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The El Vizcaino Biosphere Reserve is located in Baja California Sur, Mexico. This vast protected area is renowned for its biodiversity and ecological significance, particularly as a critical habitat for the Eastern subpopulation of the North Pacific Gray Whale. This project explores the perception and sustainability of the whale-watching industry in Guerrero Negro, and its role in conservation efforts. Through stakeholder interviews and analysis of management plans and specific research, the study examines the success of conservation strategies and the potential for increased tourism in the region. The end product, an informational StoryMap created using ArcGIS Pro, aims to promote ecotourism while fostering a deeper understanding of the importance of proper management and collaboration among stakeholders in preserving this unique marine environment. The project’s success will be measured by its ability to engage a wider audience and facilitate the connection between ecotourism and conservation in El Vizcaino Biosphere Reserve.Please see media created for this project here: https://storymaps.arcgis.com/stories/10ca0e02402440b1b9f0a113b1accb89

Suspended oysters employ physiological strategies to adjust their metabolic needs with the available food resources. Using the biodeposition method, the feeding and processing behavior of Pacific oysters (Crassostrea gigas) was investigated with a field study comparing four periods (May, July, October, and December 2016) with different upwelling intensities in the coastal lagoon of San Quintin Bay (Mexico). We calculated physiological feeding responses throughout the culture cycle, including the clearance rate (CR), filtration rate (FR), net organic ingestion rate (NOIR), net organic absorption rate (NOAR), net organic selection efficiency, net absorption efficiency, and the ammonium excretion rate (AER). The dietary quality predictors showed large fluctuations in terms of total particulate material, organic fraction of seston, and chlorophyll concentration. Unlike the pumping activity, FR, NOIR, and NOAR were related to upwelling conditions, and C. gigas removed twofold, ingested fourfold, and assimilated fivefold more of the organic suspended material during the upwelling season compared with periods of weak upwelling. C. gigas showed the potential of depositing nearly twice the organic biodeposits to the sediments during the intense upwelling events. The highest AER was recorded in July and October, suggesting that seasonal temperature variation is the most important exogenous factor regulating nitrogen metabolism, even in a subtropical environment. Also, mechanistic models incorporating dietary quality predictors to the feeding and processing response functions of C. gigas were performed. We conclude that coastal upwelling plays an important bottom-up control on oysters' feeding and processing activity, and our results facilitate further studies of the carrying capacity of embayments influenced by eastern boundary current systems. [ABSTRACT FROM AUTHOR]

Coastal lagoons are among the most important, but also threatened, marine systems of our planet. Rainfall, wind, seawater, and freshwater discharges control water circulation in lagoons, determining the water properties that are vital for the lagoon's biodiversity. The present work is the first study on the circulation patterns and seasonal variability of hydrological parameters in Antinioti lagoon in western Greece, building a reference level on our knowledge of the hydrodynamic functioning of this marine ecosystem. This study shows that the lagoon's water properties' fluctuations and circulation variability are affected by an antagonistic effect between freshwater (river discharge, underground spring, rainfall) and seawater inputs. This effect, influenced by atmospheric forcing (rainfall, atmospheric temperature), controls the heat and salt budgets of the lagoon. Nevertheless, the lagoon keeps an almost balanced annual cycle, returning from June 2020 to June 2021 to similar values for all parameters. [ABSTRACT FROM AUTHOR]

Dinoflagellates belonging to the genus Hematodinium are key parasites of marine crustaceans, primarily decapods. In this study, we document the first report of H. perezi Chatton & Poisson, 1930 on the African Atlantic coast. This is also the first parasite record in the invasive non-native Atlantic blue crab Callinectes sapidus Rathbun, 1896 in Morocco. Specimens of C. sapidus were sampled in winter 2023 from two Ramsar sites on the Moroccan Atlantic, namely Merja Zerga and Oualidia Lagoons, and were screened to detect the presence of parasites in their hemolymph. Based on staining fresh hemolymph smears, we did not detect Hematodinium in any of the 36 investigated individuals (20 and 16 from Merja Zerga and Oualidia Lagoons, respectively), probably due to methodological artifacts. The PCR-based method was revealed to be more accurate in diagnosing the Hematodinium parasite. It showed that at Merja Zerga Lagoon, 13 individuals of C. sapidus were infected by the parasite (prevalence: 65%) in comparison to four at Oualidia Lagoon (25%). Genetic analysis, based on the ITS1 rDNA gene from Hematodinium, confirmed the sequences as being those of Hematodinium perezi. [ABSTRACT FROM AUTHOR]

Mytilopsis sallei is a small bivalve that has invaded Asian waters, including southeast Asia. This shellfish has become a pest in coastal and estuary waters in Southeast Asia. This study is the first report on the presence and structure of the M. sallei population in Indonesia, precisely in the coastal lakes of Medan City, North Sumatra Province. This research was conducted in Lake Siombak, Medan City, North Sumatra, which is one of the tropical tidal lakes in Indonesia. Mytilopsis sallei shellfish samples were taken for a year from September 2018--August 2019. Mytilopsis sallei were obtained using a Petersen Grab with a mouth opening of 30 x 30 cm. The measurement of M. sallei consisted of the shell length, shell width, shell thickness, and body weight. The analysis of the population structure parameters with ELEFAN I was accommodated in the FiSAT II software. Spatially, M. sallei highest density in Siombak Lake is at station 5 with 24,100 and 23,948 ind.m-2 and the lowest at station 7 is only 967 ind.m-2. Monthly, M. sallei hase the highest density in the dry season (Feb--Jul) compared to the wet season (Aug--Jan). The density of M. sallei in the dry season reaches 1213--13,187 ind.m-2 and in wet seasons reaches 369-3,029 ind.m-2. The Mytilopsis sallei in Siombak Lake has a maximum length of 42.14 mm and the smallest size is 3.00 mm. The growth model of M. sallei in Lake Siombak is Lt = 42.14 (1-e-1.1(t-0.1598)). Mytilopsis sallei recruitment took place in January (fifth month). The instantaneous mortality rate (Z) of M. sallei mussels was 5.32 with an exploitation rate (E) of 0.66. [ABSTRACT FROM AUTHOR]

