Global ocean heat content (GOHC) changes are crucial to understanding climate change, as oceans store about 91 % of the excess heat in the climate system. The thermal expansion of oceans significantly contributed to sea level rise in the twentieth century and will likely remain a major factor in the twenty-first century. This study analyzed decades of data from global ocean reanalysis and satellites, revealing that from 2014 to 2023, the annual rates of increase in GOHC and global mean sea level (GMSL) were 45.2 ± 1.78 MJ/m2 and 4.7 ± 0.23 mm, respectively. These rates are 1.7 and 1.8 times higher than those of the previous four decades. Thermal expansion alone accounts for 56 % of the total GMSL rise. A 1 °C increase in global ocean temperature would result in a 0.89-m rise in GMSL due solely to thermal expansion. GOHC variations align with GMSL changes monthly, though a three-month delay is observed in regions such as Southwest China, the Indochinese Peninsula, and the coastal Middle East. Significant increases in both GOHC and GMSL are most evident in the 20°N–40°N and 20°S–40°S regions. Since the late 1980s, greenhouse gas emissions have overtaken solar radiation as the primary driver of ocean temperature increases. Since the 1990s, the Earth's energy imbalance (EEI) has remained positive, with an annual increase of 0.03 ± 0.016 W/m2, indicating excess heat accumulation.
{"title":"Accelerated Ocean thermal expansion and its contribution to Global Sea-level rise","authors":"Ting-Yu Liang , Shih-Chun Hsiao , Han-Lun Wu , Hongey Chen , Wei-Bo Chen","doi":"10.1016/j.seares.2025.102589","DOIUrl":"10.1016/j.seares.2025.102589","url":null,"abstract":"<div><div>Global ocean heat content (GOHC) changes are crucial to understanding climate change, as oceans store about 91 % of the excess heat in the climate system. The thermal expansion of oceans significantly contributed to sea level rise in the twentieth century and will likely remain a major factor in the twenty-first century. This study analyzed decades of data from global ocean reanalysis and satellites, revealing that from 2014 to 2023, the annual rates of increase in GOHC and global mean sea level (GMSL) were 45.2 ± 1.78 MJ/m<sup>2</sup> and 4.7 ± 0.23 mm, respectively. These rates are 1.7 and 1.8 times higher than those of the previous four decades. Thermal expansion alone accounts for 56 % of the total GMSL rise. A 1 °C increase in global ocean temperature would result in a 0.89-m rise in GMSL due solely to thermal expansion. GOHC variations align with GMSL changes monthly, though a three-month delay is observed in regions such as Southwest China, the Indochinese Peninsula, and the coastal Middle East. Significant increases in both GOHC and GMSL are most evident in the 20°N–40°N and 20°S–40°S regions. Since the late 1980s, greenhouse gas emissions have overtaken solar radiation as the primary driver of ocean temperature increases. Since the 1990s, the Earth's energy imbalance (EEI) has remained positive, with an annual increase of 0.03 ± 0.016 W/m<sup>2</sup>, indicating excess heat accumulation.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102589"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-06-01Epub Date: 2025-05-19DOI: 10.1016/j.seares.2025.102593
Lei Zhang , Xiaodong Ma , Xiang Wan , Weishuai Xu , Xiaoqing Sun , Maolin Li
Mesoscale eddies significantly impact the thermohaline structure of the ocean on a global scale. However, current three-dimensional reconstruction techniques for mesoscale eddies, based on multi-source data fusion, tend to focus on the profile while neglecting the depiction of mesoscale eddies in higher dimensions through three-dimensional structures. To address this issue, we first propose a hybrid recognition algorithm for mesoscale eddies. We then extract the dataset based on the recognition results and ocean reanalysis, transforming the mesoscale eddies reconstruction problem into a prediction problem of layer depth sequences, and implement the model construction using deep learning technology. Simultaneously, we incorporate the globally uniform vertical and horizontal structure of mesoscale eddies into the model input module as a binding physical mechanism and add an attention mechanism to enhance the model's output. Experiments demonstrate that the model developed in this paper performs comparably to the base model in deep learning metrics, exhibits specific advantages in measuring the three-dimensional structure of mesoscale eddies from multiple perspectives, and shows robust generalization across different oceanic regions and data sources. Inspired by the work of many researchers, this paper achieves promising results in the three-dimensional reconstruction of mesoscale eddies, offering valuable insights for deep learning research in marine data-related fields.
