Pub Date : 2025-12-05DOI: 10.1016/j.rsma.2025.104690
Eghbali Azar, Safaie Mohsen, Daliri Moslem
This study investigated the population structure and reproductive biology of M. stridulans in the coastal waters of the Persian Gulf (Hormozgan Province) using bottom trawl sampling conducted over 16 months (October 2023 to January 2025). A total of 619 specimens were analyzed (414 females and 205 males). Carapace length (CL) ranged from 7 to 23 mm in females and 8.5–16 mm in males. The CL-weight (W) relationships yielded b values of 2.55 for females and 2.85 for males, indicating a negative allometric growth in both sexes. The monthly sex ratio (male to female) was significantly skewed toward females(1:2), with males predominating in the 9–13 mm CL classes, whereas females dominated in larger size classes. Reproductive analysis showed that this species is capable of spawning year-round, with a pronounced peak in April (spring). Female sexual maturity was first recorded at 14 mm CL, while the size at 50 % maturity (Lm50) was estimated at 19.23 mm CL. Growth parameters for females (CL∞= 29 mm, K=1.6 yr−1) exceeded those of males (CL∞= 24 mm, K=1.4 yr−1). Total (Z), natural (M), and fishing (F) mortality rates for females were estimated at 7.37, 2.41, and 4.96 yr−1, respectively, whereas the corresponding values for males were 4.83, 2.33, and 2.50 yr−1. Exploitation rates revealed greater fishing pressure on females (E = 0.67) than on males (E = 0.52). In conclusion, the findings confirmed the presence of pronounced sexual dimorphism in M. stridulans.
本研究利用底拖网取样（2023年10月至2025年1月），对波斯湾（霍尔木兹甘省）沿海海域的stridulans种群结构和生殖生物学进行了研究。共分析标本619只，其中雌虫414只，雄虫205只。甲壳长度（CL）雌虫为7 ~ 23 mm，雄虫为8.5 ~ 16 mm。CL-weight (W)关系的b值分别为2.55和2.85，表明两性均呈负异速生长。月性别比（雌雄比）明显向雌性倾斜（1:2），雄性在9-13 mm CL类中占主导地位，而雌性在较大的类中占主导地位。繁殖分析表明，该物种全年产卵，4月（春季）产卵高峰明显。雌性性成熟首次记录在14 mm CL，而在50 %成熟度（Lm50）的大小估计在19.23 mm CL。雌性的生长参数（CL∞= 29 mm， K=1.6 yr−1）大于雄性（CL∞= 24 mm， K=1.4 yr−1）。估计雌性的总死亡率(Z)、自然死亡率(M)和捕捞死亡率(F)分别为7.37、2.41和4.96 yr - 1，而雄性的相应值为4.83、2.33和2.50 yr - 1。雌鱼的捕捞压力（E = 0.67）大于雄鱼（E = 0.52）。综上所述，研究结果证实了棘球霉存在明显的性别二态性。
{"title":"Population parameters and reproductive biology of the fiddler shrimp, Metapenaeopsis stridulans (Alcock, 1905), in the Persian Gulf","authors":"Eghbali Azar, Safaie Mohsen, Daliri Moslem","doi":"10.1016/j.rsma.2025.104690","DOIUrl":"10.1016/j.rsma.2025.104690","url":null,"abstract":"<div><div>This study investigated the population structure and reproductive biology of <em>M. stridulans</em> in the coastal waters of the Persian Gulf (Hormozgan Province) using bottom trawl sampling conducted over 16 months (October 2023 to January 2025). A total of 619 specimens were analyzed (414 females and 205 males). Carapace length (CL) ranged from 7 to 23 mm in females and 8.5–16 mm in males. The CL-weight (W) relationships yielded <em>b</em> values of 2.55 for females and 2.85 for males, indicating a negative allometric growth in both sexes. The monthly sex ratio (male to female) was significantly skewed toward females(1:2), with males predominating in the 9–13 mm CL classes, whereas females dominated in larger size classes. Reproductive analysis showed that this species is capable of spawning year-round, with a pronounced peak in April (spring). Female sexual maturity was first recorded at 14 mm CL, while the size at 50 % maturity (Lm<sub>50</sub>) was estimated at 19.23 mm CL. Growth parameters for females (CL<sub>∞</sub>= 29 mm, <em>K</em>=1.6 yr<sup>−1</sup>) exceeded those of males (CL<sub>∞</sub>= 24 mm, <em>K</em>=1.4 yr<sup>−1</sup>). Total (<em>Z</em>), natural (<em>M</em>), and fishing (<em>F</em>) mortality rates for females were estimated at 7.37, 2.41, and 4.96 yr<sup>−1</sup>, respectively, whereas the corresponding values for males were 4.83, 2.33, and 2.50 yr<sup>−1</sup>. Exploitation rates revealed greater fishing pressure on females (<em>E</em> = 0.67) than on males (<em>E</em> = 0.52). In conclusion, the findings confirmed the presence of pronounced sexual dimorphism in <em>M. stridulans</em>.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104690"},"PeriodicalIF":2.4,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691316","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}
Pub Date : 2025-12-05DOI: 10.1016/j.rsma.2025.104692
Fuyuan Chen , Qiushun Wang , Jian Zeng , Li Li , Zhiguo He