Diatoms are among the most common epibionts and have been recorded on the surfaces of various living substrates, either plants or animals. However, studies on them are still scarce in view of the many substrata available. In this study, epibiotic diatoms living on Callinectes bellicosus were identified for the first time from a subtropical coastal lagoon in Northwest Mexico. We tested the null hypothesis that the diatom flora living on the carapaces of C. bellicosus would not be similar to that recorded for mangrove sediments, its typical habitat. The epibiotic diatoms were brushed off from the carapaces of two specimens, acid-cleaned, mounted in synthetic resin, and identified based on frustule morphology. This way, 106 taxa from 46 genera were recorded, including 25 singletons, and 6 new records for the Mexican northwest region. The best-represented genera were Nitzschia (10 taxa), Mastogloia (9), Diploneis (8), Navicula (7), Amphora (5), Cocconeis (5), Tryblionella (4), and Gyrosigma (4). Species composition included 93% of local taxa, thus refuting the proposed hypothesis and supporting the alternate one. Although the estimated species richness was lower than that in sediments, it deems the green crab carapace a favorable substrate for the growth of benthic diatoms. [ABSTRACT FROM AUTHOR]

Araruama Lagoon is one of the world's largest permanent hypersaline lagoons, and knowledge about the reproduction of fish assemblages is very scarce. This study aimed to evaluate the reproductive functionality of fishes of the Araruama Lagoon in the seasons of 2011, using functional diversity metrics. We also assessed the influence of abiotic factors (salinity, temperature, dissolved oxygen, and pH) on the distribution of sexes and reproductive stages of fish assemblages. Gonads were analyzed in 709 fish across 18 species, mainly females and juveniles. In winter, when there was a lower abundance of species, the highest reproductive incidence (gonadal development/maturation) and high salinity occurred. Summer and spring corresponded with the highest percentage of juveniles. Salinity was the abiotic factor behind the structuring of the community, while the temperature set off the start of the reproductive cycle in autumn. Thus, Araruama Lagoon played a crucial role as a nursery and reproductive area for the fish assemblage. Reproduction in Araruama Lagoon (2011). The vertical arrows indicate the main abiotic variables: temperature and salinity, which structure the fish community. Colors indicate larger (darker) and smaller (lighter) numerical values. The graphs show the percentage of juveniles, males and females, in the seasons corresponding to each season: spring (green), summer (yellow), autumn (orange), and winter (gray). The number of fish next to each graph indicates fish abundance in season, and fish colors indicate diversity. [ABSTRACT FROM AUTHOR]

Tidal inlet structures are engineering projects with associated benefits related to flood control, water quality enhancement, and coastal protection. This study analyzes the performance of hydraulic gates on a stabilized inlet in estuarine systems by developing a simplified hydraulic model that considers inlet and outlet water levels. The proposed model was applied to the stabilized tidal inlet structure in Cartagena de Indias, Colombia. This model offers a practical tool for engineers and designers operating estuarine systems. The analysis focuses on the coastal lagoon of Ciénaga de la Virgen. The proposed model was successfully calibrated using two water sensors, with extreme input and outlet flow rates of approximately 260 m3/s and 110 m3/s, respectively. The average daily output volume in the system is 3,361,000 m3, while the average daily input volume is 3,200,000 m3. Consequently, the manipulation of the opening gates results in a decrease in the estuarine water level, potentially by as much as 25 cm, which local authorities can use to make decisions to reduce extreme water levels during flooding events. [ABSTRACT FROM AUTHOR]

The study objective was to evaluate human faecal contamination impacts in the Yal-ku lagoon in the Mexican Caribbean and to estimate adenovirus infection and illness risks associated with recreational exposure during water activities. A total of 20 water samples (10 from each site × two sites) (50 L) were collected monthly over a period of 12 months from two selected sampling sites in the swimming area of the Yal-ku lagoon. The occurrence of faecal-associated viruses was explored, and human adenovirus (HAdV) and pepper mild mottle virus (PMMoV) concentrations were quantified. A quantitative microbial risk assessment (QMRA) model was used to estimate exposure and subsequent adenovirus infection and illness risk for 1 h of swimming or snorkelling. Somatic and F + -specific coliphages occurred in 100% of the samples. Both HAdV and PMMoV were detected at a 60% frequency thereby indicating persistent faecal inputs. PMMoV concentrations (44–370 GC/L) were relatively lower than the concentrations of HAdV (64–1,000 GC/L). Estimated mean adenovirus risks were greater for snorkelling than for swimming by roughly one to two orders of magnitude and estimated mean illness risks for snorkelling were >32/1,000. Human faecal contamination is frequent in the Yal-ku lagoon, which is associated with human gastrointestinal illness. HIGHLIGHTS Human faecal contamination detected in a Mexican Caribbean lagoon.; The rainfall seasons posed the greatest risk.; Estimated risks were greater for snorkelling than for swimming by one to two orders of magnitude.; Estimated mean illness risks for snorkelling were >32/1,000.;

Coastal lagoons are environmentally and naturally dynamic areas crucial for fish reproduction and nursery. Thus, this research aims to evaluate the importance of the species performing their biological processes and development in this ecosystem. For this purpose, a subtropical coastal lagoon in the Gulf of California was taken as a case study, where four sampling seasonal campaigns were performed within the lagoon (internal zones) and the marine environment (external) nearby zones from 2016 to 2017. Diversity, evenness, and dominance indices were determined, and the number of individuals, size, length at first maturity, and reproductive period of each species were analyzed to obtain fish use of the lagoon. This coastal lagoon shows a high abundance of juvenile organisms in the cold season, whereas mature adults were mostly present during the warm season. Environmental variables influencing fish species development and distribution, such as sea surface temperature, salinity, and chlorophyll-a, were detected. To conclude, the subtropical coastal lagoon in the Gulf of California is an important nursery area where reproduction occurs mostly near adjacent areas. [ABSTRACT FROM AUTHOR]

Raygoza-Alcantar, L.N.; Vázquez, G., and Rodríguez-Zaragoza, F.A., 2024. Spatiotemporal relationship between diatom diversity and environmental gradients at La Mancha coastal lagoon (Veracruz, Mexico). Journal of Coastal Research, 40(2), 366–381. Charlotte (North Carolina), ISSN 0749-0208. This study analyzed the composition and distribution of diatoms in the La Mancha tropical coastal lagoon, Veracruz, Mexico, under different environmental conditions. Water samples were collected from the surface and bottom of the lagoon at five sites during the "nortes" (cold winter fronts), dry, and rainy seasons. The physical and chemical variables of the lagoon water were also analyzed. Diatom taxa were identified and quantified. Sixty-five taxa were determined and classified according to functional groups. Sites 1 and 2 were considered potential sources of nutrients and folin phenol active substances (FPAS). In addition, two horizontal gradients were observed. The first concerned nutrient concentration, which increased in the area of the mouth of the Caño Grande River and decreased towards the bar. The second was a salinity gradient characterized by high values in the area of the bar and decreasing values towards the river mouth. Diatom richness and diversity were higher in the areas influenced by the opening of the bar and the Caño Grande River discharges in the "nortes" season. Diatom composition varied across seasons, sites, and depth levels; functional groups only varied between sites (p ≤ 0.05). A redundancy analysis recorded the species that responded to the salinity and temperature gradients, including Paralia sulcata, Odontella spp., and Grammatophora oceanica. The species that responded to high nutrient concentrations, total phosphorus, and transparency were Aulacoseira granulata, Stephanocyclus meneghinianus, Ulnaria ulna, Gyrosigma acuminatum, Navicula subrhynchocephala, and Amphipleura pellucida in different seasons in the area close to the river mouth and mangrove swamp. The correlation between diatom density and FPAS indicates that Psammodictyon constrictum and Amphiprora pseudoduplex have optimal growth when the FPAS concentration increases. [ABSTRACT FROM AUTHOR]

