Regional Studies in Marine Science最新文献

{"title":"Anthropogenic and climate driven threats to sea turtle habitats on Karnataka’s Coastline","authors":"Bindu Sulochanan ,&nbsp;Veena Shettigar ,&nbsp;Sujitha Thomas ,&nbsp;Shelton Padua ,&nbsp;K.S. Sobhana","doi":"10.1016/j.rsma.2025.104539","DOIUrl":"10.1016/j.rsma.2025.104539","url":null,"abstract":"<div><div>Sea turtle nesting and foraging habitats along the Karnataka Coast were evaluated using a multi-dimensional framework that integrated local ecological knowledge from resident fishermen, spatial estimation of beach nesting zones, analysis of storm events in the Arabian Sea, decadal coastal productivity trends, and vessel traffic distribution patterns. Sightings and strandings comprised of a hawksbill turtle, two green turtles and seven olive ridleys. The spatial analysis of beach zones showed a maximum nesting area of 0.068 km² per kilometer of shore. The resident fisher population (52.77 %) attributed loss of sea turtle nesting grounds to sea erosion and seawalls. The seawalls were laid on 36 % of the surveyed beach segments. Decadal assessments of coastal water productivity, based on Chlorophyll-a (Chl-a) concentrations, indicate that 45.9 % of the observations were classified within the 'good' trophic status category. The sea surface temperature (SST) and Chl-a differed distinctly between near shore areas and deeper waters (10–29 m depth), indicating that the latter were influenced by coastal currents and ENSO events. Pearson’s correlation analysis revealed a positive correlation between SST and salinity (r = 0.53), and a negative correlation between SST and Chl-a (r = -0.14), offering insights into ecosystem dynamics. From 2012–2023, the Indian subcontinent experienced eighty-eight North Indian Ocean storms, highlighting the urgent need for climate-resilient conservation strategies. According to vessel traffic analysis, 56 % of fishing vessels were operating at speeds below 0.6 knots, suggesting potential opportunities to engage fishermen in conservation initiatives. Soft engineering structures are essential to protect turtle nesting habitats and safeguard coastal communities.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104539"},"PeriodicalIF":2.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269645","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":"The killing of the sacred embryos: Impacts of polystyrene nanoplastics on early life stages of the tropical sand dollar Mellita quinquiesperforata","authors":"Catarina Serrão ,&nbsp;Renato Henrique Martins Galdino ,&nbsp;Wagner de Mendonça Faustino ,&nbsp;Luis Fernando Marques-Santos","doi":"10.1016/j.rsma.2025.104541","DOIUrl":"10.1016/j.rsma.2025.104541","url":null,"abstract":"<div><div>Nanoplastics are emerging contaminants of significant concern for the marine environment. However, their effects on the embryonic and larval development of tropical marine invertebrates remain poorly understood. This study aimed to investigate the impact of amine-functionalized (PS-NH₂) and carboxyl-functionalized (PS-COOH) polystyrene nanoparticles on fertilization, embryonic development, and larval stages of the tropical sand dollar <em>Mellita quinquiesperforata</em>. Adult specimens were collected on the northeastern coast of Brazil. Eggs, sperm, embryos, and larvae were exposed to both types of nanoplastics at concentrations ranging from 0.005 to 5.0 mg·L⁻¹ . The PS-COOH suspensions in tropical natural seawater formed larger aggregates than PS-NH₂, with PS-COOH reaching the micrometer scale while PS-NH₂ remained in the nanometric range. The results revealed that only PS-NH₂ at the highest concentration (5 mg·L⁻¹) were toxic, inhibiting fertilization and causing mortality in both gastrulae and larvae stages. In contrast, PS-COOH (5 mg·L⁻¹) were internalized by newly fertilized eggs, persisted in blastomeres throughout development, and accumulated in the larval digestive tract without showing apparent toxic effects. Our findings highlight the toxicity of PS-NH₂, raise concerns about potential long-term damage, and emphasize the need for policies to mitigate the risks of plastic contamination in tropical marine ecosystems.