2026-10-15T22:10:25Z https://emt.pensoft.net/oai.php

10.3897/emt.1.116778 2024-01-25 emt

Estuarine Management and Technologies: A way forward for estuarine research Haddout,Soufiane K L,Priya Casila,Joan Cecilia Hoguane,Antonio Ljubenkov,Igor Israelsson,Peter Kantamaneni,Komali Carvalho Junior,Oldemar Kurniawan,Tonni Agustiono Rathnayake,Upaka Khajenoori,Leila Esteban,M. Dolores Zhang,Jian Hait,Subrata Soeprobowati,Tri Aksun Tümerkan,Elif Tugce Editorial Estuarine Management and Technologies 1: 1-6 Editorial info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2024 Editorial text/html info:doi:10.3897/emt.1.116778 https://doi.org/10.3897/emt.1.116778 https://emt.pensoft.net/article/116778/ https://emt.pensoft.net/article/116778/download/pdf/ en

10.3897/emt.1.121901 2024-05-20 emt

Understanding sedimentary dynamics and bottom sediment characteristics in Bons Sinais Estuary – Mozambique: Insights from statistical analysis and Pejrup diagram Hoguane,Cesar Mativane,Jessica da Cruz,Nacir Leitao Machaieie,Helder Arlindo Bons Sinais Estuary bottom sediments grain size parameters pollution sediments statistics Estuarine Management and Technologies 1: 7-18 This article addresses the Bons Sinais Estuary sedimentary dynamics and bottom sediment characterization and its implication to pollution, based on bottom sediment grain size and statistical parameters. There were collected 15 bottom sediment samples with a Van veen sampler, which were further analysed by sieve and pipette methods. Sand was the most dominant textural class (51%), followed by silt (25%) and clay (24%). The sedimentary dynamics have varied from moderate to high. Both size of sediments and Pejrup diagram suggests that the hydrodynamics of this Estuary is high. Although the percentage of coarse sediments is higher, the estuary is susceptible to pollution, as the amount of thinner sediments is considerable regarding the values of skewness. These results may be useful to environmental management actions including pollutants tracking. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2024 Research Article text/html info:doi:10.3897/emt.1.121901 https://doi.org/10.3897/emt.1.121901 https://emt.pensoft.net/article/121901/ https://emt.pensoft.net/article/121901/download/pdf/ en

10.3897/emt.1.119588 2024-06-07 emt

Factors affecting scum formation and the use of electronic nose to identify fundamental odor properties in urban estuaries Casila,Joan Cecilia Okuyama,Ryohei Yokoyama,Katsuhide Estuary management River odor Salt intrusion Shakujii River Sumida River Estuarine Management and Technologies 1: 39-56 The foul odor of rivers is often linked to poor water quality and unhealthy air. In this study, variations in water quality and hydrodynamics near the confluence of the Shakujii and Sumida Rivers in Tokyo, Japan, were monitored, and their effects on sum generation were analyzed. The Shakujii River, facing scum and odor issues, was monitored hourly for on-site scum coverage. Samples of scum, sediment, and water were collected and subjected to odor analysis. The odor characteristics were assessed using an electronic nose odor machine and then correlated with human olfactory sense. Results indicated that salinity, dissolved oxygen (DO), rainfall, sediment, and topography influenced scum formation. Scum coverage was higher when salinity was below 1 psu and DO was below 6 mg/L. Organic acids (14.2%) and hydrogen sulfide (14.4%) were the primary odor components of sediment in the Shakujii River. In the Sumida River sediments, organic acids (4%) and sulfurs (1%) were prominent. The Shakujii River sediment exhibited the highest odor index and showed a 62.43% similarity with scum. These results could support efforts to address scum and odor issues in the area. They could provide new insights into on-site formation based on actual river hydrodynamics and water quality variations. Graphical abstract info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2024 Research Article text/html info:doi:10.3897/emt.1.119588 https://doi.org/10.3897/emt.1.119588 https://emt.pensoft.net/article/119588/ https://emt.pensoft.net/article/119588/download/pdf/ en

10.3897/emt.1.120413 2024-06-07 emt

Estuary fluvial flooding: the example of the watercourse Miljašić jaruga in the town of Nin (Croatia) Ljubenkov,Igor Oskoruš,Dijana Rubinić,Josip Peša,Ivan Papić,Jovan Croatia embankment estuary flash flood Estuarine Management and Technologies 1: 19-37 The Miljašić jaruga is one of the most important watercourses in Zadar County (Dalmatia, Croatia). The total length of this area is approximately 16 km, with an associated topographic catchment of approximately 191 km2. The downstream portion of the stream is influenced by the sea (estuary). The hydrological regime of the Miljašić jaruga is strongly influenced by climatic features; therefore, for most of the year, there is an outflow of catchment waters, whereas in the summer dry months, the river bed is mostly without outflow. It is also common for extreme precipitation to occur after a long dry period, resulting in sudden increase in water levels and flash floods. One such extreme event occurred on September 11, 2017, when a severe storm followed by heavy rain affected Zadar and its hinterlands. On that occasion, approximately 240 mm/m2 fell in Zadar over a period of 6 h, with an intensity of up to 70 mm/m2/h. Such extreme rainfall activated violent and torrential runoff, flooding, and damage in the entire catchment area of the Miljašić jaruga, particularly in the most downstream part of the basin, in the area of the estuary and the town of Nin. Numerous infrastructural and communal facilities have been damaged, including the Nin Salt Works. This paper presents the hydrological analysis of a flash flood event in the Miljašić jaruga estuary. A hydrological series of 26 and 27 years were compared, whereas the longer series include historical flood, using three distributions: normal, log-normal and Gamma. The relevant hydrological parameters (water levels and flows) used for dimensioning the flood defense system show great variability depending on the available data (time series) and calculation methodology. For example, variation of flow rate reached 41 m3/s for 100-year high waters, that is, from 60 m3/s (n = 26, normal distribution) to 101 m3/s (n = 27, log-normal distribution). In engineering practice, the unreliability of the estimation of statistical quantities should be considered to improve the effectiveness of flood defense systems. The rehabilitation and reconstruction work conducted after a flood on hydrotechnical structures (embankments) in the estuary area is described. In addition, there is a need for adequate water management across the entire basin, such as the construction of retention and barriers, which would increase the level of flood protection in the most downstream parts, i.e., the estuary. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2024 Research Article text/html info:doi:10.3897/emt.1.120413 https://doi.org/10.3897/emt.1.120413 https://emt.pensoft.net/article/120413/ https://emt.pensoft.net/article/120413/download/pdf/ en

