Continental Shelf Research最新文献

{"title":"Exploring the causal relationships between environmental factors and benthos distributions in an intertidal algal reef ecosystem via a structural equation model","authors":"Chun-Wei Wu ,&nbsp;Shih-wei Liao ,&nbsp;Showe-Mei Lin ,&nbsp;Shou-Chung Huang ,&nbsp;Chang-Po Chen ,&nbsp;Po-Kang Shih ,&nbsp;Hwey-Lian Hsieh","doi":"10.1016/j.csr.2024.105382","DOIUrl":"10.1016/j.csr.2024.105382","url":null,"abstract":"<div><div>Algal reefs are unique and valuable yet poorly understood marine ecosystems. The causal relationships between environmental driving forces and biotic community distributions in an algal reef ecosystem were assessed to fill large scientific gaps. Using a structural equation model (SEM) coupled with factor analysis, we established a well-fitted algal reef SEM. This model revealed that there were two subsystems, one operating primarily above the reef laminated substratum and the other beneath the surface. The crustose coralline algae (CCA) and non-CCA cover areas were affected, with an inverse trend between the two, by river inputs, as indicated by NH₃-N concentrations, and by the seasonal rhythm of riverine NO₃-N concentrations. The trends revealed spatial competition between the two algal groups. The CCA coverage and epifaunal gastropod density responded positively to the presence of pebble habitat. Notably, sand coverage and its variation did not hinder the coverage of the two macrophytes. However, the epifaunal gastropod and arthropod densities were negatively regulated by the sand coverage variability. The infaunal arthropod density was positively influenced by the sediment heavy metal content. Among the biotic communities, the non-CCA cover area negatively affected the infaunal polychaeta density. Furthermore, the increasing infaunal polychaete density increased those of sipunculans, bivalves, and arthropods, implying co-occurrence. This SEM revealed that riverine nutrients, pebble habitat type and sand coverage variability were significant environmental drivers in organizing the biotic communities in an algal reef ecosystem.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105382"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concentrations, spatial distributions, and origins of natural aliphatic lipids and sterols in sediments of Obhur Lagoon, Red Sea Coast, Saudi Arabia","authors":"Ahmed I. Rushdi ,&nbsp;Hattan A. Alharbi ,&nbsp;Najeeb Rasul ,&nbsp;Abdulqader Bazeyad ,&nbsp;Bernd R.T. Simoneit ,&nbsp;Miguel A. Goni ,&nbsp;Khalid F. Al-Mutlaq","doi":"10.1016/j.csr.2024.105370","DOIUrl":"10.1016/j.csr.2024.105370","url":null,"abstract":"<div><div>Samples from the upper surface sediments of Obhur Lagoon, located north of Jeddah, were collected to analyze the concentrations, spatial distribution, and origins of natural lipids. The lagoon was segmented into three zones based on their surrounding ecosystems: Z I (adjacent to inland areas), Z II (the transitional region between Z I and the coastal Z III), and Z III (the coastal region). The primary natural biogenic lipid compounds found in the total extractable organic matter (TEOM) included <u>n</u>-alkanes (partial), fatty acids, fatty alcohols, and steroids. The <u>n</u>-alkanes of biogenic origin were primarily derived from terrestrial higher plant wax, decreasing from approximately 38% in Z I to 12% in Z III. Conversely, contributions from aquatic algae and diatoms increased from about 1% to 8% from Z I to Z III, while microbial inputs declined from roughly 3%–0.5% over the same zones. The relative concentrations of fatty acids from higher plants varied, accounting for about 6% in Z I, 4% in Z II, and 5% in Z III. Aquatic algae sources contributed approximately 80% in all regions, and microbial inputs slightly decreased from 14% to 12% from Z I to Z III. Terrestrial inputs of fatty <u>n</u>-alcohols declined from around 32% in Z I to 11% in Z III, while contributions from aquatic algae and diatoms decreased from about 62% to 45% from Z I to Z III, with microbial inputs remaining around 10%. Steroid inputs from terrestrial plants decreased from 37% in Z I to 16% in Z III, while those from aquatic biota increased from 58% in Z I to 76% in Z III. The microbial inputs of steroids were highest in Z III (11.5%), followed by Z II (9.9%) and Z I (9.4%). The total natural lipid contributions from terrestrial sources decreased from 42.8% in Z I to 19.2% in Z III, while the aquatic source component increased from 53.0% in Z I to 77.4% in Z III. These results suggest that the lagoon's biogeochemistry is influenced by the surrounding ecosystems, lagoon hydrodynamics, and local human and social activities.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105370"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145104","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}

