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Governments play crucial roles in addressing social-ecological traps – situations where feedbacks between social and ecological systems lead to reinforcement between resource degradation and livelihood impoverishment. While it is widely recognized that resolving these traps necesitates integrated measures, empirical studies often focus on the impact of individual measures. This paper investigates all measures employed by the local government to address traps in small-scale fisheries and aquaculture and examines how these measures contribute to solving the traps. Based on empirical data from the Tam Giang lagoon, Central Viet Nam, it finds that the goverment develops measures that align with "good practices" which focus on both ecological and social challenges. Yet, in practice, it prioritizes addressing ecological challenges over the social ones. The government primarily directs resources and efforts toward combating resource degradation. Measures that tackle the high dependency on fisheries resources and lack of alternative livelihoods are often sidelined. These practices fail to address the key drivers and reinforceing feedbacks that create the social-ecological trap. The paper highlights gaps between science, policy and practice in addressing social-ecological traps. Bridging these gaps and transforming government responses to the traps require effective communication of scientific knowledge to the government; facilitation of collaborations among researchers, policymakers, managers and practictioners; provision of financial support to the goverment and addressing the lack of political will of the government. [ABSTRACT FROM AUTHOR]

Enhalus acoroides (L.f.) Royle is a large and important foundation seagrass species in the tropical Indo-Pacific. The northern marginal populations in China have been declining over the last decades. The reproductive phenology and fruit set of this dioecious seagrass were investigated from June 2017 to February 2018 in two areas in Li'an lagoon, Hainan Island, China. We found that E. acoroides flowered year-round. However, the flowering intensity varied among seasons and was highest in the summer and lowest in the winter. The shoot sex ratio was male-biased, and the pollen-ovule ratio was approximately 104: 1, based on the sex ratio and the number of male florets per inflorescence. Female and male plants flowered at the same time in this population. Despite the high reproductive investment in terms of flower formation observed throughout the year, the abundance of the mature fruits was low, possibly due to physical disturbance and cover by epiphyte and algae. This study provides insight into the reproductive ecology of E. acoroides, which will be useful for the future conservation of this threatened seagrass. [ABSTRACT FROM AUTHOR]

Global climate change has generated an increasing number of environmental problems, especially in Mediterranean coastal areas, such as the Po Delta (PD), where shellfish production has undergone an overall decline because of strong environmental changes. The present study is centred on assessing the fundamental ecological aspects in one of the most crucial European shellfish production lagoons, Sacca degli Scardovari (SC), addressing phytoplankton community parameters directly affecting shellfish production, namely, chemotaxonomic composition, size fractions, and total biomass, in relation to the physicochemical properties of the water column and mussel filtering activity. Our findings suggest that the phytoplankton community structure, its role within the lagoon food web and its production cycles depend on two distinct allogenic inputs, which shape the community differently and exert substantial control on shellfish production. At the same time, the suspended mussel biomass strongly controls the phytoplankton size composition, as their growth is largely supported by nanophytoplankton. As the Po River collects the drainage waters of the Italian side of the entire Alpine Arch, the phytoplankton dynamics reported here represent a useful baseline for further addressing issues of climatic changes affecting lagoon ecology. We believe that our study presents an innovative tool for the planning and management of interventions aimed at enhancing national mussel production without neglecting aspects of environmental protection or the integrity of the coastal system, with significant scientific implications. [ABSTRACT FROM AUTHOR]

The ecological importance of macrophytes is well known and reflected in nature protection law, for example, as a key biological quality element. However, the socio-economic role, such as the impact of macrophyte presence on recreational activities, is often overlooked. The purpose of this study was to assess the human benefits (or ecosystem services) provided by macrophytes. We developed a list of 25 macrophyte ecosystem services and 79 assessment indicators based on expert knowledge and literature data. First, hypothetical scenarios of coastal lagoons were developed to assess the impact of different ecological states (i.e., macrophyte coverage) and management measures (i.e., fisheries) on the ecosystem service provision. Scenario assessments were carried out by stakeholder workshops and literature search. Second, the ecosystem service potential of submerged and emergent macrophyte habitats were assessed by macrophyte experts and literature data. Results showed that cultural services are most important in terms of the overall actual provision of ecosystem services (scenario assessment) but also showing highest potential of the hypothetical ecosystem service provision (habitat assessment). Highest overall potential is shown for reeds and tall forb communities (83 out of maximum 125), followed by seagrass beds (71) and seaweed communities (61). Our ecosystem service assessment approaches (i.e., scenario and habitat-based) using socio-cultural data (i.e., stakeholders and experts-based) and biophysical data (i.e., indicators-based) can serve as supportive tools for coastal management and policy implementation visualizing the benefits of macrophytes to humans. [ABSTRACT FROM AUTHOR]

Urban tropical lagoons are commonly impacted by silting, domestic sewage and industrial wastes and the dredging of their sediments is often required to minimize environmental impacts. However, the ecological implications of land disposal of dredged sediments are still poorly investigated in the tropics. Aiming to contribute to filling this gap, an ecotoxicological evaluation was conducted with dredged sediments from Tijuca Lagoon (Rio de Janeiro, Brazil) using different lines of evidence, including soil and sediment characterization, metal determination, and acute and avoidance bioassays with Eisenia andrei. Two different dredged sediment samples, a sandy sediment and another muddy one, were obtained in two distinct and spatially representative sectors of the Tijuca Lagoon. The sediments were mixed with an artificial soil, Ferralsol and Spodosol to obtain doses between 0 (pure soil) and 12%. The sediment dose that caused mortality (LC50) or avoidance responses (EC50) to 50% of the organisms was estimated through PriProbit analysis. Metal concentrations and toxicity levels were higher in the muddy sediment (artificial soil LC50 = 3.84%; Ferralsol LC50 = 4.58%; Spodosol LC50 = 2.85%) compared to the sandy one (artificial soil LC50 = 10.94%; Ferralsol LC50 = 14.36%; Spodosol LC50 = 10.38%), since fine grains tend to adsorb more organic matter and contaminants. Mortality and avoidance responses were the highest in Spodosol due to its extremely sandy texture (98% of sand). Metal concentrations in surviving earthworms were generally low, except sodium whose bioaccumulation was high. Finally, the toxicity is probably linked to marine salts, and the earthworms seem to accumulate water in excess to maintain osmotic equilibrium, increasing their biomass. [ABSTRACT FROM AUTHOR]

Hydrodynamic processes are a major driver for marine systems, linking marine organisms with their environment. However, a lack of hydrodynamic data at an ecologically relevant spatial resolution has stymied our understanding of reef function, as exemplified by Lizard Island on the Great Barrier Reef. To address this gap, 23 to 27 Marotte HS current meters were deployed over three periods, collecting 15 months of current velocity data. Combining these data with wind and tide datasets, we provide a preliminary description of the circulation in the Lizard Island lagoon, examining wind and tide influence, and flushing time. During south-easterly trade winds, flood tides flow through the Lagoon Entrance, while wind-induced waves cross the Bird-South crest, driving a north-westerly flow through Loomis Channel and across the western lagoon. Ebb tides flow east–south-east through the Lagoon Entrance and south-west through the Palfrey-South channel. Tides contribute a mean of 20.4% to the overall current speed, particularly in deeper sites with less reef interference, while shallow sites were more influenced by wind. Lizard Island lagoon flushing times ranged from a few hours to 10 days; longer during periods with low wind speeds. Hindcast flushing times during the 2016 coral bleaching event (following 8 Degree Heating Weeks) were approximately 22 h, suggesting that flushing time likely had minimal influence on bleaching. Our analyses provide initial insights into the circulation of the Lizard Island system and aid understanding of the potential relationships between reef organisms and their physical environment, bridging the gap between ecology and hydrodynamics. [ABSTRACT FROM AUTHOR]