{"title":"Three-dimensional thermohaline reconstruction of mesoscale eddies under remote sensing observation: From the perspective of deep learning of layer depth sequences with fusion of physical mechanisms","authors":"Lei Zhang , Xiaodong Ma , Xiang Wan , Weishuai Xu , Xiaoqing Sun , Maolin Li","doi":"10.1016/j.seares.2025.102593","DOIUrl":"10.1016/j.seares.2025.102593","url":null,"abstract":"<div><div>Mesoscale eddies significantly impact the thermohaline structure of the ocean on a global scale. However, current three-dimensional reconstruction techniques for mesoscale eddies, based on multi-source data fusion, tend to focus on the profile while neglecting the depiction of mesoscale eddies in higher dimensions through three-dimensional structures. To address this issue, we first propose a hybrid recognition algorithm for mesoscale eddies. We then extract the dataset based on the recognition results and ocean reanalysis, transforming the mesoscale eddies reconstruction problem into a prediction problem of layer depth sequences, and implement the model construction using deep learning technology. Simultaneously, we incorporate the globally uniform vertical and horizontal structure of mesoscale eddies into the model input module as a binding physical mechanism and add an attention mechanism to enhance the model's output. Experiments demonstrate that the model developed in this paper performs comparably to the base model in deep learning metrics, exhibits specific advantages in measuring the three-dimensional structure of mesoscale eddies from multiple perspectives, and shows robust generalization across different oceanic regions and data sources. Inspired by the work of many researchers, this paper achieves promising results in the three-dimensional reconstruction of mesoscale eddies, offering valuable insights for deep learning research in marine data-related fields.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102593"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-06-01Epub Date: 2025-05-06DOI: 10.1016/j.seares.2025.102590
Aníbal Sánchez , Paula Celis-Plá , Marco Fusi , Lucas Bravo-Guzmán , Simone Baldanzi
Incorporating near-natural variation of marine environmental variables into experimental designs is becoming imperative to make ecologically relevant inferences about ecophysiological responses to climate global change. Dissolved Oxygen (DO) is among the most important environmental variable in marine ecosystems and fluctuates strongly in coastal habitats, due to physical and biological phenomena. However, many technical challenges are still imposing high-cost equipment to ensure a complete mimicry of DO fluctuations in manipulative experiments. Here, we propose a simple and cost-effective methodology to simulate the oxygen fluctuations in the laboratory through to marine primary producers as source of natural fluctuations. We tested the physiological status (Yield II and Fv/fm) as a proxy of oxygen evolution, and photoprotective responses (phenolic production), as metabolic stress indicator in five different biomasses (200–400–600-800-1000 g; that correspond to 6–12–18-24-30 g l−1, respectively) of the macroalgae Lessonia spicata exposed to 7 days of artificial light (photoperiod of 12:12 h day: night) within replicated aquaria. We showed that each biomass exhibited a unique fully functional oxygen fluctuating profile with different average DO saturations, harmonic oscillations and rates of DO production/consumption. Biomasses <600 g showed no significant changes in the physiological status of macroalgae (Yield II and Fv/fm) and photoprotective responses (phenolic production) during the 7 days experiment, while effects of the environmental stress were found at greater biomasses (800 and 1000 g). We successfully tested a method that can produce daily cycles of DO fluctuations in seawater trough to marine primary producers under controlled environment conditions. Our quantitative method provides cost-effective control the DO fluctuations in experimental set-ups with the use of a primary producers that can be replicated at low cost in virtually any laboratory worldwide using other species of marine algae, representing a highly effective method to control experimental settings that involve testing of fluctuating and ecologically relevant levels of dissolved oxygen.