10.3897/emt.1.130278 2024-10-21 emt

Predicting chlorophyll-a dynamics in the Ashtamudi estuary using ANN and ANFIS techniques K L,Priya Haddout,Soufiane Casila,Joan Cecilia ANFIS ANN Chlorophyll-a estuary eutrophication prediction Estuarine Management and Technologies 1: 57-68 Excessive nutrients and associated high chlorophyll-a concentration are of growing concern to the public health due to the occurrence of eutrophication in aquatic bodies. Continuous monitoring of chlorophyll-a has limitations, thereby necessitating the development of prediction models. Even though chlorophyll-a prediction models are numerous, they rarely fit into estuarine conditions, which is encountered with dynamic mixing of freshwater and sea water. Thus, the present study identifies the most appropriate driving factors that are relevant for estuarine conditions through chlorophyll-a prediction models developed using Artificial Neural Network and Adaptive Neuro Fuzzy Inference System (ANFIS) approaches in the Ashtamudi estuary, India. Salinity, which is an indirect measure of the estuarine mixing intensity, has been used to replicate the dynamic mixing in the estuary. The results indicate that the model incorporating salinity along with total nitrogen, total phosphorous and turbidity well-predicted chlorophyll-a concentration with a coefficient of determination ranging from 0.73 to 0.99. General Regression Neural Network (GRNN) and ANFIS models outperformed Back Propagation Neural Network (BPNN) and Recurrent Neural Network (RNN) models. Of the various ANFIS models, the ones that used Gaussian and Generalized Bell membership functions were most appropriate for the prediction of chlorophyll-a than the models with triangular and trapezoidal membership functions. The study identified that the models that considered salinity were less sensitive and can be used for modelling chlorophyll-a. The chlorophyll-a was observed to have a direct influence of salinity at salinity values greater than 5‰. The study highlighted that estuarine mixing further enhances the primary productivity through increased penetration of light leading to higher chlorophyll-a concentration. Further the study emplasized that the predictive models are important tools fitting well within estuarine environments due to its replicability. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2024 Research Article text/html info:doi:10.3897/emt.1.130278 https://doi.org/10.3897/emt.1.130278 https://emt.pensoft.net/article/130278/ https://emt.pensoft.net/article/130278/download/pdf/ en

10.3897/emt.1.137829 2024-12-19 emt

Delta flood risk analysis: case study from the Neretva River (Croatia) Ljubenkov,Igor Kvesić,Draženka Erceg,Joško Delta Croatia flood Neretva risk Estuarine Management and Technologies 1: 69-93 Floods play an important role in deltas, particularly in their geomorphological and ecological processes. Current deltas are exposed to strong anthropogenic influences. In the Neretva River Delta (Croatia), which is located in the Mediterranean, numerous hydrotechnical facilities have been built for flood protection and flow regulation. The level of flood protection has significantly increased compared to natural conditions, because the main cause of flooding in this delta is fluvial flow, but there are still certain risks for material assets and the population. The hydrological regime of the Neretva River is strongly influenced by reservoirs and hydropower plants built upstream of the basin. This study presents a simulation of floods in the Neretva River Delta for various return periods (from 5 to 1000 years) to assess damages and risks. The extent of flooding is classified into three statistical levels: high, medium, and low probability. Floods in this area can cover approximately 110 km2 with a low probability of flooding and material damage of approximately 250 million Euros. The average number of potential human victims would be 0.67 per year, and the potential average annual damage would be 11.63 million Euros, in the Donja Neretva according to the conditions of 2015. Climate change would increase the mentioned risks of floods, the potential number of victims and damage by 31 and 41%, respectively. Based on a multi-criteria analysis, protective measures including the construction of embankments and self-regulating gate were proposed. Their implementation would reduce the average annual potential number of victims and the average material damage by 70% and 83%, respectively. The results of this study should be used to identify critical areas and make decisions to improve the flood protection system in the delta area, as well as to improve water management in the entire basin, which is located in the territory of two countries Croatia and Bosnia and Herzegovina. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2024 Research Article text/html info:doi:10.3897/emt.1.137829 https://doi.org/10.3897/emt.1.137829 https://emt.pensoft.net/article/137829/ https://emt.pensoft.net/article/137829/download/pdf/ en

10.3897/emt.2.149362 2025-03-21 emt

Remote sensing to detect source-to-sink dynamics Nones,Michael Remote sensing satelite source-to-sink dynamics Estuarine Management and Technologies 2: 1-3 A brief overview of the keynote "Remote sensing to detect source-to-sink dynamics" planned for the 1st International Conference on Technological and Research Advancements in Coastal and Estuarine Systems 2025 (TRACE2025) is given here, via both a video and a short summary. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Video paper in 180s text/html info:doi:10.3897/emt.2.149362 https://doi.org/10.3897/emt.2.149362 https://emt.pensoft.net/article/149362/ https://emt.pensoft.net/article/149362/download/pdf/ en

10.3897/emt.2.151294 2025-04-25 emt

Is it possible to evaluate the energy contributions of an estuary? Carvalho Junior,Oldemar D'Aquino,Carla de Abreu Ecosystem modelling Environmental Management Emergy Assessment Estuarine Management and Technologies 2: 5-7 This study conducts an emergy analysis to explore the natural physical foundation supporting the ecological organization of the Araranguá River estuary, located in the southern region of Santa Catarina, Brazil. The primary aim is to assess the emergy signature of renewable natural energy sources within the Araranguá River and quantify their emergy contributions to the system. The energy model developed for the study area is based on a detailed account of the system, incorporating expert insights, literature reviews, and field research. This is followed by the creation of an energy diagram to represent the system visually. Energy sources, stores, and flows within the system are then evaluated and described. The total environmental energy sources required to sustain the Araranguá River estuary amount to 2.07 million emReais annually, including associated imagery. By successfully employing emergy analysis, this study identifies the key energy sources that uphold the structure of the estuary. These findings can support informed decision-making and the formulation of public policies, such as resource allocation and conservation strategies. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Video paper in 180s text/html info:doi:10.3897/emt.2.151294 https://doi.org/10.3897/emt.2.151294 https://emt.pensoft.net/article/151294/ https://emt.pensoft.net/article/151294/download/pdf/ en

10.3897/emt.2.157458 2025-07-17 emt

Assessment of ecological and human health concerns associated with heavy metal poisoning in the sediments of Western St. Martin’s Island, Bangladesh Bhuyan,Md. Simul Bakar,Muhammad Abu Islam,Md. Tarikul Meraj,Gowhar Kunda,Mrityunjoy Ali,Mir Mohammad Hossain,Nazmul Roy,Ranjan Shaha,Dinesh Chandra Iheanacho,Stanley Mansour,Lamjed Rabaoui,Lotfi Jilani Di Paola,Davide Ecologically Critical Area Ecological and human health risk assessment Heavy metals Sediment St. Martin’s Island Estuarine Management and Technologies 2: 9-42 St. Martin’s Island (SMI) was designated an Ecologically Critical Area by the Bangladesh government in 1999 to preserve its biodiversity. Heavy metals (HMs) pollution is a critical environmental problem, driven primarily by anthropogenic activities, that causes various environmental impacts, including the contamination of marine resources. This study aimed to investigate the presence of HMs in marine sediments and evaluate the potential risks they pose to the marine environment and human health (adults and children). Atomic Absorption Spectrometry was used to assess the HMs in composite sediment samples collected from 12 sampling sites along the west coast of SMI. The average (±SD) HM concentrations (mg/kg) found, in descending order, were Mn (317.58±48.1) > Fe (168.42±35.46) > Zn (31.17±6.34) > Ni (24.17±6.41) > Cr (12.17±3.18) > Pb (6.52±1.03) > Cu (5.16±0.94). All detected HMs concentrations were below the allowable levels and considerably lower than those reported in other studies. The Risk Index (RI) results suggest that the marine ecosystem along the west coast of SMI did not surpass the low-moderate risk line (ranging from 0.23 to 6.18 with a mean of 4.68). Furthermore, the sediment quality indices used, including the contamination factor, geo-accumulation index, and pollution load index, indicated that metal contamination levels were within acceptable limits and did not adversely affect sediment quality. Human health risk assessment demonstrated that for each age group of the SMI population, the non-carcinogenic Hazard Index (HI) was significantly below the threshold limit (HI < 1), indicating low risk. In addition, the total carcinogenic risk was below the risk threshold range (10-4 to 10-6). Safeguarding the health of the SMI population and the integrity of the marine ecosystem will require HM monitoring and the execution of strict regulations to reduce HM pollution. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Research Article text/html info:doi:10.3897/emt.2.157458 https://doi.org/10.3897/emt.2.157458 https://emt.pensoft.net/article/157458/ https://emt.pensoft.net/article/157458/download/pdf/ en