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104541"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269597","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":"Can ocean acidification alleviate carbon deficiency in eelgrass Zostera marina clonal ramets under conditions of nutrients, sulfate and ocean acidification?","authors":"Qiyin Tan,&nbsp;Qinxia Yang,&nbsp;Hang Zhang,&nbsp;Weidong Gu,&nbsp;Qinyi He,&nbsp;Yanlin Wang,&nbsp;Hongzhan Liu,&nbsp;Changzi Ge","doi":"10.1016/j.rsma.2025.104548","DOIUrl":"10.1016/j.rsma.2025.104548","url":null,"abstract":"<div><div>Carbon deficiency in the eelgrass caused by nutrient eutrophication and high concentrations of sulfate causes eelgrass mortality; however, ocean acidification provides sufficient carbon. Thus, it is inferred that ocean acidification might reduce the carbon deficiency. To verify this hypothesis, eelgrass clonal ramets were exposed to 72—h combined conditions of ocean acidification (CO₂), nitrate (NO₃-N), ammonia (NH₄-N), phosphate (PO₄-P) and sulfate (SO₄-S). The pigment contents were affected by nutrients; however, the <em>Chl a</em>/<em>b</em> ratio was inhibited by the interaction between CO₂ and NO₃-N and was promoted by interaction between NO₃-N and NH₄-N. The soluble protein contents in leaves were increased by CO₂; however, the soluble protein contents in roots were reduced by CO₂. The soluble sugar contents in the leaves had negatively correlation with the interaction between NO₃-N and CO₂. Moreover, the SOD activities of the rhizomes were inhibited by CO₂. All these findings suggest that ocean acidification does not seem to effectively alleviate the deficiency of soluble carbon in eelgrass under eutrophication and high concentrations of sulfate; however, the eelgrass mortality rate was inhibited by CO₂ and the interaction between PO₄-P and SO₄-S. Thus, eelgrass has extremely complex carbon supply and conversion mechanisms to ensure its survival under composite conditions or eelgrass has another mechanism of death in eutrophication.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104548"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269598","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 diversity, analyzing community structure, and mapping mangrove distribution at Lothian Wildlife Sanctuary: A lesser-explored model Island in Indian Sundarbans","authors":"Rajat Kanti Sarkar ,&nbsp;Shramana Ghosh ,&nbsp;Raju Biswas ,&nbsp;Satyajit Oraon ,&nbsp;Tanushree Gaine ,&nbsp;Sharadindu Adak ,&nbsp;Punarbasu Chaudhuri ,&nbsp;Swati Gupta Bhattacharya ,&nbsp;Kashinath Bhattacharya","doi":"10.1016/j.rsma.2025.104545","DOIUrl":"10.1016/j.rsma.2025.104545","url":null,"abstract":"<div><div>The vast Sundarbans, located in the southern part of the Gangetic Delta encompassing Eastern India and Bangladesh, stretches between the Hooghly River (India) to the west and the Meghna River (Bangladesh) to the east. The present study focused on the Indian Sundarbans, situated within the North and South 24 Parganas districts of West Bengal. The study was conducted at tiger free Lothian Island, designated as a Wildlife Sanctuary in 1976. The whole Island was divided into 36 grids, each covering an area of 1 sq. km. This study involved a quantitative analysis of the plant community in each grid, employing 100 sq. m quadrats as sampling units. A total of 56 plant species were identified, including 25 true mangroves, 13 mangrove associates, and 18 exotic plants. This study revealed the presence of 10 additional true mangrove species and 5 more mangrove associates compared to prior research. Notably, <em>Avicennia marina</em> and <em>Avicennia alba</em> displayed the highest Important Value Indices (IVI), followed by <em>Excoecaria agallocha</em> and <em>Ceriops decandra</em>. Analysis of species diversity, utilizing various indices, indicated that Lothian Island possesses high plant diversity and a balanced species distribution. Through dendrogram analyses, five distinct plant community types were discerned. Spatial distribution data highlighted the prevalence of three <em>Avicennia</em> species, accompanied by associated plants like <em>Aegialitis rotundifolia</em> and <em>Excoecaria agallocha</em>. These species showed distribution patterns across varying soil pH and salinity levels on the Island. But surprisingly, no significant correlations were found between environmental parameters and diversity indices within the mangrove plant community based on Pearson's correlation coefficient.</div><div>The present study showcased the wide dispersion of <em>Avicennia marina</em>, <em>Avicennia alba</em>, and <em>Avicennia officinalis</em> from lower to higher salinity level on Lothian Island. This contrasts with earlier reports that noted restricted <em>Avicennia</em> distribution due to lower historical salinity levels on the Island.