In macro-tidal estuaries, understanding sediment stratification is crucial for accurately quantifying sediment transport. However, in-situ observations from a long-term perspective, especially during both wet and dry years, remain scarce. In this study, field data collected in wet and dry years from both downstream and upstream reaches are employed to elucidate the characteristics of sediment stratification and associated transport. Results show significant variability in tidal current and sediment concentration, with peak sediment concentration exceeding 10 kg/m³ during spring tides. The gradient Richardson number frequently exceeds the critical value of 0.25 during flood tides, indicating stable stratification, especially in the wet year. The magnitude of sediment stratification is quantified using the potential energy anomaly, which reaches a maximum of 284 J/m3 in the wet year, demonstrating that a significant energy input is required to achieve complete mixing during tidal cycles. At the upstream Qibao station, the instantaneous sediment transport during the flood tide was 13.2 times larger than during the ebb tide, with a sharp increase of 306.4 kg/m/s during tidal bore events. Tidal pumping and Eulerian advection are identified as the dominant mechanisms governing net sediment transport in both wet and dry years. The findings highlight the critical role of hydro-sediment dynamics modulated by riverbed morphology in controlling sediment transport regimes, providing quantitative insight into stratification processes under different years.
{"title":"Characteristics of sediment stratification and transport in the macro-tidal Qiantang Estuary, China","authors":"Fuyuan Chen , Qiushun Wang , Jian Zeng , Li Li , Zhiguo He","doi":"10.1016/j.rsma.2025.104692","DOIUrl":"10.1016/j.rsma.2025.104692","url":null,"abstract":"<div><div>In macro-tidal estuaries, understanding sediment stratification is crucial for accurately quantifying sediment transport. However, in-situ observations from a long-term perspective, especially during both wet and dry years, remain scarce. In this study, field data collected in wet and dry years from both downstream and upstream reaches are employed to elucidate the characteristics of sediment stratification and associated transport. Results show significant variability in tidal current and sediment concentration, with peak sediment concentration exceeding 10 kg/m³ during spring tides. The gradient Richardson number frequently exceeds the critical value of 0.25 during flood tides, indicating stable stratification, especially in the wet year. The magnitude of sediment stratification is quantified using the potential energy anomaly, which reaches a maximum of 284 J/m<sup>3</sup> in the wet year, demonstrating that a significant energy input is required to achieve complete mixing during tidal cycles. At the upstream Qibao station, the instantaneous sediment transport during the flood tide was 13.2 times larger than during the ebb tide, with a sharp increase of 306.4 kg/m/s during tidal bore events. Tidal pumping and Eulerian advection are identified as the dominant mechanisms governing net sediment transport in both wet and dry years. The findings highlight the critical role of hydro-sediment dynamics modulated by riverbed morphology in controlling sediment transport regimes, providing quantitative insight into stratification processes under different years.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104692"},"PeriodicalIF":2.4,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145746944","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}
Pub Date : 2025-12-03DOI: 10.1016/j.rsma.2025.104689
Putu Satya Pratama Atmaja , I Putu Yogi Darmendra , Elok Faiqoh , I Wayan Gita Krishna Dananjaya , Bela Nuegiarti , Ray Ryther Amgra
Seagrass meadows are critical coastal ecosystems providing vital ecological services, yet they are increasingly threatened by anthropogenic pressures, particularly in tourism-driven regions such as the Lesser Sunda Islands of Indonesia. This study aimed to assess the ecological condition of seagrass meadows in a total of 17 sites across Bali, Nusa Lembongan, and Lombok using the Seagrass Ecological Quality Index (SEQI), which integrates five ecological parameters: species richness, seagrass cover, macroalgae cover, epiphyte cover, and water transparency. Field data were collected using standardized transect-quadrat methods aligned with COREMAP-CTI protocols. The SEQI values were analyzed to determine ecological status and spatial variability. The results revealed a gradient in seagrass condition, with several sites such as Sanur, Samuh, Jungut Batu, and Mangrove Point classified as having good ecological status (SEQI > 0.69), while others including Gondol, Gili Sulat, and Penyabangan displayed moderate to poor conditions (SEQI < 0.68). One-way ANOVA indicated significant spatial differences in seagrass cover, macroalgal and epiphytic overgrowth, and water clarity (p < 0.05), suggesting varying degrees of environmental stress. These patterns highlight the vulnerability of seagrass ecosystems to localized human impacts, especially from tourism, sedimentation, and nutrient enrichment. This study provides a baseline assessment for seagrass health in the Lesser Sunda Islands and demonstrates the utility of SEQI as a cost-effective, scalable tool for monitoring. Findings underscore the need for targeted conservation strategies and sustainable tourism practices to safeguard these valuable ecosystems.