{"title":"Determining meteorological tidal transport through a channel on the coast","authors":"Chunyan Li","doi":"10.1016/j.csr.2024.105394","DOIUrl":"10.1016/j.csr.2024.105394","url":null,"abstract":"<div><div>Transient weather systems are often associated with alternating warm and cold advections of air masses and changing wind directions, which drive coastal ocean and estuarine waters to oscillate quasi-periodically. Quantifying water transport under these meteorologically induced oscillations — between inland waterways and the coastal ocean — helps to interpret land-ocean interactions, sediment transport, and other effects of migrating weather systems. The challenge lies in the difficulty of obtaining continuous, long-term direct measurements of transport due to logistical constraints. Here, we apply a method to determine the meteorological tide-induced volume transport of water using an intensive survey. We correlate transport values measured by a boat-mounted ADCP with vertically averaged velocities from a bottom-mounted ADCP, which recorded a much longer time series. The correlation is then used to compute transport over the period of the bottom-mounted ADCP deployment. Observations were conducted at Belle Pass, Port Fourchon. The transport data revealed the impact of weather systems, including four cold fronts. A model of volume transport, accounting for rotary cold front wind variations, was applied, where both along-channel and along-coastline wind components contribute to the remote wind effect, leading to a more complex response to passing weather systems. The local wind effect is much smaller than the remote wind effect, and transport is primarily controlled by water level fluctuations resulting from open boundary input. Finally, the channel orientation relative to the coastline is found to be critical in determining both the magnitude and phase of the transport.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105394"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145169","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}

{"title":"A dead zone on the north-western Bay of Bengal's continental margin and its alarming impact on the distribution of demersal fishes","authors":"Manjebrayakath Hashim,&nbsp;B.R. Smitha,&nbsp;K.V. Aneesh Kumar","doi":"10.1016/j.csr.2024.105398","DOIUrl":"10.1016/j.csr.2024.105398","url":null,"abstract":"<div><div>Hypoxia in the mesopelagic and demersal realms of marine ecosystems directly or indirectly affects fish population structure, community composition and ecosystem functioning. This may result in excess mortality or the emigration of organisms from the area, resulting in <em>dead zones</em>. The present study reports on a <em>dead zone</em> on the north-western Bay of Bengal's continental margin with no discernible fish catch. The phenomenon is associated with stratification, small residence time of suspended matter in the water column and weak vertical/horizontal mixing due to a retention area (and increased biological flux) observed in the region as a result of cooccurring warm and cold core eddies, resulting intense decompose activities in the regional bottom. As with similar ocean zones globally, dominance of a single species (<em>Parascombrops pellucidus</em>) around the zone's periphery (<em>edge effect</em>) is also reported which is attributed to their feeding patterns, locomotory characteristics, prey preferences and availability. The <em>dead zone</em>'s seasonal occurrence indicates the influence of natural or anthropogenically induced climatic variability can even affect demersal/bottom-dwelling organisms. The present work discusses the drivers and implications of <em>dead zones</em> using in situ oceanographic and fishery data, remote sensing observations and model outputs.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105398"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145281","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}