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104545"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269599","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":"Presence and seasonal distribution of microplastics in beach sand of Kuşadası-Davutlar-Güzelçamlı coastal region of Aydın province in Türkiye","authors":"Esin Poyrazoğlu Çoban ,&nbsp;Hatice Çelik Yılmaz ,&nbsp;Ayçanur Bozdağ ,&nbsp;Hacı Halil Bıyık","doi":"10.1016/j.rsma.2025.104542","DOIUrl":"10.1016/j.rsma.2025.104542","url":null,"abstract":"<div><div>Microplastic pollution has become an increasingly global problem due to the unconscious use of products containing plastic and the rapid increase in the world population. Studies conducted in aquatic environments such as sea and freshwater in Türkiye are not sufficient. In particular, there are no studies on microplastic pollution in Aydın province, located on the Aegean Sea coast in the southwest of Türkiye. Therefore, this study generally provides a comprehensive assessment of the presence and status of microplastics on Aydın beaches. For this purpose, microplastic pollution was investigated in beach sand collected from 10 stations in the Kuşadası-Davutlar-Güzelçamlı coastline of Aydın province located on the Aegean Sea coast of Turkey in autumn, winter, spring and summer seasons. Microplastics (MPs) collected seasonally from the stations were evaluated in terms of abundance, size, color and shape. The average MP value at each beach in four seasons were found as Güzelçamlı Beach (119.39 ± 30), Venüs Beach 1 (126.32 ± 41.38), Venüs Beach 2 (73.6 ± 11.25), Davutlar Youth Camp Beach (103.34 ± 65.57), Sevgi Beach (87.28 ± 43.18), Davutlar Beach (84.21 ± 33.18), Nazilli Site (131.53 ± 53.63), Kuşadası Central Public Beach (68.24 ± 40.76), Kadınlar Beach (103.05 ± 27.95), Long Beach (59 ± 42.84). The most dominant MPs at the stations in all seasons were found to be 5 mm in size. In addition, the most dominant color among the MPs collected in four seasons was blue, followed by green and white. On the other hand, the most dominant MP shapes in all four seasons were determined as fragment, films and fibers, respectively. This study presents detailed MPs data around the coastal area of Aydin Province for the first time; thus, it can help in develop appropriate strategies for MP pollution.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104542"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269641","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":"Unveiling nutritional indices and chemical composition of bull’s eye (Priacanthus hamrur) fish: Comprehensive insights for health and nutrition","authors":"Ravi Baraiya ,&nbsp;Vijayakumar Renuka ,&nbsp;Radhika Rajasree Santha Rabindranath","doi":"10.1016/j.rsma.2025.104540","DOIUrl":"10.1016/j.rsma.2025.104540","url":null,"abstract":"<div><div>The rising demand for seafood worldwide has produced considerable waste during processing. This study assessed the nutritional constituents of the waste and edible portions generated during the processing of <em>Priacanthus hamrur</em> fish. The study results revealed that the edible portion contributes 49.84 ± 1.18 %, which can be utilized for direct consumption, and the remaining 50 % was considered waste. The highest protein % (wet weight basis) was found in the skin (25.70 ± 0.47 %), followed by mince (18.65 ± 0.38 %). The viscera exhibited a high fat (13.66 ± 0.24 %) and a lower relative moisture content. In the essential amino acids, viscera exhibited the significantly (p &lt; 0.05) highest amino acids (48.03 ± 0.37 g/100 g of protein), followed by mince (39.87 ± 0.83 g/100 g), head (38.73 ± 1.91 g/100 g), and frame (35.07 g/100 g), skin (25.29 ± 1.57 g/100 g). Total polyunsaturated fatty acids (PUFA) content in mince, head, frame, viscera, and skin was determined to be 25.73 ± 0.47 %, 32.39 ± 0.26 %, 27.60 ± 0.96 %, 15.86 ± 0.10 %, and 34.29 ± 0.65 %, respectively. The PUFA/SFA ratio was higher in the skin (0.91 ± 0.02). The lipid quality values ranged from 12.98 ± 0.56–23.39 ± 0.89, indicating high-quality lipids. The skin contained the highest magnesium, calcium, and phosphorus levels, at 1.82 ± 0.13, 53.13 ± 0.53, and 64.18 ± 0.08 g/kg, respectively. These findings demonstrate that the discarded components of <em>P. hamrur</em> have considerable nutritional value, indicating their potential as sustainable resources for human consumption and biotechnological applications.