Pub Date : 2026-01-01Epub Date: 2025-10-27DOI: 10.1016/j.csr.2025.105594
Katarína Holcová , Martina Havelcová , Sanah Shaikh , Markéta Chroustová , Katarína Šarinová , Filip Scheiner , Petr Kraft , Ivana Sýkorová , Rastislav Milovský
This study investigates fossil seagrass accumulations in the Pliocene–Pleistocene Kritika Formation on Rhodes Island using geochemical, organic petrology and palaeobiological proxies. The studied section can be correlated with the lower Calabrian (1.7–1.6 Ma). Inorganic geochemistry revealed fluctuations between freshwater and marine environments, suggesting a dynamic estuarine environment, as supported by the analysed δ13Corg values, which varied from −25.0 to −23.5 ‰. High concentrations of terrestrial organic matter indicate significant riverine input to the coastal area under warm and humid climatic conditions. Further, elevated Ni (720–1100 ppm) and Co (41–60 ppm) concentrations in the sediments indicate a basic/ultrabasic (ophiolitic) sediment source in the catchment area. The absence of marine organisms in these accumulations and reduced estuarine salinity suggest that Posidonia leaves were transported within the estuary rather than deposited in situ. Organic geochemical analyses revealed minor peaks of submerged plant-specific n-alkanes (C21, C23, C25) similar to modern dead Posidonia accumulations. Abundant short even n-alkanes (C16, C18) associated with heterotrophic bacteria and fungi are also present, indicating microbial decomposition. Identical geochemical signatures in samples without Posidonia body fossils confirmed the presence of amorphous organic matter of seagrass origin, further demonstrating that organic geochemical proxies can identify ancient seagrass meadows even in the absence of body fossils.
{"title":"Early Pleistocene fossil seagrass assemblages on Rhodes Island – a proof of allochthonous origin","authors":"Katarína Holcová , Martina Havelcová , Sanah Shaikh , Markéta Chroustová , Katarína Šarinová , Filip Scheiner , Petr Kraft , Ivana Sýkorová , Rastislav Milovský","doi":"10.1016/j.csr.2025.105594","DOIUrl":"10.1016/j.csr.2025.105594","url":null,"abstract":"<div><div>This study investigates fossil seagrass accumulations in the Pliocene–Pleistocene Kritika Formation on Rhodes Island using geochemical, organic petrology and palaeobiological proxies. The studied section can be correlated with the lower Calabrian (1.7–1.6 Ma). Inorganic geochemistry revealed fluctuations between freshwater and marine environments, suggesting a dynamic estuarine environment, as supported by the analysed δ<sup>13</sup>C<sub>org</sub> values, which varied from −25.0 to −23.5 ‰. High concentrations of terrestrial organic matter indicate significant riverine input to the coastal area under warm and humid climatic conditions. Further, elevated Ni (720–1100 ppm) and Co (41–60 ppm) concentrations in the sediments indicate a basic/ultrabasic (ophiolitic) sediment source in the catchment area. The absence of marine organisms in these accumulations and reduced estuarine salinity suggest that <em>Posidonia</em> leaves were transported within the estuary rather than deposited <em>in situ</em>. Organic geochemical analyses revealed minor peaks of submerged plant-specific <em>n</em>-alkanes (C<sub>21</sub>, C<sub>23</sub>, C<sub>25</sub>) similar to modern dead <em>Posidonia</em> accumulations. Abundant short even <em>n</em>-alkanes (C<sub>16</sub>, C<sub>18</sub>) associated with heterotrophic bacteria and fungi are also present, indicating microbial decomposition. Identical geochemical signatures in samples without <em>Posidonia</em> body fossils confirmed the presence of amorphous organic matter of seagrass origin, further demonstrating that organic geochemical proxies can identify ancient seagrass meadows even in the absence of body fossils.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105594"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-08DOI: 10.1016/j.csr.2025.105583
Spyros Sergiou, Dimitra Ntrouva, Maria Geraga, Dimitris Christodoulou, George Papatheodorou
The Patras Gulf Pockmark Field (PGPF), located in a shallow, tectonically active marine basin in western Greece, offers a unique setting for studying lithological and geochemical variability in an urban-influenced cold-seep environment. Here we examine nine short sediment cores (∼30 cm) collected from both within pockmarks and the surrounding seafloor to assess sediment texture, elemental composition, and anthropogenic impacts. We find that pockmark sediments are finer-grained, better-sorted, less bioclastic, more organic-rich, and higher in trace metals loads compared to the surrounding seafloor. The sedimentary, geochemical, and hydrodynamic processes within the pockmarks follow the pockmark morphology; the larger the pockmark is, the more terrigenous, fine-grained, and metal-enriched the sediment is, and less oxygenation characterizes the bottom waters. Multivariate factor analysis identified five dominant geochemical processes. Factors 1 and 2, prevailing outside the pockmarks, reflect clay–metal sorption processes and the anticorrelation between bioclastic material and fine-grained terrigenous inputs. Within pockmarks, Factor 3 indicates anthropogenic sources of Ag, Hg, and Zn through organic carbon–metal sequestration, especially in the southern sector of PGPF, influenced by Glafkos River discharges. Factor 4 reflects localized contamination by Zr, Ta, and Nb, while Factor 5 captures sulfidic, low-oxygen conditions linked to redox dynamics. Despite documented fluid escape activity, no clear imprints of active seepage were observed in the studied pockmark sediments. These findings emphasize the dual control of geomorphology and anthropogenic forcing on geochemical processes in shallow marine cold-seep environments, with implications for trace metal mobility, sediment trapping efficiency, and environmental monitoring in similar settings.
