Regional Studies in Marine Science最新文献

{"title":"A pilot study of fish biodiversity with a highlight of chondrichthyans in Hong Kong waters using environmental DNA metabarcoding","authors":"Rongjie Zhao ,&nbsp;Veronica Tsz Tung Lam ,&nbsp;Yifang Chen ,&nbsp;Jonathan Yat Fung Sit ,&nbsp;Jianlong Li ,&nbsp;Kenneth Mei Yee Leung ,&nbsp;Meng Yan","doi":"10.1016/j.rsma.2025.104194","DOIUrl":"10.1016/j.rsma.2025.104194","url":null,"abstract":"<div><div>Assessing marine fish biodiversity, particularly high trophic level and conservation value species like chondrichthyans (sharks, rays, and skates), is crucial for evaluating the health of local fisheries and the sustainability of coastal ecosystems. Hong Kong boasts a diverse coastal ecosystem and harbors a wide variety of marine fish species. Yet traditional fish survey methods often fall short of efficiently assessing local fish diversity. In this study, we employed the non-invasive environmental DNA (eDNA) method, to evaluate the overall fish diversity in Hong Kong, with a focus on chondrichthyans. We collected full-depth water samples from the eastern, southern, and western waters of Hong Kong. The primer set <em>Elas12S</em> was used to target chondrichthyans, while <em>12S_V5</em> was used to screen for all fish species. We successfully detected five chondrichthyan species (<em>Scoliodon laticaudus</em>, <em>Scoliodon macrorhynchos</em>, <em>Gymnura japonica</em>, <em>Telatrygon zugei</em>, and <em>Hemitrygon bennettii</em>), two of which are Near Threatened and two are Vulnerable according to the IUCN Red List. The eDNA data unveiled 136 fish species from 54 families within Hong Kong’s coastal waters, with <em>Mugil cephalus</em> exhibiting the highest level of abundance. The indicator species utilized to assess environmental conditions differed substantially across distinct hydrographic zones. Our findings in this eDNA pilot study conducted in Hong Kong demonstrate that the eDNA method can be applied to detect targeted, vulnerable or near-threatened fish species, such as sharks and rays. Furthermore, this rapid detection methodology could have valuable applications for long-term biodiversity monitoring and marine conservation. To enhance the eDNA method and its accuracy in species identification, we recommend establishing a comprehensive reference database of DNA barcodes for local fish species and investigating appropriate sampling efforts in the highly diverse waters of Hong Kong.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104194"},"PeriodicalIF":2.1,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143881538","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":"Assessment of coastal vulnerability along Bangladesh coast using analytical hierarchical process (AHP)","authors":"Shakila Kayum ,&nbsp;Yukihiro Shimatani ,&nbsp;Tomoko Minagawa","doi":"10.1016/j.rsma.2025.104211","DOIUrl":"10.1016/j.rsma.2025.104211","url":null,"abstract":"<div><div>Situated within one of the world’s largest basins, the Ganges-Brahmaputra-Meghna (GBM), Bangladesh frequently experiences natural disasters due to itsgeomorphological setup. Situated along the southern edge of Bangladesh and open to the Bay of Bengal, this coastline experiences regular and diverse natural disasters. Owing to climate change, the coastline of Bangladesh is expected to become more vulnerable over time. Consequently, it is essential to understand the spatio-temporal dimensions of vulnerability and reinforce the resilience of coastal communities. This study utilized Remote Sensing and GIS techniques in combination with Multi-Criteria Decision Making (MCDM) and the Analytical Hierarchical Process (AHP) to establish a Coastal Vulnerability Index (CVI) of Bangladesh coast. AHP was conducted in ArcGIS version 10.5, using two geological parameters, five physical process variables, and three socio-economic parameters. Several thematic maps were created for each parameter using ArcGIS and reclassified according to vulnerability rankings. Ultimately, a CVI was developed, categorizing vulnerability into three classes: moderately vulnerable, vulnerable, and highly vulnerable. Results indicate that approximately 70 % of coastal areas are vulnerable, while 29 % area fall within moderate to high vulnerability zones. Around 1 % of the area in Khulna District, Satkhira District, and Char Fasson of Bhola District is classified as highly vulnerable. Considering the coastline, 28 km is highly vulnerable, 315 km moderately vulnerable, and 196 km vulnerable. This study will provide valuable insights for government officials, local administrators, coastal planners, and decision-makers in developing a risk management plan for sustainable long-term coastal management.