10.3897/emt.2.158168 2025-08-01 emt

Estuary. A systems perspective Carvalho Junior,Oldemar Biodiversity Climate Change Economy Emergy Sociology Sustainability System Theory Thinking Systems Estuarine Management and Technologies 2: 43-70 Estuaries are complex, dynamic ecosystems where freshwater meets saltwater, supporting diverse biological, physical, and chemical processes. Systems theory offers a holistic framework for understanding these environments by emphasizing interconnectedness, feedback loops, emergent properties, and hierarchical organization. This approach enables researchers and managers to identify root causes of ecological issues rather than addressing isolated symptoms. Emergy analysis, developed by Howard T. Odum (Odum 1983), provides a systems-based method to quantify all energy and material flows in solar emjoules, offering a unified metric for evaluating sustainability, ecosystem services, and human impacts. By applying systems principles, such as transformation of inputs, energy-material-information requirements, storage and structure, and feedback reinforcement, this study demonstrates how estuaries can be analysed and managed more effectively. Case studies from the Herring River Estuary (USA), mangrove restoration projects in Southeast Asia, and wetland conservation in the Liaohe Estuary (China) illustrate the practical value of systems thinking and emergy synthesis in guiding restoration and policy decisions. The article also reflects on broader implications, examining how systems thinking challenges capitalist reductionism and informs alternative economic models such as degrowth and circular economies. It highlights the importance of cultural re-engagement through literature and storytelling in fostering ecological awareness and collective action. Ultimately, integrating systems thinking into coastal management supports regenerative, equitable, and resilient strategies that align ecological health with social well-being. This work underscores the transformative potential of systems theory and emergy analysis in confronting global challenges such as climate change, biodiversity loss, and unsustainable development. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Education & Communication text/html info:doi:10.3897/emt.2.158168 https://doi.org/10.3897/emt.2.158168 https://emt.pensoft.net/article/158168/ https://emt.pensoft.net/article/158168/download/pdf/ en

10.3897/emt.2.165887 2025-09-01 emt

A new non-native species detected through citizen science: the presence of a Macrobrachium species (Decapoda, Palaemonidae) in the Guadalquivir River estuary (SW Spain), with an overview of its global spread F. de Carvalho-Souza,Gustavo Cuesta,Jose A. González-Ortegón,Enrique Bioinvasion commercial shrimp exotic first record Iberian Peninsula prawn Estuarine Management and Technologies 2: 71-86 Non-native species are of global conservation concern. Spain is also facing the same challenge, especially due to increasing marine traffic, global trade, and ocean warming. Herein, we report Macrobrachium cf. nipponense from a local fisherman through a citizen science initiative. This is the first record of any species of the genus Macrobrachium in the Iberian Peninsula and the westernmost record of this genus in the European waters. In October 2024, an individual was fished at the mouth of the Guadalquivir River. Accidental transport via ballast water is a likely vector for its introduction into the Guadalquivir River estuary, potentially facilitated by increased maritime traffic from the Danube River Basin as a result of the ongoing war between Russia and Ukraine. Our findings highlight the importance of early detection and continuous ecological monitoring, particularly approaches that incorporate citizen science, as effective tools for tracking non-native species. Engaging local stakeholders, such as fishers, can enhance detection capacity and contribute valuable data to inform for future management strategies aimed at preventing the establishment and spread of non-native and invasive species in the Guadalquivir River and other vulnerable aquatic systems. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Research Article text/html info:doi:10.3897/emt.2.165887 https://doi.org/10.3897/emt.2.165887 https://emt.pensoft.net/article/165887/ https://emt.pensoft.net/article/165887/download/pdf/ en

10.3897/emt.2.169780 2025-11-13 emt

The monetary counterflow. A regenerative model for estuarine ecosystems Carvalho Junior,Oldemar Emergy Valuation Ecosystem Services Sustainability Indicators Ecological Economics Regenerative Model Mai Po Reserve Estuarine Management and Technologies 2: 87-100 This study evaluates the ecological and economic sustainability of the Mai Po Marshes, a Ramsar-designated wetland in Hong Kong, using emergy analysis and a novel monetary counterflow model. The objective is to determine whether financial inflows function as a regenerative counterflow by reinvesting in natural and social capital. The analysis employs standard emergy accounting methods to compute key sustainability indicators, including the Investment Ratio (IR), Environmental Loading Ratio (ELR), Yield Ratio (YR), and Emergy Density (ED). It also introduces a new metric, the Net Monetary Flow Rate (NMFR), to assess the balance between economic returns and environmental costs. Results indicate a total emergy output of 26.39E+17 sej/year and an emergy density of 6.94E+11 sej/m²/year, reflecting high ecological productivity. The NMFR is positive (+634.000 US$/year), demonstrating net financial support, yet reinvestment is channeled predominantly into management and environmental education rather than direct ecological restoration. Notably, staff knowledge accounts for 92% of the emergy associated with the education function, underscoring human capital as a central regenerative asset. The study concludes that Mai Po’s current sustainability relies on institutional stewardship rather than ecological self-sufficiency. Achieving true regeneration will require policies that mandate direct financial reinvestment into mangrove restoration and other natural capital enhancements. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Research Article text/html info:doi:10.3897/emt.2.169780 https://doi.org/10.3897/emt.2.169780 https://emt.pensoft.net/article/169780/ https://emt.pensoft.net/article/169780/download/pdf/ en

10.3897/emt.2.175774 2025-12-08 emt

Influence of basement rock lithology on soil hydraulic conductivity and grain size distribution in lateritic soils of western Uganda: Implications for estuarine management Hailu,Haftay Texture Depth Grading coefficients Hydraulic behavior Parent rock Estuarine Management and Technologies 2: 101-118 The main focus of this study is to assess the control of grain size distribution, lithology, and depth on hydraulic conductivity (K_Hazen) within five weathered basement rocks (gneiss, gneiss-volcanics, quartzite, and granite) by means of statistical, regression, and mixed-effects modeling methods underpinned by hydrogeological interpretation. For this purpose, a total of 24 soil samples were analyzed using the GGU-SIEVE program, focusing on the determination of uniformity coefficient (Cu), coefficient of curvature (Cc), and hydraulic conductivity (K_Hazen). The investigation also included analysis of median-grain distribution, gradation, permeability, and soil type classifications, which are vital for sustainable soil management in regions with variable geological bedrocks, like in western Uganda. The results for Cu values range from 15 to 439, Cc ranges from 0.2 to 1.8, and K ranges from 5.8 × 10-8 to 1.3 × 10-4 m/s. These results demonstrate that the soils exhibit a wide range of textural variations and depth-dependent permeability trends. Gneiss-derived soils are permeable and exhibit moderate gradation. The quartzite and granite soils are more broadly graded but less porous, resulting from denser packing and finer matrix content. On the other hand, the gneiss-volcanics profile presents an intermediate characteristic due to mixed lithological influence. Based on statistical analysis, K decreases systematically with depth and is positively correlated with Cu and negatively with the percentage of fines. This is also confirmed by the model diagnostics, which suggest that K is jointly controlled by such factors as lithology, grain-size heterogeneity, and depth-dependent structure, with Cu emerging as a strong predictor, with the mixed-effects framework proving effective to model subsurface variability. These results underline the role of the controlling variables related to the parent rock and the intensity of weathering in influencing soil texture, gradation, shape (structure), and hydrologic response, which should be considered for erosion risk management, geotechnical study, and subsurface flow modeling in basement terrains. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Research Article text/html info:doi:10.3897/emt.2.175774 https://doi.org/10.3897/emt.2.175774 https://emt.pensoft.net/article/175774/ https://emt.pensoft.net/article/175774/download/pdf/ en