Patras Gulf Pockmark Field （PGPF）位于希腊西部一个浅层、构造活跃的海相盆地，为研究城市影响的冷渗环境中的岩性和地球化学变化提供了独特的环境。在这里，我们研究了从麻坑和周围海底收集的9个短沉积物岩心（~ 30厘米），以评估沉积物的质地、元素组成和人为影响。我们发现，与周围的海底相比，麻子沉积物颗粒更细，分选更好，生物碎屑更少，有机物含量更高，微量金属含量更高。麻坑内的沉积、地球化学和水动力过程遵循麻坑的形态；麻坑越大，沉积物的陆源性越强，颗粒越细，金属含量越高，底部水体的氧合作用越少。多因素分析确定了5个主要的地球化学过程。因子1和因子2在麻坑外普遍存在，反映了粘土-金属的吸附过程以及生物碎屑物质与细粒陆源输入物之间的反相关性。在麻坑内，因子3表明银、汞和锌的人为来源是通过有机碳金属固存，特别是在PGPF南段，受Glafkos河排放的影响。因子4反映了Zr、Ta和Nb的局部污染，而因子5捕获了与氧化还原动力学相关的硫化物、低氧条件。尽管记录了流体逸出活动，但在研究的麻坑沉积物中没有观察到明显的活动渗流痕迹。这些发现强调了在浅海冷渗环境中，地貌和人为强迫对地球化学过程的双重控制，对类似环境下的微量金属流动性、沉积物捕获效率和环境监测具有重要意义。
{"title":"Lithological and geochemical differentiations in an urbanized, shallow marine cold-seep environment. The case of Patras Gulf active pockmark field","authors":"Spyros Sergiou, Dimitra Ntrouva, Maria Geraga, Dimitris Christodoulou, George Papatheodorou","doi":"10.1016/j.csr.2025.105583","DOIUrl":"10.1016/j.csr.2025.105583","url":null,"abstract":"<div><div>The Patras Gulf Pockmark Field (PGPF), located in a shallow, tectonically active marine basin in western Greece, offers a unique setting for studying lithological and geochemical variability in an urban-influenced cold-seep environment. Here we examine nine short sediment cores (∼30 cm) collected from both within pockmarks and the surrounding seafloor to assess sediment texture, elemental composition, and anthropogenic impacts. We find that pockmark sediments are finer-grained, better-sorted, less bioclastic, more organic-rich, and higher in trace metals loads compared to the surrounding seafloor. The sedimentary, geochemical, and hydrodynamic processes within the pockmarks follow the pockmark morphology; the larger the pockmark is, the more terrigenous, fine-grained, and metal-enriched the sediment is, and less oxygenation characterizes the bottom waters. Multivariate factor analysis identified five dominant geochemical processes. Factors 1 and 2, prevailing outside the pockmarks, reflect clay–metal sorption processes and the anticorrelation between bioclastic material and fine-grained terrigenous inputs. Within pockmarks, Factor 3 indicates anthropogenic sources of Ag, Hg, and Zn through organic carbon–metal sequestration, especially in the southern sector of PGPF, influenced by Glafkos River discharges. Factor 4 reflects localized contamination by Zr, Ta, and Nb, while Factor 5 captures sulfidic, low-oxygen conditions linked to redox dynamics. Despite documented fluid escape activity, no clear imprints of active seepage were observed in the studied pockmark sediments. These findings emphasize the dual control of geomorphology and anthropogenic forcing on geochemical processes in shallow marine cold-seep environments, with implications for trace metal mobility, sediment trapping efficiency, and environmental monitoring in similar settings.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105583"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-29DOI: 10.1016/j.csr.2025.105593
Seerangan Manokaran , Thadickal V. Joydas , Paravanparambil Rajakumar Jayachandran , Jayanath Gopi , Omer Reshi , Karuppasamy P. Manikandan , Mohamed A. Qurban
The ecosystem functions of macrobenthic invertebrates were studied in the Red Sea. In total, 193 taxa were recorded. The functional traits of biomass (B) and density (D), such as infauna with internal irrigation (B - 53.4 %), blind-ended burrows, no burrow systems (D - 44.5 %), surface filter (B - 41.5 %), and surface deposit feeders (D - 50.8 %) were dominant attributes with significant regional and depth differences. However, irrigation depth 0 to 2 – 5 cm (B - 50 %, D - 45 %); movements through the sediment matrix mobility pattern (B - 68.3 %, D - 47.2 %), and reworking superficial modifiers (B - 54.2 %, D - 45.2 %) also significantly dominated. The functional individuals, biomass, richness, density, and diversity were 11 ± 1 (Mean ± SE) species m−2, 1.25 ± 0.26 g m−2, 1.70 ± 0.13 Fd’, 361 ± 57 ind. m−2, and 2.76 ± 0.11FH' (log2). These indices decreased with increased depth and were higher in the north compared to the central region. The composition of bioturbation potential community index (BPc) and bio-irrigation potential community index (IPc) values was significantly (P < 0.05) higher in the north (29.46 ± 5.48, and 42.12 ± 10.33) and shallower (55.32 ± 12.79, and 83.76 ± 26.93) depth zones. The taxa Aglaophamus dibranchis, holothuria, sand dollar, and Glycinde sp.1 were responsible for higher BPc, and the taxa sand dollar, Spionidae indet. Notomastus latericeus, Glycinde sp.1, and Prionospio spp. contributed higher to IPc. The environmental variables MGS, silt/clay, depth, latitude (region), As, and Fe influenced functional density (P = 0.191) and biomass (P = 0.182), and MGS, depth, latitude, As, Mn, and Pb also influenced bioturbation (P = 0.224) and bio-irrigation (P = 0.218) of the macrobenthic community. Generally, the functional attributes influence deep-sea nutrient cycling by enhancing benthic and pelagic coupling processes on the Red Sea coast, particularly in relation to coastal developmental activities.
