 95. The predictions for cumulative displacements showed that the vertical subsidence processes will continue and reach −339 mm on 31 December 2023, with increasing spatial coverage and the potential to impact a higher number of wells. The hydrological analyses in the Tengiz oilfield clearly demonstrated that water flow has been moving towards the detected hotspot of subsidence and that its accumulation will increase with increasing subsidence. This detected subsidence hotspot was observed at a crossing with a seismic fault that might always be subject to reactivation. The role of this seismic fault should also be investigated as one of the ground deformation-controlling factors, even though this area is not considered seismically active. The primary practical and scientific values of these studies were identified for the operational risk assessment and maintenance needs of oilfield and gas field operators.

Trans-Caspian International Transport Route Infrastructure Assessment Using Simulation Modelling

Abstract The Trans-Caspian International Transport Route (TITR) is one of the main transport corridors between China and Europe. It passes through the territory of Kazakhstan, as well as the countries of the South Caucasus, Turkey, and Iran, and contributes to the full realisation of transit and export opportunities of these countries. Each country participating in the development of TITR is implementing projects to increase the capacity of its transit infrastructure, but the potential of this route has not yet been fully realised. The reason for this is both high tariffs for sea and rail transport and insufficiently short transport times, which are dependent on the parameters and methods of using the infrastructure. This paper is devoted to the study of the TITR railway infrastructure located in Kazakhstan. The developed simulation model allows estimating the impact of infrastructure parameters of the railway track on the movement time of a container train from the PRC border to the ports of Aktau and Kuryk on the Caspian Sea coast.

The Effect of Using a Geopedological Approach in Determining Land Quality Indicators, Land Degradation, and Development (Case Study: Caspian Sea Coast)

This study addresses the escalating global concern surrounding land degradation (LD) and its far-reaching implications on water and nutrient availability, as well as on human health and well-being. Focused on the southeastern Caspian Sea region, this research employs a novel remote sensing geo-pedological methodology to comprehensively assess soil and land quality dynamics, particularly influenced by salts, and investigates the intricate relationship between LD and soil development. The study area, marked by a susceptibility to seawater level fluctuations and diverse landforms (lagoons, barriers, and coastal plains) offers a unique opportunity for geopedologic analysis. Utilizing particle size distribution data, six distinct landforms are identified, providing insights into the region’s complex sedimentary history. A soil quality assessment is conducted remotely through the calculation of two indexes—the Integrated Quality Index (IQI) and the Nemoro Quality Index (NQI)—employing both Total Data Set (TDS) and Minimum Data Set (MDS) methodologies. The investigation highlights the role of soluble salts in shaping soil quality, thereby influencing LD and development dynamics. The differentiation of landforms significantly enhances classification accuracy, providing a more nuanced understanding of the multifaceted factors governing LD. The study’s implications extend beyond the southeastern Caspian Sea region, and demonstrate that the potential for incorporating a geopedologic approach when assessing soil and land quality dynamics in arid regions globally. Our analytic approach can inform policymakers and land managers when making decisions to combat LD and foster sustainable land development. This research also contributes towards advancing knowledge in geopedology by providing a robust foundation for future studies aimed at enhancing land management practices in the face of ongoing environmental challenges.

Genetic structure of black soldier flies in northern Iran.

The black soldier fly (BSF), Hermetia illucens, is known for nutrient-recycling through the bioconversion of organic waste into protein-rich insect larvae that can be processed into an animal feed ingredient. However, information on species distribution and its genetic structure in Iran is scarce. We directed a survey on the Caspian Sea coast, with a reconstructing demographic relationships study using two parts of mitochondrial cytochrome C oxidase 1 (COI) gene (barcode and 3' end regions) and nuclear internal transcribed spacer 2 (ITS2) to identify BSF' genetic diversity in retrospect to the global diversity and the potential origin of the Iranian BSF population. Larvae and adults were recovered from highly decomposed poultry manure, in May 2020. Sequence analysis of both regions of COI gene (about 1500 bp) revealed a single haplotype, identical to that of haplotype C, a worldwide commercial strain originated from Nearctic, Palearctic, or African biogeographic regions. However, the ITS2 locus was confirmed to be invariable across samples from diverse biogeographic regions. The results proved the presence of BSF in north of Iran. However, it is not possible to determine with certainty when and where this species first established in Iran, and they have likely been released to nature due to the existence of companies importing and breeding such flies. Due to heavy international trading, the introduction and settlement of this fly in the southern coasts of the country is highly suggested.

A new mite species of Pseudoleptus Bruyant (Tenuipalpidae), and two new records (Tetranychidae, Linotetranidae) reported from the Caspian Sea coasts in Iran.