An increase in water temperature is one of the main factors that can potentially modify biogeochemical dynamics in lowland rivers, such as the removal and recycling of nitrogen (N). This effect of climate change on N processing deserves attention, as it may have unexpected impacts on eutrophication in the coastal zones. Intact sediment cores were collected seasonally at the closing section of the Po River, the largest Italian river and one of the main N inputs to the Mediterranean Sea. Benthic oxygen fluxes, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) rates were measured using laboratory dark incubations. Different temperature treatments were set up for each season based on historical data and future predictions. Higher water temperatures enhanced sediment oxygen demand and the extent of hypoxic conditions in the benthic compartment, favoring anaerobic metabolism. Indeed, warming water temperature stimulated nitrate (NO3−) reduction processes, although NO3− and organic matter availability were found to be the main controlling factors shaping the rates between seasons. Denitrification was the main process responsible for NO3− removal, mainly supported by NO3− diffusion from the water column into the sediments, and much more important than N recycling via DNRA. The predicted increase in the water temperature of the Po River due to climate change may exert an unexpected negative feedback on eutrophication by strongly controlling denitrification and contributing to partial buffering of N export in the lagoons and coastal areas, especially in spring. [ABSTRACT FROM AUTHOR]

Estimations of ecosystem metabolism have rarely been used to quantify productivity in structural reductionist approaches for the description of phytoplankton composition. However, estimations of ecosystem metabolism could contribute to a better understanding of the relationship between phytoplankton composition and ecosystem functioning. To examine this, we investigated the community structure of phytoplankton in a set of Mediterranean coastal lagoons (natural and artificial) during a hydrological cycle to identify the most important environmental variables determining phytoplankton species composition. The focus of the study was on the quantification of productivity-related variables using estimations of ecosystem metabolism, such as different proxies for the estimation of the production-to-biomass ratio and of the relative importance of K- and r-strategies, which are commonly used conceptually but not quantified. Our results demonstrated differences in phytoplankton composition between seasons, due to the dominant hydrological pattern of flooding confinement in the salt marsh, and between lagoons that were caused by different levels of nutrient availability. Moreover, there was a notable decrease in the production/biomass ratio and a prevalence of K-strategists with seasonal succession, as predicted by Margalef's mandala. Thus, the results showed that estimations of ecosystem metabolism are useful for the higher frequency quantification of important ecological variables, and contribute to a better understanding of planktonic assemblages, and physical and chemical changes, in these fluctuating ecosystems. [ABSTRACT FROM AUTHOR]

Aquatic environments, including their flora and fauna, are known reservoirs of pathogenic Vibrio species. This study aimed to determine the diversity and antimicrobial susceptibility of bacteria from water hyacinth (Eichornia crassipes) and surrounding waters in Lagos lagoons. Bacteria isolation, phenotypic, and genotypic analysis were conducted using standard microbiology and molecular methods..Sampled lagoons exhibited physicochemical parameters such as dissolved oxygen (4.76—6.91 mgL−1) and biochemical oxygen demand (80.5 – 242 mgL−1) that exceeded permissible levels, indicating pollution. A total of 41 bacterial isolates were recovered from water hyacinth samples and surrounding lagoon waters. Twelve (29.26%) were Vibrio strains, comprising 4 (9.8%) Vibrio cholerae, 3 (7.3%) V. paracholerae, 2 (4.9%) V. parahaemolyticus, 2 (4.88%) V. injensis and 1 (2.4%) V. mimicus. Of the 4 V. cholerae isolates, 1 belonged to the O1 serotype. Vibrio species were exclusively recovered from water samples. Phylogenetic analysis of the Vibrio strains isolated from different lagoons showed genetic relatedness. All 41(100%) bacteria isolates displayed pan sensitivity to meropenem, while the highest resistance rate 27(65.9%) was recorded for amoxicillin + clavulanic acid. Multiple antibiotic resistance index of 8/12 (66.7%) of multidrug resistant Vibrio isolates was > 0.2 (20%) which could imply a high risk source of contamination in the environment where they were isolated. tdh, trh, and t1 genes were detected in V. parahaemolyticus isolates. Although, water hyacinth in this study did not harbored Vibrio species, the lagoon remains a source of pathogenic drug resistant Vibrio species. Therefore, surveillance should be enhanced. [ABSTRACT FROM AUTHOR]

This work is devoted to the study of the abundance, distribution and growth performance of five Mugilidae species in three types of coastal habitats (coastal sea, estuaries and lagoon) located in a limited geographical area in the south-western Mediterranean (eastern coast of Algeria). The four sites considered (Caroube Beach, Mellah Lagoon, Boukhmira and Mafragh Estuaries) are differentiated by their salinity, which evolves at different intervals. The five species enter the considered paralic environments at very small sizes (2–3 cm TL). Regardless of site, Liza saliens is the most abundant (46.92%), followed by Liza aurata (23.72%), Chelon labrosus (13.96%), Liza ramada (11.80%) and Mugil cephalus (3.50%). Each species has a different occupation profile for each site (date of recruitment, relative abundance and demographic structure). The same is true for daily growth, which is better at Mafragh for L. saliens (0.7 ± 0.13 mm/day), at Boukhmira and Mafragh for L. aurata (0.53 ± 0.08 and 0.48 ± 0.09 mm/day, respectively), at Caroube for L. ramada (0.58 ± 0.12 mm/day) and at Mellah for C. labrosus (0.59 ± 0.14 mm/day) and M. cephalus (0.68 ± 0.17 mm/day). The closeness of the daily growth values for the five species to data obtained by various multi-year ageing methods (scalimetry, otolithometry) shows the validity of using otolith microstructures to determine the age of juvenile 0+ Mugilidae. This study shows heterogeneity in the relative abundance, demographic structure and somatic development of the five species considered depending on their habitat and suggests the influence of certain abiotic parameters on some of them. The two most interesting species for aquaculture (Liza ramada and M. cephalus) are relatively the least abundant, but still have interesting potential for freshwater aquaculture, because of their euryhalinity and their interesting maximum length, as well as their relatively fast growth in freshwater. The results of this study are of an applied nature because they contribute to the development of extensive mugilid aquaculture. [ABSTRACT FROM AUTHOR]