{"title":"Ecosystem function: Trait diversity, bioturbation, and bio-irrigation potentials of macrobenthic invertebrate communities in the Red Sea","authors":"Seerangan Manokaran , Thadickal V. Joydas , Paravanparambil Rajakumar Jayachandran , Jayanath Gopi , Omer Reshi , Karuppasamy P. Manikandan , Mohamed A. Qurban","doi":"10.1016/j.csr.2025.105593","DOIUrl":"10.1016/j.csr.2025.105593","url":null,"abstract":"<div><div>The ecosystem functions of macrobenthic invertebrates were studied in the Red Sea. In total, 193 taxa were recorded. The functional traits of biomass (B) and density (D), such as infauna with internal irrigation (B - 53.4 %), blind-ended burrows, no burrow systems (D - 44.5 %), surface filter (B - 41.5 %), and surface deposit feeders (D - 50.8 %) were dominant attributes with significant regional and depth differences. However, irrigation depth 0 to 2 – 5 cm (B - 50 %, D - 45 %); movements through the sediment matrix mobility pattern (B - 68.3 %, D - 47.2 %), and reworking superficial modifiers (B - 54.2 %, D - 45.2 %) also significantly dominated. The functional individuals, biomass, richness, density, and diversity were 11 ± 1 (Mean ± SE) species m<sup>−2</sup>, 1.25 ± 0.26 g m<sup>−2</sup>, 1.70 ± 0.13 Fd’, 361 ± 57 ind. m<sup>−2</sup>, and 2.76 ± 0.11FH' (log<sup>2</sup>). These indices decreased with increased depth and were higher in the north compared to the central region. The composition of bioturbation potential community index (BPc) and bio-irrigation potential community index (IPc) values was significantly <em>(P < 0.05)</em> higher in the north (29.46 ± 5.48, and 42.12 ± 10.33) and shallower (55.32 ± 12.79, and 83.76 ± 26.93) depth zones. The taxa <em>Aglaophamus dibranchis,</em> holothuria, sand dollar, and <em>Glycinde</em> sp.1 were responsible for higher BPc, and the taxa sand dollar, Spionidae indet. <em>Notomastus latericeus</em>, <em>Glycinde</em> sp.1, and <em>Prionospio</em> spp. contributed higher to IPc. The environmental variables MGS, silt/clay, depth, latitude (region), As, and Fe influenced functional density (<em>P = 0.191</em>) and biomass (<em>P = 0.182</em>), and MGS, depth, latitude, As, Mn, and Pb also influenced bioturbation (<em>P = 0.224</em>) and bio-irrigation (<em>P = 0.218</em>) of the macrobenthic community. Generally, the functional attributes influence deep-sea nutrient cycling by enhancing benthic and pelagic coupling processes on the Red Sea coast, particularly in relation to coastal developmental activities.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105593"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145467271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-22DOI: 10.1016/j.csr.2025.105599
Lydia B. Ladah , Andrea Lievana Mactavish , María del Refugio Barba López , James J. Leichter , Fabian J. Tapia , Anatoliy Filonov
The supply of meroplanktonic larvae to coastal habitats by physical transport mechanisms is important for the persistence of benthic marine invertebrate populations. Larvae can accumulate in convergent bands that are often visible as smooth surface slicks in areas where surfactants reduce capillary waves. Slicks can form above passing troughs of internal waves, which occur on most coasts during stratified periods. In this study, during periods of strong internal wave forcing under spring tide conditions in three bays along the Mexican coastline, we sampled high-frequency (f ≥ 1 cycle h−1) changes in the abundance of marine meroplankton. Concurrently, we recorded visual observations of surface slicks and measured physical conditions in the water column (i.e., temperature and currents). Surface slicks were observed at all three sites, with over 70% occurring at times theoretically predicted from current flows. The slick periods showed warmer temperatures or lower strain values, suggesting slicks may be associated with warm convergence zones. Chthamaloid cyprids and mussel veligers were the dominant meroplankton found, with their abundance being significantly greater (2–6 times) within slicks at all sites and a significant positive relationship with temperature found at 2 of the 3 sites. These results support the hypothesis that plankton accumulation does occur in visible surface slicks. We propose that the slicks measured in this study were related to internal wave convergence zones, meriting further exploration as important mechanisms of plankton accumulation.