A new species of the genus Pseudoleptus Bruyant, 1911 (Tenuipalpidae), Pseudoleptus avicennai sp. nov., is described and illustrated based on female specimens collected from bermudagrass, Cynodon dactylon (Poaceae), in Iran. This is the first report of C. dactylon as a host plant for Tenuipalpidae in Iran. In addition, the species Neopetrobia (Neopetrobia) mcgregori (Pritchard & Baker, 1955) (Tetranychidae) and Linotetranus sibiriensis Khaustov & Khaustov, 2023 (Linotetranidae) are recorded for the first time from Iran.

The relationship between the large-scale relative vorticity fields and precipitation over Iran

Abstract This study examines the relationship between relative vorticity, a key variable in mid-latitude synoptic motions, and precipitation in Iran. Using the S-mode PCA, activity centers of relative vorticity and precipitation were identified. Canonical correlation analysis (CCA) was applied to the factor scores of these centers to reveal coupled patterns of relative vorticity and precipitation. The analysis is based on 500- and 850-hPa relative vorticity fields at 2.5° grid points (10°–70° E and 10°–70° N) and uses monthly relative vorticity values from NCEP-DOE reanalysis databases (1981–2020) along with standardized rainfall data from 97 Iranian synoptic stations. Three main CCA patterns reveal connections: 500-hPa relative vorticity changes in the eastern Mediterranean, Middle East, and Iran relate to eastern Iran's precipitation. Relative vorticity over Eastern Europe inversely correlates with southern Caspian Sea coast precipitation. Changes over Turkey and Cyprus can affect northwestern Iran's rainfall. The changes in 850-hPa relative vorticity over the Arabian Sea inversely link to eastern Iran's precipitation, while those over the eastern Mediterranean directly connect to western Iran's precipitation. Relative vorticity changes in Eastern Europe negatively correlate with southwestern Caspian Sea coast precipitation.

INTEGRATED APPROACH TO ACCOUNTING ENVIRONMENTAL FACTORS IN MODELS OF THE CURRENT DISTRIBUTION AND CLIMATIC DYNAMICS OF AMBROSIA ARTEMISIIFOLIA L. IN THE CAUCASUS

Current climate change, habitat degradation and road network development contribute to the invasion of alien plant species in areas of more northern latitudes and higher altitudes. Using the maximum entropy method (Maxent), we built the spatial distribution models of Ambrosia artemisiifolia , considering abiotic, biotic and anthropogenic factors, and area accessibility. Maps of the species current distribution in the Caucasus and its range dynamics according to the climate change scenarios were constructed. The most important variables determining A. artemisiifolia spatial localization in the region were as follows: distance to roads (not more than 0-5 m), terrain roughness (gentle areas) and humidity (climate from semi-arid to pergumid). The 0-5 m distance is also characterized by the area accessibility factor (species dispersal capacity), which contributed about 47% to the final model. Species dispersal beyond roadsides was hindered by forests and meadows with the probability of A. artemisiifolia occurrence not exceeding 0.01%. The species core ranges were predicted in foothills and low mountains of the Western and Central Caucasus, Western and Central Transcaucasia, the northwestern Lesser Caucasus and the Caspian Sea coast. The species invasion in highlands could occur along the gentle river valleys that concentrate the main mountain roads. According to the pessimistic and optimistic climate change scenarios, by 2100 the decline in optimal A. artemisiifolia habitats will be 87 and 27%, respectively, and will affect mainly the plain areas of the currently most humid regions. The main core ranges were predicted in the middle mountains and highlands of the Caucasus.

Molecular Characterization of Paederus Spp (Coleoptera: Staphylinidae, Paederinae) the Agent of Human Linear Dermatitis in the Caspian Sea Coast, North of Iran.

A combined morphological and molecular survey was performed to determine the agent of human linear dermatitis Paederus Fabricius, 1775 (Coleoptera: Staphylinidae, Paederinae) species composition in Mazandaran Province in the Caspian Sea coast in northern Iran, where most of linear dermatitis cases of the country occurred. Altogether, 397 Paederus specimens were collected from May to August 2021 and classified using morphological characters and ITS2-rDNA sequence analysis. Morphological investigation revealed that all the specimens were Paederus fuscipes. ITS2 polymerase chain reaction (PCR) direct-sequences and the profiles of restriction fragment length polymorphism (RFLP) derived from digestion of PCR products by HinfI, HpaII, and SalI enzymes were identical confirming the morphological results, implying that all specimens belonged to a single taxon. Paederus fuscipes (Fabricius, 1775) is considered the dominant taxon and responsible for linear dermatitis in Mazandaran Province. To our knowledge, we have provided the first molecular typing of Paederus beetles at the species level, suggesting that ITS2-rDNA characterization is an alternative tool for species discrimination of Paederus spp.