将海洋环境变量的近自然变化纳入实验设计中,对气候全球变化的生态生理反应做出与生态相关的推断变得势在必行。溶解氧(DO)是海洋生态系统中最重要的环境变量之一,由于物理和生物现象,在沿海生境中波动剧烈。然而,许多技术挑战仍然强加高成本的设备,以确保在操作实验中完全模仿DO波动。在这里,我们提出了一种简单而具有成本效益的方法来模拟实验室中的氧气波动,通过海洋初级生产者作为自然波动的来源。我们测试了5种不同生物量(200-400-600-800-1000 g;(分别对应于6-12-18-24-30 g l−1),即在复制水族箱内暴露于7天的人工光照(光周期为昼夜12:12 h)。我们发现,每种生物量都表现出独特的全功能氧波动曲线,具有不同的平均DO饱和度、谐波振荡和DO生产/消耗速率。在7天的试验中,600 g生物量对大型藻类的生理状态(产量II和Fv/fm)和光保护反应(酚生成)没有显著影响,而在更大生物量(800和1000 g)中发现了环境胁迫的影响。我们成功地测试了一种方法,该方法可以在受控环境条件下向海洋初级生产者产生海水槽中DO波动的每日循环。我们的定量方法提供了成本效益高的控制实验设置中溶解氧波动的方法,使用初级生产者,可以在世界上几乎任何实验室使用其他种类的海洋藻类以低成本复制,这是一种非常有效的方法,可以控制涉及测试波动和生态相关溶解氧水平的实验设置。
{"title":"Generating ecologically relevant oxygen fluctuations using marine primary producers under laboratory conditions","authors":"Aníbal Sánchez , Paula Celis-Plá , Marco Fusi , Lucas Bravo-Guzmán , Simone Baldanzi","doi":"10.1016/j.seares.2025.102590","DOIUrl":"10.1016/j.seares.2025.102590","url":null,"abstract":"<div><div>Incorporating near-natural variation of marine environmental variables into experimental designs is becoming imperative to make ecologically relevant inferences about ecophysiological responses to climate global change. Dissolved Oxygen (DO) is among the most important environmental variable in marine ecosystems and fluctuates strongly in coastal habitats, due to physical and biological phenomena. However, many technical challenges are still imposing high-cost equipment to ensure a complete mimicry of DO fluctuations in manipulative experiments. Here, we propose a simple and cost-effective methodology to simulate the oxygen fluctuations in the laboratory through to marine primary producers as source of natural fluctuations. We tested the physiological status (Yield II and <em>F</em><sub><em>v</em></sub><em>/fm</em>) as a proxy of oxygen evolution, and photoprotective responses (phenolic production), as metabolic stress indicator in five different biomasses (200–400–600-800-1000 g; that correspond to 6–12–18-24-30 g l<sup>−1</sup>, respectively) of the macroalgae <em>Lessonia spicata</em> exposed to 7 days of artificial light (photoperiod of 12:12 h day: night) within replicated aquaria. We showed that each biomass exhibited a unique fully functional oxygen fluctuating profile with different average DO saturations, harmonic oscillations and rates of DO production/consumption. Biomasses <600 g showed no significant changes in the physiological status of macroalgae (Yield II and <em>F</em><sub><em>v</em></sub><em>/fm</em>) and photoprotective responses (phenolic production) during the 7 days experiment, while effects of the environmental stress were found at greater biomasses (800 and 1000 g). We successfully tested a method that can produce daily cycles of DO fluctuations in seawater trough to marine primary producers under controlled environment conditions. Our quantitative method provides cost-effective control the DO fluctuations in experimental set-ups with the use of a primary producers that can be replicated at low cost in virtually any laboratory worldwide using other species of marine algae, representing a highly effective method to control experimental settings that involve testing of fluctuating and ecologically relevant levels of dissolved oxygen.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102590"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143929492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-06-01Epub Date: 2025-04-24DOI: 10.1016/j.seares.2025.102585
Yaxiong Han , Liangyong Chu
With the continued growth of the global maritime economy and trade, the shipping industry faces a variety of safety and security challenges. Maritime safety management(MSM) and maritime emergency management(MEM) are complementary to each other, and together they form a comprehensive maritime safety system. The International Maritime Organization (IMO) has established a framework for MEM through a series of conventions. Existing review articles in the field of MSM focus more on the prevention and control of maritime accidents. However, there is a significant lack of systematization for MEM research focusing on the response and disposal of maritime emergencies. To achieve this, this paper first identified 1399 important papers on MEM research from the China National Knowledge Infrastructure (CNKI) and Web of Science (WoS) databases from 2000 to 2024 by screening using PRISMA flow diagram. Second, the knowledge map of MEM research was constructed by using the bibliometric analysis tools CiteSpace and VOSviewer. Then, through the multidimensional analysis of the knowledge map for MEM research, the lineages, themes, hotspots, and trends of MEM research were systematically clarified. Finally, suggestions for the future development of MEM are made from the three dimensions. The systematic review of MEM research in this paper could help researchers to clarify the hotspots and trends for current MEM research, and provide new perspectives and theoretical support for research in this field.