{"title":"Elevated meroplankton abundance in surface slicks during internal wave forcing at three coastal sites in Mexico","authors":"Lydia B. Ladah , Andrea Lievana Mactavish , María del Refugio Barba López , James J. Leichter , Fabian J. Tapia , Anatoliy Filonov","doi":"10.1016/j.csr.2025.105599","DOIUrl":"10.1016/j.csr.2025.105599","url":null,"abstract":"<div><div>The supply of meroplanktonic larvae to coastal habitats by physical transport mechanisms is important for the persistence of benthic marine invertebrate populations. Larvae can accumulate in convergent bands that are often visible as smooth surface slicks in areas where surfactants reduce capillary waves. Slicks can form above passing troughs of internal waves, which occur on most coasts during stratified periods. In this study, during periods of strong internal wave forcing under spring tide conditions in three bays along the Mexican coastline, we sampled high-frequency (f ≥ 1 cycle h<sup>−1</sup>) changes in the abundance of marine meroplankton. Concurrently, we recorded visual observations of surface slicks and measured physical conditions in the water column (i.e., temperature and currents). Surface slicks were observed at all three sites, with over 70% occurring at times theoretically predicted from current flows. The slick periods showed warmer temperatures or lower strain values, suggesting slicks may be associated with warm convergence zones. Chthamaloid cyprids and mussel veligers were the dominant meroplankton found, with their abundance being significantly greater (2–6 times) within slicks at all sites and a significant positive relationship with temperature found at 2 of the 3 sites. These results support the hypothesis that plankton accumulation does occur in visible surface slicks. We propose that the slicks measured in this study were related to internal wave convergence zones, meriting further exploration as important mechanisms of plankton accumulation.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105599"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-24DOI: 10.1016/j.csr.2025.105568
Carlos Alberto da Silva Junior , Guilherme Burg Mayer , Áthila Andrade Bertoncini , Rafael de Lima , Renato Hajenius Aché de Freitas
{"title":"Corrigendum to “A three-year survey of hatched elasmobranch egg capsules on Santa Catarina Island, Southern Brazil” [Cont. Shelf Res. 293 (2025) 105528]","authors":"Carlos Alberto da Silva Junior , Guilherme Burg Mayer , Áthila Andrade Bertoncini , Rafael de Lima , Renato Hajenius Aché de Freitas","doi":"10.1016/j.csr.2025.105568","DOIUrl":"10.1016/j.csr.2025.105568","url":null,"abstract":"","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105568"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-01DOI: 10.1016/j.csr.2025.105602
Jeancarlo M. Fajardo-Urbina , Ulf Gräwe , Herman J.H. Clercx , Theo Gerkema , Matias Duran-Matute
This study identifies and quantifies the distinct contributions of wind and tides to the variability of Lagrangian residual transport in the Dutch Wadden Sea (DWS), a mesotidal system of interconnected tidal basins of high ecological relevance. A three-dimensional hydrodynamic model and offline particle tracking were used to simulate the transport of particle patches over individual tidal periods of the record 1980-2015 using depth-averaged currents. This transport was decomposed into the net displacement of their center of mass (advection) and the tidally averaged rate of change of dispersion from their center of mass (the dispersion coefficient). The results reveal that advection is predominantly wind-driven on the temporal scale of events. Strong winds from the North Sea aligned with the topographical orientation of the system trigger advection comparable to the width of the basins. Although the role of tides in advection is secondary, they induce residual circulation cells near the inlets, particularly evident during weak wind conditions. In contrast, dispersion is controlled by the tides and exhibits filamentous structures with large values around all the DWS inlets. The strength of these structures has a linear correlation with the tidal amplitude, which is mainly modulated by the spring-neap cycle. However, the location of these structures changes predominantly from shallow areas surrounding the channels when particles are released at high tide to within the channels when released at low tide. These findings underscore the distinct separable roles of wind and tides in Lagrangian residual transport within event-driven, multi-inlet coastal systems such as the DWS.