10.3897/emt.2.172938 2025-12-08 emt

Integrating nature-based solutions in estuary management: A climate mitigation perspective from Demak, Central Java Soeprobowati,Tri Khotimperwati,Lilih Jumari,Jumari Helmi,Muhammad Nature-based Solutions estuarine management climate resilience Demak mangrove restoration sustainable aquaculture Bedono Estuarine Management and Technologies 2: 119-140 Estuaries are vital ecosystems that play a crucial role in mitigating the impacts of climate change. They act as natural buffers against rising sea levels and coastal erosion while serving as significant carbon sinks due to their diverse and productive ecosystems. Integrating Nature-based Solutions (NbS) into estuary management offers a promising approach to mitigate the impacts of climate change while enhancing ecosystem services and community resilience. This study focuses on the potential of NbS in managing estuaries in Demak, Central Java, a region highly vulnerable to coastal hazards such as erosion, flooding, and land subsidence. Key strategies explored include mangrove restoration, sustainable aquaculture, and community-driven conservation efforts. The findings demonstrate that these approaches can reduce the risks associated with climate change, improve biodiversity, and support local livelihoods by providing sustainable economic opportunities. Mangrove restoration in Bedono Village, Demak, illustrates how Nature-based Solutions (NbS) and hybrid engineering can address coastal subsidence, tidal flooding, and ecological degradation. Field observations (2022–2025) show that mangrove rehabilitation supported by permeable brushwood barriers has increased sediment accretion by 5–15 cm/year and enabled natural recruitment of Avicennia and Rhizophora, contributing to shoreline stabilization. Community-led restoration achieved estimated mangrove survival rates of 60–70%, while participatory activities involving youth and women strengthened local livelihoods and environmental stewardship. Comparative analysis with other Indonesian and regional projects highlights the effectiveness of integrating community engagement with low-cost engineering. The Bedono model demonstrates the potential of NbS to enhance coastal resilience, support carbon sequestration, and align with national climate strategies, offering a replicable framework for vulnerable estuarine regions. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Research Article text/html info:doi:10.3897/emt.2.172938 https://doi.org/10.3897/emt.2.172938 https://emt.pensoft.net/article/172938/ https://emt.pensoft.net/article/172938/download/pdf/ en

10.3897/emt.2.176870 2025-12-08 emt

The enigmatic blue-green iridescence of Sapphirina ovatolanceolata (Dana, 1849) (Crustacea, Copepoda, Sapphirinidae): a live observation from the Lakshadweep waters Radhakrishnan,Radhika Jayachandran,PR K.S.,Santu S,Bijoy Nandan Indian Ocean iridescence Kavaratti optical adaptation pelagic copepods Estuarine Management and Technologies 2: 141-149 The marine planktonic cyclopoid copepod genus Sapphirina is renowned for its striking iridescence, yet in situ observations of this phenomenon are relatively rare. This structural iridescence arises from the interference and reflection of light by thin, multilayered hexagonal guanine crystal platelets in the integument. The dazzling colors, which range from red to blue or violet, vary among species and are displayed exclusively by males. This feature likely serves as an adaptation for mate recognition, intraspecific communication, and predator avoidance through rapid shifts to transparency. During a field expedition near Kavaratti Island in the Lakshadweep archipelago (India) in January 2020, we observed a distinctive “jeweled” appearance of the seawater surface at about 8:30 AM. Investigation revealed that the phenomenon was caused by a swarm of Sapphirina ovatolanceolata males exhibiting brilliant blue-green iridescence. This short communication documents the occurrence and identification of S. ovatolanceolata from Lakshadweep waters, providing live photographic evidence of its blue-green iridescence in the natural environment. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Rapid Communication text/html info:doi:10.3897/emt.2.176870 https://doi.org/10.3897/emt.2.176870 https://emt.pensoft.net/article/176870/ https://emt.pensoft.net/article/176870/download/pdf/ en

10.3897/emt.2.167289 2025-12-11 emt

Assessment of ecosystem services provided by lagoonal seaweeds and seagrasses along the Moroccan coast Houssa,Rachida REZZOUM,Nor-Eddine CHRIFI,Ouafa El Mouttaqui,Sara EL ASRI,Fatima ZIDANE,Hakima algae ecosystem services invasive algae lagoon ecosystem Moroccan Coast seagrass Estuarine Management and Technologies 2: 151-184 This study assesses the ecosystem services provided by algae and seagrass species structuring the lagoonal ecosystems along the Moroccan Atlantic coast, with a focus on the Oualidia Lagoon. A comprehensive literature review was conducted to identify and evaluate the contributions of key native species (Gracilaria gracilis, Ulva spp., Cystoseira humilis, Fucus spiralis, and Zostera noltei) and the invasive species Sargassum muticum to Marine and Coastal Ecosystem Services (MCES). A semi-quantitative approach was applied to integrate the functional and spatial value of each species into the overall assessment of MCES. Results indicate that 70–85% of potential services are documented, with native species mainly contributing to regulating and supporting services, while S. muticum shows a negative impact on about 43% of them. Current exploitation remains limited, except for agar-agar extraction from Gracilaria, confirming the low use of provisioning services. Overall, 25–30% of potential services are underutilized, aligning with the Ramsar site’s emphasis on sustainable use. Promoting native algae cultivation could enhance local economic and ecological outcomes while contributing to multiple SDGs, including food security, climate action, and biodiversity conservation. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Mini-Review text/html info:doi:10.3897/emt.2.167289 https://doi.org/10.3897/emt.2.167289 https://emt.pensoft.net/article/167289/ https://emt.pensoft.net/article/167289/download/pdf/ en

10.3897/emt.2.176866 2025-12-23 emt

Accumulation of trace metals in tissues of the Oriental river prawn Macrobrachium nipponense (Arthropoda, Crustacea, Decapoda, Palaemonidae) from polluted waters in southwestern Ukraine Lepekha,Anastasiia Koshelev,Oleksandr Stepien,Carol Kvach,Yuriy Bioaccumulation decapods ecosystem services human impact pollution toxicity Estuarine Management and Technologies 2: 185-204 We report on the bioaccumulation of trace metals (Mercury-Hg, Copper-Cu, Cadmium-Cd, Lead-Pb) in tissues of the invasive Oriental river prawn (Macrobrachium nipponense) sampled from three water body areas in southwestern Ukraine: (sampling site 1) Sukhyi Lyman, (2) Cuciurgan Reservoir, and (sites 3-4) two locations in the Danube delta. Results are consistent with the hypothesis that the absorption of microquantities of trace metals from water by hydrobionts primarily depends on the relative concentration of each element. The higher its respective dissolved concentration, the higher is the metals corresponding absorption by the prawn. Our study showed that trace metal contamination of the prawns did not exceed either the national (Ukraine) or the international standard levels for crustaceans. In terms of chemical contamination, all water areas appear to meet present-day Ukraine and International guidelines for Oriental river prawn aquaculture and/or its commercial harvesting. However, given the present levels and ongoing potential for additional trace metal contaminations, and accompanying or currently unassessed pollutants, as well as their likelihoods of complex chemical, biological, and ecosystem interactions, accelerated by anthropogenic unknowns as the Russia-Ukraine War drags on, extreme caution is warranted for aquaculture, commercial fishing, and recreational harvest of the Oriental river prawn as well as other seafood species in Ukraine’s waters. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2025 Research Article text/html info:doi:10.3897/emt.2.176866 https://doi.org/10.3897/emt.2.176866 https://emt.pensoft.net/article/176866/ https://emt.pensoft.net/article/176866/download/pdf/ en