随着全球海洋经济和贸易的持续增长,航运业面临着各种安全与安保挑战。海上安全管理与海上应急管理是相辅相成的,共同构成了一个完整的海上安全体系。国际海事组织(IMO)通过一系列公约建立了MEM的框架。现有的男男性行为领域的综述文章更多地集中在预防和控制海上事故上。然而,对于以海上突发事件的响应和处置为重点的MEM研究,目前明显缺乏系统化。为此,本文首先利用PRISMA流图筛选了2000 - 2024年中国知网(CNKI)和Web of Science (WoS)数据库中关于MEM研究的1399篇重要论文。其次,利用文献计量分析工具CiteSpace和VOSviewer构建了MEM研究的知识图谱。然后,通过对memm研究知识图谱的多维度分析,系统梳理了memm研究的脉络、主题、热点和趋势。最后,从三个维度对MEM的未来发展提出了建议。本文对MEM研究进行系统回顾,有助于厘清当前MEM研究的热点和趋势,为该领域的研究提供新的视角和理论支持。
{"title":"A systematic review and bibliometric analysis for maritime emergency management","authors":"Yaxiong Han , Liangyong Chu","doi":"10.1016/j.seares.2025.102585","DOIUrl":"10.1016/j.seares.2025.102585","url":null,"abstract":"<div><div>With the continued growth of the global maritime economy and trade, the shipping industry faces a variety of safety and security challenges. Maritime safety management(MSM) and maritime emergency management(MEM) are complementary to each other, and together they form a comprehensive maritime safety system. The International Maritime Organization (IMO) has established a framework for MEM through a series of conventions. Existing review articles in the field of MSM focus more on the prevention and control of maritime accidents. However, there is a significant lack of systematization for MEM research focusing on the response and disposal of maritime emergencies. To achieve this, this paper first identified 1399 important papers on MEM research from the China National Knowledge Infrastructure (CNKI) and Web of Science (WoS) databases from 2000 to 2024 by screening using PRISMA flow diagram. Second, the knowledge map of MEM research was constructed by using the bibliometric analysis tools CiteSpace and VOSviewer. Then, through the multidimensional analysis of the knowledge map for MEM research, the lineages, themes, hotspots, and trends of MEM research were systematically clarified. Finally, suggestions for the future development of MEM are made from the three dimensions. The systematic review of MEM research in this paper could help researchers to clarify the hotspots and trends for current MEM research, and provide new perspectives and theoretical support for research in this field.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102585"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-06-01Epub Date: 2025-04-21DOI: 10.1016/j.seares.2025.102586
Le Thanh Ha
The purpose of this study is to empirically investigate how climate-related financial policies affect marine living resource performance in order to demonstrate how they contribute to a sustainable blue economy. We use five different indicators to evaluate blue economies' efficiency and sustainability in European regions. These indicators include the value added at the factor costs of small-scale capture fisheries; shellfish aquaculture; freshwater aquaculture; marine aquaculture; and large-scale capture fisheries. The findings of our assessment show how crucial climate-related measures are to increasing the sustainability of the blue economy in the European area between 2010 and 2019. The research findings reveal the varying impacts of climate-related financial policies on blue economy sustainability across different quantiles.