{"title":"Tidal and wind-driven spatiotemporal variability in the residual displacement and dispersion of Lagrangian particles in a system of intertidal basins","authors":"Jeancarlo M. Fajardo-Urbina , Ulf Gräwe , Herman J.H. Clercx , Theo Gerkema , Matias Duran-Matute","doi":"10.1016/j.csr.2025.105602","DOIUrl":"10.1016/j.csr.2025.105602","url":null,"abstract":"<div><div>This study identifies and quantifies the distinct contributions of wind and tides to the variability of Lagrangian residual transport in the Dutch Wadden Sea (DWS), a mesotidal system of interconnected tidal basins of high ecological relevance. A three-dimensional hydrodynamic model and offline particle tracking were used to simulate the transport of particle patches over individual tidal periods of the record 1980-2015 using depth-averaged currents. This transport was decomposed into the net displacement of their center of mass (advection) and the tidally averaged rate of change of dispersion from their center of mass (the dispersion coefficient). The results reveal that advection is predominantly wind-driven on the temporal scale of events. Strong winds from the North Sea aligned with the topographical orientation of the system trigger advection comparable to the width of the basins. Although the role of tides in advection is secondary, they induce residual circulation cells near the inlets, particularly evident during weak wind conditions. In contrast, dispersion is controlled by the tides and exhibits filamentous structures with large values around all the DWS inlets. The strength of these structures has a linear correlation with the tidal amplitude, which is mainly modulated by the spring-neap cycle. However, the location of these structures changes predominantly from shallow areas surrounding the channels when particles are released at high tide to within the channels when released at low tide. These findings underscore the distinct separable roles of wind and tides in Lagrangian residual transport within event-driven, multi-inlet coastal systems such as the DWS.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105602"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Human activities significantly influence carbon sequestration and carbon stock in seagrass ecosystems; however, their impacts on small islands remain understudied. Based on this gap, this study quantified seagrass carbon stocks across Indonesian islands, examining spatial variability and anthropogenic pressures. Carbon stocks were measured using the Loss on Ignition (LOI) method. Results showed relatively high values, with biomass ranging from 0.65 to 11.25 tC ha−1 (4.01 ± 2.84 tC ha−1), sediment from 22.46 to 98.53 tC ha−1 (52.77 ± 17.61 tC ha−1), and total carbon from 22.70 to 98.53 tC ha−1 (56.78 ± 20.45 tC ha−1). Significant spatial differences were observed among islands and land-use categories, indicating that average or constant values cannot be reliably applied for national carbon estimates. Anthropogenic activities also had a marked effect, underscoring the need to integrate human impacts into management and conservation strategies. These findings provide essential baseline data for national carbon accounting while highlighting the ecological and climate importance of small-island seagrass ecosystems. Protecting and restoring seagrass meadows should be prioritized as a dual strategy for climate adaptation and biodiversity conservation.