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104540"},"PeriodicalIF":2.4,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269642","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":"Unveiling deep-sea fish communities through eDNA analysis during extreme upwelling events in Pantar Strait, Indonesia","authors":"Yulita Dwi Astuti ,&nbsp;Nining Nursalim ,&nbsp;Muhammad Danie Al Malik ,&nbsp;Ekitia Reyza Syakal ,&nbsp;Lilik Maslukah ,&nbsp;Yusuf Jati Wijaya ,&nbsp;Rizki Taqwa Putranto ,&nbsp;Heru Nur Krisna ,&nbsp;Ikhsan Mustaqim ,&nbsp;Azza Fidyani Sintania Susanti ,&nbsp;R. Dwi Susanto ,&nbsp;Ni Kadek Dita Cahyani ,&nbsp;Anindya Wirasatriya","doi":"10.1016/j.rsma.2025.104536","DOIUrl":"10.1016/j.rsma.2025.104536","url":null,"abstract":"<div><div>Extreme upwelling in the Pantar Strait is a unique phenomenon that occurs for 1–3 days between August and November, with a frequency of twice per day, each event lasting approximately one hour. Due to the dramatic drop in sea surface temperature (SST) by more than 10°C brought on by tidal forces, this phenomenon is known as an extreme upwelling event (EUE). The cold water is estimated to originate from a depth of approximately 1000 m. One of the major questions regarding this phenomenon is its biological aspect, specifically the composition of the deep-sea fish community that ascends along with the cold water. This study uses an environmental DNA (eDNA) analysis approach during EUEs to determine the abundance, distribution, diversity, and dominance of these fish communities. Given that morphological identification is challenging, eDNA offers an advantage by detecting DNA released into the environment (water) and carried to the surface during upwelling. This study found 323 different kinds of fish at three different times: before, during, and after the upwelling, by focusing on the 12S rRNA gene and sequencing using Third Generation Sequencing (TGS) methods. The study successfully identified several deep-sea fish species, such as <em>Benthosema fibulatum, Dasyscopelus asper, Diaphus garmani, Diaphus suborbitalis, and Diaphus watasei</em>, likely originating from depths of approximately &gt;1000 m. This provides an indication of the source of the upwelled cold water. In the future, further research focusing on different taxa, such as invertebrates and microorganisms, could complement our understanding of the EUE phenomenon.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104536"},"PeriodicalIF":2.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269644","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":"Population genetic structure of commonly caught commercial shark species along the Indian coast","authors":"Sudha Kottillil ,&nbsp;Chetan Rao ,&nbsp;Kartik Shanker","doi":"10.1016/j.rsma.2025.104533","DOIUrl":"10.1016/j.rsma.2025.104533","url":null,"abstract":"<div><div>Sharks are a highly threatened group of marine vertebrates which are susceptible to anthropogenic factors, particularly overfishing, with India being one of the top shark fishing nations globally. Unregulated and largescale take is known to reduce genetic diversity with negative consequences for population health. This lack of knowledge on genetic structure can hamper stock assessments and management of fisheries. Given the paucity of studies on the genetics of Indian sharks, we examined population genetic structure within a few commonly caught sharks along the Indian coast. We collected tissue samples and generated molecular data (mtDNA COI) for three commonly caught commercial species – <em>Alopias pelagicus</em>, <em>Scoliodon laticaudus</em> and <em>Sphyrna lewini</em> – and two species of bamboo sharks (<em>Chiloscyllium arabicum</em> and <em>Chiloscyllium griseum</em>) – along both the east and west coasts of India. Median-joining haplotype networks and Maximum Likelihood Trees using primary and secondary data were constructed and an AMOVA was used to determine patterns of population genetic structure. Within the shark species, there was no significant genetic structuring in populations from the two Indian coasts, indicating gene flow across the Arabian Sea and Bay of Bengal. Additionally, <em>C. arabicum</em> individuals from the Arabian Sea and <em>C. burmensis</em> sequences from both coasts clustered together, casting doubt on the validity of these species. These results suggest a lack of strong geographical structure within sharks in the northern Indian Ocean, but finer-scale markers may provide more insights.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104533"},"PeriodicalIF":2.