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104211"},"PeriodicalIF":2.1,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887892","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":"Cadmium and rising tides: Amplified greenhouse gas emissions from mangrove sediment","authors":"Hengzhi Yin ,&nbsp;Ruili Li ,&nbsp;Xiaofeng Wu ,&nbsp;Yuefei Huang ,&nbsp;Guanghui Lin ,&nbsp;Bing Li ,&nbsp;Guanqian Wang","doi":"10.1016/j.rsma.2025.104200","DOIUrl":"10.1016/j.rsma.2025.104200","url":null,"abstract":"<div><div>Mangrove ecosystems, renowned for their carbon sequestration capabilities, also contribute to the emission of greenhouse gases from their sediments. They are under stress from human activities and global changes, such as heavy metal pollution and rising sea levels, which can affect carbon stability and greenhouse gas emissions. However, the combined impact of these factors is not fully understood to date. This study assessed the impact of cadmium contamination at varying levels of inundation depths on the emission of CO₂, N₂O, and CH₄ from mangrove sediments. The findings indicated that increased inundation depth intensifies the effect of low cadmium concentrations on CO₂ emissions, with sediment CO₂ flux doubling from 3430 μmol m⁻² h⁻¹ to 6720 μmol m⁻² h⁻¹. In contrast, deeper water levels reduced N₂O emissions in the presence of high cadmium concentrations, lowering sediment N₂O flux from 14.10 μmol m⁻² h⁻¹ to 10.13 μmol m⁻² h⁻¹. These results highlight that the combined effects of rising inundation depth and cadmium pollution can enhance greenhouse gas emissions from mangrove sediments. It is crucial to consider the synergistic effects of pollution and rising sea levels on the stability of sediment carbon and gas emission rates in the conservation and management of mangroves. Such assessments will bolster efforts to protect blue carbon and achieve carbon neutrality in the future.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104200"},"PeriodicalIF":2.1,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878667","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":"A low-cost methodology for estimating beach-stranded plastic pellets using drone-based aerial photographs and marine natural wracks as proxy","authors":"G.M. Izar ,&nbsp;T.Y. Tan ,&nbsp;S.T. Martinez ,&nbsp;G.O. da Rocha ,&nbsp;A.C.R. Albergaria-Barbosa","doi":"10.1016/j.rsma.2025.104198","DOIUrl":"10.1016/j.rsma.2025.104198","url":null,"abstract":"<div><div>We established a relationship between natural wrack debris and plastic pellet density on a sandy beach using Unmanned Aerial Vehicles (UAV), a <em>low-cost</em> quadcopter drone. Floating marine debris (natural or anthropogenic), including plastic pellets, tend to coalesce, drift, and strand together on sandy beaches. Drones are a cheap and widely available technology. Here, we verified whether it is plausible to indirectly estimate plastic pellet densities using drone aerial photos by identifying the local coverage of natural debris. Pellets and natural debris were manually sampled <em>in situ</em> on two beaches on the coast of São Paulo (Brazil) to verify the relationship between them. Once a model was established, drone aerial photos were taken on the largest beach (Itaguaré - 2 km in length), and heat maps of the distribution of natural debris from both methods were compared. The regression models from the field method predicted pellet densities with 45 % accuracy. Other factors not considered in this study (wave energy and sediment composition) may have influenced this accuracy. However, when comparing the pellet dispersion heat maps obtained from both methods (manual sampling and drone-based aerial photos), it can be conclude that the drone-based method was effective, especially in identifying hot spots for pellet entries onto beaches. The drone-based method allows a single person to evaluate the occurrence of plastic pellets in 35 thousand times more beach area than the conventional field methodology in just over 1 h of flight. This method is fast, easy, scalable, and accessible.