Burullus lagoon is part of Egypt's protected area network. The lagoon serves as a reservoir for drainage water discharged from agricultural areas, and the lake's sediments provide a unique opportunity to record environmental behavior and reconstruct of the heavy metal contamination history. In the present study, the sediment chronology, sedimentation rates, and metal accumulation fluxes were estimated in four sediment cores using 210Pb dating models to evaluate how human activities have affected the coastal environment. Using the radioisotopes 210Pb and 137Cs, radiometric dating was carried out using gamma-ray spectrometry. At the Egypt Second Research Reactor (ETRR-2), the element concentrations were determined using the instrumented neutron activation analysis (INAA- k0 method). Our findings show that the constant rate of supply (CRS), which has been verified with the peak of artificial radionuclide 137Cs, is the best model performed for the chronology of Burullus Lagoon. The average sedimentation rate, according to 210Pb dating models, is 0.85 cm/year. The large variation in sedimentation rates, especially after the 1990s, is consistent with an increase in the anthropogenic flux of heavy metals. This may be led into a significant environmental problem such as reducing the size of the lake and degrading the quality the water in Burullus Lagoon. Enrichment factor (EF) of the studied elements displayed the following order: Cl > Ca > Na > Br > Zn > Ta > Ti > V > Cr > Sc > Mg > Mn > Fe > Hf which is higher than unity. Furthermore, the Nemerow pollution index (PI Nemerow) revealed that pollution was increasing in the direction of the drains and slightly polluted. Consequently, pollutant indices showed that urbanization and industrial development may have increased the depositional fluxes of the metals in sediments over time. [ABSTRACT FROM AUTHOR]

A 120-day field study was conducted in a Malaysian mangrove ecosystem to investigate the effect of mesh size (0.20 mm, 0.50 mm, and unprotected leaf litter/open litter) on litter decomposition and associated carbon (C)/nitrogen (N) release from two mangrove species, namely Bruguiera gymnorrhiza and Rhizophora mucronata. We hypothesized that excluding fauna from various functional groups through the use of litter mesh bags would significantly impact the decay rates and related dynamics of C and N among the treatments. As expected, marked differences in the decay rate were observed among treatments, with higher decay rates in the unprotected litter. Notably, the decay rates for B. gymnorrhiza were significantly greater than those observed for R. mucronata. Microbial communities played a more substantial role in decomposition, contributing 49%, surpassing the impact of macrofauna (29% contribution) and mesofauna (25% contribution). Consistent with our hypothesis, significant differences in C and N loss were observed among treatments for both species over time. Our findings underscore the influential role of various soil faunal functional groups in litter decomposition, significantly contributing to the release of C and N. This emphasizes their crucial role in the biogeochemical cycling of C and N in blue carbon ecosystems. [ABSTRACT FROM AUTHOR]

Rapid changes in sea ice extent and changes in freshwater inputs from land are rapidly changing the nature of Arctic estuarine ecosystems. In the Beaufort Sea, these nearshore habitats are known for their high productivity and mix of marine resident and diadromous fishes that have great subsistence value for Indigenous communities. There is, however, a lack of information on the spatial variation among Arctic nearshore fish communities as related to environmental drivers. In summers of 2017–2019, we sampled fishes in four estuarine ecosystems to assess community composition and relate fish abundance to temperature, salinity, and wind conditions. We found fish communities were heterogeneous over larger spatial extents with rivers forming fresh estuarine plumes that supported diadromous species (e.g., broad whitefish Coregonus nasus), while lagoons with reduced freshwater input and higher salinities were associated with marine species (e.g., saffron cod Eleginus gracilis). West–East directional winds accounted for up to 66% of the community variation, indicating importance of the wind-driven balance between fresh and marine water masses. Salinity and temperature accounted for up to 54% and 37% of the variation among lagoon communities, respectively. Recent sea ice declines provide more opportunity for wind to influence oceanographic conditions and biological communities. Current subsistence practices, future commercial fishing opportunities, and on-going oil and gas activities benefit from a better understanding of current fish community distributions. This work provides important data on fish spatial distributions and community composition, providing a basis for fish community response to changing climatic conditions and anthropogenic use. [ABSTRACT FROM AUTHOR]

While seagrass meadows are perceived to be pertinent blue carbon reservoirs, they also potentially release methane (CH4) into the atmosphere. Seasonal and diurnal variations in CH4 emissions from a subtropical hypersaline lagoon dominated by Halodule wrightii in southern Texas, USA, on the northwest coast of the Gulf of Mexico were investigated. Dissolved CH4 concentrations decreased in the daytime and increased overnight during the diel observation period, which could be explained by photosynthesis and respiration of seagrasses. Photosynthetic oxygen was found to significantly reduce CH4 emissions from seagrass sediment. Diffusive transport contributed slightly to the release of CH4 from the sediment to the water column, while plant mediation might be the primary mechanism. The diffusive CH4 flux at the sea-air interface was 12.3–816.2 µmol/m2 d, over the range of the sea-air fluxes previously reported from other seagrass meadows. This was related to relatively higher dissolved CH4 concentrations (11.6–258.2 nmol/L) in a mostly closed lagoon with restricted water exchange. This study emphasizes seagrass meadows in the subtropical hypersaline lagoon as a source of atmospheric CH4, providing insights into the interactions between seagrass ecosystems and methane dynamics, with potential implications for seagrass meadow management and conservation efforts. [ABSTRACT FROM AUTHOR]

Although the effect of salinity on phytoplankton community structure has been studied in many coastal lagoons at different times, it has not been studied simultaneously in different lagoons that are not on the same delta but are geographically close to each other. In the present study, the effect of temporal and spatial changes in salinity on the phytoplankton biovolume, species richness, diversity, and species composition was investigated seasonally in 2020 and 2021 in 6 coastal lagoons of Marmara Basin (Türkiye). In more saline lagoons, phytoplankton biovolume, species richness, diversity, and the total number of species were lower. In lagoons which salinity values were approximate, the species composition was similar. Although the salinity in the lagoons did not show significant change seasonally, biovolume values were lower in Mert lagoon in the fall of 2020 when the salinity values were higher compared to the spring of 2021. Moreover, the considerable decrease in salinity shifted the dominant species structure from high salinity optima species to low salinity optima species in this lagoon. Other effective parameters in the seasonal distribution of dominant species were detected as temperature, dissolved oxygen, alkalinity, and nitrate nitrogen. [ABSTRACT FROM AUTHOR]

Millions of tonnes of oil lie entombed within wrecks from two world wars which, when released, can cause environmental devastation. Wrecks are predominantly risk assessed by the Global North Nations responsible, resulting in an epistemology that separates human from nature. This research aimed to decolonise risk assessments to capture the spatially heterogeneous nature of human vulnerability to oil pollution. Triangulation analysis of interviews and official reports relating to the USS Mississinewa oil spill identified three Global South issues a Eurocentric risk assessment failed to capture: region-specific meteorological conditions causing the leak, remoteness making external resources slow to arrive, and the impact of the fishery closure on traditional subsistence lifestyles. A vulnerability assessment is proposed to prioritise wrecks in susceptible locations. Recommendations are made for a collaborative approach to wreck management by including local voices, resisting the Global North assumption of generality, and recognising the priorities of those living with wrecks. [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]

Ecological disturbances such as fish kills can negatively impact ecosystem processes in coastal lagoons. To gain an understanding of factors causing fish kills, we examined conditions associated with a summertime fish kill in a northeastern Pacific coastal lagoon (Rodeo Lagoon, CA, USA). Examination of available data indicated the fish kill was likely caused by hypoxia involving the following etiology: (1) strong onshore winds (up to 12 m/s) mixed a stratified water column, (2) water column mixing transported nutrients from near the bed into the photic zone, (3) increased nutrient concentrations in the photic zone (> 200%) together with high solar irradiance fueled a phytoplankton bloom, (4) death and decomposition of phytoplankton (72% decrease in abundance) contributed to biological oxygen demand that led to (5) hypoxic conditions (as low as 0.6 mg/L) that caused the fish kill. The event resulted in the death of an estimated 3677 Tidewater Goby (Eucyclogobius newberryi), a species listed as endangered under the US Endangered Species Act, and numerous (but not enumerated) Threespine Stickleback (Gasterosteus aculeatus), unidentified sculpins (Cottidae), and macroinvertebrates (primarily Amphipoda). The processes contributing to the event are likely re-occurring phenomena responsible for observed periodic fish kills. Coastal lagoons with limited freshwater inflows and connection to the Pacific Ocean may retain nutrients and be susceptible to similar events. [ABSTRACT FROM AUTHOR]