While the role that groundwater discharge plays in supporting primary production in coastal ecosystems is well recognized, there is still limited evidence on its impacts higher up the food chain. In this study, we investigate the role of groundwater discharge in supplying nitrogen and carbon to the Mediterranean mussels (Mytilus galloprovincialis) in the Salses-Leucate lagoon (France). Nitrogen (δ15N) and carbon (δ13C) isotope values in the mantle and gill tissues of Mediterranean mussels are used to trace nitrogen and carbon sources at groundwater-exposed sites and a control site. Our results show similar isotope values for mantle and gill tissues, likely due to relatively stable environmental conditions in the study sites and to the biochemical composition of tissues. Diet shift, fractionation, and the physiological function of tissues could also explain this observation. δ15N values in mussel tissues increase overall in winter at both the groundwater-influenced sites (4.9 to 7.8‰) and the control site (3.4 to 8.5‰) in comparison with those in autumn (3.5 to 7.4‰ at the groundwater-influenced sites and 4.5 to 6.9‰ at the control site), likely due to reduced food supply and slower metabolism in winter, resulting in 15N enrichment. In contrast, mussel δ13C values decrease in winter at the groundwater-influenced sites (− 23.4 to − 21.6‰) and the control site (− 22.0 to − 19.0‰), suggesting input from 13C-depleted sources originating from groundwater input. The comparison of the isotopic values of mussel tissues and potential food sources indicates that the main diet of M. galloprovincialis in the Salses-Leucate lagoon is a mixture of groundwater particulate organic matter (POM), lagoon POM, and marine POM (POM as a proxy of phytoplankton). Depleted δ13C values in mussel tissues, particularly at groundwater-exposed sites, provide evidence of uptake of groundwater-derived nutrients. The ecological benefit of groundwater input on filter feeders results from local increases in food availability (mainly phytoplankton), supported by groundwater-derived nitrogen and carbon. In summary, this study shows the combined (a) indirect effect of groundwater discharge on mussel growth via uptake of their food, phytoplankton, and (b) the likely direct feeding of groundwater POM by M. galloprovincialis. It thus shows the important ecological implication of groundwater inputs in coastal lagoon food webs. [ABSTRACT FROM AUTHOR]

Sustainable water resources management requires monitoring and assessment of water quality in addition to quantity. Coastal lagoons play a critical role for the people and the ecosystem at large. Water quality monitoring and assessment for lagoons in Sri Lanka is important considering its services to the country. However, due to a lack of resources, most of the lagoons are not monitored and reported properly for further action. This study aims to develop a protocol in terms of monitoring sites, parameters, and frequency for water quality monitoring using a case study in a coastal lagoon, in Sainthamaruthu, Sri Lanka. The physicochemical parameters were measured weekly at eighteen monitoring sites for 4 months during the dry season from June to September 2022. Cluster analysis (CA) along with Inverse Distance Weighted (IDW) interpolation technique revealed that a minimum of three sites out of 18 are sufficient for monitoring water quality in the lagoon. In light of Principal Component Analysis (PCA) and Discriminant Analysis (DA), it was decided to retain temperature, pH, turbidity, Total Dissolved solids (TDS), Electrical Conductivity (EC), and Dissolved Oxygen (DO) in monitoring programs, since they cumulatively account for 79% of the variation in water quality in the lagoon spatially and temporally. Monitoring turbidity, TDS, and EC at weekly interval, while monitoring temperature, pH, and DO at biweekly or monthly is recommended. A further indication of the lagoon's water quality is that the mean values for turbidity (27 NTU), EC (754 μS/cm), and DO (4.6 ppm) higher than ambient standards, while TDS (344 ppm) and pH (6.98) are within. Therefore, we conclude that the lagoon requires remediation measures to be suitable for environmental purposes during dry periods. [ABSTRACT FROM AUTHOR]

The study objective was to evaluate human faecal contamination impacts in the Yal-ku lagoon in the Mexican Caribbean and to estimate adenovirus infection and illness risks associated with recreational exposure during water activities. A total of 20 water samples (10 from each site × two sites) (50 L) were collected monthly over a period of 12 months from two selected sampling sites in the swimming area of the Yal-ku lagoon. The occurrence of faecal-associated viruses was explored, and human adenovirus (HAdV) and pepper mild mottle virus (PMMoV) concentrations were quantified. A quantitative microbial risk assessment (QMRA) model was used to estimate exposure and subsequent adenovirus infection and illness risk for 1 h of swimming or snorkelling. Somatic and Fþ -specific coliphages occurred in 100% of the samples. Both HAdV and PMMoV were detected at a 60% frequency thereby indicating persistent faecal inputs. PMMoV concentrations (44-370 GC/L) were relatively lower than the concentrations of HAdV (64-1,000 GC/L). Estimated mean adenovirus risks were greater for snorkelling than for swimming by roughly one to two orders of magnitude and estimated mean illness risks for snorkelling were .32/1,000. Human faecal contamination is frequent in the Yal-ku lagoon, which is associated with human gastrointestinal illness. [ABSTRACT FROM AUTHOR]