{"title":"Spatial variation in the ecological condition of seagrass meadows in the Lesser Sunda Islands, Indonesia: A SEQI-based framework","authors":"Putu Satya Pratama Atmaja , I Putu Yogi Darmendra , Elok Faiqoh , I Wayan Gita Krishna Dananjaya , Bela Nuegiarti , Ray Ryther Amgra","doi":"10.1016/j.rsma.2025.104689","DOIUrl":"10.1016/j.rsma.2025.104689","url":null,"abstract":"<div><div>Seagrass meadows are critical coastal ecosystems providing vital ecological services, yet they are increasingly threatened by anthropogenic pressures, particularly in tourism-driven regions such as the Lesser Sunda Islands of Indonesia. This study aimed to assess the ecological condition of seagrass meadows in a total of 17 sites across Bali, Nusa Lembongan, and Lombok using the Seagrass Ecological Quality Index (SEQI), which integrates five ecological parameters: species richness, seagrass cover, macroalgae cover, epiphyte cover, and water transparency. Field data were collected using standardized transect-quadrat methods aligned with COREMAP-CTI protocols. The SEQI values were analyzed to determine ecological status and spatial variability. The results revealed a gradient in seagrass condition, with several sites such as Sanur, Samuh, Jungut Batu, and Mangrove Point classified as having good ecological status (SEQI > 0.69), while others including Gondol, Gili Sulat, and Penyabangan displayed moderate to poor conditions (SEQI < 0.68). One-way ANOVA indicated significant spatial differences in seagrass cover, macroalgal and epiphytic overgrowth, and water clarity (p < 0.05), suggesting varying degrees of environmental stress. These patterns highlight the vulnerability of seagrass ecosystems to localized human impacts, especially from tourism, sedimentation, and nutrient enrichment. This study provides a baseline assessment for seagrass health in the Lesser Sunda Islands and demonstrates the utility of SEQI as a cost-effective, scalable tool for monitoring. Findings underscore the need for targeted conservation strategies and sustainable tourism practices to safeguard these valuable ecosystems.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104689"},"PeriodicalIF":2.4,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691310","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}
Pub Date : 2025-12-03DOI: 10.1016/j.rsma.2025.104686
M.A. Abdul Razaque , Abdul Jaleel , Saraswathi Ragesh , Narayan Panda , K.S. Arya , T.R. Gireeshkumar , K.R. Muraleedharan
Mudbanks are unique, transient coastal phenomena characterised by calm, turbid waters and high productivity, frequently reported along the southwest coast of India, especially along the Kerala coast. The Alappuzha mudbank, located away from riverine inputs, becomes active during the southwest monsoon. Previous studies on this mudbank have largely focused on primary and secondary production and fisheries, while information on other biotic components, especially benthic invertebrates that play crucial functional roles in marine ecosystems, remains limited. The present study examines seasonal variations in the macrofaunal community of the Alappuzha mudbank. Depth-stratified samples were collected from November 2021 to October 2022, covering pre-monsoon, monsoon, and post-monsoon seasons, at depths from 3 to 8 m. Macrofaunal abundance varied between 0 and 7625 ind./m2 with an average value of 510 ± 1413 ind./m2. Unlike typical coastal systems, the total macrofaunal standing stock was lowest (100 ± 118 ind./m2) during the mudbank (monsoon). The highest abundance was recorded during the post-monsoon season, with a mean value of 973 ± 2199 ind./m2. Biomass of total macrofauna followed the same trend, with monsoon months recorded the lowest values (1.8 ± 1.8 g/m2) followed by post-monsoon (3.2 ± 3.6 g/m2). Polychaetes, crustaceans, and molluscs were the dominant groups, with polychaetes accounting for 86 % of total abundance and biomass. Paraprionospio pinnata, Cossura coasta, and Lumbrineris meteorana were the dominant, stress-tolerant species. This study revealed a reduction in macrofauna during the active phase of the Alappuzha mudbank, which may be due to unconsolidated and unstable substratum, which results in minimal trophic support to the demersal fishery.