Urbanization in watersheds leads to the introduction of sources of microplastics and other pollutants in water bodies. However, the effect of urbanization on microplastic pollution and the relationship between microplastics and water quality are not well understood. We assessed the distribution of microplastics in tributaries urbanized, non-urbanized and in the receiving lagoon body of Conceição Lagoon watershed. The results show that urbanization significantly affects water quality but does not differentiate tributaries in terms of microplastic concentrations. Microplastic concentrations were lower in the receiving lagoon body compared with the tributaries, highlighting their importance in microplastic pollution in the studied lagoon. Microplastic concentration was correlated with low N:P ratios in the lagoon and associated with high levels of total phosphorus, which indicate the discharge of effluents. The correlations between microplastic concentration, water temperature, and dissolved oxygen in the lagoon were based on the temporal variations of these variables. Precipitation and wind velocity had influence on microplastic distribution in the watershed. Our findings underscore the importance of evaluating water quality parameters and meteorological variables to comprehend the microplastic distribution at small watersheds. [ABSTRACT FROM AUTHOR]

The very shallow marine basin of Puck Lagoon in the southern Baltic Sea, on the Northern coast of Poland, hosts valuable benthic habitats and cultural heritage sites. These include, among others, protected Zostera marina meadows, one of the Baltic's major medieval harbours, a ship graveyard, and likely other submerged features that are yet to be discovered. Prior to this project, no comprehensive high-resolution remote sensing data were available for this area. This article describes the first Digital Elevation Models (DEMs) derived from a combination of airborne bathymetric LiDAR, multibeam echosounder, airborne photogrammetry and satellite imagery. These datasets also include multibeam echosounder backscatter and LiDAR intensity, allowing determination of the character and properties of the seafloor. Combined, these datasets are a vital resource for assessing and understanding seafloor morphology, benthic habitats, cultural heritage, and submerged landscapes. Given the significance of Puck Lagoon's hydrographical, ecological, geological, and archaeological environs, the high-resolution bathymetry, acquired by our project, can provide the foundation for sustainable management and informed decision-making for this area of interest. [ABSTRACT FROM AUTHOR]

Cage farming in brackishwater resources is an emerging activity in India. Scientific planning and implementation would promote livelihood enhancement and sustainable development for the coastal community. Lagoons and backwaters are often developed for tourism and water sports activities. Identification of potential cage farming locations would improve aqua tourism and generate additional revenue for the fisherman. Hence, this study aims to locate viable cage farming locations in the Muttukadu brackishwater ecosystem, one of the most important lagoon systems on the east coast of Chengalpattu district, Tamil Nadu, for aqua tourism development. Water quality, environmental, and accessibility factors were considered the main factors for identifying suitable cage farming sites. Fourteen designated sampling points covering the lagoon were identified, and water samples were collected and analyzed at monthly intervals from December 2019 to January 2022. Each factor was further sub-classified and ranked by assigning appropriate weightage using the fuzzy analytic hierarchy process (FAHP), one of the multiple-criteria decision-making (MCDM) methods. For sustainable farming, it is important to consider ecologically sensitive areas and other constraining factors. ArcGIS Pro was used to map all the factors for identifying potential cage farming sites. The result shows the potential area available for cage farming development is about 11.52 ha, out of which 0.93 ha is highly suitable, and 10.59 ha is moderately suitable. [ABSTRACT FROM AUTHOR]

Cyanobacteria are recognised for their pivotal roles in aquatic ecosystems, serving as primary producers and major agents in diazotrophic processes. Currently, the primary focus of cyanobacterial research lies in gaining a more detailed understanding of these well-established ecosystem functions. However, their involvement and impact on other crucial biogeochemical cycles remain understudied. This knowledge gap is partially attributed to the challenges associated with culturing cyanobacteria in controlled laboratory conditions and the limited understanding of their specific growth requirements. This can be circumvented partially by the culture-independent methods which can shed light on the genomic potential of cyanobacterial species and answer more profound questions about the evolution of other key biogeochemical functions. In this study, we assembled 83 cyanobacterial genomes from metagenomic data generated from environmental DNA extracted from a brackish water lagoon (Chilika Lake, India). We taxonomically classified these metagenome-assembled genomes (MAGs) and found that about 92.77% of them are novel genomes at the species level. We then annotated these cyanobacterial MAGs for all the encoded functions using KEGG Orthology. Interestingly, we found two previously unreported functions in Cyanobacteria, namely, DNRA (Dissimilatory Nitrate Reduction to Ammonium) and DMSP (Dimethylsulfoniopropionate) synthesis in multiple MAGs using nirBD and dsyB genes as markers. We validated their presence in several publicly available cyanobacterial isolate genomes. Further, we identified incongruities between the evolutionary patterns of species and the marker genes and elucidated the underlying reasons for these discrepancies. This study expands our overall comprehension of the contribution of cyanobacteria to the biogeochemical cycling in coastal brackish ecosystems. [ABSTRACT FROM AUTHOR]

The striped mullet Mugil cephalus is a species of high commercial value with a spawning season that spans from autumn to winter in coastal areas of the northern Gulf of Mexico. The objective of this project was to study an annual cycle of monthly stages of M. cephalus sexual maturity in two southern Gulf of Mexico localities during 2018, to compare results with those reported for the rest of the Gulf of Mexico, and to analyze the spawning temporality vs. tidal oscillations. Specimens were obtained monthly (January–December 2018) from commercial captures collected in Alvarado Lagoon, Veracruz and Puerto Ceiba, Tabasco. Total length, standard length, and total weight were recorded after the fish were eviscerated and the gonads were separated, and sex, eviscerated weight, gonad weight, and the stage of sexual maturity were recorded. A Gonadosomatic Index was obtained, and the gonads with vitellogenetic development were observed to determine the spawning season. M. cephalus spawns simultaneously in both localities, together with virtually synchronous spawning throughout the Gulf of Mexico, from October to March in northern localities and from December to January in southern areas of the Gulf of Mexico. Meteorological tides produced by the "northers" throughout the Gulf of Mexico seem to trigger spawning migrations. The synchronous spawning of M. cephalus supports the evidence that this is a panmictic population in the Gulf of Mexico. [ABSTRACT FROM AUTHOR]