The Brazilian coastal zone comprises several types of environments, including lagoons and beaches, chosen for this study, which evaluate benthic meiofauna spatial distribution patterns in three areas, suffering different disturbance levels, throughout the Brazilian Amazon coast. Sediments from three areas (São Marcos Beach – Low level of disturbance; Calhau Beach – Medium level of disturbance; and Jansen Lagoon – High level of disturbance), in São Luís city (Maranhão, Brazil), were sampled for meiofauna assessments, granulometry and organic matter analyses. A total of 7,254 meiofaunal organisms were identified, 4,371 at São Marcos Beach, 1,856 at Jansen Lagoon, and 1,027 at Calhau Beach. The findings indicate that richness, density, and community structures differed significantly among the sampled areas. Nematoda and Copepoda were the most abundant groups. Copepoda stood out in São Marcos Beach compared to other taxa. Nematoda dominated in Jansen Lagoon. Calhau Beach presented the lowest density and richness values, with Tardigrada as the predominant meiofaunal group. Additionally, the composition of meiofauna was influenced by environmental variables, such as salinity, OM, sediment grain size and nitrate concentration, as well as anthropogenic activities taking place in the sampled areas. Considering the lack of studies in the region with this focus, it is expected that the results presented will contribute to public policies development aimed to conservation of the coastal zone in São Luís. [ABSTRACT FROM AUTHOR]

Coastal lagoons are highly dynamic ecosystems that are continually changing in shape and size due to natural processes. This study used satellite imagery, remote sensing, and GIS mapping, along with historical wind and wave data, to comprehensively explore the long-term changes occurring at the Khenifiss Lagoon entrance and its downstream main channel, which is one of the most important wetlands protected by the Ramsar Convention in Morocco. By employing thorough image selection, rigorous corrections, and intricate processing and analysis techniques, this research shed light on the evolution of sediment deposition areas, eroded zones, vegetation coverage, and locations, where dune influence affected sedimentation in this dynamic coastal ecosystem. The investigation spanned from 1984 to 2019 and relied on the analysis of Landsat optical images gathered in 1984, 1990, 2000, 2009, and 2019. During the study period, the entrance to the Khenifiss Lagoon (Foum Agouitir) gradually enlarged, increasing from 1450 m in 1984 to 1650 m in 2019. Concurrently, vegetation coverage within the lagoon's entrance and main channel increased from 53.54 hectares in 2009 to 103.9 hectares in 2019, resulting in a significant decrease in total water body extent. Sediment deposition impacts 206 hectares, considerably surpassing the erosion-affected area of 99.14 hectares. This significant difference emphasizes the rising dominance of sedimentation over erosion at the Khenifiss Lagoon entrance zone. The processes of sedimentation within the lagoon are largely influenced by the dune's advance, which has resulted in silt deposition over an area of approximately 57.39 hectares. These findings highlight the lagoon's exposure to progressive closure and strongly support the need to start a monitoring program to evaluate the lagoon's changing condition, especially at the entrance and the main channel. This study puts forth several recommendations for implementing management strategies aimed at ensuring the sustainability of this coastal ecosystem. [ABSTRACT FROM AUTHOR]

Very complex aquatic ecosystem, the mangrove forest colonizes coastal lagoons, estuaries and deltas in tropical and subtropical zones. This study investigates the impact of mangrove vegetation on tidal propagation in the Somone Coastal Lagoon, located on the Senegalese small coast. The analysis of new field data is complemented with the application of a 3D circulation model accounting for vegetation. The analysis of well-reproduced water levels and currents over the whole lagoon make it possible to spatially study the amplitudes of the main tidal harmonics, semi-diurnal (M2), diurnal (K1) and the major overtide (M4). The comparison between our baseline model accounting for vegetation and a configuration without vegetation reveals firstly that the mangrove strongly attenuates tidal propagation in the lagoon, whit a stronger impact on semi-diurnal waves than diurnal waves. Tidal currents are also strongly reduced when the mangrove is accounted for, even close to the inlet mouth, far away from vegetation areas. The mangrove also enhances tidal asymmetry and promotes ebb dominance, both in terms of duration (ebbs last from 0.5 up to 3 h more than floods) and current magnitude (ebb currents are about 50% stronger). Spring tides accentuate ebb-dominance compared to neap tides, where tidal asymmetry is weaker. [ABSTRACT FROM AUTHOR]

The composition of fish assemblages in the Alvarado Lagoon System was updated with information collected between 1966 and 2008, divided into nine collection periods. A temporal analysis of the variation in species richness, species richness indices, rarity, and composition of ecological and trophic guilds was also carried out. A total of 113 species were recognized, 66 of which were present in most of the collection periods, forming a group with a constant presence in the lagoon system, in which marine and freshwater species predominated. This group showed the highest levels of similarity between collection periods; this was confirmed by the richness and rarity indices. Functionally, the composition of the ecological and trophic guilds did not show significant differences. The composition of the trophic guilds showed a prevalence of invertebrate consumers, macrocrustaceans, and small fish, supporting the fact that migratory marine species were the most numerous, with minor contributions from the other guilds. The contribution of marine or freshwater visitor species was not important in the characteristics of the assemblages. These results suggest that the environmental conditions of the Alvarado Lagoon System have remained without severe changes during the study period, thus allowing both the constancy of the fish community and that of the ecological and trophic guilds. [ABSTRACT FROM AUTHOR]

Lagoons, significant coastal wetlands, stand out for their vital role in the cycles and transformations of phosphorus. However, the relationship between the spatial distributions of various phosphorus forms in the soil and sediments of lagoon areas remains unclear. This study investigated the phosphorus fractions and distribution patterns in the soil and sediments from Shimei Inland Sea, Hainan Province, China, and identified the factors controlling phosphorus distribution and its relationship with lagoon eutrophication. The results revealed significant enrichment of inorganic phosphorus (IP) in the Shimei Inland Sea (64.1–679.0 mg/kg) and offshore areas (56–627.2 mg/kg), while organic phosphorus (OP) was relatively concentrated in land (60–744.3 mg/kg), suggesting that the productivity of the terrestrial ecosystem controlled the OP content and IP formed from the mineralization of OP was more likely to leach into the water and combine with minerals. Total phosphorus (TP) content was negatively affected by pH, and organic matter, cation exchange capacity and iron/aluminum oxides showed significant positive correlations with TP content. These findings highlighted the coupled impact of soil and sediment physicochemical properties on phosphorus enrichment and transformation, providing theoretical support for the ecological restoration of ecosystems in tropical coastal wetlands. [ABSTRACT FROM AUTHOR]

The Ria de Aveiro lagoon has been considered one of the most important Southern European long-term monitoring sites (LTER-site) concerning climate change and anthropogenic pollution. Nevertheless, studies concerning pesticide contamination herein are few and mostly outdated. Here, 56 pesticides dissolved in the aqueous phase (DAP) and suspended particulate matter (SPM) were examined to fill the knowledge gap, considering the hydrophobic nature of most evaluated compounds. Water samples were taken seasonally from eight sites, and both DAP and SPM fractions were analysed by gas-chromatography-mass spectrometry. The annual average concentrations of fungicides, herbicides and insecticides were ≈57 ng/L, ≈409 ng/L and ≈1058 ng/L in DAP and ≈7 μg/g, ≈28 μg/g and ≈67 μg/g in SPM. These pesticides and the excessive phosphate concentrations suggest that the lagoon's water quality may be hazardous to biota and humans. Invertebrates were identified as the most threatened trophic level using deterministic risk assessment, with chlorpyriphos and chlorfenvinphos being the primary culprits. Acute experiments with Artemia and Daphnia supported the suppositions.