{"title":"Hotspots of human impact on the seafloor in the Southwestern Baltic Sea","authors":"Giuliana Andrea Díaz-Mendoza ,&nbsp;Knut Krämer ,&nbsp;Gitta Ann von Rönn ,&nbsp;Christoph Heinrich ,&nbsp;Klaus Schwarzer ,&nbsp;Hans-Christian Reimers ,&nbsp;Christian Winter","doi":"10.1016/j.csr.2024.105362","DOIUrl":"10.1016/j.csr.2024.105362","url":null,"abstract":"<div><div>The Southwestern Baltic Sea is a notable example of intense human impact on the seafloor in a confined shallow marine environment. Various marks left by dredging, dumping, fishing, anchoring, among others, reflect the different pressures on the seafloor. These activities represent cumulative stressors for marine ecosystems, potentially leading to habitat modification or loss. Characterizing and quantifying the extent of the different pressures is essential for understanding the system and evaluating the environmental status outlined by different legal frameworks. Here, the effects of different human activities on the seafloor in exemplary hotspots in the SW Baltic Sea are visualized and assessed. Actual anthropogenic marks are compared with assessments based on commonly accessible regional and local information from remote sensing data and institutional sources. About 36% of the seafloor of the investigated area is influenced, mainly by bottom trawling, propeller scouring, anchoring, and dumping. More than 91% of the human footprint corresponds to trawl marks, mainly affecting soft substrates. In addition, from 15% to 47% of the seafloor is disturbed in selected ‘detail areas' within the hotspots. Comparisons with indirect data used for regional pressure estimation demonstrate how hydroacoustic data can enhance assessments of seabed physical pressures. However, quantitative comparisons are challenging, especially when information on human activities is limited or when seafloor recovery rates in relation to the frequency of anthropogenic pressures are unknown.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105362"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructures along the Indian west-coast continental shelf: layering and vertical mixing","authors":"Mayur Gachake ,&nbsp;Anoop A. Nayak ,&nbsp;P. Amol ,&nbsp;P.N. Vinayachandran","doi":"10.1016/j.csr.2024.105360","DOIUrl":"10.1016/j.csr.2024.105360","url":null,"abstract":"&lt;div&gt;&lt;div&gt;During the month of October, the West Indian Coastal Current (WICC) is in a stage of transition from equatorward to poleward flow. The sea surface salinity near the Indian Coast is lower in the south compared to the north. Whereas the sea surface temperature is higher in the north than in the south. A salinity maximum (SM, Salinity &lt;span&gt;&lt;math&gt;&lt;mo&gt;≥&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; 35.7 psu) exists in the sub-surface between depth ranges of 50–80 m. &lt;em&gt;In situ&lt;/em&gt; vertical microstructure profiles collected along the continental shelf off the West Coast of India (WCI) for the first time, are used in this study to characterize vertical mixing under these complex thermodynamic regimes. Estimated sectional mean (median) values of the dissipation rates of turbulent kinetic energy (&lt;span&gt;&lt;math&gt;&lt;mi&gt;ɛ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;) and thermal variance (&lt;span&gt;&lt;math&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;) are in the range &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) W kg&lt;sup&gt;−1&lt;/sup&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;9&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;°&lt;/mo&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; s&lt;sup&gt;−1&lt;/sup&gt; respectively. Sectional mean (median) values of the diapycnal diffusivity (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) and eddy thermal diffusivity (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) are in the range &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) m&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; s&lt;sup&gt;−1&lt;/sup&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105360"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145102","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}

{"title":"Source/sink of CO2 in the southwestern part of Peter the Great Bay (sea of Japan)","authors":"Petr P. Tishchenko,&nbsp;Pavel Ya Tishchenko","doi":"10.1016/j.csr.2024.105391","DOIUrl":"10.1016/j.csr.2024.105391","url":null,"abstract":"<div><div>In this study, the carbon dioxide (CO₂) system on the continental shelf of the southwestern part of Peter the Great Bay (PGB), Sea of Japan was investigated during the autumn of 2015. During this season, the PGB represents an ocean-dominated shelf interaction system as the source of nutrients on the shelf is the subsurface part of the Sea of Japan. Weak seasonal upwelling occurred during the study period (October 20–23, 2015), forming a two-layer water structure on the shelf with a sharp pycnocline. The upper warm layer (12–15 °C) is characterized by nutrient depletion and supersaturation of dissolved oxygen concentrations (apparent oxygen utilization (AOU) &lt; 0), and it simultaneously acts as a sink to atmospheric carbon dioxide (<em>p</em>CO₂&lt;<em>p</em>CO_2atm). The layer beneath the pycnocline is characterized by low temperatures (2–5 °C) and a high concentration of nutrients; it exhibits an oxygen deficit (AOU&gt;0) and an excess of carbon dioxide (<em>p</em>CO₂&gt;<em>p</em>CO_2atm). Nitrate concentrations in the near-bottom layer of the waters suggest that these waters upwelled to the PGB shelf at depths of 200–300 m in the open Japan-East Sea. We observed a high intensity of photosynthesis corresponding to the pycnocline zone, with chlorophyll <em>a</em> concentration exceeding 10 mg/m³, which was attributed to the phytoplankton bloom. The estimated primary production in the euphotic layer of the southwestern part of PGB is up to 4.98 gC m⁻² day⁻¹. Based on the dissolved inorganic carbon (DIC)/nutrient ratio in the subsurface waters of the northwestern Sea of Japan, the shelf becomes a sink for atmospheric carbon dioxide after upwelling. Owing to the heating of surface waters during summer, the PGB acts as a source of CO₂ to the atmosphere.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105391"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145171","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}