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104198"},"PeriodicalIF":2.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876820","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":"Occurrence of the invasive swim bladder parasite Anguillicola crassus in European eels (Anguilla anguilla) in Güllük Lagoon, Türkiye","authors":"Ergi Bahrioğlu","doi":"10.1016/j.rsma.2025.104202","DOIUrl":"10.1016/j.rsma.2025.104202","url":null,"abstract":"<div><div>In the present study, the prevalence, mean intensity, and abundance of the nematode parasite <em>Anguillicola crassus</em> were investigated for European eels caught in the Güllük Lagoon, Muğla, Türkiye. Additionally, prevalence, mean intensity, and abundance data were examined for the data published from other European eel habitats in Türkiye. The same data was used to analyze the variations between freshwater and brackish water habitats. The first published research on <em>A. crassus</em> infestations was reported from the Ceyhan River (Türkiye) in 2005. 120 adult (sexually differentiated) <em>Anguilla anguilla</em> were collected between June 2023 and May 2024. Ten specimens were collected monthly to determine seasonal variations of <em>A. crassus</em> infection. During the study period, <em>A. crassus</em> was observed in all months except August 2023, March 2024, and April 2024. 14 % of the eels were found to be infected by A<em>. crassus</em>. Mean prevalences were 13.33 % ± 15.28, 20.0 % ± 10.0, 20.0 % ± 10.0, and 3.33 % ± 5.77 in summer, autumn, winter, and spring, respectively. Statistically significant differences were found for the prevalence data between spring-autumn (Mann-Whitney U = 0.5, p &lt; 0.05) and spring-winter. Mean abundances in all samples were 1.63 ± 1.60, 3.63 ± 1.76, 2.80 ± 1.76, and 1.17 ± 2.02 for summer, autumn, winter, and spring, respectively. Mean intensities in all samples were 9.23 ± 8.59, 18.23 ± 4.13, 13.07 ± 4.78, and 11.67 ± 20.21 for summer, autumn, winter, and spring, respectively. There were no statistical differences between all seasons for abundance and mean intensity. <em>A. crassus</em> infestation was low in abundance and prevalence and probably affects the eel population less than in other habitats. However, in terms of mean intensity, it is suggested that it may cause stress in the life of infected eels individually, during the silvering process, and migration.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104202"},"PeriodicalIF":2.1,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890832","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 stock status and abundance trends of King Mackerel (Scomberomorus cavalla) using a maturity-based approach: A comparison across local and regional scales","authors":"Luís Henrique França ,&nbsp;Alexandre Ricardo dos Santos Jr. ,&nbsp;Walter Dennis Menezes de Oliveira ,&nbsp;Beatrice Padovani Ferreira ,&nbsp;Jorge Eduardo Lins Oliveira ,&nbsp;Marcelo Francisco Nóbrega","doi":"10.1016/j.rsma.2025.104207","DOIUrl":"10.1016/j.rsma.2025.104207","url":null,"abstract":"<div><div>The king mackerel (<em>Scomberomorus cavalla</em>) is one of the most important fishing resources in Northeast Brazil; however, little is known about the status of its stocks, largely due to a limitation of monitoring data. In this context, simple maturity-based approaches to stock status are useful to provide a general panorama of exploitation in the absence of thorough time series. We evaluated abundance (CPUE) trends and stock-status of king mackerel at regional and local scales: the REVIZEE program (1998–2000), covering almost all of Northeast Brazil, and the REPENSAPESCA project (2019–2021), with landings recorded only in the state of Rio Grande do Norte. Both projects followed handline and gillnet fleets. Abundance trends were analyzed through Generalized Additive Models (GAM). Maturity-based stock status was used to categorize size classes into juveniles, adults below optimal catch length (<em>L</em>_<em>opt</em>), adults at <em>L</em>_<em>opt</em> and mega-spawners. Abundance trends reveal the susceptibility of the species to be caught in conditions representing the outer continental shelf, likely due to an habitat preference, and higher catch in the first semester. Stock indicators show that the most frequent maturity class were adults below <em>L</em>_<em>opt</em>, while