{"title":"Macrofaunal communities of a unique sedimentary environment: The Alappuzha mudbank, southwest coast of India","authors":"M.A. Abdul Razaque , Abdul Jaleel , Saraswathi Ragesh , Narayan Panda , K.S. Arya , T.R. Gireeshkumar , K.R. Muraleedharan","doi":"10.1016/j.rsma.2025.104686","DOIUrl":"10.1016/j.rsma.2025.104686","url":null,"abstract":"<div><div>Mudbanks are unique, transient coastal phenomena characterised by calm, turbid waters and high productivity, frequently reported along the southwest coast of India, especially along the Kerala coast. The Alappuzha mudbank, located away from riverine inputs, becomes active during the southwest monsoon. Previous studies on this mudbank have largely focused on primary and secondary production and fisheries, while information on other biotic components, especially benthic invertebrates that play crucial functional roles in marine ecosystems, remains limited. The present study examines seasonal variations in the macrofaunal community of the Alappuzha mudbank. Depth-stratified samples were collected from November 2021 to October 2022, covering pre-monsoon, monsoon, and post-monsoon seasons, at depths from 3 to 8 m. Macrofaunal abundance varied between 0 and 7625 ind./m<sup>2</sup> with an average value of 510 ± 1413 ind./m<sup>2</sup>. Unlike typical coastal systems, the total macrofaunal standing stock was lowest (100 ± 118 ind./m<sup>2</sup>) during the mudbank (monsoon). The highest abundance was recorded during the post-monsoon season, with a mean value of 973 ± 2199 ind./m<sup>2</sup>. Biomass of total macrofauna followed the same trend, with monsoon months recorded the lowest values (1.8 ± 1.8 g/m<sup>2</sup><sup>)</sup> followed by post-monsoon (3.2 ± 3.6 g/m<sup>2</sup>). Polychaetes, crustaceans, and molluscs were the dominant groups, with polychaetes accounting for 86 % of total abundance and biomass. <em>Paraprionospio pinnata</em>, <em>Cossura coasta</em>, and <em>Lumbrineris meteorana</em> were the dominant, stress-tolerant species. This study revealed a reduction in macrofauna during the active phase of the Alappuzha mudbank, which may be due to unconsolidated and unstable substratum, which results in minimal trophic support to the demersal fishery.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104686"},"PeriodicalIF":2.4,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145746945","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}
Pub Date : 2025-12-02DOI: 10.1016/j.rsma.2025.104688
Wei Mao , Wenyun Guo , Jianzhong Ge , Pingxing Ding
Extensive coastal and offshore engineering is conducted primarily for economic development or safety. Understanding of the induced modulations in hydrodynamics is an important foundation for engineering benefits and environmental safety. Construction of the Yangshan Deepwater Harbour (YDH) has intensively altered local geometry and topography, and induced significant changes in tidal dynamics. In this study, the modulations of currents, especially the residual currents and water fluxes, along with its four-phase construction are carefully examined through application of a high-resolution unstructured-grid numerical model. Results show that the YDH’s construction significantly weakened local tidal currents, especially those in the Inner Harbour Area (IHA), but strengthened currents in narrow passages. The constructions significantly adjust Eulerian residual current, especially around islands, thus modulations in the Eulerian residual transport current. A stagnant zone is developed by the first phase construction and shifted by the following constructions. It is pushed westward by the Stokes residual current. Tidal fluxes in most of the remaining passages are increased by the YDH’s construction, mainly relating to the deeper topography and stronger currents, but the net tidal fluxes are reduced. The residual momentum balance is controlled by a quasi-Bernoulli equilibrium between barotropic pressure gradient and advection terms, the relative contributions of the pressure term and the convective term have changed. Although this is a site-specific study, the findings may be applicable to engineering influence analysis in other coasts.
