Regional Studies in Marine Science最新文献

{"title":"Microplastics in the Southern Brazilian estuary: Interactions between environment, morphology, and seasonal variation","authors":"Vanessa F. Fonseca ,&nbsp;Raimara S. Gomes ,&nbsp;Crislaine F. Bertoldi ,&nbsp;Camila C. Passos ,&nbsp;Décio Semensatto ,&nbsp;Andreia N. Fernandes","doi":"10.1016/j.rsma.2025.104517","DOIUrl":"10.1016/j.rsma.2025.104517","url":null,"abstract":"<div><div>Estuaries are complex environments rich in biodiversity, making it challenging to understand the distribution and occurrence of microplastics due to the multiple variables that can influence the movement of these particles. Based on this, this study evaluated the influence of different environmental aspects on the distribution and transport of microplastics in the surface waters of the Tramandaí River estuary. An average occurrence of 14.21 ± 3.07 items L⁻¹ was identified, with a predominance of white/transparent fibers smaller than 500 µm in size. PE and PP were the predominant polymers with an average carbonyl index (CI) of 0.77 ± 0.41. From the results, it was observed that periods with little rainfall can decrease the occurrence of microplastics in the surface water of the studied estuary but increase the predominance of white or colorless particles and fragments. Additionally, anthropogenic activity and water depth influenced the occurrence and form of particles in the surface waters. Furthermore, the progressive approach to the sea decreased the occurrence of blue microplastics and increased the abundance of smaller particles. Finally, the change in tides directly impacted only the estuary point, influencing the occurrence and shape of the particles. Thus, the results demonstrated that several factors interfered with the abundance and characteristics of the microplastics found in the Tramandaí River basin. The estuary point was influenced by the largest number of variables, highlighting the complexity of these environments. Additionally, the importance of evaluating not only aspects intrinsic to the sampling site but also seasonal factors was emphasized.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104517"},"PeriodicalIF":2.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining horizontal and vertical distributions of polar cod (Boreogadus saida) in the Bering Sea and western Arctic Ocean using traditional sampling and environmental DNA metabarcoding","authors":"Woo-Seok Gwak ,&nbsp;Jee-Hoon Kim ,&nbsp;Kyoung-Ho Cho ,&nbsp;Eun-Jin Yang","doi":"10.1016/j.rsma.2025.104522","DOIUrl":"10.1016/j.rsma.2025.104522","url":null,"abstract":"<div><div><em>Boreogadus saida</em>, commonly known as polar cod, is a key species in Arctic marine ecosystems that is also an indicator of environmental change. This study examined the spatial distribution of <em>B. saida</em>, which typically inhabits circumpolar waters ranging in temperature from −2 to 8°C. Age classification based on size was performed on fish samples collected using ring nets, frame trawl nets, and hand nets. The results demonstrated that most individuals collected by ring and frame trawl nets in the southern Chukchi Sea (SCS) and East Siberian Sea (ESS) during late July and early August were age-0, while those collected in mid-August were age-1 and age-2. The individuals collected by hand net in the surface of the ESS and the northern Chukchi Sea (NCS) were all in age-1 and age-2 + . Smaller larvae collected in the ESS suggested local spawning grounds. Environmental factors, particularly temperature and prey availability, were found to influence habitat selection. To complement traditional sampling methods, environmental DNA (eDNA) metabarcoding using MiFish primers was conducted at various horizontal and vertical sites across the Bering Sea (BS), Chukchi Sea (CS), and ESS. <em>B. saida</em> eDNA was detected from surface waters to a maximum depth of 1804 m at temperatures ranging from −1.6 to 4.4°C, which demonstrated the utility of eDNA for mapping both horizontal and vertical distributions. These findings highlight the value of integrating eDNA metabarcoding with conventional techniques to clarify <em>B. saida</em>’s distribution and life history. They also emphasize the broader potential of eDNA monitoring as a sensitive, non-invasive framework for Arctic biodiversity assessment. Taken together, our results underscore not only the current distribution of <em>B. saida</em> but also the promise of eDNA as a foundation for long-term, ecosystem-wide monitoring in a rapidly changing Arctic.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104522"},"PeriodicalIF":2.