Antibiotics as emerging contaminants have received much attention in recent years. Anaerobic digestion of animal manure contained antibiotics serves as an important reservoir of antibiotics in intensive farms. However, it is still lack of research report on antibiotics in duck farms in China, especially treated by anaerobic lagoon (CAL) process. This study analyzed residual concentrations of 15 common veterinary antibiotics in digested slurry (DS) collected from CAL and advanced treatments in an intensive duck farm in Jiangsu Province, China. The CAL treatment could effectively remove the target antibiotics, and the removal rates of tetracyclines (TCs), sulfonamides (SAs), and quinolones (QLs) ranged 93.8–100%, 51.5–98.9%, and 70.3–91.3%, respectively. The maximum residual concentrations of TCs, SAs, and QLs were 2.36, 4.02, and 29.30 µg/L, respectively, in DS samples. Advanced treatments including sedimentation tank, aeration tank, and ozonation could completely eliminate on most of target antibiotics, except for sulfamonomethoxine, sulfapyridine, and norfloxacin. The results of the ecological risk assessment indicated that residual antibiotics in DS samples can cause hazards to microorganisms and plants in the soil environment. The associated advanced treatment of DS samples still indicated potential ecological risk to aquatic environment, especially for ciprofloxacin. The residual antibiotics in DS samples collected from CAL and associated advanced treatments in an intensive duck farm increase their potential risks to the soil and aquatic ecosystems. The findings provide more information for investigating antibiotic residues in intensive farming, as well as insights into the far-reaching ecological risks of using the DS obtained from CAL treatments. [ABSTRACT FROM AUTHOR]

Mangrove species are shrubs and trees that are ecologically efficient and salt tolerant, predominantly grow in the intertidal region where land and ocean meet. These protects the shoreline from erosion, natural calamities, and climate change. Mapping, monitoring, and assessment of mangrove species are important for the conservation, restoration, and protection purposes. Earth observation using remote sensing satellite data plays a vital role in mapping and monitoring land-surface features. Studying mangroves with remote sensing also helps to track seasonal changes and understand how these ecosystems work. In the present study Mangrove species in and around Eastern Lagoon National Park of Abu Dhabi, United Arab Emirates, is mapped using the Multispectral Landsat 8 OLI data. It has been found that a large part of the area is covered by grey mangroves (i.e., Avicennia marina), including salt marshes. Vegetation indices like RVI, NDVI, SAVI, AVI, and CMRI are derived for mapping and health assessment to categorize mangrove species in high, medium, and low phenology activity, and found the maximum productivity was attained during March 2020 (0 to 366 days). Multispectral reflectance spectra of homogenous units were also collected and classified. For the first time, the satellite-based phenological information has been derived in the region using Landsat 8 OLI data, which will help in understanding biodiversity, climate change impacts, and human activities, and enabling decision-makers for the protection and sustainable use of these valuable coastal ecosystems. [ABSTRACT FROM AUTHOR]

The paper describes integrated research of the Krasnaya and Varkutsyakha rivers of Vaygach Island in the 2023 summer low water period, carried out by the Northwestern Branch of the Shirshov Institute of Oceanology. This research is aimed at studying the specifics of mixing zone formation for Arctic island lagoon estuaries. The maximum suspended particulate matter concentrations were found near the upper boundary of the mixing zone. The maximum metal accumulation zones were observed in the frontal area of estuaries and in the upper part for manganese and arsenic. [ABSTRACT FROM AUTHOR]

Purpose: To study the morphology of all the life stages and the life cycle of the parasitic isopod Cymothoa indica Schioedte and Meinert, 1884, and its prevalence in different commercial fishes in the Chilika Lagoon, India. Methods: From April 2021 to December 2022, different life stages of the said parasites were collected from five different fish species from four localities of the Chilika Lagoon. The parasites were carefully removed from the host with a pair of forceps and then identified following standard literature and description. The morphology of all life stages, life cycle, and prevalence of the isopod C. indica were carried out as per the standard protocol. Results: A total of 1252 host fishes were analysed. The total prevalence was 44.5%. The host with the highest prevalence of C. indica was Glossogobius giuris, with 58.79% of the hosts parasitized by at least one parasite individual. Followed by the host Datnoides polota (50.98%), Johnius dussumieri (46.25%), Etroplus suratensis (28.45%) and the least prevalence was in Lates calcarifer (14.70%). The description of the life stages is based on the observation of 523 females, 116 males, 46 Juveniles, and 50 embryonic stages of the said parasites. Conclusion: The description of all the life stages and life cycles certainly helps to identify this species with clarity and ease in understanding the species' biology. In future, this study may be helpful in the effective management towards the improvement of aquaculture productivity. [ABSTRACT FROM AUTHOR]

This work focused on assessing of the risk associated with the consumption of bivalve mollusks, potentially contaminated with phycotoxins. The studied phycotoxins are saxitoxin (STX), okadaic acid (OA), dinophysistoxins (DTXs), yessotoxins (YTXs), pectenotoxins (PTX), azaspiracids (AZAs), and domoic acid (DA). These toxins were investigated in three species of bivalve mollusks (Anadara senilis, Crassostrea gasar, and Perna perna), originating from the Ebrié lagoon. Chemical analyses were carried out by LC-MS/MS, HPLC-FLD, and HPLC-UV. The level of OA and DTXs, STX, and DA was 10.92 µg OA eq./kg, 9.6 µg STX eq./kg, and 0.17 mg DA eq./kg, respectively. The level of PTXs and AZAs was 3.3 µg PTX-2 eq./kg and 13.86 µg AZA-1 eq./kg; that of YTXs was 0.01 mg YTX eq./kg. The daily exposure dose (DED) was 0.019 µg OA eq./kg bw for OA and DTXs; 0.285 µg DA eq./kg bw for DA; 0.006 µg PTX-2 eq./kg bw for PTXs; 0.016 µg STX eq./kg bw for STX; 0.01 µg YTX eq./kg bw for YTXs; and 0.024 µg AZA-1 eq./kg bw for AZAs for the oyster Crassostrea gasar. These estimated values are lower than the acute reference dose (ARfD) of each phycotoxin recommended by the European Food Safety Agency (EFSA). The risk of harmful effects is acceptable. The absence of risk is valid only for the study period (11 months) and concerns coastal populations living near the sampling points. [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]

Agua Hedionda Lagoon (AHL), a tidal estuary located on the southern California coast, supports a diverse ecosystem while serving numerous recreation activities, a marine fish hatchery, a shellfish hatchery, and the largest desalination plant in the western hemisphere. In this work, a 1-year time series of carbon dioxide data is used to establish baseline average dissolved inorganic carbon conditions in AHL. Based on a mass balance model of the outer basin of the lagoon, we propose that AHL is a source of inorganic carbon to the adjacent ocean, through advective export, at a rate of 5.9 × 106 mol C year−1, and a source of CO2 to the atmosphere of 0.21 × 106 mol C year−1 (1 mol C m−2 year−1), implying a net heterotrophic system on the order of 6.0 × 106 mol C year−1 (30 mol C m−2 year−1). Although variable with a range throughout the year of 80% about the mean, the ecosystem remained persistently heterotrophic, reaching peak rates during the summer season. Using results from the mass balance, the annual cycle of selected properties of the aqueous CO2 system (pH, pCO2, and CaCO3 saturation state) were mathematically decomposed in order to examine the relative contribution of drivers including advection, ecosystem metabolism, and temperature that act to balance their observed annual cycle. Important findings of this study include the identification of advection as a prime driver of biogeochemical variability and the establishment of a data-based estimate of mean flushing time for AHL. [ABSTRACT FROM AUTHOR]