Desalination plant feasibility and site selection on the southern Caspian Sea coasts using SAW and TOPSIS multi-criteria analysis

Desalination plant feasibility and site selection on the southern Caspian Sea coasts using SAW and TOPSIS multi-criteria analysis

Stakeholder consensus suggests strategies to promote sustainability in an artisanal fishery with high rates of poaching and marine mammal bycatch

Abstract Illegal fishing for high value species in artisanal fisheries drives incidental catch and declines of marine mammals and other large vertebrates of conservation importance around the world. Engaging with stakeholders is essential to understand which strategies will be effective in motivating the development of more sustainable practices, and disengagement from illegal fisheries. Here we present the results of a Q study carried out in autumn 2018 with 50 stakeholders from the Caspian Sea coast of Dagestan (Russian Federation), including fishers illegally targeting sturgeon (Acipenseridae) and Caspian seals Pusa caspica, traders and fisheries managers. We assess viewpoints on biodiversity governance; illegal, unreported and unregulated (IUU) fishing; illegal wildlife trade (IWT) and conservation. Three distinct viewpoint groups emerged from a factor analysis, which we designated as ‘Nostalgists’, ‘Optimists’ and ‘Pessimists’. Nostalgists were concerned with decline in environmental quality, and emphasised a need for increased centralised involvement of authorities reminiscent of the old Soviet system. Optimists expressed support for a well‐regulated legal fisheries sector, while Pessimists were very aware of the negative impact of illegal fisheries and IWT, but felt they could not be controlled. Among all groups we found a strong desire for alternative livelihoods (ALs), improved sustainability and agreement on the potential effectiveness of marine protected areas (MPAs) and increased regulation, even if some stakeholders felt they were not achievable goals. We used our results to inform three workshops in which Dagestani fishers and fishery experts discussed potential conservation interventions, and the barriers to their implementation. Six action types were identified including enhanced law enforcement, increased regulation, protected areas, alternative livelihoods, reducing demand for sturgeon and seal products and the need for further research to guide policy development. This consensus suggests that communities are willing to reduce participation in illegal fishing given appropriate support. The socioeconomic factors driving illegal fisheries and bycatch for Caspian seals parallel those for other endangered marine mammals such as Vaquita Phocoena sinus and suggest that Q studies could be applied in other artisanal fisheries with high rates of marine mammal bycatch to help identify policy interventions supported by involved communities. Read the free Plain Language Summary for this article on the Journal blog.

Archaeological evidence for two culture diverse Neanderthal populations in the North Caucasus and contacts between them.

Neanderthals were widespread during the Middle Palaeolithic (MP) across Europe and Asia, including the Caucasus Mountains. Occupying the border between eastern Europe and West Asia, the Caucasus is important region regarding the Neanderthal occupation of Eurasia. On current radiometric estimates, the MP is represented in the Caucasus between about 260-210 ka and about 40 ka. Archaeological record indicates that several culture diverse MP hominin populations inhabited the Caucasus, but the region complex population history during this period remains poorly understood. In this paper, we identify for the first time the archaeological evidence indicating contacts between two culture diverse MP Neanderthal populations in the North Caucasus and discuss the nature of these contacts. Basing on the lithic assemblages that we excavated at Mezmaiskaya cave in the north-western Caucasus (Kuban River basin) and Saradj-Chuko grotto in the north-central Caucasus (Terek River basin), dating from MIS 5 to MIS 3, and comparative data from other MP sites in the Caucasus, we identify two large cultural regions that existed during the late MP in the North Caucasus. The distinctive toolkits and stone knapping technologies indicate that the MP assemblages from Mezmaiskaya cave and other sites in the west of North Caucasus represent a Caucasian variant of the Eastern Micoquian industry that was wide spread in central and eastern Europe, while the assemblages from Saradj-Chuko Grotto and other sites in the east of North Caucasus closely resemble the Zagros Mousterian industry that was wide spread in the Armenian Highlands, Lesser Caucasus and Zagros Mountains. The archaeological evidence implies that two culture diverse populations of Neanderthals settled the North Caucasus during the Late Pleistocene from two various source regions: from the Armenian Highlands and Lesser Caucasus along the Caspian Sea coast, and from Russian plain along the Sea of Azov coast.