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269643","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":"Births and abortions in wild pinnipeds along the southern Brazilian coast","authors":"Renan C. de Lima ,&nbsp;Sérgio C. Estima ,&nbsp;Paula L. Canabarro ,&nbsp;Karina R. Groch ,&nbsp;Fábio P. da Conceição ,&nbsp;Silvina Botta ,&nbsp;Valentina Franco-Trecu ,&nbsp;Julieta D. Cebuhar ,&nbsp;Caio R. Soares-Oliveira ,&nbsp;Carlos de Oliveira ,&nbsp;Andrine P. da Silva ,&nbsp;Larissa R. de Oliveira","doi":"10.1016/j.rsma.2025.104526","DOIUrl":"10.1016/j.rsma.2025.104526","url":null,"abstract":"<div><div>Pinnipeds exhibit diverse reproductive strategies influenced by ecological and environmental factors. Most species breed in well-established colonies that offer sheltered habitats, stable substrates, and reliable prey availability. However, rare reproductive events beyond range can provide insights into population dynamics, including shifts in distribution, and emerging threats, such as habitat disturbance and disease transmission. Here, we document the first records of pinniped births and abortions in the Brazilian coast between 1979 and 2024. These events were documented as part of systematic marine mammal stranding programs conducted year-round in the states of Rio Grande do Sul and Santa Catarina. Four births were recorded, two southern elephant seals (<em>Mirounga leonina</em>) and two South American fur seals (SAFS) (<em>Arctocephalus australis</em>). In addition, 11 abortion events were recorded—two confirmed (one subantarctic fur seal, <em>A. tropicalis</em>, and one South American sea lion (SASL), <em>Otaria flavescens</em>) and nine inferred cases involving SASLs and SAFSs, and unidentified fur seals. We speculate that live births in Brazil resulted from young females’ inexperience, including limited prior reproductive activity and poorly developed site fidelity, as well as possible disorientation. However, given their rarity and the unsuitability of the sites where they occurred, such events are unlikely to indicate broader shifts in distribution. Abortions may have occurred as an attempt to reallocate resources for survival and/or as a direct response to stress, reflecting underlying life-history trade-offs influenced by individual condition and external pressures. While the number of reproductive events recorded is low and insufficient to draw population-level conclusions, these rare cases offer unique insights. Continued monitoring and interdisciplinary investigation are essential to understand their causes and broader conservation implications.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104526"},"PeriodicalIF":2.4,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269600","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":"Anthropogenic impacts on water quality: Assessment of DO, BOD, caffeine, and coliforms in the Paraíba River estuary – PB","authors":"Raissa Tavares Estevam Ramalho ,&nbsp;Wellington da Silva Lyra ,&nbsp;David Douglas de Sousa Fernandes ,&nbsp;Edilene Dantas Teles Moreira ,&nbsp;Ulrich Vasconcelos","doi":"10.1016/j.rsma.2025.104531","DOIUrl":"10.1016/j.rsma.2025.104531","url":null,"abstract":"<div><div>Water availability and quality are critical global issues intensified by population growth, economic development, and changing consumption patterns. In Brazil, 37.5 % of residents lack access to domestic sewage collection; the rates are higher in Paraíba (50.92 %) and Cabedelo (75.17 %), although 100 % of the collected sewage in Cabedelo is treated. We assessed physicochemical and microbiological parameters, as well as caffeine levels, in the waters of the Paraíba River estuary, a conservation-priority system. Dissolved oxygen (DO) frequently fell below recommended thresholds: 67.25 % of samples were &lt; 3.0 mg L⁻¹, indicating severe hypoxia. Biochemical oxygen demand (BOD) showed median values of 2.4 mg L⁻¹ upstream and 2.9 mg L⁻¹ downstream, indicating organic loading, although within permissible limits for treated effluents. Thermotolerant coliforms exceeded 4000 CFU 100 mL⁻¹ in 63.3 % (upstream) and 70.0 % (downstream) of samples, with medians of 5950 and 9900 CFU 100 mL⁻¹ , respectively, evidencing substantial microbiological deterioration. The chromatographic method predicted caffeine with an RMSEP of 0.14 mg L⁻¹ and a REP of 9.49 %. A principal component analysis mirrored the univariate findings: BOD was systematically higher downstream; CONAMA coliform thresholds were exceeded more frequently downstream; and DO showed no clear spatial gradient because it is temporally conditioned by tides and rainfall. Overall, the results reveal degraded environmental conditions, underscoring the need for continuous monitoring and targeted mitigation to reduce anthropogenic pressures on the estuary. This study provides new regional evidence to inform public policies for sustainable water management, aligned with Sustainable Development Goals 6, 14, and 3.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"91 ","pages":"Article 104531"},"PeriodicalIF":2.4,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221630","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}