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ecological vulnerability assessment of mangroves along coasts of China's mainland based on remote sensing and multi-criteria approach","authors":"Siyang She ,&nbsp;Hao Chen ,&nbsp;Jianghao Xu ,&nbsp;Jihong Chen ,&nbsp;Chuan Pang ,&nbsp;Chengkun Liu","doi":"10.1016/j.rsma.2025.104521","DOIUrl":"10.1016/j.rsma.2025.104521","url":null,"abstract":"<div><div>With the expansion of human activities in coastal areas, China's mangrove ecosystems face increasingly severe environmental risks. Scientific assessment of their ecological vulnerability is essential for sustainable protection. This study constructs a comprehensive assessment model, combining game theory weighting method with two improved objective weighting models to quantify the impact of historical data from 2003 to 2023 on current vulnerability. The assessment system covers four criteria layers and 16 indicator layers, and multi-criteria decision analysis (MCDA) is used for weighted calculation. The results show that 77.76 % of mangrove areas have low vulnerability, while high-vulnerability areas are mainly concentrated in the Pearl River Delta, central Fujian and southern Zhejiang. Sensitivity analysis shows that the pressure of socio-economic activities has the most significant impact on vulnerability (mean sensitivity of 73.52 %), followed by marine industry (53.14 %) and pollution control (51.1 %), and the natural conditions of mangroves have the least impact (30.98 %). The study found that external pressure (such as economic activities and industrial development) is the main driving factor of mangrove vulnerability, while natural factors have a weaker effect. This study provides a scientific basis for the assessment of mangrove ecological vulnerability, supports government management and ecological protection policy formulation, and promotes the coordination of economic development and mangrove protection in coastal areas.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104521"},"PeriodicalIF":2.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dominant contribution of land-based aquaculture to coastal organic matter and nutrient loads: Quantifying particulate organic carbon and ammonium fluxes from Jeju Island, South Korea","authors":"Yujin Kim ,&nbsp;GyuRi Kim ,&nbsp;Min-Young Lee ,&nbsp;Sung-Eun Park ,&nbsp;Chung-Sook Kim ,&nbsp;Tae-Hoon Kim","doi":"10.1016/j.rsma.2025.104520","DOIUrl":"10.1016/j.rsma.2025.104520","url":null,"abstract":"<div><div>Land-based aquaculture farms (LAFs) are rapidly expanding on Jeju Island, South Korea, raising concerns about their environmental impact on coastal ecosystems. However, the quantitative contribution of LAFs to coastal nutrient loading remains inadequately understood. This study quantified the net fluxes of key pollutants from LAFs on Jeju Island by measuring concentrations of particulate organic carbon (POC), dissolved organic carbon (DOC), and dissolved inorganic nutrients (DIN, DIP, DSi) in the influent and effluent of four representative farms during the spring, summer, and autumn of 2019. Although the effluent concentrations of DOC, DIN, DIP, and DSi were comparable to influent levels, POC and ammonium (NH₄⁺) concentrations were significantly higher in the effluent (66 ± 24 µM and 24 ± 12 µM, respectively) than in the influent (7.5 ± 1.0 µM and 0.8 ± 0.2 µM, respectively), identifying them as primary pollutants associated with aquaculture activities. Effluent POC concentrations peaked in the summer, coinciding with increased feeding rates. Time-series observations capturing feeding-induced variations were used to estimate the net annual fluxes of POC and NH₄⁺ from all LAFs on Jeju Island at 35.7 × 10⁷ mol yr⁻¹ and 16.6 × 10⁷ mol yr⁻¹, respectively. Notably, the NH₄⁺ flux from LAFs was approximately 10 times greater than the combined fluxes from submarine groundwater discharge (SGD) and wastewater treatment plants (WWTPs), establishing LAFs as the primary source of bioavailable nitrogen in the coastal waters of Jeju Island. These findings highlight the urgent necessity for revising current environmental regulations by implementing nutrient-specific standards for aquaculture effluent to mitigate eutrophication and protect the ecological integrity of coastal ecosystems on Jeju Island.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104520"},"PeriodicalIF":2.