{"title":"Modulation of residual current and water flux by the construction of Yangshan deep-water harbour, Shanghai, China","authors":"Wei Mao , Wenyun Guo , Jianzhong Ge , Pingxing Ding","doi":"10.1016/j.rsma.2025.104688","DOIUrl":"10.1016/j.rsma.2025.104688","url":null,"abstract":"<div><div>Extensive coastal and offshore engineering is conducted primarily for economic development or safety. Understanding of the induced modulations in hydrodynamics is an important foundation for engineering benefits and environmental safety. Construction of the Yangshan Deepwater Harbour (YDH) has intensively altered local geometry and topography, and induced significant changes in tidal dynamics. In this study, the modulations of currents, especially the residual currents and water fluxes, along with its four-phase construction are carefully examined through application of a high-resolution unstructured-grid numerical model. Results show that the YDH’s construction significantly weakened local tidal currents, especially those in the Inner Harbour Area (IHA), but strengthened currents in narrow passages. The constructions significantly adjust Eulerian residual current, especially around islands, thus modulations in the Eulerian residual transport current. A stagnant zone is developed by the first phase construction and shifted by the following constructions. It is pushed westward by the Stokes residual current. Tidal fluxes in most of the remaining passages are increased by the YDH’s construction, mainly relating to the deeper topography and stronger currents, but the net tidal fluxes are reduced. The residual momentum balance is controlled by a quasi-Bernoulli equilibrium between barotropic pressure gradient and advection terms, the relative contributions of the pressure term and the convective term have changed. Although this is a site-specific study, the findings may be applicable to engineering influence analysis in other coasts.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104688"},"PeriodicalIF":2.4,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691315","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}
Pub Date : 2025-12-02DOI: 10.1016/j.rsma.2025.104685
Carla S.R. Huber , Bruno W. Giraldes , Felipe Torquato , Luciano K. Huber , Pedro Maria Abreu Ferreira , Laura R.P. Utz
Extreme weather effects on marine communities are of utmost relevance and remain poorly understood. Hyper-arid mangroves represent unhospitable habitats hosting planktonic/benthic communities under such conditions. In this study, a hyper-arid mangrove and its immediately adjacent beach were sampled over 12 months, covering all four seasons, using tidal movements. The communities were dominated by calanoid copepods, crustacean zoeae, and ostracods — ecologically relevant groups that play key roles in nutrient cycling and trophic dynamics. Planktonic/benthic communities at Al Dakhira Mangrove exhibited remarkable tolerance to extreme salinity (up to 70 ppt) and high water temperatures (up to 40° C), conditions by far exceeding those of typical mangrove systems. Distinct community compositions were observed between the mangrove’s main channel and its riparian area, despite being less than 2 m apart. Assemblages tended to display demersal behavior at the riparian channel, despite its intimate proximity to the main channel, as indicated by beta diversity indices in summer and by trajectory analysis in all seasons. Functional diversity showed a seasonal rise in detritivores after summer, likely a latent response to extreme temperatures. This study stands as a pioneer descriptor of planktonic and benthic communities using tidal movements while also assessing a plausible migration of species at the mangrove to a nearby beach.
{"title":"Zooplankton/Benthos community composition and dynamics in a hyper-arid mangrove system and its adjacent beach","authors":"Carla S.R. Huber , Bruno W. Giraldes , Felipe Torquato , Luciano K. Huber , Pedro Maria Abreu Ferreira , Laura R.P. Utz","doi":"10.1016/j.rsma.2025.104685","DOIUrl":"10.1016/j.rsma.2025.104685","url":null,"abstract":"<div><div>Extreme weather effects on marine communities are of utmost relevance and remain poorly understood. Hyper-arid mangroves represent unhospitable habitats hosting planktonic/benthic communities under such conditions. In this study, a hyper-arid mangrove and its immediately adjacent beach were sampled over 12 months, covering all four seasons, using tidal movements. The communities were dominated by calanoid copepods, crustacean zoeae, and ostracods — ecologically relevant groups that play key roles in nutrient cycling and trophic dynamics. Planktonic/benthic communities at Al Dakhira Mangrove exhibited remarkable tolerance to extreme salinity (up to 70 ppt) and high water temperatures (up to 40° C), conditions by far exceeding those of typical mangrove systems. Distinct community compositions were observed between the mangrove’s main channel and its riparian area, despite being less than 2 m apart. Assemblages tended to display demersal behavior at the riparian channel, despite its intimate proximity to the main channel, as indicated by beta diversity indices in summer and by trajectory analysis in all seasons. Functional diversity showed a seasonal rise in detritivores after summer, likely a latent response to extreme temperatures. This study stands as a pioneer descriptor of planktonic and benthic communities using tidal movements while also assessing a plausible migration of species at the mangrove to a nearby beach.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104685"},"PeriodicalIF":2.4,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691374","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}
Lake Nakaumi, Japan, a brackish enclosed lagoon, has been significantly modified since the 20th century. We investigated spatiotemporal changes in meiobenthic Ostracoda, total organic carbon (TOC), and total sulfur (TS) from five sedimentary cores, reconstructing climatic and anthropogenic impacts since the Little Ice Age (LIA). Novel environmental ranks from S to F in the order of the higher degree of salinity and/or dissolved oxygen, were established using a modern analog technique on ostracod assemblages. TOC profiles showed similar vertical trends with chronologically correlated minima. Prior to 1600, ostracod assemblages possibly reflected the Spörer Minimum solar activity decline. During the mid-17th century cooling to the LIA’s end (mid-19th century), reduced ostracod abundance and diversity suggest increased water stagnation and stratification driven by high precipitation and low surface salinity. Lake circulation was weakest during the Maunder Minimum, corresponding to the lowest environmental rank. Then, ostracod diversity and abundance increased, peaking in 1850–1860, reaching the highest environmental rank by ∼1920 because of the increased seawater inflow from the Sea of Japan due to global sea-level rise. An artificial dike at the seawater entrance (1922–1930) caused rapid increase in TOC and TS, indicating intensified eutrophication and organic pollution, which peaked in the eastern lake during the 1960s–1970s. Later interventions (water barrier gate, dikes, dredging, land reclamation; 1968–1981) accelerated eutrophication and stagnation in western/southern sites. Despite improved water and bottom conditions in the east due to altered seawater inflow, the environmental rank became extremely low in all the sites. Post-1920, anthropogenic influences superseded natural climatic changes in shaping the lake’s water, bottom, and ostracod conditions.