Coastal lagoons are among the most important, but also threatened, marine systems of our planet. Rainfall, wind, seawater, and freshwater discharges control water circulation in lagoons, determining the water properties that are vital for the lagoon’s biodiversity. The present work is the first study on the circulation patterns and seasonal variability of hydrological parameters in Antinioti lagoon in western Greece, building a reference level on our knowledge of the hydrodynamic functioning of this marine ecosystem. This study shows that the lagoon’s water properties’ fluctuations and circulation variability are affected by an antagonistic effect between freshwater (river discharge, underground spring, rainfall) and seawater inputs. This effect, influenced by atmospheric forcing (rainfall, atmospheric temperature), controls the heat and salt budgets of the lagoon. Nevertheless, the lagoon keeps an almost balanced annual cycle, returning from June 2020 to June 2021 to similar values for all parameters.

With the aim to assess how environmental heterogeneity affect fish assembly patterns, we evaluated species co-occurrence and nestedness in 16 lentic environments in a drying coastal plain of Southeast Brazil. We calculated the frequency of co-occurrence and nestedness for 13 quarterly campaigns exclusively for fish species tolerant to a narrow range of low water salinity (stenohaline) and to wider range of water salinity (euryhaline) and for all species together, and assessed its significance with null models. We employed a Principal Component Analysis (PCA) to explore temporal trends in physical and chemical parameters of water and to detect those that most influenced environmental heterogeneity. Linear regressions assessed the potential effect of each parameter that most influenced the PCA on co-occurrence. Few campaigns presented nonrandom patterns of community composition, and only for euryhaline or for all species considered together. Communities shifted to anti-nested and negative species co-occurrence with the increase of environmental heterogeneity. Parameters related to desiccation (salinity and depth) affected euryhaline species co-occurrence. Together, these results revealed group-dependent responses to drought according to physiological tolerances. This study improves our understanding of how the predicted increase in precipitation anomalies may disassembled aquatic communities of coastal plains in the face of climatic changes. [ABSTRACT FROM AUTHOR]

The Oualidia lagoon on the Atlantic coast of Morocco provides important ecosystem services such as aquaculture, fisheries, tourism and high ecological and biological productivity. This is the first study to describe the spatio-temporal distribution of the crustacean community and potential controlling factors in the coastal waters of the Oualidia lagoon. Crustaceans were sampled with a Van Veen grab during two surveys in winter and summer 2013, and taxonomic composition and diversity were determined at 43 sampling sites. Of the eighteen crustacean taxa recorded, fifteen were new to Oualidia Lagoon. Sphaeroma serratum was the most abundant species in both seasons. Organic matter and chlorophyll a content were higher, temperature and salinity were lower in winter than in summer. The structure of the crustacean assemblages was characterised by the formation of two main clusters, organised according to a downstream gradient. Canonical Correspondence Analysis (CCA) showed that granulometry, organic matter and salinity strongly influenced the distribution pattern of crustaceans in the lagoon. [ABSTRACT FROM AUTHOR]

Lake Manzala, the largest Egyptian coastal lake, is one of the most valuable fish sources in Egypt, which contributes about 14% to the total annual Egyptian fisheries production. However, given that Lake Manzala suffers from major environmental and fisheries problems, an ambitious national project for the dredging, purification, and development of this lake was established in 2017. Hence, this study was conducted to assess seasonal diversity and to provide an inventory of fish species at Lake Manzala during dredging operations. Five seasonal surveys were conducted during the period from 2019 to 2021. By using different fishing gears and methods operating in the lake, a total of 7774 fish and crustaceans—belonging to 29 fish species and three crustacean species that clump into 21 families—were collected from Lake Manzala. During the study period, the family Cichlidae showed the highest occurrence of about 70%. The marine-brackish species recorded the highest aquatic environment (milieu) diversity with 34.4% of the collected species, but only 12.5% of the freshwater species. Six of the collected fish species were recorded of Indo-pacific origin, as Lissepsian migrant species. In this study, the diversity index (H) was calculated, ranging between 1.13 and 1.77. As indicated by the seasonal variation of the diversity index, the highest diversity index of Lake Manzala was evident in autumn 2019 and spring 2021 at 1.700 and 1.365, respectively. The governmental dredging and cleaning operations in the lake have a relative impact on the species composition in this area. Further studies are recommended after the completion of these operations to confirm the impact of dredging on species composition alteration.

Dinoflagellates belonging to the genus Hematodinium are key parasites of marine crustaceans, primarily decapods. In this study, we document the first report of H. perezi Chatton & Poisson, 1930 on the African Atlantic coast. This is also the first parasite record in the invasive non-native Atlantic blue crab Callinectes sapidus Rathbun, 1896 in Morocco. Specimens of C. sapidus were sampled in winter 2023 from two Ramsar sites on the Moroccan Atlantic, namely Merja Zerga and Oualidia Lagoons, and were screened to detect the presence of parasites in their hemolymph. Based on staining fresh hemolymph smears, we did not detect Hematodinium in any of the 36 investigated individuals (20 and 16 from Merja Zerga and Oualidia Lagoons, respectively), probably due to methodological artifacts. The PCR-based method was revealed to be more accurate in diagnosing the Hematodinium parasite. It showed that at Merja Zerga Lagoon, 13 individuals of C. sapidus were infected by the parasite (prevalence: 65%) in comparison to four at Oualidia Lagoon (25%). Genetic analysis, based on the ITS1 rDNA gene from Hematodinium, confirmed the sequences as being those of Hematodinium perezi.

Diatoms are among the most common epibionts and have been recorded on the surfaces of various living substrates, either plants or animals. However, studies on them are still scarce in view of the many substrata available. In this study, epibiotic diatoms living on Callinectes bellicosus were identified for the first time from a subtropical coastal lagoon in Northwest Mexico. We tested the null hypothesis that the diatom flora living on the carapaces of C. bellicosus would not be similar to that recorded for mangrove sediments, its typical habitat. The epibiotic diatoms were brushed off from the carapaces of two specimens, acid-cleaned, mounted in synthetic resin, and identified based on frustule morphology. This way, 106 taxa from 46 genera were recorded, including 25 singletons, and 6 new records for the Mexican northwest region. The best-represented genera were Nitzschia (10 taxa), Mastogloia (9), Diploneis (8), Navicula (7), Amphora (5), Cocconeis (5), Tryblionella (4), and Gyrosigma (4). Species composition included 93% of local taxa, thus refuting the proposed hypothesis and supporting the alternate one. Although the estimated species richness was lower than that in sediments, it deems the green crab carapace a favorable substrate for the growth of benthic diatoms.