New data on the formation of local variations in the Upper Paleolithic of the Caucasus

As of today, very few Upper Paleolithic sites are known on both the southern and the northern slopes of the Caucasus. Their materials allow tracing settlement dynamics in the region from 40/39 to 20 cal ka BP. The change of the research methodology, which today is focused on thorough excavations involving a range of natural science disciplines for complex investigation of the materials, including complete water sieving of the cultural de-posits, enables obtaining many new, often unique data on human occupation, life-support strategies, and adapta-tions of humans in different periods of the Upper Paleolithic in the Caucasus. In our paper, a wide range of issues is discussed, concerned with the cultural affinity, diversity, and interaction of the Upper Paleolithic population of the Caucasus. The earliest Upper Paleolithic industries (40–35 cal ka BP) of the southern as well as the northern slopes of the Caucasus show the closest affinity. Studies of the raw-material strategies indicate the presence of contacts between populations of the northwestern and South Caucasus throughout the entire Upper Paleolithic and the development of extensive social networks. During the Late Upper Paleolithic period, the materials of the North and South Caucasus acquire certain features of distinctiveness, as in the stone industry and in bone tools and decorations. The appearance of geometric microliths in the South Caucasus contemporaneously with the Near East attests to the contacts between these regions. The delivery of seashells from the Caspian Sea coast to the Lesser Caucasus also indicates the southeastern direction of the contacts. The import of seashells from the Black Sea coast to the northwestern Caucasus indicates the southwestern direction of contacts. The unique finds that have analogies in the Upper Paleolithic of the Russian Plain indicate contacts between populations of the northwestern Caucasus and the Russian Plain that belong to different cultural areas. The current data demon-strate formation of local differences in the culture of the Upper Paleolithic populations in both the South and the North Caucasus, including under the influence of the neighboring regions.

Status of Rumex palustris (Polygonaceae) in the flora of Iran: an overview of current taxonomy, anatomy and ecology

Rumex palustris (Polygonaceae) is recorded as a new taxon for the flora of Iran. The species was firstly collected from the seasonal wet dune slacks on south Caspian Sea coast, northern Iran. A full morphological description, the anatomical details of stem and leaf, along with illustrations and a distribution map are provided. Moreover, the species is morphologically and anatomically compared with R. dentatus and R. maritimus. The salient features are compared with those of related species and discussed.

THE FIRST FLUSH ANALYSIS OF STORMWATER RUNOFF IN A HUMID CLIMATE

This study focuses on the pollutants from urban runoff to Zarjoob River, which is one of the rivers leading to Anzali International Wetland, which was listed in the Montreux Record in 1993 as a site in need of priority conservation. Storm water runoff from a residential area in Rasht (the largest city on Iran’s Caspian Sea coast) was monitored in this study during thirteen rainfall events, with a total of 58 storm runoff samples collected from 2018 to 2019. In most rainfall events, the mean concentration of total suspended solids (TSS) and chemical oxygen demand (COD) were higher than the other pollutants. The event mean concentrations (EMC) of TSS loads ranged from 57.3 mg/L to 682.5 mg/L and from 46.7 mg/L to 590.4 mg/L for COD. The site mean concentrations (SMC) for TSS, COD, total phosphorus (Total P), nitrate-nitrogen (NO3-N), and total lead (Pb) were 219, 205, 1.91, 20.63, and 0.25 mg/L, respectively. The first flush coefficient (b) was used to evaluate the first flushing of various events. The results of the study confirmed that the first flush occurred in all events, and the average ranking of first flush strength among the pollutants was COD > NO3-N > TP > Pb > TSS. Controlling one-third of the initial runoff volume appeared to be critical for managing the quality of urban rivers in humid regions. The findings of this study can be applied to urban runoff management strategies in cities with similar climatic conditions.

Tracking of sea level impact on Caspian Ramsar sites and potential restoration of the Gorgan Bay on the southeast Caspian coast.

The situation of Ramsar sites along the Caspian Sea coast has deteriorated over the past decades, and this is more noticeable in the narrow coastal strip of the south Caspian Sea. In this study we investigate how the Caspian Sea level changes affect the coastal Ramsar sites. Particularly, we focus on the Gorgan Bay in the southeast corner of the Caspian Sea, which is experiencing extensive water level decline, even desiccation. We used satellite images from three periods corresponding to periods of two sea level falls and one sea level rise, in order to decipher spatio-temporal changes of the wetlands. We conducted field campaign in the Gorgan Bay for sampling and measurement of physical, chemical and biological parameters. We simulated water circulation for the past, current and future conditions of the Gorgan Bay, which is essential to sustain better water exchange between the Bay and the Caspian Sea. We applied dust simulation in the case of a total desiccation of the Gorgan Bay. The result shows that the total area of the Caspian coastal Ramsar sites during the two periods of the sea level fall is almost the same; however, the aerial changes in the southern wetlands are more visible. Nutrient and plankton analysis of the Gorgan Bay display mainly mesotrophic conditions, in some areas close to eutrophic ones. The average current velocity in the main inlet is 2.5 cms-1. Dust simulation indicates that in case of the Gorgan Bay desiccation, it will become a dust source for the surrounding area up to 60 km. Simulation of the water circulation with dredging of inlets (future scenario), indicates that the water exchange velocity doubles compared to the current scenario. A recommended inlet maintenance would accelerate water circulation and reduce residence time, which will lead to better trophy and prevent bay desiccation.