{"title":"Spatiotemporal controls on meiobenthos (Ostracoda) and environments in a brackish lagoon, Lake Nakaumi (SW Japan) since the Little Ice Age","authors":"Toshiaki Irizuki , Koji Seto , Ryohei Kawakami , Hiroaki Shakutsui , Minori Narita , Katsura Yamada , Kotaro Hirose , Ren Nishizaki , Shigenori Kawano , Ritsuo Nomura","doi":"10.1016/j.rsma.2025.104687","DOIUrl":"10.1016/j.rsma.2025.104687","url":null,"abstract":"<div><div>Lake Nakaumi, Japan, a brackish enclosed lagoon, has been significantly modified since the 20th century. We investigated spatiotemporal changes in meiobenthic Ostracoda, total organic carbon (TOC), and total sulfur (TS) from five sedimentary cores, reconstructing climatic and anthropogenic impacts since the Little Ice Age (LIA). Novel environmental ranks from S to F in the order of the higher degree of salinity and/or dissolved oxygen, were established using a modern analog technique on ostracod assemblages. TOC profiles showed similar vertical trends with chronologically correlated minima. Prior to 1600, ostracod assemblages possibly reflected the Spörer Minimum solar activity decline. During the mid-17th century cooling to the LIA’s end (mid-19th century), reduced ostracod abundance and diversity suggest increased water stagnation and stratification driven by high precipitation and low surface salinity. Lake circulation was weakest during the Maunder Minimum, corresponding to the lowest environmental rank. Then, ostracod diversity and abundance increased, peaking in 1850–1860, reaching the highest environmental rank by ∼1920 because of the increased seawater inflow from the Sea of Japan due to global sea-level rise. An artificial dike at the seawater entrance (1922–1930) caused rapid increase in TOC and TS, indicating intensified eutrophication and organic pollution, which peaked in the eastern lake during the 1960s–1970s. Later interventions (water barrier gate, dikes, dredging, land reclamation; 1968–1981) accelerated eutrophication and stagnation in western/southern sites. Despite improved water and bottom conditions in the east due to altered seawater inflow, the environmental rank became extremely low in all the sites. Post-1920, anthropogenic influences superseded natural climatic changes in shaping the lake’s water, bottom, and ostracod conditions.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104687"},"PeriodicalIF":2.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691311","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}
Pub Date : 2025-11-29DOI: 10.1016/j.rsma.2025.104672
Scott N. Evans , Nick Konzewitsch , Rachel Marks , Renae K. Hovey , Lynda M. Bellchambers
Satellite-derived ocean water quality products offer cost-effective, broadscale monitoring solutions for ecosystem-based fisheries management. However, their application in nearshore, turbid environments requires rigorous validation. This study assessed the performance of satellite-derived sea surface temperature, turbidity, and chlorophyll-a products against a five-year (2016-2020) in-situ dataset from Exmouth Gulf, Western Australia; a remote embayment supporting key nursery habitats for ecologically, socially and commercially important fish and fisheries.
In-situ loggers, Secchi depth, and datasonde deployments were compared with GHRSST, MODIS-Aqua, and CMEMS satellite-derived products. Strong alignment was found between satellite-derived and in-situ benthic temperatures during non-winter months (R² > 0.94), with winter overestimation likely associated with reduced vertical mixing under calmer conditions. Satellite-derived turbidity correlated well with Secchi depth (R² = 0.805), and generalised linear models revealed spatial location and wind direction as primary turbidity drivers. In contrast, satellite-derived chlorophyll-a consistently overestimated field observations and showed no significant correlation, likely due to shallow water interference and low ambient productivity.
A significant bushfire adjacent to Exmouth Gulf was serendipitously observed during the study in March 2018, revealed a compelling link between terrestrial disturbance and benthic light anomalies, supported by both in-situ logger data and satellite-derived turbidity. These findings highlight the value of integrating satellite and in-situ monitoring to detect environmental anomalies and support responsive fisheries management. This study demonstrates the utility and limitations of remote sensing for ocean water quality assessment in complex coastal systems and reinforces the need for site-specific validation when integrating satellite data into operational ecosystem-based fisheries management frameworks.