Lake Manzala, the largest Egyptian coastal lake, is one of the most valuable fish sources in Egypt, which contributes about 14% to the total annual Egyptian fisheries production. However, given that Lake Manzala suffers from major environmental and fisheries problems, an ambitious national project for the dredging, purification, and development of this lake was established in 2017. Hence, this study was conducted to assess seasonal diversity and to provide an inventory of fish species at Lake Manzala during dredging operations. Five seasonal surveys were conducted during the period from 2019 to 2021. By using different fishing gears and methods operating in the lake, a total of 7774 fish and crustaceans—belonging to 29 fish species and three crustacean species that clump into 21 families—were collected from Lake Manzala. During the study period, the family Cichlidae showed the highest occurrence of about 70%. The marine-brackish species recorded the highest aquatic environment (milieu) diversity with 34.4% of the collected species, but only 12.5% of the freshwater species. Six of the collected fish species were recorded of Indo-pacific origin, as Lissepsian migrant species. In this study, the diversity index (H) was calculated, ranging between 1.13 and 1.77. As indicated by the seasonal variation of the diversity index, the highest diversity index of Lake Manzala was evident in autumn 2019 and spring 2021 at 1.700 and 1.365, respectively. The governmental dredging and cleaning operations in the lake have a relative impact on the species composition in this area. Further studies are recommended after the completion of these operations to confirm the impact of dredging on species composition alteration. [ABSTRACT FROM AUTHOR]

Coastal lagoons are vulnerable to eutrophication processes. In this study, we evaluate the eutrophication process in the restricted, arid subtropical Tóbari coastal lagoon, located in the eastern coast of the Gulf of California, where the main source of nutrient inputs and other pollutants is agricultural wastewater from the Yaqui Valley. The Assessment of Estuarine Trophic Status (ASSETS) model and the Trophic State Index (TRIX) were used to evaluate eutrophication. Overall, ASSETS showed that the Tóbari lagoon has a moderate eutrophication process, with seasonal symptoms of hypoxia, increased phytoplankton biomass, dominance of macroalgae (indicative of nutrient enrichment), and blooms development of potentially harmful algae species. The TRIX showed that the lagoon is mesotrophic most of the year. Challenges of environmental management detected correspond to reducing the input of nutrients and others contaminants from anthropic sources: agriculture, shrimp farming, livestock, and urban zones. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate and compare feeding responses of the non-native and native bivalves, the dark false mussel Mytilopsis leucophaeata and the scorched mussel Brachidontes darwinianus, respectively, by offering different concentrations of seston from the coastal lagoon where these species coexist after dark false mussel introduction (Rodrigo de Freitas Lagoon, Rio de Janeiro-Brazil). For this purpose, independent laboratory experiments were carried out under five concentrations of seston to test the differences in clearance and ingestion rates of bivalves as a function of increasing concentrations of suspended particulate matter (SPM) on seston. In addition, from the integrated analysis of data obtained in experiments, it can be inferred about the efficiency levels of these species to remove SPM from seston and their effects on water turbidity and nutrient concentrations (total carbon, nitrogen, and phosphorus). Our hypothesis was that the non-native bivalve is more efficient to clear and ingest SPM from seston compared to the native one, which may lead to competitive advantages to the successful invasion of M. leucophaeata in coastal lagoons. Native species did not show a significant difference in clearance and ingestion rates with increasing concentrations of seston. Whereas the non-native bivalve showed a slight tendency to increase its clearance and ingestion rates with the increase in seston concentrations, evidencing its plasticity to adjust its feeding responses. The native bivalve was significantly more efficient to clear and ingest SPM at the lower seston concentration (i.e., close to natural concentrations found in the lagoon) compared to the non-native bivalve, which, on the other hand, showed a significant increase in its ingestion rates at the higher concentration tested (140 mg SPM L-1). Thus, the present results did not suggest food competition between the non-native M. leucophaeata and the native B. darwinianus in the introduced system. However, M. leucophaeata increased its feeding response with experimental increment in seston concentration, which suggests species ability to benefit from conditions of increased inputs of organic matter and higher primary production that could mediate its establishment in introduced systems. [ABSTRACT FROM AUTHOR]

Transitional waters are fragile ecosystems with high ecological values, representing the breeding and resting sites for rare and threatened species. They warrant particular attention in regards to protection, as they experience numerous anthropogenic threats. The present review aims to analyze the recent literature on Aphanius fasciatus, currently considered one of the most strictly estuarine-dependent fish species, thus affected by the degradation of lagoon habitats, and to discuss its suitability as a sentinel species for protection of the quality of transitional water environments. The analysis and discussion highlight the potential applicability of the molecular, cellular, and physiological responses of this species as diagnostic tools for detecting the subtle effects induced by environmental pollution on the biota in transitional water environments. Moreover, the suitability of the responses of this species is suggested in the wider framework of the One Health perspective, which considers human and animal health and the environmental state to be highly interconnected, sharing common aspects. To date, omics technologies show great potential in reacquiring novel knowledge on the responses of the organisms to environmental changes and to the alterations of the environmental health status. Therefore, considering the relevant potential of this organism as a sentinel species, many efforts are required in the near future to improve the quantity and quality of the omics tools that refer to A. fasciatus. [ABSTRACT FROM AUTHOR]

Tidal inlet structures are engineering projects with associated benefits related to flood control, water quality enhancement, and coastal protection. This study analyzes the performance of hydraulic gates on a stabilized inlet in estuarine systems by developing a simplified hydraulic model that considers inlet and outlet water levels. The proposed model was applied to the stabilized tidal inlet structure in Cartagena de Indias, Colombia. This model offers a practical tool for engineers and designers operating estuarine systems. The analysis focuses on the coastal lagoon of Ciénaga de la Virgen. The proposed model was successfully calibrated using two water sensors, with extreme input and outlet flow rates of approximately 260 m3/s and 110 m3/s, respectively. The average daily output volume in the system is 3,361,000 m3, while the average daily input volume is 3,200,000 m3. Consequently, the manipulation of the opening gates results in a decrease in the estuarine water level, potentially by as much as 25 cm, which local authorities can use to make decisions to reduce extreme water levels during flooding events.