Lagoons are a major coastal environment in West Africa. They provide a plethora of resources, ecosystem services and economic benefits yet a diverse set of inter-connected stressors are a challenge to their sustainability. A scoping study of the published literature pertaining to lagoons within the region was undertaken to reveal the nature of these stressors and identify gaps in knowledge, providing a resource to inform coastal management practices and reveal areas for future study. Thirty-one lagoons were identified from the scoping exercise covering Nigeria, Benin, Togo, Ghana, Cote D'Ivoire, Liberia and Senegal. The DAPSI(W)R(M) framework was used to structure analysis of the literature and surface key environmental themes. Key drivers and activities established are the use of lagoon resources and expansion of lagoon settlements. The resultant identified pressures are waste, overuse of resources, and urban growth as well as climate change. Resultant stage changes are the degradation of water quality and ecosystems with impacts for the health of lagoon organisms and humans. Responses to changes were identified as a combination of punitive legislation, participatory management approaches and solutions focused on ecosystem restoration and engineering of the physical environment. Gaps identified include research on waste and aspects of climate change mitigation and adaptation. Also notable is a lack of multi- and interdisciplinary studies that address the inter-connecting stressors experienced at lagoons and studies of multiple lagoons. Studies also tend to be problem-focused with solutions rarely presented, limiting their applicability to inform management practices. [ABSTRACT FROM AUTHOR]

Eelgrass beds provide a habitat for many high-value fishery resources, and provisioning services, one of the ecosystem services, need to be quantified. However, few examples have been evaluated spatially. We determined the distribution of eelgrass beds in Lake Notoro, a marine lagoon in Hokkaido, Japan, and quantified the provisioning services by the eelgrass beds in relation to Pandalus latirostris, a fishery resource. Acoustic measurement surveys of the eelgrass beds and catch surveys of the shrimp were conducted in July and August 2015. The relationship between catch per unit effort (CPUE) of shrimp and the distribution of eelgrass beds was shown. The estimated distribution area of eelgrass beds was 7.07 km2. Shrimp was frequently caught at water depths of 3–5 m, approximately 200 m from the edge of the eelgrass beds. The expected catch of shrimp in the fishing area of Lake Notoro in 2015 was 25.37 tons and US$ 463.6 thousand. Eelgrass beds were found to affect the fisheries production not only on the inside but also at the edge and outside. The entire coastal space should be evaluated, while considering the effect of the distribution of eelgrass beds, to quantify the provisioning services. [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]

This study performed toxicity assays with microalgae, microcrustaceans, and fish as well as evaluated biochemical and behavioral biomarkers in fish and microcrustaceans to assess the quality of the surface water of Mirim Lagoon, which belongs to one of the largest hydrographic basins in the world, located in southern Brazil. Three distinct sampling periods were chosen (January, March, and June 2022) based on the rice plantation dynamics which is the main activity surrounding the lagoon. In January, the plantation is irrigated; in March, the water is drained into the Mirim Lagoon, and July is the off-season. Concerning toxicity tests, there was significant inhibition in microalgae growth when exposed to water collected in March, but no mortality was observed for Ceriodaphia dubia, Daphnia magna, and Danio rerio. Regarding biomarkers, behavioral variables contributed more to the higher values of the Integrated Biomarker Response (IBR) index for both D. magna and D. rerio, in March. The Redundancy Analysis (RDA) indicated a correlation between the biomarkers for both organisms and abiotic parameters, mainly nutrients (total phosphorus and total nitrogen), thermotolerant coliforms, total solids, and turbidity. Spatially, there was no difference during monitoring, but the most significant ecotoxicological effects were observed in March. Multivariate analysis and the IBR index proved to be useful tools for monitoring of water bodies such as Mirim Lagoon. [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]

Coastal zones have great environmental and economic importance, since anthropogenic activities are very intense, and consequently, their water quality can be affected. Spatial and temporal variations in physicochemical parameters [temperature, pH, electrical conductivity (EC), salinity, dissolved oxygen (DO) and turbidity] in the surface water from the São Lourenço Watershed, a coastal zone in southern Brazil, were investigated. The influence of Patos Lagoon on the watershed in dry periods was confirmed by the increase in salinity and EC of up to 6.43 and 10,810.00 µS cm−1, respectively. In addition, the DO content with low values at the mouth in some samplings, below the Brazilian legislation, calls attention for the water quality. The principal component analysis showed considerable differences in the lower course by comparison with the upper course and the middle course due to climatic and anthropogenic factors. Results from the monitoring enabled to understand fluvial dynamics involving the system of a watershed that contributes to disposal in coastal lagoons through seasonal and climatic factors. Besides, from a managerial point of view, the obtained results support effective decision-making for the preservation of coastal ecosystems. [ABSTRACT FROM AUTHOR]

Laboratory experiments were conducted to determine the thermal tolerance of the living ostracod Cyprideis sp. from a lagoon known as Murray's Pool on the east coast of Bahrain, in the western Arabian Gulf. Our experimental trials, run in duplicate using a semi-controlled thermal incubator, demonstrate the resilience of the ostracod community to elevated temperatures. We observed that ostracod specimens begin to enter an inactive condition or become comatose at about 39.4 °C, and with increase in temperatures, half of the specimens died or did not recover at 51.8 °C. At 53.5 °C, total mortality is observed with no indication of recovery. These observations have implications for climate change predictions in the western Gulf region, as water temperatures in the lagoon reach 42 °C in summer, while the substrate temperatures on mud flats exposed during low tide exceed the lethal limit of the ostracods during the summer months. [ABSTRACT FROM AUTHOR]

Lake Nokoué, a major component of the hydrographic system of the Ouémé delta, is the largest lagoon-estuarine ecosystem in Benin. Recent studies have shown that benthic processes would actively participate in the maintenance of the eutrophication and biogeochemical cycle of this ecosystem. In order to understand the implication of the bottom on the quality of the waters of the lake, a monthly follow-up of ten (10) parameters of quality of the waters of the bottom was undertaken from July 2020 to December 2021 on a network of nineteen (19) stations distributed on the whole lake. Univariate and multivariate analysis techniques were used to assess the spatial and temporal dynamics of these waters. The Kruskal–Wallis test, PCA, correlation analysis and discriminant analysis all showed a very marked influence of the hydrological regime on the concentration of nutrients compared to the influence of anthropogenic activities around the lake and an influence of climatic conditions on internal processes. Indeed, water inflows from the Ouémé watershed are the main contributors of phosphorus in the lake while benthic processes are the most important contributors of nitrogen. Cluster analysis defined three significantly different areas in Lake Nokoué: the channel, the centre of the lake and the river mouth. A single station in each cluster could be used for a spatial assessment of water quality over the entire lake. [ABSTRACT FROM AUTHOR]

An important component of global climate influencing ecological systems is the El Niño Southern Oscillation (ENSO), which affects hydrological conditions in coastal environments around the world. Based on long-term time series of monthly sampling (1997–2019), we investigated the influence of remote (ENSO) and local environmental factors on the juvenile's abundance of the Argentine menhaden Brevoortia pectinata in a subtropical estuary. We also evaluated if the abundance over the years is decreasing due to the negative effects of higher intense El Niño events. Despite the apparent increase in abundance over the years, time series decomposition and mixed models did not reveal an increasing trend along the studied period (Chisq = 2.62; p = 0.289). The overall interannual trend varied across sampling sites, and a trend of increasing abundance over the years was observed only at the estuary site closest to the sea (Chisq = 5.59; p = 0.018). The most parsimonious GAM model revealed that salinity, temperature, and ENSO (based on the Oceanic Niño Index, ONI) explained 23.8% of the abundance variation of B. pectinata juveniles. There was a negative effect on the abundance during El Niño years, especially during more intense events (ONI > 1.5), but no apparent effects were observed for La Niña events. Our findings revealed that the variations in the abundance of this species depend not only on local factors such as temperature and salinity, but also on global climatic phenomena that influence estuarine hydrology. [ABSTRACT FROM AUTHOR]