the proportion of adults within <em>L</em>_<em>opt</em> varied between 21.5 % and 30.6 %.Although gillnetting accounted for a relatively small portion of the total fishing effort, it presented a significant concern due to the high capture rate of juvenile specimens, as this gear type is known for its low selectivity. Increasing the mesh size could help reduce the capture of undersized individuals of this species. In addition, regulating the seasonal use of gillnets by avoiding periods of recruitment in this area could further minimize juvenile bycatch. Possible mega-spawners were caught within sustainable limits. All results were similar at local and regional scales, revealing the usefulness of limited monitoring and its possible application for management at different scales.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104207"},"PeriodicalIF":2.1,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876733","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":"First report of monovitellinic twin embryos of Bignose fanskate, Symterygia acuta Garman 1877 (Rajiformes, Arhynchobatidae)","authors":"Paola Vivian-Vásquez ,&nbsp;Vinicius Domingues ,&nbsp;Maria Cristina Oddone","doi":"10.1016/j.rsma.2025.104206","DOIUrl":"10.1016/j.rsma.2025.104206","url":null,"abstract":"<div><div>This study reports the first case of monovitellinic twins in <em>Sympterygia acuta</em>, found in its natural habitat. While embryonic development in this species typically results in a single embryo per egg capsule, two embryos were found sharing a single yolk sac. The egg capsule and embryos exhibited morphological characteristics within the normal range for the species, though differences in the size and thickness of the yolk stalk were noted. This case is compared to other reports of monozygotic twins in fish and elasmobranchs, but the exact causes remain unknown. Potential environmental or evolutionary influences are discussed.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104206"},"PeriodicalIF":2.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876734","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":"Regional environmental degradation after mid-2010s, possible links with flow pattern change in a semi-enclosed sea (Ise Bay, Japan)","authors":"Kazuhiro Aoki ,&nbsp;Shigeho Kakehi ,&nbsp;Sayaka Sogawa ,&nbsp;Kazuhiro Hanyu ,&nbsp;Asatarou Tsuge ,&nbsp;Rentarou Nakashima","doi":"10.1016/j.rsma.2025.104205","DOIUrl":"10.1016/j.rsma.2025.104205","url":null,"abstract":"<div><div>Worldwide, oligotrophication has been revealed to be occurring under the reduction of the anthropogenic nutrient load in coastal waters. Recent environmental changes such as oligotrophication and/or climate change have been reported in previous studies, however outcomes differ depending on the situation. This study demonstrated the environmental degradation during the 2000s–2010s based on in-situ data in Ise Bay, a semi-enclosed bay in Japan, and examines about the contribution of a change in the flow pattern (offshore water intrusion) using a diagnostic hydrodynamic model. Oligotrophication, increased DIN/DIP ratio and increased thickness of the low DO water mass occurred in the mid-2010s when the fisheries yield decreased. Results of a diagnostic model suggest that the flow pattern in spring and autumn alternated to a horizontal circulation from an estuarine vertical circulation. The flow pattern change contributed to the environmental degradation (oligotrophication and hypoxia) in the western area which is hardly influenced by the offshore water intrusion.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104205"},"PeriodicalIF":2.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873478","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":"Spatial variation and environmental risk of hazardous industrial effluents in the Gomezpuram Water Channel, Gulf of Mannar, India","authors":"Muthu Ponmani ,&nbsp;Samiyappan Manickavasagam","doi":"10.1016/j.rsma.2025.104204","DOIUrl":"10.1016/j.rsma.2025.104204","url":null,"abstract":"<div><div>This study investigated the Gomezpuram Water Channel in the Gulf of Mannar, India, for the first time regarding spatial variations in water quality. Standard methods were adopted to evaluate water samples collected between October and November 2022. Due to the manifestation of hypersaline algae (<em>Dunaliella</em> sp.), the