{"title":"The role of climate-related financial policies in improving marine living resources toward sustainable blue economy over quantiles","authors":"Le Thanh Ha","doi":"10.1016/j.seares.2025.102586","DOIUrl":"10.1016/j.seares.2025.102586","url":null,"abstract":"<div><div>The purpose of this study is to empirically investigate how climate-related financial policies affect marine living resource performance in order to demonstrate how they contribute to a sustainable blue economy. We use five different indicators to evaluate blue economies' efficiency and sustainability in European regions. These indicators include the value added at the factor costs of small-scale capture fisheries; shellfish aquaculture; freshwater aquaculture; marine aquaculture; and large-scale capture fisheries. The findings of our assessment show how crucial climate-related measures are to increasing the sustainability of the blue economy in the European area between 2010 and 2019. The research findings reveal the varying impacts of climate-related financial policies on blue economy sustainability across different quantiles.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102586"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-06-01Epub Date: 2025-03-26DOI: 10.1016/j.seares.2025.102583
Qianli Ma , Wenbo Wu , Hongxiao Liu , Bo Wang , Hao Li
The COVID-19 pandemic has highlighted the urgent need for policy-driven improvements in inspection protocols at international ports, particularly for refrigerated goods, which are vulnerable to virus transmission through external packaging. This study addresses the increased inspection demands during health emergencies, where inspection rates may rise from 10 % to 100 %, requiring a combination of advanced scanning technologies and meticulous manual checks. Such escalated inspection efforts inevitably lead to substantial logistical backlogs, exacerbating port congestion, prolonging dwell times, and increasing the risk of cargo spoilage due to temperature fluctuations. This study introduces a sophisticated scheduling model for container inspection operations, designed to align with current health policy frameworks. The model incorporates specific time windows and temperature controls to mitigate the risks associated with extended storage times. Furthermore, it examines the policy implications of varying the deployment of Automated Guided Vehicles (AGVs) and inspection platforms to optimize throughput and minimize operational delays during crises. Empirical results suggest that prioritizing the expansion of inspection infrastructure, coupled with strategic AGV adjustments, significantly enhances operational efficiency and ensures compliance with health policies during emergencies.
{"title":"Optimization of inspection and transit scheduling for imported refrigerated containers under public health emergencies","authors":"Qianli Ma , Wenbo Wu , Hongxiao Liu , Bo Wang , Hao Li","doi":"10.1016/j.seares.2025.102583","DOIUrl":"10.1016/j.seares.2025.102583","url":null,"abstract":"<div><div>The COVID-19 pandemic has highlighted the urgent need for policy-driven improvements in inspection protocols at international ports, particularly for refrigerated goods, which are vulnerable to virus transmission through external packaging. This study addresses the increased inspection demands during health emergencies, where inspection rates may rise from 10 % to 100 %, requiring a combination of advanced scanning technologies and meticulous manual checks. Such escalated inspection efforts inevitably lead to substantial logistical backlogs, exacerbating port congestion, prolonging dwell times, and increasing the risk of cargo spoilage due to temperature fluctuations. This study introduces a sophisticated scheduling model for container inspection operations, designed to align with current health policy frameworks. The model incorporates specific time windows and temperature controls to mitigate the risks associated with extended storage times. Furthermore, it examines the policy implications of varying the deployment of Automated Guided Vehicles (AGVs) and inspection platforms to optimize throughput and minimize operational delays during crises. Empirical results suggest that prioritizing the expansion of inspection infrastructure, coupled with strategic AGV adjustments, significantly enhances operational efficiency and ensures compliance with health policies during emergencies.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102583"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2025-03-18DOI: 10.1016/j.seares.2025.102581
Dandan Wu , Yuefan Wang , Jinchen Li , Bilin Liu , Gaohua Ji
Copepods are a crucial component of marine ecosystems, serving as a primary food source for numerous marine species and playing a significant role in aquatic food webs. Traditional morphological identification methods are often challenging due to the small size and subtle morphological differences among species. Molecular identification techniques have emerged as powerful tools for species discrimination. This study evaluates the effectiveness of the nuclear 28S ribosomal RNA (28S rRNA) and mitochondrial cytochrome c oxidase I (COI) genes in identifying copepod species from the Northwest Pacific. Zooplankton samples were collected using vertical net tows from 32 stations across an area of 1,320,000 km2 in the Northwest Pacific. We analyzed sequences and conducted phylogenetic analyses on planktonic copepods. We obtained 110 valid 28S rRNA sequences from 45 species, representing 2 orders, 15 families, and 29 genera, and 62 valid COI sequences from 30 species. Notably, this study provides the first 28S rRNA and COI sequence data for Euchaeta tenuis, Euchirella indica and Scolecithricella vittata. Our findings indicate that the average interspecific genetic distances for 28S rRNA and COI are approximately 93.0 and 53.0 times higher, respectively, than the average intraspecific genetic distances, meeting the requirements for DNA barcoding. While COI-based barcodes exhibited distinct barcode gaps, 28S rRNA showed a 7 % overlap between intra- and interspecific genetic distances; however, Jeffries-Matusita (J-M) statistical test confirmed a significant gap for 28S rRNA. Compared to COI, 28S rRNA is more effective in delineating genera and higher taxonomic levels such as families revealed by phylogenetic analyses. Additionally, 28S rRNA demonstrated higher amplification success rates and comparable species-level identification performance to COI.