Lagos Lagoon is a very popular lagoon in Lagos state that receives effluents from neighboring industries. These effluents tend to increase the level of contaminants in the lagoon, thereby creating more stressors for aquatic animals. Determination of polycyclic aromatic hydrocarbons (PAHs) in four commonly consumed fish species from the lagoon and the prediction of possible health risks associated with their consumption were performed in this study. Various levels of PAH were detected in the fish tissues with the highest total concentration of PAH in Sarothoredon melanotheron. High concentrations of benzo(a)pyrene were noticed in Sarothoredon melanotheron and Ethmalosa fimbriata, and their values were above the guideline value of 0.002 μg/g. The dietary daily intake (DDI) value in S. melanotheron 82.00 ×10−5 μg/g/day was highest. Carcinogenic toxic equivalents (TEQ) showed that consumption of S. melanotheron had higher potential to pose carcinogenic risks, while the excess cancer risk (ECR) index for the PAHs in all the assessed fish species was beyond threshold values indicating potential carcinogenic risk from their consumption. No significant association was found between the concentration of PAHs and the size of the fish. Target hazard quotient (THQ) results suggested absence of potential non-carcinogenic risk if individual PAH in the fish are consumed frequently. The study however established possible carcinogenic human health risk from consumption of the fish obtained from Lagos Lagoon. The study recommends monitoring of contamination and consumption of fish from harvest sites within the study region. [ABSTRACT FROM AUTHOR]

The present work assesses the temporal distribution pattern and geochemical changes of rare earth elements and Yttrium, Scandium, Thorium, and Uranium delivery into the Oualidia lagoon. Two sediment cores were retrieved from the Oualidia lagoon and analyzed using neutron activation analysis. The results indicated that heavy rare earth elements are slightly enriched the sediment cores over light rare earth elements. The highest values of REEs were recorded in the top layers of the cores and depleted with depth, suggesting a possible change in factors controlling their accumulation, including mechanical, chemical, and environmental parameters such as weathering intensity, grain size, and Fe-Mn oxides. The sediments display positive Ce anomalies, which are probably related to the submarine weathering process and detrital input. Noting also the variation of hydrodynamics conditions and confinement of the upstream part of the lagoon played a key role in changing the sediment origins. Thus, further investigation of REEs origin in the Oualidia lagoon sediment is required to identify their sources, provenances, and the factors controlling their spatial and vertical distributions. However, these results provide baseline data of occurring changes in REEs geochemical composition and constitute a typical study case to understand the link between sedimentary and geochemistry processes in a lagoonal ecosystem. [ABSTRACT FROM AUTHOR]

As part of a long-term study on the effects of nitrogen (N) loading in a shallow temperate lagoon, we measured rates of N2 fixation associated with seagrass (Zostera marina) epiphytes during the summer from 2005 to 2019, at two sites along a gradient from where high N groundwater enters the system (denoted SH) to a more well-flushed outer harbor (OH). The data presented here are the first such long-term N2 fixation estimates for any seagrass system and one of the very few reported for the phyllosphere in a temperate system. Mean daily N2 fixation was estimated from light and dark measurements using the acetylene reduction assay intercalibrated using both incorporation of 15N2 into biomass and a novel application of the N2:Ar method. Surprisingly, despite a large inorganic N input from a N-contaminated groundwater plume, epiphytic N2 fixation rates were moderately to very high for a seagrass system (OH site 14-year mean of 0.94 mmol N m−2 d−1), with the highest rates (2.6 mmol N m−2 d−1) measured at the more N-loaded eutrophic site (SH) where dissolved inorganic N was higher and soluble reactive phosphorus was lower than in the better-flushed OH. Over 95% of the total N2 fixation measured was in the light, suggesting the importance of cyanobacteria in the epiphyte assemblages. We observed large inter-annual variation both within and across the two study sites (range from 0.1 to 2.6 mmol N fixed m−2 d−1), which we suggest is in part related to climatic variation. We estimate that input from phyllosphere N2 fixation over the study period contributes on average an additional 20% to the total daily N load per area within the seagrass meadow. [ABSTRACT FROM AUTHOR]

A general geographic characteristic of the Vistula basin and mouth area is given; brief data on the modern hydrological regime of the river mouth are presented. The history of floods in the Vistula delta and their studies is considered in detail, as well as delta evolution and the dynamics of its hydrographic network. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the level of pollution, sources and potential risk of heavy metals (Zn, Cu, Mn, Cd, Cr, Ni, Fe and Pb) and arsenic (As) in four dry riverbeds affected by mine tailing, which drain into one of the biggest coastal lagoon of Europe (Mar Menor). El Beal, La Carrasquilla, Las Matildes and Ponce dry riverbeds sediments were sampled along its course (20, 18, 13, 19 samples were collected, respectively), and total/soluble metal(loid)s, water soluble ions, nitrogen, and organic/inorganic carbon contents were analyzed. Spatial distribution, principal component analysis (PCA), hierarchical cluster analysis (HCA), contamination factor (Cf), pollution load index (PLI) and potential ecological risk index (RI) were used to identify the possible sources of metal(loid)s and to assess the sediment pollution status. The results showed that the mean total concentrations of As, Cu, Cd, Mn, Zn and Pb exceeded the natural background levels of the study area, with the highest values located close to the mining areas. Correlation and cluster analysis identified that Cd and Zn were associated mainly with anthropogenic activities for all riverbeds, while Cr and Ni come from parent. PLI graded the four riverbeds as contaminated by heavy metals, while RI manifested that 100% of samples located in El Beal, La Carrasquilla and Las Matildes had a significantly high ecological risk. Therefore, this study suggests that mine wastes are the main source of metal(loids) contamination in the dry riverbeds, which results can be used to design actions and measures to reduce the environmental impact of metal(loid)s in the Mar Menor coastal lagoon. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems play a vital role in sustaining human populations; however, these environments are increasingly subject to human interference, driven by land use modifications, species introductions, pollution, and habitat loss. We sampled the ichthyofauna and collected environmental variables from 24 coastal streams in northeastern Brazil. Fish composition, abundance, and biomass served as the response variables, while physicochemical data, hydrological attributes, riparian characteristics, and substrate composition were considered as predictor variables. Our main objective was to evaluate the impact of a riparian land use gradient, ranging from conserved to degraded scenarios (i.e., forested, grassy, and urban streams), on the structure of fish assemblages. To achieve this, the graphical relationship of ABC plots and their W values between the three sets of streams was evaluated, and a Hellinger transformation-based Redundancy Analysis (tb-RDA) was conducted and we compared fish composition among the stream categories using a PERMANOVA test. We identified that the W values of forested and urban streams were significantly different, indicating a shift from k to r-strategists; the tb-RDA revealed three stream categories: (i) forested streams and their association with Anablepsoides bahianus and Parotocinclus cf. jumbo, (ii) grassy streams and their association with Poecilia vivipara and Astyanax cf. bimaculatus, and (iii) urban streams and their relationship with Poecilia reticulata and Oreochromis niloticus. We also found important differences between fish composition along the riparian land use gradient, with urban streams showing a significant divergence from grassy and forested streams. We observed a loss of native species and an introduction of exotic species in the evaluated gradient, consistent with the premises of niche theory. [ABSTRACT FROM AUTHOR]