Lagoons, significant coastal wetlands, stand out for their vital role in the cycles and transformations of phosphorus. However, the relationship between the spatial distributions of various phosphorus forms in the soil and sediments of lagoon areas remains unclear. This study investigated the phosphorus fractions and distribution patterns in the soil and sediments from Shimei Inland Sea, Hainan Province, China, and identified the factors controlling phosphorus distribution and its relationship with lagoon eutrophication. The results revealed significant enrichment of inorganic phosphorus (IP) in the Shimei Inland Sea (64.1–679.0 mg/kg) and offshore areas (56–627.2 mg/kg), while organic phosphorus (OP) was relatively concentrated in land (60–744.3 mg/kg), suggesting that the productivity of the terrestrial ecosystem controlled the OP content and IP formed from the mineralization of OP was more likely to leach into the water and combine with minerals. Total phosphorus (TP) content was negatively affected by pH, and organic matter, cation exchange capacity and iron/aluminum oxides showed significant positive correlations with TP content. These findings highlighted the coupled impact of soil and sediment physicochemical properties on phosphorus enrichment and transformation, providing theoretical support for the ecological restoration of ecosystems in tropical coastal wetlands.

The Mar Menor lagoon (SE Spain) suffers a severe eutrophication process aggravated since the collapse of the lagoon in 2016. Together with it, the populations of the flat oyster Ostrea edulis have been decimated in the lagoon, but also in the European seas, where the species and the habitats provided by it have mainly disappeared. The Mar Menor Oyster Initiative’s main objectives are gaining knowledge on the nutrient extraction capability of the Mar Menor flat oyster and developing the required tools for restoration and bioextraction actions. The project RemediOS, within the framework of the Mar Menor Oyster Initiative, aims to obtain flat oyster seed using the decimated local broodstock to provide the initiative with an oyster population to work with. The present work describes the results of the first attempt of Mar Menor local broodstock reproduction in captivity. Larvae produced in the hatchery accounted for 57.5 million, of which 11.8 million were cultured and 0.68 million survived to settlement and metamorphosis.

The Oualidia lagoon on the Atlantic coast of Morocco provides important ecosystem services such as aquaculture, fisheries, tourism and high ecological and biological productivity. This is the first study to describe the spatio-temporal distribution of the crustacean community and potential controlling factors in the coastal waters of the Oualidia lagoon. Crustaceans were sampled with a Van Veen grab during two surveys in winter and summer 2013, and taxonomic composition and diversity were determined at 43 sampling sites. Of the eighteen crustacean taxa recorded, fifteen were new to Oualidia Lagoon. Sphaeroma serratum was the most abundant species in both seasons. Organic matter and chlorophyll a content were higher, temperature and salinity were lower in winter than in summer. The structure of the crustacean assemblages was characterised by the formation of two main clusters, organised according to a downstream gradient. Canonical Correspondence Analysis (CCA) showed that granulometry, organic matter and salinity strongly influenced the distribution pattern of crustaceans in the lagoon.

The present study aimed to evaluate and compare feeding responses of the non-native and native bivalves, the dark false mussel Mytilopsis leucophaeata and the scorched mussel Brachidontes darwinianus, respectively, by offering different concentrations of seston from the coastal lagoon where these species coexist after dark false mussel introduction (Rodrigo de Freitas Lagoon, Rio de Janeiro-Brazil). For this purpose, independent laboratory experiments were carried out under five concentrations of seston to test the differences in clearance and ingestion rates of bivalves as a function of increasing concentrations of suspended particulate matter (SPM) on seston. In addition, from the integrated analysis of data obtained in experiments, it can be inferred about the efficiency levels of these species to remove SPM from seston and their effects on water turbidity and nutrient concentrations (total carbon, nitrogen, and phosphorus). Our hypothesis was that the non-native bivalve is more efficient to clear and ingest SPM from seston compared to the native one, which may lead to competitive advantages to the successful invasion of M. leucophaeata in coastal lagoons. Native species did not show a significant difference in clearance and ingestion rates with increasing concentrations of seston. Whereas the non-native bivalve showed a slight tendency to increase its clearance and ingestion rates with the increase in seston concentrations, evidencing its plasticity to adjust its feeding responses. The native bivalve was significantly more efficient to clear and ingest SPM at the lower seston concentration (i.e., close to natural concentrations found in the lagoon) compared to the non-native bivalve, which, on the other hand, showed a significant increase in its ingestion rates at the higher concentration tested (140 mg SPM L−1). Thus, the present results did not suggest food competition between the non-native M. leucophaeata and the native B. darwinianus in the introduced system. However, M. leucophaeata increased its feeding response with experimental increment in seston concentration, which suggests species ability to benefit from conditions of increased inputs of organic matter and higher primary production that could mediate its establishment in introduced systems.

Coastal lagoons provide many important services to human society, but their year-round use for aquaculture introduces large amounts of sewage. The contamination of antibiotic resistance genes (ARGs) is therefore of great concern. In this study, 50 ARGs subtypes, two integrase genes (intl1, intl2), and 16S rRNA genes were detected by high-throughput quantitative PCR, and standard curves of all target genes were prepared for quantification. The occurrence and distribution of ARGs in a typical coastal lagoon (XinCun lagoon, China) were comprehensively explored. We detected 44 and 38 subtypes of ARGs in the water and sediment, respectively, and discuss the various factors influencing the fate of ARGs in the coastal lagoon. Macrolides-lincosamides-streptogramins B was the primary ARG type, and macB was the predominant subtype. Antibiotic efflux and antibiotic inactivation were the main ARG resistance mechanisms. The XinCun lagoon was divided into eight functional zones. The ARGs showed a distinct spatial distribution owing to the influence of microbial biomass and anthropogenic activity in different functional zones. Fishing rafts, abandoned fish ponds, the town sewage zone, and mangrove wetlands provided a large quantity of ARGs to the XinCun lagoon. Nutrients and heavy metals also significantly correlated with the fate of the ARGs, especially NO 2 −-N and Cu, which cannot be ignored. It is noteworthy that lagoon-barrier systems coupled with persistent pollutant inputs result in coastal lagoons acting as a "buffer pool" for ARGs, which can then accumulate and threaten the offshore environment. [Display omitted] [ABSTRACT FROM AUTHOR]