10.3897/emt.3.183489 2026-01-08 emt

Forty years of Projeto Lontra: Lessons learned and the future of otter-led estuarine conservation Carvalho Junior,Oldemar Emergy accounting Population reinforcement Shared stewardship Otter presence intensity Non-invasive breeding Transformity Estuarine Management and Technologies 3: 1-21 Over four decades, Projeto Lontra has pioneered otter-led estuarine conservation in Brazil, generating one of the world’s longest continuous datasets on Lontra longicaudis and its habitats. This Expert View synthesizes eight foundational lessons distilled from 40 years of applied science, community engagement, and adaptive management across the Atlantic Forest, Pantanal, and Amazon. We demonstrate how 14-year monitoring (2003–2017) revealed a >90% decline in otter presence intensity—leading to a Critically Endangered classification for the Santa Catarina Island population—and how integrating emergy theory, non-invasive reproductive protocols (88% pup survival across 10 events, 2017–2024), and shared stewardship models transformed conservation practice. Critically, we show that the otter functions not merely as a bioindicator but as a high-transformity species (2.26 × 10²² seJ/J) whose presence quantifies estuarine integrity at systemic, energetic, and cultural levels. All protocols and datasets are released under CC0 1.0, supporting global replication. As Projeto Lontra enters its 40th year, this article affirms a covenant—not of mastery, but of humility: conservation succeeds when science, technology, and relationship converge to reweave broken ecological and social threads. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Expert View text/html info:doi:10.3897/emt.3.183489 https://doi.org/10.3897/emt.3.183489 https://emt.pensoft.net/article/183489/ https://emt.pensoft.net/article/183489/download/pdf/ en

10.3897/emt.3.183511 2026-01-22 emt

Why African estuaries matter? An expert perspective on regional and global sustainability Hoguane,Antonio Hoguane,Cesar African estuaries biodiversity climate change coastal management conservation ecosystem services sustainability Estuarine Management and Technologies 3: 23-40 African estuaries are critical ecosystems that serve as vital interfaces between terrestrial and marine environments, playing indispensable roles in regional and global sustainability. Africa possess the second largest river in the world, the Congo river. This review article synthesizes expert perspectives on the multifaceted importance of these dynamic systems, highlighting their ecological, economic, and social contributions. We explore their significance as biodiversity hotspots, nurseries for commercially important species, natural filters for pollutants, and buffers against climate change impacts. Furthermore, the article examines the threats facing African estuaries, including pollution, habitat degradation, overexploitation, and climate change, and discusses the implications for human well-being and ecosystem resilience. Key findings of this review is stated as follows: The total outflow from African rivers into the adjoining seas is estimated at 3,271.4 km3 per year, representing approximately 8.7% of the global river flow into the oceans; People living on African deltas and estuaries were estimated at approximately 62 million people in 2017, representing about 19% of the total population living in deltas; and the overall economic income value generated by the harbour operations in Dakar, Abidjan, Lagos, Alexandria, Durban, Mombasa, and Maputo is estimated to be 22–37 billions of USD annually. By integrating current research and expert insights, we underscore the urgent need for integrated management strategies and conservation efforts to safeguard these invaluable natural assets for present and future generations. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Expert View text/html info:doi:10.3897/emt.3.183511 https://doi.org/10.3897/emt.3.183511 https://emt.pensoft.net/article/183511/ https://emt.pensoft.net/article/183511/download/pdf/ en

10.3897/emt.3.182442 2026-01-29 emt

Monitoring land cover dynamics in the Bahr Al-Najaf wetland: A transferable remote sensing framework for inland and coastal wetland management (2002–2025) Al-Helaly,Emad Al Rammahi,Ali H. Muhsin,Israa J. Bahr Al-Najaf Iraq water crisis Land cover/use change random forest remote sensing urban expansion Estuarine Management and Technologies 3: 41-63 The Bahr Al-Najaf depression is a unique geological and ecological feature in Iraq that has undergone significant environmental transformations over the past two decades. This study quantifies the spatiotemporal dynamics of Land Use and Land Cover (LULC) changes in the depression from 2002 to 2025 using a multi-sensor remote sensing approach based on Landsat and High-Resolution Google Earth imagery. The Random Forest (RF) machine learning algorithm was implemented to classify the region into five distinct classes: Deep Water, Shallow Water, Dry Soil, Wet Soil, and Built-up Areas. The classification model, optimized with 500 decision trees and validated using a stratified random sampling of 250 ground-truth points, achieved a high overall accuracy of 92.1%. The results reveal a dramatic and irreversible urban expansion, with built-up areas increasing by 192%, growing from 29.26 km2 (6.71%) in 2002 to 85.46 km2 (19.61%) in 2025, predominantly encroaching on the stable eastern plateau. In contrast, hydrological features exhibited severe instability; total water surface area plummeted from 155.70 km2 (35.73%) in 2002 to a critical low of 47.40 km2 (10.87%) during the 2015 drought peak. While a partial recovery was observed in subsequent years – aligning with NASA’s regional observations – the water extent remained at 74.12 km2 by 2025, failing to reach its initial baseline. Analysis of the Digital Terrain Map (DTM) confirms that topographic constraints play a deterministic role in directing urban growth, while the depression’s low-lying center remains vulnerable to hydrological shocks. These findings highlight a critical shift toward an anthropogenically modified landscape, demonstrating a robust remote sensing framework that is directly transferable to estuarine, lagoonal, and deltaic wetlands. Ultimately, this study provides critical insights for the integrated management of fragile hydrological systems facing similar anthropogenic and climate-induced stresses globally. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Research Article text/html info:doi:10.3897/emt.3.182442 https://doi.org/10.3897/emt.3.182442 https://emt.pensoft.net/article/182442/ https://emt.pensoft.net/article/182442/download/pdf/ en

10.3897/emt.3.185117 2026-02-02 emt

Otters as bioindicators of estuarine health: Scientific gaps, field-based insights, and a framework for future research Bez Birolo,Alessandra Tosatti,Marcelo Carvalho Junior,Oldemar Haddout,Assiya Apex predators bibliometric analysis bioindicators conservation contaminants ecosystem health eDNA estuarine health fisheries impacts habitat management heavy metals IUCN long-term datasets Lontra longicaudis management microplastics monitoring Neotropical otter otters pollution Scopus sentinel species temperate systems trophic interactions tropical coastal Brazil Estuarine Management and Technologies 3: 65-78 Estuaries are vital ecosystems bridging terrestrial and marine environments, supporting nutrient cycling, biodiversity, and services like flood protection. Yet, they face threats from pollution, habitat fragmentation, overfishing, and climate change, demanding robust bioindicators for effective monitoring. This synthesis highlights otters—semi-aquatic mustelids such as the Neotropical otter (Lontra longicaudis), North American river otter (Lontra canadensis), and sea otter (Enhydra lutris)—as integrative sentinels, leveraging their reliance on clean water, diverse prey, and connected habitats, plus their meso-predator roles in food webs. Based on 40 years of Projeto Lontra fieldwork in Brazil’s Peri Lagoon and global studies, we detail otters’ bioindicator value: habitat specificity (e.g., 30% sighting drops in fragmented areas), contaminant sensitivity (bioaccumulation of POPs, metals, microplastics; 66% Toxoplasma positivity), behavioral proxies (spraints showing diet shifts: 70–80% fish), and top-down effects (e.g., suppressing invasive crabs to stabilize marshes, as in 2025 California research). A Scopus bibliometric analysis (1986–2025) exposes biases: 6,300 publications dominated by temperate species (>70% on sea/Eurasian otters), with tropical/estuarine gaps (Neotropical otter: 211 documents, Brazil at 49%). Persistent challenges include sublethal contaminant effects, dispersal, density regulation, and socioeconomic integration. We propose a seven-pillar framework: population scaling, density studies, impact quantification, monitoring harmonization, reintroductions, socioeconomic balancing, and pathogen considerations. This promotes interdisciplinary, equitable collaborations to advance otter-based estuarine management. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Editorial text/html info:doi:10.3897/emt.3.185117 https://doi.org/10.3897/emt.3.185117 https://emt.pensoft.net/article/185117/ https://emt.pensoft.net/article/185117/download/pdf/ en