{"title":"From pixels to policy: Calibration of satellite-derived ocean water quality metrics to guide EBFM in Exmouth Gulf, Western Australia","authors":"Scott N. Evans , Nick Konzewitsch , Rachel Marks , Renae K. Hovey , Lynda M. Bellchambers","doi":"10.1016/j.rsma.2025.104672","DOIUrl":"10.1016/j.rsma.2025.104672","url":null,"abstract":"<div><div>Satellite-derived ocean water quality products offer cost-effective, broadscale monitoring solutions for ecosystem-based fisheries management. However, their application in nearshore, turbid environments requires rigorous validation. This study assessed the performance of satellite-derived sea surface temperature, turbidity, and chlorophyll-<em>a</em> products against a five-year (2016-2020) in-situ dataset from Exmouth Gulf, Western Australia; a remote embayment supporting key nursery habitats for ecologically, socially and commercially important fish and fisheries.</div><div>In-situ loggers, Secchi depth, and datasonde deployments were compared with GHRSST, MODIS-Aqua, and CMEMS satellite-derived products. Strong alignment was found between satellite-derived and in-situ benthic temperatures during non-winter months (<em>R</em>² > 0.94), with winter overestimation likely associated with reduced vertical mixing under calmer conditions. Satellite-derived turbidity correlated well with Secchi depth (<em>R²</em> = 0.805), and generalised linear models revealed spatial location and wind direction as primary turbidity drivers. In contrast, satellite-derived chlorophyll-<em>a</em> consistently overestimated field observations and showed no significant correlation, likely due to shallow water interference and low ambient productivity.</div><div>A significant bushfire adjacent to Exmouth Gulf was serendipitously observed during the study in March 2018, revealed a compelling link between terrestrial disturbance and benthic light anomalies, supported by both in-situ logger data and satellite-derived turbidity. These findings highlight the value of integrating satellite and in-situ monitoring to detect environmental anomalies and support responsive fisheries management. This study demonstrates the utility and limitations of remote sensing for ocean water quality assessment in complex coastal systems and reinforces the need for site-specific validation when integrating satellite data into operational ecosystem-based fisheries management frameworks.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104672"},"PeriodicalIF":2.4,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691314","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}
Pub Date : 2025-11-28DOI: 10.1016/j.rsma.2025.104678
Elena Rybakova , Elena Krylova , Vladimir Mordukhovich
We compared fauna as well as community composition and structure of two types of chemosynthesis-based ecosystems (CBEs) located in the western part of the Bering Sea (BS) about 800 km apart: cold methane seeps on the Koryak slope (400–429 m, 647–695 m) and hydrothermal vents on Piip Volcano (368–495 m). We identified regional differences of faunas between seeps and vents in the BS compared with two regions, the Japanese archipelago (JA) (vents in the Okinawa Trough and on the Izu–Bonin Arc and seeps off the JA) and the Guaymas Basin (GB). In three regions compared, CBEs are located in relative proximity to each other at similar bathyal depths. In the BS, most of the fauna of CBEs is represented by background species with only 18 obligate species (6 %). The overall number of species at seeps (245) is 3.5 times higher than at vents (72). The number of obligate species is also higher at seeps (12) than at vents (10), with 22 % (4 species) of shared obligate seep and vent species. Species richness decreased in the order: the deeper seeps at 647–695 m depth (236), vents (72), the shallower seeps at 400–429 m depth (34). Background macrofauna dominates in numbers of individuals at seeps at both depth ranges whereas obligate macrofauna dominates at the vent. The BS data are similar to that around the JA in the proportion of shared obligate seep and vent species and differ from those of the JA and GB by lower numbers of obligate taxa of species and supraspecific levels, and confirmed chemosymbiotic species. Regional differences may be related to the narrow vertical range, shallow depths, low variability of reducing environments in the BS, as well as the young age of vents on Piip Volcano.