The irrational use of water bodies has been a main concern worldwide, requiring the steady monitoring of water sources in order to track whether the water quality parameters are within the guidelines limits. Therefore, the current study aims to evaluate the water quality of Mirim Lagoon by using a water quality index and statistical methods. Also, this study seeks to analyze, by the correlation matrix, the influence of the parameters used in WQI on the results of the index for Mirin Lagoon, as well as compare and validate, via a significance test, the results of WQIValentini with the results of WQICETESB, widely applied in Brazil. The water samples analyzed in this study were collected over the years 2018, 2019, 2020, 2021, and 2022 from several monitoring points of Mirim Lagoon and analyzed regarding the parameters dissolved oxygen, thermotolerant coliforms, pH, biochemical oxygen demand, temperature, total nitrogen, total phosphorus, turbidity, and total solids. The WQICETESB results of the monitoring points in Mirim Lagoon ranged from 58.3 to 81, falling within acceptable and good water quality, respectively. Regarding the correlation-WQI parameter, phosphorus was the most representative parameter for the WQICETESB result in the monitoring points ML1, ML2, ML3, ML4, and ML5, while the thermotolerant coliforms was the most significant parameter for the points ML6 and ML7. On the other hand, the WQIValentini results ranged from 48.0 to 76.9, maintaining the absolute majority within acceptable and good ranges. Moreover, in order to compare the results of WQICETESB with the WQIValentini, and, hence, prove or disprove the equivalence of both, a paired t-test was used, demonstrating that there is no significant variation between both indexes. The results of this study enabled us to evaluate the Mirim Lagoon water quality by using WQICETESB and WQIValentini, as well as by using multivariate statistical methods. In addition, regarding the use of the WQIValentini to assess Mirin Lagoon water quality, there was evidence that this index generates results statistically indistinguishable from those generated by the WQICETESB, proving its applicability for water quality monitoring of this lagoon. Furthermore, it is worth mentioning that the use of an adequate equation with fewer variables provides a reduction in the costs of physicochemical and microbiological analysis, which may encourage environmental agencies to invest more in water quality monitoring. [ABSTRACT FROM AUTHOR]

Seagrasses assimilate nitrogen (N) and phosphorus (P) from their environment over the course of the growing period, reflecting long-term, system-wide environmental conditions. We examined the role of two Texas seagrasses, Halodule wrightii and Thalassia testudinum, as indicators of N and P conditions in the western Gulf of Mexico via their tissue isotopic (δ15N) and stoichiometric (N:P) ratios. Leaf tissue samples were collected from 285 sampling sites in the Lower Laguna Madre from 2011 to 2018. Data were used to develop interpolated maps of δ15N signatures and N:P ratios across the region. We found that higher variability in H. wrightii metrics reflected the higher sensitivity of this species to short term changes in nutrient sources. T. testudinum exhibited a narrower range in isotopic ratios and N:P values (mean standard deviation of 1.6‰ and 11, respectively compared to 2.4‰ and 12.5 for H. wrightii), indicative of its relatively slow leaf turnover. The highest δ15N values (7–9‰) were recorded near the mouth of the Arroyo Colorado, which carries discharges from a large, urbanized region into an otherwise highly oligotrophic lagoon. Elevated N:P ratios in both species (60–80) were prevalent in the upper reaches of the lower Laguna, likely reflecting inorganic-N inputs by large expanses of N-fixing cyanobacterial mats on nearby wind tidal flats. These metrics reveal that seagrass tissues can serve as valuable indicators of inorganic-N sources in low-inflow estuarine systems where freshwater input is negligible or absent for extended periods of time. [ABSTRACT FROM AUTHOR]

Mediterranean coastal lagoons provide important ecological functions and nature's contribution to people, but they are particularly vulnerable to multiple pressures due to their location at the land-sea interface and the many activities they host. Numerous research and monitoring programs have been conducted to study the functioning of Mediterranean coastal lagoons and to improve their ecological and chemical status, especially since the 2000s with the EU Water Framework Directive. However, many coastal lagoons still had not achieved a good ecological status by 2018. The soft-bottom benthic ecosystem plays a crucial role in the functioning of shallow coastal lagoons, regulating among others nutrient and oxygen fluxes, and hosting a high biodiversity. The alteration of this compartment by anthropogenic pressures is therefore a major problem. Through a literature review, this paper aims to summarize information available on the impacts of the five main human-induced pressures — i.e. exploitation of natural resources, habitat destruction, climate change, pollution and alien invasive species — on the soft-bottom benthic ecosystem in Mediterranean coastal lagoons (period 2000—2022), and to identify perspectives for future research that can contribute to the improvement of monitoring programs. Our review shows that resource exploitation and nutrient pollution have been the two most studied pressures whereas research is still underdeveloped on the impacts of climate change, invasive alien species, and contaminants of emerging concern. We also found that the recording and quantification of pressures is still poor, and that their cumulative effect is poorly understood. In terms of indicators, the microbial and microphytobenthic compartments are being overlooked and functional approaches could be strengthened. This review could help scientists realign research on pressures of priority interest and thus better assist stakeholders in managing coastal lagoons in times of global changes. [ABSTRACT FROM AUTHOR]

Mediterranean coastal lagoons are affected by multiple threats (demographic pressures, eutrophication, climate change) expected to increase in the future and impact the ecosystem services provided. Conservation norms and scientific studies usually focus on large lagoons (> 0.5 km2) due to their economic importance, while they ignore smaller lagoons. These are poorly understood and often unprotected, despite their prevalence within the Mediterranean region and their importance. Qualitative and quantitative characterisation of small lagoons, in terms of functioning and sensitivity to global and local changes, are needed to develop appropriate management strategies. For this purpose, this work provides the first inventory of all Corsican lagoons and has investigated three of them of small size (Arasu, Santa Giulia, Balistra), characterised by contrasting anthropogenic contexts (highly modified/disturbed, medium disturbance, quasi-pristine). At the regional level, 91 of the 95 lagoons identified are < 0.5 km2, making Corsica a good example for the study of small Mediterranean lagoons. The three case studies showed differences in their seasonal biogeochemical cycles and phytoplankton communities (biomass, diversity, photosynthetic efficiency). Arasu and Santa Giulia lagoons showed an increase in watershed urbanisation (+ 12% and + 6% in 30 years), high phytoplankton biomass, low diversity and blooms of potentially harmful dinoflagellates. Conversely, Balistra lagoon showed a good status overall, but some anthropogenic pollution sources within its watershed. This study demonstrates the importance of small lagoons at regional and Mediterranean scale, and provides knowledge on studied local sites but also potential applications elsewhere. The importance of an integrated approach considering lagoons within their adjacent connected systems (watershed and sea) and anthropogenic contexts is highlighted. [ABSTRACT FROM AUTHOR]