10.3897/emt.3.183343 2026-03-04 emt

Mechanistic drivers of cyanobacterial dominance and eukaryotic algal decline in estuarine ecosystems: integrating nutrient stoichiometry and thermal stratification R,Nandakumar M,Jayaprakashvel Barathan,Balaji Prasath CyanoHAB dead zones estuaries food web disruption Estuarine Management and Technologies 3: 79-86 Cyanobacteria in estuarine ecosystems outcompete eukaryotic algae through the synergistic interaction of nutrient flexibility, buoyancy control, and thermal stratification. Although these changes in the ratio of nitrogen to phosphorus (N: P) are usually detrimental to eukaryotic taxa, specific cyanobacteria either fix atmospheric nitrogen (N2) or can store phosphorus, and are able to grow during nutrient-limited phases. This review identifies critical low N: P thresholds and temperature ranges that trigger a shift from diatom-rich to cyanobacteria-dominated states. Rising global temperatures and stratification of water columns aid the utilization of gas vesicles and help cyanobacteria to reach the surface, where they absorb sunlight and effectively suppress competing organisms. Their high tolerance to warmer water and formation of toxins protect them against grazing pressures that normally regulate the algal populations. The resulting feedback loop involves thick cyanobacterial mats which increase surface temperatures and cause hypoxia through decomposition, which in turn leads to loss of biodiversity and collapse of existing algal-based food web. These findings provide a mechanistic predictive framework for estuarine management, emphasizing that climate-induced warming necessitates more stringent, dual-nutrient (N and P) reduction targets to prevent the onset of toxic monocultures. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Rapid Communication text/html info:doi:10.3897/emt.3.183343 https://doi.org/10.3897/emt.3.183343 https://emt.pensoft.net/article/183343/ https://emt.pensoft.net/article/183343/download/pdf/ en

10.3897/emt.3.186569 2026-03-19 emt

Macroalgae in coastal lagoons: a systematic review from Brazil Amaral,Hanna Brum François Copertino,Margareth Creed,Joel Christopher Aquatic ecology bioindicators coastal ecosystems lagoon studies marine conservation seaweed Estuarine Management and Technologies 3: 87-112 Coastal lagoons (CLs) are important ecosystems that perform relevant ecological functions and provide goods and services essential to human well-being. Lagoons occupy 13% of the planet’s coastal area, but due to intense urbanization of their surroundings, they are among the most threatened ecosystems globally. Macroalgae play an important role in ecosystem functioning and are widely used as effective bioindicators for environmental monitoring. Despite this we know little about the distribution of CLs in Brazil and less about the macroalgae they may contain. We mapped lagoons using Google Earth and assessed macroalgae presence through a systematic literature review (September 2021–March 2022) of five databases and two languages using the keywords: (alga OR seaweed) AND (lagoon) AND (Brasil* OR Brazil*). We identified 300 unevenly distributed lagoons along the Brazilian coast with little floristic similarity. The Rio Grande ecoregion had the highest concentration of CLs (n = 124), followed by the northeast and southeast; three of 17 coastal states had none. We catalogued 213 macroalgae taxa in 48 studies across only 11 lagoons, with little similarity among lagoons. Most research focused on two, the Patos and Araruama Lagoons. The lack of studies of macroalgae represents a significant knowledge gap for Brazil’s coastal zone — we don’t know if these lagoons are highly unique (high beta diversity) or simply understudied. We encourage more targeted research on lagoons such as the PELD long-term monitoring programs so that the flora may be used for monitoring ecological status. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Review Article text/html info:doi:10.3897/emt.3.186569 https://doi.org/10.3897/emt.3.186569 https://emt.pensoft.net/article/186569/ https://emt.pensoft.net/article/186569/download/pdf/ en

10.3897/emt.3.183953 2026-03-25 emt

Review on plastic-derived chemical pollutants in estuarine ecosystems: Assessing the scale of microplastic contamination A R,Nisari K R,Renjith Microplastics plastic plastic additives Estuarine Management and Technologies 3: 113-121 The major source of synthetic additives in estuarine ecology is plastic contamination and its dispersion. Therefore, the plastic-related chemicals can be used as an indicator of microplastic pollution in various environmental niches. The persistence and accumulation characteristics of these chemicals enhance their transfer to water, sediment, and biotic materials. These chemicals are endocrine disruptors and mutagens that affect the next generation. Systematic scientific approaches are essential for the remedial measures and sustainable environmental management processes. Graphical Abstract info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Mini-Review text/html info:doi:10.3897/emt.3.183953 https://doi.org/10.3897/emt.3.183953 https://emt.pensoft.net/article/183953/ https://emt.pensoft.net/article/183953/download/pdf/ en

10.3897/emt.3.188082 2026-03-27 emt

Environmental consequences of ship-induced drawdown in shallow waterways Kang,Naiyu Terziev,Momchil Incecik,Atilla Drawdown environmental impact inland navigation inland waterways shallow water ship hydrodynamics ship primary waves Estuarine Management and Technologies 3: 123-134 Much attention has been devoted to detrimental impacts of shipping on coastal and inland infrastructure recently. Yet, transport over water remains several times more energy efficient than alternative transport modes and therefore plays a crucial role in global energy efficiency and decarbonisation strategies. Understanding and predicting these impacts is thus essential for developing effective mitigation strategies where necessary. Among the main phenomena causing damage to estuarine and other inland infrastructure is the so-called drawdown, a part of ship-generated primary wave system, representing a local depression of the water surface induced by vessel motion, particularly evident in shallow or confined waterways. This phenomenon alters nearshore hydrodynamics and sediment stability, and the associated return currents can also mobilise or erode bed morphology. Moreover, rapid water level depressions and subsequent surges pose safety hazards to recreational users and swimmers in nearshore zones. Understanding the environmental implications of drawdown is therefore critical for managing sediment dynamics, bank stability, and public safety in intensively navigated waterways. Exiting research on ship-induced drawdown is reviewed, integrating shallow and confined water ship hydrodynamics, ecological impacts, and mitigation strategies. The analysis highlights environmental effects associated with drawdown-induced sediment resuspension and shoreline erosion and identifies knowledge gaps in predictive modelling and ecosystem management. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Mini-Review text/html info:doi:10.3897/emt.3.188082 https://doi.org/10.3897/emt.3.188082 https://emt.pensoft.net/article/188082/ https://emt.pensoft.net/article/188082/download/pdf/ en

10.3897/emt.3.190933 2026-05-08 emt

Sustainable biomethane production from marine algae: challenges and process strategies BIANCO,Francesco Anaerobic digestion biomethane marine algae pretreatment scale-up Estuarine Management and Technologies 3: 135-146 Marine algae have gained increasing attention as sustainable substrates for biomethane production due to their rapid growth, high photosynthetic efficiency, and adaptability to saline cultivation conditions. This study evaluates recent advances in anaerobic digestion of marine micro- and macroalgae, focusing on the main technological challenges and process strategies to improve methane production. Methane yields from marine algal biomass vary widely depending on species and operating conditions, ranging from approximately 0.05–0.58 m3 CH4 kg–1 VS. Key limitations include salinity-induced inhibition of methanogenic microorganisms, resistant algal cell walls that limit hydrolysis, and free ammonia toxicity (above 1500–3000 mg NH3/L) associated with the breakdown of high protein content. Several strategies have been proposed to address these challenges, including pretreatment technologies, co-digestion with other organic substrates, microbial acclimation to saline environments, and integration of anaerobic digestion within algal biorefinery systems (e.g., lipid extraction). This mini review demonstrated that marine algae can serve as a viable feedstock for biomethane production in coastal bioenergy systems, although further research is needed to improve process efficiency and enable large-scale implementation. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Mini-Review text/html info:doi:10.3897/emt.3.190933 https://doi.org/10.3897/emt.3.190933 https://emt.pensoft.net/article/190933/ https://emt.pensoft.net/article/190933/download/pdf/ en