{"title":"Carbon stocks on the intertidal seagrass meadow of the Indonesian Islands: Spatial and anthropogenic activities variability","authors":"Fery Kurniawan , Agustin Rustam , Robba Fahrisy Darus , Fauziyah , Almira Nadia Kusuma , Muhammad Noval Alghifari , Luky Adrianto , Yonvitner","doi":"10.1016/j.csr.2025.105604","DOIUrl":"10.1016/j.csr.2025.105604","url":null,"abstract":"<div><div>Human activities significantly influence carbon sequestration and carbon stock in seagrass ecosystems; however, their impacts on small islands remain understudied. Based on this gap, this study quantified seagrass carbon stocks across Indonesian islands, examining spatial variability and anthropogenic pressures. Carbon stocks were measured using the Loss on Ignition (LOI) method. Results showed relatively high values, with biomass ranging from 0.65 to 11.25 tC ha<sup>−1</sup> (4.01 ± 2.84 tC ha<sup>−1</sup>), sediment from 22.46 to 98.53 tC ha<sup>−1</sup> (52.77 ± 17.61 tC ha<sup>−1</sup>), and total carbon from 22.70 to 98.53 tC ha<sup>−1</sup> (56.78 ± 20.45 tC ha<sup>−1</sup>). Significant spatial differences were observed among islands and land-use categories, indicating that average or constant values cannot be reliably applied for national carbon estimates. Anthropogenic activities also had a marked effect, underscoring the need to integrate human impacts into management and conservation strategies. These findings provide essential baseline data for national carbon accounting while highlighting the ecological and climate importance of small-island seagrass ecosystems. Protecting and restoring seagrass meadows should be prioritized as a dual strategy for climate adaptation and biodiversity conservation.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105604"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-11DOI: 10.1016/j.csr.2025.105590
Pedro T. Gomes , Renato Henriques , Marcos Rubal , Diana Azevedo , Diego Carreira-Flores
Geospatial information is fundamental for understanding marine biodiversity patterns, species distribution, and environmental change. However, traditional methods for obtaining high-resolution bathymetric data are expensive and time-consuming, limiting data availability and creating significant gaps, particularly in coastal zones. This study explores the potential of consumer-grade sonars (fish finders) as cost-effective tools to improve bathymetric maps and support habitat mapping along a coastal area in northern Portugal. We compared bathymetric data collected by consumer-grade devices with publicly available digital elevation models (DEM) from EMODNET and high-resolution, survey-grade multibeam sonar data from the APA COSMO project. Results revealed strong agreement between consumer-grade sonar data and EMODNET DEM, with substantial improvement in local detail and acceptable errors (RMSE and MAE low; Pearson correlation coefficients from 0.957 to 0.963). Comparisons with COSMO DEM also showed good coherence, highlighting a significant increase in detail proportional to sampling density, though still lacking the fine resolution provided by the professional-grade COSMO dataset. Despite inherent limitations in precision and depth range, consumer-grade sonars proved highly valuable, offering practical solutions for low-resource, small-scale projects, environmental monitoring, and ecological habitat mapping. This study supports integrating these affordable devices into marine research workflows, significantly enhancing bathymetric data availability and spatial resolution, especially where detailed professional data are unavailable or economically unfeasible.
{"title":"Assessing the potential of consumer-grade fish finders to improve coastal habitat mapping in data-poor areas","authors":"Pedro T. Gomes , Renato Henriques , Marcos Rubal , Diana Azevedo , Diego Carreira-Flores","doi":"10.1016/j.csr.2025.105590","DOIUrl":"10.1016/j.csr.2025.105590","url":null,"abstract":"<div><div>Geospatial information is fundamental for understanding marine biodiversity patterns, species distribution, and environmental change. However, traditional methods for obtaining high-resolution bathymetric data are expensive and time-consuming, limiting data availability and creating significant gaps, particularly in coastal zones. This study explores the potential of consumer-grade sonars (fish finders) as cost-effective tools to improve bathymetric maps and support habitat mapping along a coastal area in northern Portugal. We compared bathymetric data collected by consumer-grade devices with publicly available digital elevation models (DEM) from EMODNET and high-resolution, survey-grade multibeam sonar data from the APA COSMO project. Results revealed strong agreement between consumer-grade sonar data and EMODNET DEM, with substantial improvement in local detail and acceptable errors (RMSE and MAE low; Pearson correlation coefficients from 0.957 to 0.963). Comparisons with COSMO DEM also showed good coherence, highlighting a significant increase in detail proportional to sampling density, though still lacking the fine resolution provided by the professional-grade COSMO dataset. Despite inherent limitations in precision and depth range, consumer-grade sonars proved highly valuable, offering practical solutions for low-resource, small-scale projects, environmental monitoring, and ecological habitat mapping. This study supports integrating these affordable devices into marine research workflows, significantly enhancing bathymetric data availability and spatial resolution, especially where detailed professional data are unavailable or economically unfeasible.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105590"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Interactions between oceanic mesoscale currents and inertia-gravity waves (IGWs) are thought to facilitate the energy transition toward submesoscale regimes. Such mesoscale–submesoscale transition processes involve unbalanced motions, such as the IGWs, making it difficult to distinguish between them in observational data. Using across-shelf scale-selective filters, we separated the IGWs from a quasi-geostrophic (QG) current, the Coastal Oyashio (CO), based on a CTD-measured hydrographic section with ∼2-km resolution across the Pacific shelf off southeast Hokkaido, Japan, and clarified the mesoscale–submesoscale transition processes in this IGW–QG coupled system. To determine the optimum smoothing scale , we formulated indices based on non-dimensional numbers such as the Rossby number and the Richardson number , calculated from the CTD-derived along-shelf baroclinic velocity. Applying a low-pass filter with to the in-situ density section, where and were of magnitude O(1), resulted in a smoothed section where both and were reduced to ∼O(0.1), with . The smoothed isopycnals were sloped over the Rossby radius of deformation , consistent with the geostrophic adjustment theory. More quantitatively, the diagnosis yielded an optimal smoothing scale of = 6 km. The IGWs propagating along the subsurface pycnocline, characterized by 1 km (i.e., a wavelength around 6 km, ), were successfully separated from the baroclinic jet structure of the CO, which had 10 km. As a result, our observations revealed a hybrid of symmetric and gravitational instability associated with IGW-breaking near the core of the CO baroclinic jet.