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical profiles of microplastics in coastal sediments of Panjang Island, Java Sea","authors":"Dwi Amanda Utami ,&nbsp;Tubagus Solihuddin ,&nbsp;Elizabeth C. Sibert ,&nbsp;Anne Cohen ,&nbsp;Sri Yudawati Cahyarini","doi":"10.1016/j.rsma.2025.104518","DOIUrl":"10.1016/j.rsma.2025.104518","url":null,"abstract":"<div><div>The proliferation of plastic pollution has led to the widespread accumulation of microplastics (MPs) in marine ecosystems. While surface sediment contamination is relatively well studied, knowledge of vertical MP distribution within sediment columns remains limited. This study examines the abundance, vertical distribution, and characteristics of MPs in subtidal and intertidal sediments of Panjang Island, Java Sea. Fifteen shallow (10 cm) and three deep (∼100 cm) sediment cores were analyzed for MP abundance, morphology, size, color, and polymer using microscopy and ATR-FTIR. MPs were detected in all cores, with an average concentration of 0.49 ± 0.28 MPs g⁻¹ in surface sediments. The highest surface concentration (2.08 ± 0.22 MPs g⁻¹) occurred in the southwest, a sheltered site with greater anthropogenic influence, while the lowest (0.05 ± 0.07 MPs g⁻¹) was recorded in the northwest, a remote and less disturbed area. Fibers dominated particle types. White, black, and blue were the most common colors, and size distributions were skewed toward particles &lt;1 mm. Polypropylene and polyethylene were the most frequent polymers, reflecting their widespread use and persistence. Vertical profiles revealed higher MP concentrations near the surface, indicating intensified inputs in recent decades. No MPs were detected below 70 cm, suggesting limited downward migration and marking the onset of contamination during the plastic era. This study also found MPs in deeper sediment layer, likely due to post-depositional processes such as bioturbation. These findings demonstrate that sediment cores serve as valuable archives of historical MP deposition, capturing both global production trends and local environmental influences, and provide a basis for targeted management strategies.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104518"},"PeriodicalIF":2.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ciguatera poisoning trends in Florida using a predictive hybrid model","authors":"Daniel Breininger ,&nbsp;Christopher Ryzowicz ,&nbsp;Motti Goldberger ,&nbsp;Michael Splitt ,&nbsp;Robert van Woesik ,&nbsp;Nezamoddin N. Kachouie","doi":"10.1016/j.rsma.2025.104514","DOIUrl":"10.1016/j.rsma.2025.104514","url":null,"abstract":"<div><div>The aim of this study is to identify an optimal predictive model for ciguatera poisoning and to determine which variables and time lags best explain the number of cases reported in Florida between 2006 and 2020. Ciguatera poisoning is a debilitating condition caused by consuming coral reef fish contaminated with ciguatoxins, which originate from toxin-producing dinoflagellates and biomagnify through the food chain. In severe cases, the illness can be fatal. Global climate change is expected to increase both the incidence of ciguatera poisoning and its geographic range, extending from tropical and subtropical reefs into temperate regions. This makes understanding and predicting its dynamics particularly urgent, as millions of people worldwide depend on reef fish as a dietary staple. To address this need, we developed an integrated approach combining wavelet cross-coherence analysis with a count modeling framework. Candidate predictors included cumulative monthly landings of Amberjack, Red Snapper, Red Grouper, and Scamp Grouper; the number of tropical cyclones; maximum ocean temperatures; precipitation; season; and Florida’s human population. The optimal model identified was a Zero-Inflated Negative Binomial model. Results showed positive associations between ciguatera cases and (i) maximum ocean temperatures, (ii) storm frequency, (iii) fish landings, and (iv) human population size, alongside a negative relationship with precipitation. By establishing a robust predictive framework, this study advances understanding of the environmental and anthropogenic drivers of ciguatera poisoning. The findings provide a foundation for forecasting outbreaks and offer actionable insights to fisheries and public health agencies aiming to reduce risks for Florida residents and tourists.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104514"},"PeriodicalIF":2.