10.3897/emt.3.198947 2026-05-18 emt

Corrigendum: Bez Birolo A, Tosatti M, Carvalho Junior OdeO, Haddout A (2026) Otters as bioindicators of estuarine health: Scientific gaps, field-based insights, and a framework for future research. Estuarine Management and Technologies 3: 65–78. https://doi.org/10.3897/emt.3.185117 Bez Birolo,Alessandra Tosatti,Marcelo Carvalho Junior,Oldemar Haddout,Assiya Apex predators bibliometric analysis bioindicators conservation contam- inants ecosystem health eDNA estuarine health fisheries impacts habitat manage- ment heavy metals IUCN long-term datasets Lontra longicaudis management mi- croplastics monitoring Neotropical otter otters pollution Scopus sentinel species temperate systems trophic interactions tropical coastal Brazil Estuarine Management and Technologies 3: 147-148 **Corrigendum to:** Bez Birolo A, Tosatti M, Carvalho Junior OdeO, Haddout A (2026) Otters as bioindicators of estuarine health: Scientific gaps, field-based insights, and a framework for future research. Estuarine Management and Technologies 3: 65–78. https://doi.org/10.3897/emt.3.185117**Title:** Correction of pathogen prevalence citation in "Otters as bioindicators of estuarine health"**Authors:** Alessandra Bez Birolo¹, Marcelo Tosatti¹, Oldemar de Oliveira Carvalho Junior¹*, Assiya Haddout² ¹ Instituto Ekko Brasil, Florianópolis/SC, Brazil ² Ibn Tofail University, Kenitra, Morocco *Corresponding author: ocjunior@ekkobrasil.org.br**Text of the corrigendum:**On page 68, in the section "Pathogen exposure and spillover dynamics", the citation (Carvalho-Junior et al. 2025) accompanying the prevalence values for *Toxoplasma gondii* (66%) and canine distemper virus (83%) in *Lontra longicaudis* at Taim Ecological Station should read (Gonchoroski et al. 2025).**Correct reference:** Gonchoroski GZ, Reck J, Mello LS, Silveira VP, Lunge VR, Leuchtenberger C, Freitas TRO (2025) Exposure of free-living *Lontra longicaudis* to domestic carnivores and their associated pathogens in a protected area in Brazil. *Frontiers in Mammal Science* 4: 1634247. https://doi.org/10.3389/fmamm.2025.1634247This correction ensures accurate attribution of the original pathogen surveillance data. The authors apologize for the inadvertent citation error.**Impact statement:** This correction does not affect the scientific conclusions, framework, or recommendations of the original article. It solely addresses proper attribution of empirical data.**Conflicts of interest:** The authors declare no conflicts of interest.**Author contributions:** All authors approved this corrigendum.**ORCIDs:** Alessandra Bez Birolo https://orcid.org/0000-0001-7380-119X Marcelo Tosatti https://orcid.org/0009-0002-4838-0375 Oldemar de Oliveira Carvalho Junior https://orcid.org/0000-0001-7776-0022 Assiya Haddout https://orcid.org/0000-0001-7214-4044 info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Corrigendum text/html info:doi:10.3897/emt.3.198947 https://doi.org/10.3897/emt.3.198947 https://emt.pensoft.net/article/198947/ https://emt.pensoft.net/article/198947/download/pdf/ en

10.3897/emt.3.191084 2026-05-22 emt

From captive breeding to wild reintroduction: A case study of a protocol for the neotropical otter (Lontra longicaudis) in Southern Brazil Tosatti,Marcelo Esteves,Priscila Bez Birolo,Alessandra Carvalho Junior,Oldemar Brazil Captive breeding conservation protocol dehabituation Lagoa do Peri Lontra longicaudis reintroduction Estuarine Management and Technologies 3: 149-167 The Neotropical otter (Lontra longicaudis) faces population decline across its range due to habitat loss, fishing gear, pollution, roadkill, and domestic dog interactions. In Southern Santa Catarina Island, Brazil, a 36-year monitoring study at Lagoa do Peri revealed a consistent negative population trend, with at least four otter deaths registered in 2018. It created and put into effect a reintroduction protocol that combined controlled wild preparation with captive breeding in order to address this decline. Between June 2024 and June 2025, a female otter (Nanã) and male (Lucky) produced three cubs under controlled conditions at Instituto Ekko Brasil, a facility with consistent births of L. longicaudis. Two cubs (one male, one female) survived to release age. Our protocol comprised three phases: (1) biological safety screening (genetic matching, pathology testing, and deworming); (2) predatory training and dehabituation (live prey conditioning, aversion training, and “invisible keeper” strategy to prevent human imprinting); and (3) post-release monitoring using subcutaneous microchips for identification and remote camera traps. On June 4, 2025, the pair was released at Peri Lagoon under authorization from the Government State Environmental Institute (IMA) and Local Government Environmental Foundation (FLORAM). Initial monitoring indicates adaptation, with documented den usage and foraging behavior. This case demonstrates that captive-born otters can be prepared for wild reintroduction when protocols prioritize behavioral autonomy and minimal human contact. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Research Article text/html info:doi:10.3897/emt.3.191084 https://doi.org/10.3897/emt.3.191084 https://emt.pensoft.net/article/191084/ https://emt.pensoft.net/article/191084/download/pdf/ en

10.3897/emt.3.183902 2026-05-27 emt

Analyzing the factors influencing chlorophyll-a in the Ashtamudi estuary on the south-west coast of India K L,Priya R Raj,megha Nahas,Hisana K,Krishnapriya Remesh,Keerthy K R,Renjith Haddout,Soufiane Casila,Joan Cecilia ANN model Ashtamudi estuary chl-a prediction hydrodynamic parameters Estuarine Management and Technologies 3: 169-185 Eutrophication in aquatic bodies is a growing concern to the ecosystem as well as public health. Chlorophyll-a is an indicator of nutrient levels in the water body and can be considered for identifying the trophic level. Continuous monitoring of chlorophyll-a is thus a necessity and developing predictive models for chlorophyll-a can reduce the cost of analysis, time and resources. The present study firstly investigated the major controlling parameters of chlorophyll-a in the Ashtamudi wetland, India using a statistical approach. Secondly, a predictive model using Artificial Neural Network has been developed for chlorophyll-a. The study revealed that chlorophyll-a peaks during the pre-monsoon season, followed by post-monsoon and monsoon seasons. The major driving parameters of chlorophyll-a (Chl-a) were identified to be phosphates (P), nitrates (N), sulphates (S), dissolved oxygen (DO) and salinity (Sal). Further, ANN models were developed for predicting chlorophyll-a, wherein five scenarios were considered: (i) Chl-a = f(P,N,S,DO,Sal); (ii) Chl-a = f(P,N,S,Sal); (iii) Chl-a = f(P,N,Sal); (iv) Chl-a = f(P,N); (v) Chl-a = f(P). The first four scenarios yielded a similar predictability with a coefficient of determination of 0.99 with a data set collected across 41 sampling stations over 3 years, thereby revealing that phosphates and nitrates can be used for predicting chlorophyll-a and has a higher control than salinity, DO and sulphates. Further, in order to predict the chlorophyll-a on-site, the in-situ parameters namely temperature, dissolved oxygen, pH and salinity were considered for developing the model. The results revealed that salinity and pH can predict chlorophyll-a with an accuracy of 88.7% and can be used for random assessment of chlorophyll-a at site, thereby enabling the sample collection process to be streamlined. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Research Article text/html info:doi:10.3897/emt.3.183902 https://doi.org/10.3897/emt.3.183902 https://emt.pensoft.net/article/183902/ https://emt.pensoft.net/article/183902/download/pdf/ en