{"title":"Across-shelf scale-selective separation of a quasi-geostrophic current and internal gravity waves off southeastern Hokkaido, Japan","authors":"Tatsuro Karaki , Yukiko Taniuchi, Hiromi Kasai, Hiroshi Kuroda","doi":"10.1016/j.csr.2025.105606","DOIUrl":"10.1016/j.csr.2025.105606","url":null,"abstract":"<div><div>Interactions between oceanic mesoscale currents and inertia-gravity waves (IGWs) are thought to facilitate the energy transition toward submesoscale regimes. Such mesoscale–submesoscale transition processes involve unbalanced motions, such as the IGWs, making it difficult to distinguish between them in observational data. Using across-shelf scale-selective filters, we separated the IGWs from a quasi-geostrophic (QG) current, the Coastal Oyashio (CO), based on a CTD-measured hydrographic section with ∼2-km resolution across the Pacific shelf off southeast Hokkaido, Japan, and clarified the mesoscale–submesoscale transition processes in this IGW–QG coupled system. To determine the optimum smoothing scale <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span>, we formulated indices based on non-dimensional numbers such as the Rossby number <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and the Richardson number <span><math><mrow><msub><mi>R</mi><mi>i</mi></msub></mrow></math></span>, calculated from the CTD-derived along-shelf baroclinic velocity. Applying a low-pass filter with <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span> to the in-situ density section, where <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and <span><math><mrow><msubsup><mrow><mspace></mspace><mi>R</mi></mrow><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span> were of magnitude <em>O</em>(1), resulted in a smoothed section where both <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and <span><math><mrow><msubsup><mi>R</mi><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span> were reduced to ∼<em>O</em>(0.1), with <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub><mo>≈</mo><msubsup><mi>R</mi><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span>. The smoothed isopycnals were sloped over the Rossby radius of deformation <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub></mrow></math></span>, consistent with the geostrophic adjustment theory. More quantitatively, the diagnosis yielded an optimal smoothing scale of <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span> = 6 km. The IGWs propagating along the subsurface pycnocline, characterized by <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub><mo>≈</mo></mrow></math></span> 1 km (i.e., a wavelength around 6 km, <span><math><mrow><mn>2</mn><mi>π</mi><msub><mi>L</mi><mi>d</mi></msub></mrow></math></span>), were successfully separated from the baroclinic jet structure of the CO, which had <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub><mo>≈</mo></mrow></math></span> 10 km. As a result, our observations revealed a hybrid of symmetric and gravitational instability associated with IGW-breaking near the core of the CO baroclinic jet.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105606"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-20DOI: 10.1016/j.csr.2025.105592
Bora Lee , Chung Hyeon Lee , Yun-Bae Kim , Chang Hwan Kim , Chan Hong Park , Seung Ho Baek
Summer stratification strongly regulates nutrient availability and phytoplankton productivity in the East Sea. We examined the combined influences of the East Korea Warm Current (EKWC) and stratification intensity on phytoplankton communities in the Ulleung Basin during four consecutive summers (2021–2024). Years of weak EKWC transport (2021, 2023; 0.1–0.3 m s−1) coincided with restricted offshore dispersal of coastal production and lower surface chlorophyll a (Chl. a; mean 0.34 μg L−1). In contrast, strong EKWC years (2022, 2024; 0.5–0.8 m s−1) exhibited enhanced offshore dispersion and higher Chl. a (mean 0.79 μg L−1). Intensified stratification produced sharp vertical gradients in temperature (24–29 °C at 0–30 m vs. 6–13 °C at 50–100 m), salinity (31.8–32.6 vs. 33.9–34.2), and nitrate (≤5 vs. 6–12 μM), and supported the formation of subsurface chlorophyll maxima (SCM) at 13–47 m, where light and residual nutrients intersected. Community composition displayed strong vertical partitioning: pico-phytoplankton dominated nutrient-depleted surface layers (mean 61 % of biomass), while diatoms prevailed in SCM layers (38–70 %). Dinoflagellates, including Katodinium glaucum and Gyrodinium spp., increased under stratified conditions, and cryptophytes became more abundant at depth. Overall, these results demonstrate that EKWC variability controls horizontal transport of phytoplankton biomass, while stratification governs vertical zonation and taxonomic composition. As sea surface warming intensifies summer stratification, these findings provide critical baseline data for ecosystem models predicting future shifts in nutrient cycling, productivity, and food web dynamics in the East Sea.