{"title":"Growth, mortality, and predatory impact on mesozooplankton of chub mackerel Scomber japonicus larvae in an upwelling system, southern Japan","authors":"Gen Kume ,&nbsp;Hiroki Oba ,&nbsp;Masafumi Kodama ,&nbsp;Taichi Shigemura ,&nbsp;Kazuhiro Shiozaki ,&nbsp;Mutsuo Ichinomiya ,&nbsp;Tomohiro Komorita ,&nbsp;Takafumi Azuma ,&nbsp;Toru Kobari","doi":"10.1016/j.csr.2024.105399","DOIUrl":"10.1016/j.csr.2024.105399","url":null,"abstract":"<div><div>In the northern Satsunan area, southern Japan, upwellings generated by the intrusion of the Kuroshio branch current into Kagoshima Bay are observed at the bay's mouth once every two weeks in winter and spring, and the resulting nutrient supply promotes phytoplankton blooms. Currently, this is a key spawning and nursery habitat for chub mackerel <em>Scomber japonicus</em> in Japan. This study examined how water temperature and prey density influenced the growth, mortality, and predatory effects of <em>S</em>. <em>japonicus</em> larvae in the northern Satsunan area. Recent growth (measured as the average width of the last three otolith increments) of <em>S. japonicus</em> larvae was positively correlated with water temperature but not with prey density, indicating that prey abundance was adequate for larvae and that water temperature controlled their growth rate in the study area. The instantaneous daily mortality rate of <em>S</em>. <em>japonicus</em> larvae was 0.322 in 2021 and 0.252 in 2022 (equivalent to 27.5% mortality d⁻¹ in 2021 and 22.3% in 2022). The food requirements of <em>S</em>. <em>japonicus</em> larvae and mesozooplankton production were 0.00427 ± 0.00334 and 6.37 ± 3.04 mg DW m⁻³ d⁻¹, respectively. <em>S</em>. <em>japonicus</em> larvae had no significant predatory impact on mesozooplankton (0.0869 ± 0.0796%). The present study suggests that none of the plankton feeders have a significant top-down regulating effect on mesozooplankton biomass in the northern Satsunan area, which provides a good food environment for S. <em>japonicus</em> larvae.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105399"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the sources of organic matter in sediments from the Gulf of Batabanó (Cuba) using stable isotopes, aliphatic and polycyclic aromatic hydrocarbons","authors":"Imma Tolosa ,&nbsp;Marianela Mesa-Albernas ,&nbsp;Carlos M. Alonso-Hernández","doi":"10.1016/j.csr.2025.105405","DOIUrl":"10.1016/j.csr.2025.105405","url":null,"abstract":"<div><div>Samples of superficial sediments collected along the Gulf of Batabanó, Cuba were analysed for the first time to characterize contents of biogenic and anthropogenic hydrocarbon biomarkers aiming to understand sources of hydrocarbon contamination that might contribute to biodiversity loss and fisheries decline. Total Petroleum Hydrocarbon (TPH) levels, ranging from 7.8 to 54 μg g⁻¹ dry weight, fall within the range typical for non-polluted areas, suggesting minimal anthropogenic impact. The sediment's aliphatic hydrocarbon profile further supports this, showing no signs of petrogenic contamination and a variation in total ∑n-alkanes concentration between 0.31 and 8.2 μg g⁻¹ dry weight. The presence of high concentrations of highly branched isoprenoids (HBIs), ββ hopanoid compounds, and the absence of the C32-C35 extended hopane doublets, which are indicative of crude oil pollution, point to a dominance of natural organic sources. This is corroborated by δ¹³C isotopic values of specific aliphatic biomarkers, which trace back to biogenic origins such as terrestrial plant waxes, seagrass beds, and marine plankton, with the seagrass beds being the primary contributor to the organic matter in offshore sediments. Lastly, the low-level presence of polycyclic aromatic hydrocarbons (PAHs) and their pyrolytic origin pattern suggest limited contamination, likely from combustion processes rather than direct petroleum input. This comprehensive analysis underscores the importance of ongoing monitoring to preserve the ecological integrity of such marine environment.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105405"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145285","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}

{"title":"A systematic review and scientometrics analysis on microplastic pollution on coastal beaches around the globe","authors":"Nikolaos Simantiris ,&nbsp;Martha Z. Vardaki","doi":"10.1016/j.csr.2025.105424","DOIUrl":"10.1016/j.csr.2025.105424","url":null,"abstract":"<div><div>The coastlines constitute one of the most important marine environments, acting as the interface between land and sea, and a habitat for a great number of marine and terrestrial species. Coastal beaches are valuable to the coastal population, as they are of economic, ecological, cultural, and recreational importance. However, these transitional environments are subjected to several threats, with macro- and microplastic pollution directly affecting the biodiversity and coastal population. This work reviews and discusses the current state of microplastic pollution in coastal beaches around the globe in terms of occurrence, polymer types, and distribution, and describes the sources, mechanisms, and processes that control the distribution of MPs in beaches, as well as the environmental implications of microplastic pollution in these vulnerable environments.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"286 ","pages":"Article 105424"},"PeriodicalIF":2.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}