water channel has turned pink, indicating a considerable effluent discharge from different untreated salt pans and seafood processing plants. Green a lgae <em>Dunaliella salina</em> (OR772295), <em>Dunaliella pseudosalina</em> (OR772296), and <em>Dunaliella tertiolecta</em> (OR772297) were identified and confirmed through molecular characterization in the water channel for the first time. The present investigation's Water Quality Index (WQI) shows that the coastal water channel was poorly monitored, managed, and unsuitable for human consumption. A box plot compares all parameters across sampling sites to comprehend environmental data's spatial variation and distribution. Pearson's correlation shows strong positive correlations between related variables, such as TSS and TDS, and pigment concentration, indicating that these parameters increase or decrease together. A Two-way hierarchical analysis visually represents those stations 3, 4, and 5 exhibit similar water quality profiles, whereas station 1 shows distinct characteristics, likely due to localized pollution. This study provides helpful information for management purposes by illustrating the spatial differences in the water quality condition and the anthropogenic sources causing water discoloration in this water channel.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104204"},"PeriodicalIF":2.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890905","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":"Exploring the spatial and temporal dynamics of zooplankton assemblages in the Seomjin estuary and Gwangyang Bay, South Korea: A comparative analysis of Sequence Assignments Species (SAS) and Morphological Species Identification (MSI)","authors":"Joo-Yeon Kang ,&nbsp;Thodhal Yoganandham Suman ,&nbsp;Won-Seok Kim ,&nbsp;Jae-Won Park ,&nbsp;Ji-Hoon Kim ,&nbsp;Ji-Won Park ,&nbsp;Ihn-Sil Kwak","doi":"10.1016/j.rsma.2025.104201","DOIUrl":"10.1016/j.rsma.2025.104201","url":null,"abstract":"<div><div>Estuarine and coastal ecosystems are dynamic environments with strong environmental gradients that influence zooplankton community structure and distribution. Comprehending these patterns is essential for ecosystem management and biodiversity evaluation; however, traditional morphological identification consistently underestimates species diversity, as demonstrated by our comparative analysis. This research examined the structure of zooplankton communities and the distribution of copepod species along an estuarine-marine gradient in the Seomjin estuary and Gwangyang Bay, employing both Sequence Assignments Species (SAS) and Morphological Species Identification (MSI) methodologies. We collected environmental variables and zooplankton samples from six stations in May and September 2023. The Copepoda group constituted 55.1 % of the zooplankton community, with Ciliophora at 31.6 %, Meroplankton at 8.3 %, and Others at 5.0 %. SAS analysis revealed the presence of 31 copepod species distributed among three orders, exhibiting similarity values between 97.03 % and 99.29 %. We observed strong spatial and temporal variations in community structure and diversity indices. Copepod abundance significantly increased in May, especially at bay stations, whereas September showed more uniform distribution. Environmental analysis revealed that salinity and water temperature were primary drivers of species distribution, resulting in distinct species composition between estuarine and bay environments. Species diversity (H′) was consistently greater in SAS (0.69–2.92) than in MSI (0.47–1.74), with both methods indicating elevated diversity in May. NMDS analysis revealed distinct spatial separation between estuarine and bay communities, indicating the impact of environmental variables on community structure. The findings improve our understanding of zooplankton ecology in transitional waters. Both methods offer valuable insights; however, SAS consistently exhibited greater accuracy, evidenced by higher detection rates, more apparent community differences, and stronger environmental correlation, indicates its better performance for biodiversity assessment in complex estuarine ecosystems.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"86 ","pages":"Article 104201"},"PeriodicalIF":2.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873479","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}