10.3897/emt.3.190120 2026-05-28 emt

From refuge to the wild: Strengthening the neotropical otter population Carvalho Junior,Oldemar Tosatti,Marcelo Bez Birolo,Alessandra Esteves,Priscila Brazil captive breeding de-habituation estuarine conservation Lagoa do Peri Lontra longicaudis reintroduction Estuarine Management and Technologies 3: 187-199 This supplementary document provides detailed methodological and contextual information supporting the 180-second video paper submitted to the Estuarine Management and Technologies (EMT) Journal. The case study presents the successful reintroduction of two captive-born Neotropical otters (Lontra longicaudis) at the Peri Lagoon, Southern Santa Catarina Island, Brazil, on June 4, 2025. The protocol encompasses controlled reproduction, maternal-led development, predatory training, de-habituation strategies, and post-release monitoring. This document elaborates on the biological, behavioral, and conservation aspects of the reintroduction process, offering a replicable framework for otter conservation initiatives across Neotropical estuarine systems. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Video paper in 180s text/html info:doi:10.3897/emt.3.190120 https://doi.org/10.3897/emt.3.190120 https://emt.pensoft.net/article/190120/ https://emt.pensoft.net/article/190120/download/pdf/ en

10.3897/emt.3.198905 2026-07-10 emt

Assessing the dynamics and severity of seawater intrusion in a vulnerable coastal aquifer: an integrated hydrogeochemical facies and ionic ratios approach in Paravur, India KANI,MOPHIN KANI Biju,Gowry N VS,VARSHA Base exchange index cation exchange coastal aquifer management hydrogeochemistry seawater intrusion sodium hazard Estuarine Management and Technologies 3: 201-232 Coastal aquifer monitoring commonly assumes that seawater intrusion decreases progressively with increasing distance from the shoreline. However, this assumption may not hold in hydrogeologically complex coastal settings. This study investigated seawater intrusion in the Paravur coastal aquifer, Kerala, India, using an integrated hydrogeochemical framework to evaluate deviations from the conventional conservative mixing model. A total of 100 groundwater samples were collected along a 9 km coastal–inland transect during the 2025 dry season and analysed using hydrochemical facies, ionic ratios (Cl–/Na+ and Chlorinity Index), the Base Exchange Index (BEX), principal component analysis (PCA), and irrigation suitability indices including Kelly’s Ratio (KR), Magnesium Hazard (MH), Permeability Index (PI), and Residual Sodium Carbonate (RSC). Although bulk salinity declined substantially inland (mean TDS: 504.61 to 184.06 mg/L from the Core to the Outer Zone), hydrochemical indicators revealed an opposite trend. Na–Cl facies characterised inland groundwater (6–8.7 km), Cl–/Na+ ratios approaching seawater stoichiometry (1.62 ± 0.54 versus 1.81), alkaline pH, and negative BEX values, indicating ongoing salinisation. In contrast, coastal groundwater exhibited mixed sulfate-enriched facies, acidic pH, and positive BEX values, consistent with freshening influenced by anthropogenic contamination. PCA suggested a dual-process control on groundwater chemistry, with PC1 exhibiting strong loadings on Cl–, Na+, and EC, a loading pattern consistent with salinity gradients influenced by seawater mixing (52.3% of the explained variance). PC2 shows strong BEX loading with Ca2+ and Mg2+, a pattern consistent with cation-exchange (18.8%) processes. Irrigation suitability assessment revealed a marked freshening–contamination paradox. While 93–100% of samples satisfied the individual criteria for MH, PI, and RSC, 91% of samples exceeded the critical Kelly’s Ratio threshold (KR > 1), with exceedance rates of 100%, 88%, and 76% in the Core, Mid, and Outer zones, respectively, indicating that sodium hazards remained predominant despite declining salinity. These findings suggest that geological heterogeneity and exchange processes may decouple subsurface seawater distribution from surface proximity to the coast, although confirmation of subsurface flow pathways requires geophysical investigation. The study demonstrates that integrating process-based indicators (BEX and ionic ratios) with conventional water-quality indices provides a more reliable assessment of seawater intrusion and hidden sodium hazards than salinity-based monitoring alone. The results highlight the need to extend monitoring networks inland and incorporate hydrogeochemical process indicators into groundwater management strategies for complex coastal aquifer systems. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Research Article text/html info:doi:10.3897/emt.3.198905 https://doi.org/10.3897/emt.3.198905 https://emt.pensoft.net/article/198905/ https://emt.pensoft.net/article/198905/download/pdf/ en

10.3897/emt.3.189805 2026-07-24 emt

Estuarine connectivity through the lens of a top predator. Movement ecology of Lontra longicaudis as a management tool for coastal ecosystems Carvalho Junior,Oldemar Bez Birolo,Alessandra Tosatti,Marcelo Amine Sabbagh Junior,Anwar Bioindicator functional connectivity habitat fragmentation metapopulation Otter Health Index (OHI) Estuarine Management and Technologies 3: 233-261 Long-term ecological datasets are essential for understanding how landscape connectivity changes through time, yet such datasets remain exceptionally rare for tropical estuarine predators. The Neotropical Otter Project has continuously monitored Lontra longicaudis on Santa Catarina Island, southern Brazil, since 1986. This study analyzes a standardized 20-year monitoring dataset (2004–2023) to investigate movement ecology, functional connectivity, and habitat use across a freshwater–estuarine–marine landscape. Monthly field surveys conducted at six monitoring sites recorded 9,531 spraints, which were integrated with microsatellite DNA identification to reconstruct movement pathways and evaluate connectivity among habitat compartments. The analyses demonstrate that L. longicaudis regularly moves across freshwater, brackish, and marine environments through supralittoral rocky corridors, maintaining functional connectivity within a metapopulation occupying approximately 610 km2. Temporal analyses revealed a pronounced decline in movement intensity over the 20-year study period. During the same period, Santa Catarina Island experienced substantial urban expansion and infrastructure development, highlighting the need to better understand how landscape change may influence functional connectivity. These findings indicate that long-term monitoring of movement patterns provides a sensitive indicator of changes in estuarine landscape connectivity that are not detected by conventional habitat assessments. Building upon these ecological patterns, we propose the Otter Health Index (OHI), a field-based framework that integrates movement integrity, shelter availability, and dietary diversity to support rapid assessments of estuarine condition and to assist conservation planning and ecological restoration. Our results demonstrate the value of long-term movement ecology as an effective approach for evaluating functional connectivity in coastal ecosystems and reinforce the role of the Neotropical otter as a practical bioindicator of estuarine ecosystem integrity. info:eu-repo/semantics/altIdentifier/eissn/3033-022X info:eu-repo/semantics/openAccess CC BY 4.0 Pensoft Publishers 2026 Research Article text/html info:doi:10.3897/emt.3.189805 https://doi.org/10.3897/emt.3.189805 https://emt.pensoft.net/article/189805/ https://emt.pensoft.net/article/189805/download/pdf/ en