The American blue crab, Callinectes sapidus Rathbun, 1896 is native to the western Atlantic. The present work reviews the spread of C. sapidus in the European Atlantic, the Mediterranean, Black Sea and Sea of Azov, and identifies its first occurrence in the Merja Zerga and Khnifiss lagoons on the Moroccan Atlantic coast. These first and southernmost records on the African Atlantic widen the current biogeographic distribution of the species worldwide. Genetic analysis of specimens from both the Mediterranean (Marchica lagoon) and Atlantic (Merja Zerga and Khnifiss lagoons) coasts of Morocco, based on COI (Cytochrome c oxidase subunit I), confirmed the species sequences as being those of Callinectes sapidus. Moroccan populations have low haplotypic diversity with only two haplotypes (haplotype 1 and haplotype 7). These two haplotypes correspond to the two different haplotypes already found in the Mediterranean. Haplotype 1 from Merja Zerga, Marchica and Khnifiss lagoons was 100% identical to the sequences ON248058 in GenBank, while haplotype 7 from the Marchica and Merja Zerga lagoons was 100% identical to the sequences ON248059. Very likely, the origin and pathway of colonisation of the populations established in the three Moroccan lagoons is the result of the expansion of the species along the Mediterranean Sea and now the Atlantic coast of Africa. [ABSTRACT FROM AUTHOR]

As coastal social-ecological systems (SES) are used for many different purposes and subject to different stressors, they are also among the most vulnerable and change the most rapidly. To achieve resilience, coastal areas require adaptive management based on integrated interdisciplinary approaches, requiring a deep understanding of SES dynamics, i.e. the ecological and social changes that comprise synchronicities and regime shifts. For the purpose of analyzing co-evolution and regime shifts, we propose an original and operational methodology combining (i) a chronosystemic timeline approach and (ii) time series analyses based on indicators from the “Drivers-Pressures-State-Impacts-Responses” framework (14 indicators including population growth, eutrophication status, ecosystem services, management actions and climate change indicators). The methodology was tested on a SES located on the French Mediterranean coast, the Thau lagoon, whose trajectory we studied over a 5-decade period (1970–2018). Our results show that the dynamics of co-evolution and regime shifts of the SES were driven by a succession of interactions between sanitary or ecological crises and management adaptations. During the study period, this typical Mediterranean coastal SES appears to have evolved towards the multiplication of uses, improvement of water quality and more integrative management. Our methodology also highlighted three contrasting periods characterized by stable emerging properties and identified several cause-and-effect relationships, which is rare in historical analyses of SES. These cause-and-effect relationships concern major sanitary and ecological crises that have led to a reorganization of governance mechanisms and to technical remediation actions. Our approach based on long-term trajectories will help identify the conditions required for increasing the resilience of coastal SES and the best management objectives to face new challenges related to global climate change. [ABSTRACT FROM AUTHOR]

Lake Siombak is a tidal lake that is an estuary around the lake covered with various mangrove trees. It is interesting to study the fish's spatial and temporal distribution as a unique and distinctive tidal lake ecosystem. This research was conducted for a year (from September 2018 to August 2019). Fish sampling was performed by installing gill nets (mesh size 1 inch) and cast nets (mesh size 0.5 inch). Gill nets and cast nets were installed at high and low tides during the full moon. This research showed that there were 27 species of 20 families. Tilapia, Mudskipper, Indo-pacific tarpon, and mainly Rice Fish are always found in Lake Siombak. The fish group at Lake Siombak consists of freshwater fish (mainly: Tilapia, Catfish, and Snakehead), brackish fish (mainly: Mudskipper, Rice fish, and Indo-pacific tarpon), and marine fish (mainly: Milkfish, Kanda mullet, and John's snapper). The actual resident in Lake Siombak consists of Oryziidae, Tilapia, and mudskipper. Other fish are temporary resident fish except for Lutjanidae and Scatophagidae as visitor fish during high tide and high salinity periods (dry season) and Synbranchidae during low salinity (rainy season). [ABSTRACT FROM AUTHOR]

Patos Lagoon, located in southern Brazil, is the world's largest choked coastal lagoon. Studies have revealed that plastic pollution affects lagoons; however, to date, they have only focused on a few limited regions of the lagoon. Top-down quantification methods based on socio-economic data from 2010 to 2017 were used to measure the amount of plastic reaching Patos Lagoon, thus broadening the perspective of plastic pollution in this area. According to the findings, Patos Lagoon's hydrographic regions produced an average of 4.54 Mton of plastic during the studied period. 1.86 Mton was consumed on average. High- and low-density polyethylene (HDPE and LDPE, respectively), polypropylene (PP), and polyvinyl chloride (PVC) were the main resins produced. Food-related activities were the largest consumer of plastic (17.98%), indicating a higher amount of single-use plastics being used in the basin. The preforms for plastic bottles, bags, and packaging were the most commonly manufactured plastic utensils. An estimated 8 to 14% of all plastics used to end up as mismanaged waste in the Patos Lagoon hydrographic basin. This resulted in 1.73 and 10.72 Kton, or 0.5 and 3.2 g/per person/per day, of plastic waste flowing into the waters of Patos Lagoon throughout the study period. These findings can help focus on management efforts by providing managers and policymakers with information for better plastic pollution mitigation in this environment. [ABSTRACT FROM AUTHOR]

Three coastal lagoons on the Sefidrud Delta, Caspian Sea, were investigated to evaluate heavy metal pollution in sediments. Amirkola Lagoon is located in the eastern part of the delta (abandoned delta lobe) and is aged more than 500 years, whereas Kiashahr and Zibakenar lagoons are in the western or active part delta lobe and formed in the last decades. One hundred six sediment samples and three sediment cores were taken from studied lagoons. The samples were analyzed by ICP-OES. Geo-accumulation index (Igeo), contamination factor (CF), degree of contamination (Cdeg), pollution load index (PLI), and Potential ecological risk index (RI) were employed to determine heavy metal pollution for Co, Cr, Cu, Ni, Pb, V and Zn. Nonparametric statistical analysis (Two-step cluster analysis, analysis of variance, and T-test technique) was used to discriminate the pollution sources. Based on contamination indices, the Kiashahr and Zibakenar lagoons show significant to moderate contamination with Co, Cu, Pb, Zn, and V, whereas the Amirkola Lagoon samples show the lowest metal contamination. PLI values demonstrated metal contamination in the Kiashahr and Zibakenar lagoons but no contamination in the Amirkola Lagoon. Although there was a notable rise in RI values from Amirkola to two other lagoons, all indicated low ecological risk. Statistical methods designated the unique interpretation of contaminant sources. Although the same geogenic origin of sediments in the Sefidrud Delta and lagoons deposits, Co, Zn, and Pb show anthropogenic sources in the newly-formed Kiashahr and Zibakenar lagoons. [ABSTRACT FROM AUTHOR]