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the impacts of artificial inlet opening and freshwater extraction and on salinity and temperature gradients in a tropical coastal lagoon","authors":"Etzaguery Marin-Coria ,&nbsp;Alejandro Paladio-Hernández ,&nbsp;M. Luisa Martínez ,&nbsp;Valeria Chávez ,&nbsp;Rodolfo Silva","doi":"10.1016/j.rsma.2025.104512","DOIUrl":"10.1016/j.rsma.2025.104512","url":null,"abstract":"<div><div>The coastal lagoon of La Mancha, in Veracruz, Mexico, is a site of great biological, ecological, and economic importance because of its high biodiversity, tourism and fishing activities. Two current anthropogenic actions that could be altering this system are the artificial opening of the inlet by fishermen, to increase the inflow of marine organisms, and the extraction of fresh water to supply recent housing developments. To assess the impacts of these actions, a two-dimensional numerical model (Delft3D) was calibrated and validated, and the horizontal salinity and temperature gradients were simulated by varying the amounts of freshwater extraction for opened and closed inlet conditions in rainy and dry seasons. The results show that in open inlet conditions, even when the water discharged from the streams is varied due to the season, a very marked salinity gradient forms from north to south, with oligohaline, polyhaline, and euhaline conditions. When the inlet is open, in the northern part of the lagoon, most of the water body has high salinity values (35 ppt), and when the aperture closed, salinity dilutes throughout the system to mesohaline and polyhaline conditions (5−30). The freshwater demand associated with current developments in the surroundings of La Mancha, did not significantly modify the temporal and spatial distribution of temperature and salinity in the lagoon. However, the increasingly constant artificial opening of the inlet has implications for these gradients. The changes in salinity and temperature gradients are of great importance for the flora and fauna of these ecosystems. The inadequate and frequent opening of the water body to the sea alters salinity and temperature conditions which will greatly affect the biota, many of which are of commercial interest.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104512"},"PeriodicalIF":2.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevated concentration of selected heavy metals in Gadani shipbreaking area, Pakistan","authors":"Allauddin Kakar ,&nbsp;Sofi Jonsson ,&nbsp;Qaisar Mahmood","doi":"10.1016/j.rsma.2025.104507","DOIUrl":"10.1016/j.rsma.2025.104507","url":null,"abstract":"<div><div>The world's busiest ship-recycling hub, Gadani Beach in Baluchistan, Pakistan, may pollute the environment. This work provides the first complete and geographically resolved assessment of heavy metal pollution in Gadani shipbreaking region coastal sediments. Nine heavy metals were evaluated in 69 sediment samples from the shipbreaking site and a neighboring reference zone. Top 7 cm beach sand and sediments were collected from the yard zone and deconstruction zone at intertidal (0.3 m) and subtidal (2.4 m) depths. Additional sediment samples were taken from reference sites at 1.4–3 m depth. Two yard and dismantling zone replicates, and one reference site replicate were taken at each station. ICP-MS analyzed metals. Geoaccumulation Index and potential ecological risk index (PERI) were used to assess sediment contamination. Geoaccumulation Index and potential ecological risk index (PERI) were used to assess sediment contamination. Metal concentrations were 3–53 times greater in the shipbreaking area than at the reference location. The concentration hierarchy was Fe &gt; Mn &gt; Zn &gt; Pb &gt; Cr &gt; Ni &gt; As &gt; Co &gt; Cd, with Pb, Zn, and Ni above Effect Range Medium (ERM) criteria, implying ecological harm. Spearman correlation and cluster analysis showed substantial inter-metal correlations, indicating shared sources—primarily shipbreaking materials like paints, batteries, anodes, and lubricants. The yard zone was most polluted, followed by the seaward disassembly zone. Sediment Quality Guidelines (SQGs), Contamination Factor (Cf), Geoaccumulation Index (Igeo), and δ¹ ³C isotopic fingerprints identified anthropogenic oil inputs and environmental hazards. This study provides essential baseline data for regional ship recycling regulatory frameworks and environmental management.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104507"},"PeriodicalIF":2.