夏季分层对东海营养物有效性和浮游植物生产力具有重要的调节作用。研究了2021-2024年连续4个夏季，东朝鲜暖流（EKWC）和分层强度对郁陵盆地浮游植物群落的综合影响。弱EKWC输运年份（2021年，2023年；0.1-0.3 m s−1）与沿海植物在近海的有限扩散和较低的地表叶绿素a （Chl）相吻合。一个;平均0.34 μg L−1)。相比之下，强EKWC年份（2022年，2024年；0.5-0.8 m s−1）表现出增强的离岸色散和更高的Chl。a（平均0.79 μg L−1）。强化的分层作用在温度（0-30 m处24-29°C vs. 50-100 m处6-13°C）、盐度（31.8-32.6 vs. 33.9-34.2）和硝酸盐（≤5 vs. 6-12 μM）上产生了明显的垂直梯度，并支持了13-47 m处地表下叶绿素最大值（SCM）的形成，这是光和残留营养物质相交的地方。群落组成表现出较强的垂直分异：微浮游植物在营养枯竭的表层占主导地位（平均占生物量的61%），硅藻在SCM层占主导地位（38 - 70%）。甲藻（包括Katodinium glaucum和Gyrodinium spp）在分层条件下增加，隐生植物在深层变得更加丰富。总体而言，这些结果表明，EKWC变异控制浮游植物生物量的水平运输，而分层控制垂直带和分类组成。随着海面变暖加剧夏季分层，这些发现为预测东海养分循环、生产力和食物网动态的未来变化的生态系统模型提供了关键的基线数据。
{"title":"Impacts of stratified water column on summer phytoplankton community structure and dynamics in the East Sea, Korea","authors":"Bora Lee , Chung Hyeon Lee , Yun-Bae Kim , Chang Hwan Kim , Chan Hong Park , Seung Ho Baek","doi":"10.1016/j.csr.2025.105592","DOIUrl":"10.1016/j.csr.2025.105592","url":null,"abstract":"<div><div>Summer stratification strongly regulates nutrient availability and phytoplankton productivity in the East Sea. We examined the combined influences of the East Korea Warm Current (EKWC) and stratification intensity on phytoplankton communities in the Ulleung Basin during four consecutive summers (2021–2024). Years of weak EKWC transport (2021, 2023; 0.1–0.3 m s<sup>−1</sup>) coincided with restricted offshore dispersal of coastal production and lower surface chlorophyll <em>a</em> (Chl. <em>a</em>; mean 0.34 μg L<sup>−1</sup>). In contrast, strong EKWC years (2022, 2024; 0.5–0.8 m s<sup>−1</sup>) exhibited enhanced offshore dispersion and higher Chl. <em>a</em> (mean 0.79 μg L<sup>−1</sup>). Intensified stratification produced sharp vertical gradients in temperature (24–29 °C at 0–30 m vs. 6–13 °C at 50–100 m), salinity (31.8–32.6 vs. 33.9–34.2), and nitrate (≤5 vs. 6–12 μM), and supported the formation of subsurface chlorophyll maxima (SCM) at 13–47 m, where light and residual nutrients intersected. Community composition displayed strong vertical partitioning: pico-phytoplankton dominated nutrient-depleted surface layers (mean 61 % of biomass), while diatoms prevailed in SCM layers (38–70 %). Dinoflagellates, including <em>Katodinium glaucum</em> and <em>Gyrodinium</em> spp., increased under stratified conditions, and cryptophytes became more abundant at depth. Overall, these results demonstrate that EKWC variability controls horizontal transport of phytoplankton biomass, while stratification governs vertical zonation and taxonomic composition. As sea surface warming intensifies summer stratification, these findings provide critical baseline data for ecosystem models predicting future shifts in nutrient cycling, productivity, and food web dynamics in the East Sea.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105592"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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