{"title":"Methane seeps and hydrothermal vents in the Bering Sea: comparative aspects of the fauna, composition and community structure","authors":"Elena Rybakova , Elena Krylova , Vladimir Mordukhovich","doi":"10.1016/j.rsma.2025.104678","DOIUrl":"10.1016/j.rsma.2025.104678","url":null,"abstract":"<div><div>We compared fauna as well as community composition and structure of two types of chemosynthesis-based ecosystems (CBEs) located in the western part of the Bering Sea (BS) about 800 km apart: cold methane seeps on the Koryak slope (400–429 m, 647–695 m) and hydrothermal vents on Piip Volcano (368–495 m). We identified regional differences of faunas between seeps and vents in the BS compared with two regions, the Japanese archipelago (JA) (vents in the Okinawa Trough and on the Izu–Bonin Arc and seeps off the JA) and the Guaymas Basin (GB). In three regions compared, CBEs are located in relative proximity to each other at similar bathyal depths. In the BS, most of the fauna of CBEs is represented by background species with only 18 obligate species (6 %). The overall number of species at seeps (245) is 3.5 times higher than at vents (72). The number of obligate species is also higher at seeps (12) than at vents (10), with 22 % (4 species) of shared obligate seep and vent species. Species richness decreased in the order: the deeper seeps at 647–695 m depth (236), vents (72), the shallower seeps at 400–429 m depth (34). Background macrofauna dominates in numbers of individuals at seeps at both depth ranges whereas obligate macrofauna dominates at the vent. The BS data are similar to that around the JA in the proportion of shared obligate seep and vent species and differ from those of the JA and GB by lower numbers of obligate taxa of species and supraspecific levels, and confirmed chemosymbiotic species. Regional differences may be related to the narrow vertical range, shallow depths, low variability of reducing environments in the BS, as well as the young age of vents on Piip Volcano.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104678"},"PeriodicalIF":2.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747748","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}
Pub Date : 2025-11-28DOI: 10.1016/j.rsma.2025.104682
Tábata Martins de Lima , Eduardo Ávila Nunes , Allan Paul Krelling , Monica Ferreira de Costa , Bruna de Ramos
Identifying the historical importance of marine litter and developing strategies to raise public awareness are topics that remain an open and ever-growing field of research. Marine litter collections may be an innovative way to understand historical patterns of marine litter and consumption habits. Additionally, they can serve as powerful tools for increasing public awareness of marine litter and ocean-related issues. To our knowledge, the Network of Educational and Scientific Collections of Marine Litter (Re-COLIXO, Rede de Coleções Didáticas e Científicas do Lixo Marinho in Portuguese) is a novel initiative on a global scale, comprising 24 affiliated Brazilian collections in 2024. We interviewed 20 representatives from these collections, focusing on their characteristics, best practices, and challenges. Most of the collections (85 %) are located in coastal zones. The best practices were divided into three groups: Proper Cataloging and Standardization, Regular Maintenance, and Community Engagement. Similarly, the challenges were divided into three groups: Physical Space, Financial Resources, and Institutional Support. Network analysis showed Re-COLIXO as a focal point, and its establishment in 2016 stimulated the creation of new collections.
确定海洋垃圾的历史重要性和制定提高公众意识的战略仍然是一个开放和不断发展的研究领域。海洋垃圾收集可能是了解海洋垃圾历史模式和消费习惯的一种创新方式。此外，它们可以成为提高公众对海洋垃圾和海洋相关问题认识的有力工具。据我们所知，海洋垃圾教育和科学收集网络（Re-COLIXO，葡萄牙语Rede de Coleções Didáticas e Científicas do Lixo Marinho）是一项全球范围内的新举措，将于2024年由24个巴西附属收集点组成。我们采访了来自这些系列的20位代表，重点关注他们的特点、最佳实践和挑战。大多数藏品（85% %）位于沿海地区。最佳实践分为三组：适当的编目和标准化、定期维护和社区参与。同样，这些挑战被分为三组：物理空间、财政资源和机构支持。网络分析显示Re-COLIXO是焦点，它于2016年成立，刺激了新系列的创作。
{"title":"Network of educational and scientific collections of marine litter (Re-COLIXO): Made in Brazil","authors":"Tábata Martins de Lima , Eduardo Ávila Nunes , Allan Paul Krelling , Monica Ferreira de Costa , Bruna de Ramos","doi":"10.1016/j.rsma.2025.104682","DOIUrl":"10.1016/j.rsma.2025.104682","url":null,"abstract":"<div><div>Identifying the historical importance of marine litter and developing strategies to raise public awareness are topics that remain an open and ever-growing field of research. Marine litter collections may be an innovative way to understand historical patterns of marine litter and consumption habits. Additionally, they can serve as powerful tools for increasing public awareness of marine litter and ocean-related issues. To our knowledge, the Network of Educational and Scientific Collections of Marine Litter (Re-COLIXO, Rede de Coleções Didáticas e Científicas do Lixo Marinho in Portuguese) is a novel initiative on a global scale, comprising 24 affiliated Brazilian collections in 2024. We interviewed 20 representatives from these collections, focusing on their characteristics, best practices, and challenges. Most of the collections (85 %) are located in coastal zones. The best practices were divided into three groups: Proper Cataloging and Standardization, Regular Maintenance, and Community Engagement. Similarly, the challenges were divided into three groups: Physical Space, Financial Resources, and Institutional Support. Network analysis showed Re-COLIXO as a focal point, and its establishment in 2016 stimulated the creation of new collections.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"93 ","pages":"Article 104682"},"PeriodicalIF":2.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691313","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}
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