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing pollution legacies in the Suances Estuary (N Spain): Challenges for dating methods and ecological recovery after mine closure","authors":"María Jesús Irabien ,&nbsp;Alejandro Cearreta ,&nbsp;José Gómez-Arozamena ,&nbsp;Ane García-Artola ,&nbsp;Humberto Serrano-García ,&nbsp;Jon Gardoki","doi":"10.1016/j.rsma.2025.104511","DOIUrl":"10.1016/j.rsma.2025.104511","url":null,"abstract":"<div><div>Estuaries are globally threatened ecosystems, requiring urgent assessment of their historical deterioration and recovery processes to inform realistic strategies for sustainable management. This study employs an integrated, multidisciplinary approach, including analyses of trace metals, foraminifera, and radionuclides in surface samples and short (47 cm) sediment cores, to evaluate the environmental evolution of the heavily polluted Suances Estuary (N Spain) and its response to the cessation in 2003 of historical mining activities of one of Europe’s largest carbonate-hosted Pb-Zn ores, the Reocín metalliferous deposits. Core samples showed elevated concentrations of Zn (maximum value &gt;10,000 mg kg⁻¹), Pb (max. 2700 mg kg⁻¹), Cd (35.3 mg kg⁻¹), and Hg (41 mg kg⁻¹), exceeding local background values and often surpassing Sediment Quality Guidelines. Despite an overall decrease in metal concentrations from surface samples between 2003 (max. value of Zn: 11,200 mg kg⁻¹; Pb: 2200 mg kg⁻¹; Cd: 26.4 mg kg⁻¹) and 2022 (max. value of Zn: 8520 mg kg⁻¹; Pb: 990 mg kg⁻¹; Cd: 20.5 mg kg⁻¹), significant spatial variations suggest sediment redistribution within the estuary. Moreover, foraminiferal abundances remain extremely low (range of standing crops: 1–510 individuals per 80 cm³), indicating persistent unfavorable environmental conditions for life and reproduction. Abnormal ²¹⁰Pb_xs signals in the sedimentary record unveil the impact of anthropogenic events related to the development and subsequent abandonment of mining activities. These findings underscore the complexity of sediment chronologies and environmental responses in historically contaminated estuarine systems, highlighting the need for long-term monitoring programs within a multidisciplinary framework.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104511"},"PeriodicalIF":2.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Health risk and ecological assessment of potentially toxic elements in seawater along the Betoya Bay coastline, Morocco","authors":"Rihab Ben-tahar ,&nbsp;Oualid Boukich ,&nbsp;Mohammed Mahjoub ,&nbsp;Mohamed Brahmi ,&nbsp;Mashail N. Alzain ,&nbsp;Omar Noman ,&nbsp;Fahd A. Nasr ,&nbsp;Bouchra El guerrouj ,&nbsp;Youssef Smiri","doi":"10.1016/j.rsma.2025.104516","DOIUrl":"10.1016/j.rsma.2025.104516","url":null,"abstract":"<div><div>Betoya Bay, located on the Moroccan coast of the Mediterranean Sea, is a strategically important ecosystem that was significantly impacted by port development, fishing activities, and rapid urbanization. Due to the importance of the Mediterranean Sea in maritime commerce and its increased vulnerability to pollution, the quality of Betoya Bay’s waters is a major international concern. This study examined potentially toxic elements (PTEs) contamination in seawaters of Betoya Bay by collecting samples from five representative sites over the year. PTE concentrations were analyzed, water quality was assessed using ecological indices, and risks to human health were evaluated. The average concentrations (µg/L) were as follows: Zn (166.65) &gt; Pb (24.14) &gt; As (19.71) &gt; Co (8.59) &gt; Cd (3.92) &gt; Cu (3.39) &gt; Cr (0.17) &gt; Ni (&lt;DL). The heavy metal evaluation index (HEI), heavy metal pollution index (HPI), and total potential ecological risk index (PER) showed low contamination, with values ranging from 0.004 to 0.020, 0.030–0.261, and 24.43–104.32, respectively. In contrast, water quality index (WQI) showed low to moderate contamination, with values ranging from 0.48 to 2.44. Human health risk analysis revealed a total hazard quotient (THQ) below 1, indicating negligible non-carcinogenic risk. Additionally, total carcinogenic risk (TCR) values remained below the acceptable threshold (&lt;10⁻⁶), confirming tolerable exposure. Statistical analysis revealed multiple sources of pollution, suggesting a combination of anthropogenic and natural inputs. Although the results indicate low contamination and limited health risks for affected populations, it is essential to ensure continuous surveillance of water quality. Persistent anthropogenic inputs and accumulation of PTE in the environment could increase pressure on marine ecosystems and pose long-term risks to human health. Therefore, sustainable management strategies and regular monitoring programs must be implemented to anticipate these developments and preserve the ecological functionality and socioeconomic benefits of Betoya Bay.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104516"},"PeriodicalIF":2.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}