桡足类是海洋生态系统的重要组成部分,是众多海洋物种的主要食物来源,在水生食物网中发挥着重要作用。由于桡足类个体较小,且不同物种之间存在细微的形态差异,因此传统的形态鉴定方法往往具有挑战性。分子鉴定技术已成为物种鉴别的有力工具。本研究评估了核28S核糖体RNA(28S rRNA)和线粒体细胞色素c氧化酶I(COI)基因在鉴定西北太平洋桡足类物种方面的有效性。在西北太平洋 1,320,000 平方公里区域内的 32 个站点使用垂直网拖采集浮游动物样本。我们分析了序列,并对浮游桡足类进行了系统发育分析。我们获得了来自 45 个物种(代表 2 目、15 科和 29 属)的 110 条有效 28S rRNA 序列和来自 30 个物种的 62 条有效 COI 序列。值得注意的是,本研究首次提供了 Euchaeta tenuis、Euchirella indica 和 Scolecithricella vittata 的 28S rRNA 和 COI 序列数据。研究结果表明,28S rRNA 和 COI 的平均种间遗传距离分别是平均种内遗传距离的 93.0 倍和 53.0 倍,符合 DNA 条形码的要求。基于 COI 的条形码表现出明显的条形码间隙,而 28S rRNA 的种内和种间遗传距离重叠率为 7%;然而,Jeffries-Matusita(J-M)统计检验证实 28S rRNA 存在显著的间隙。与 COI 相比,28S rRNA 在划分属和更高分类级别(如系统发育分析中揭示的科)方面更为有效。此外,28S rRNA 的扩增成功率更高,与 COI 的物种鉴定性能相当。
{"title":"Evaluation of the applicability of 28S rRNA and COI genes in the molecular identification of planktonic copepods from the Northwest Pacific","authors":"Dandan Wu , Yuefan Wang , Jinchen Li , Bilin Liu , Gaohua Ji","doi":"10.1016/j.seares.2025.102581","DOIUrl":"10.1016/j.seares.2025.102581","url":null,"abstract":"<div><div>Copepods are a crucial component of marine ecosystems, serving as a primary food source for numerous marine species and playing a significant role in aquatic food webs. Traditional morphological identification methods are often challenging due to the small size and subtle morphological differences among species. Molecular identification techniques have emerged as powerful tools for species discrimination. This study evaluates the effectiveness of the nuclear 28S ribosomal RNA (28S rRNA) and mitochondrial cytochrome <em>c</em> oxidase I (COI) genes in identifying copepod species from the Northwest Pacific. Zooplankton samples were collected using vertical net tows from 32 stations across an area of 1,320,000 km<sup>2</sup> in the Northwest Pacific. We analyzed sequences and conducted phylogenetic analyses on planktonic copepods. We obtained 110 valid 28S rRNA sequences from 45 species, representing 2 orders, 15 families, and 29 genera, and 62 valid COI sequences from 30 species. Notably, this study provides the first 28S rRNA and COI sequence data for <em>Euchaeta tenuis</em>, <em>Euchirella indica</em> and <em>Scolecithricella vittata.</em> Our findings indicate that the average interspecific genetic distances for 28S rRNA and COI are approximately 93.0 and 53.0 times higher, respectively, than the average intraspecific genetic distances, meeting the requirements for DNA barcoding. While COI-based barcodes exhibited distinct barcode gaps, 28S rRNA showed a 7 % overlap between intra- and interspecific genetic distances; however, Jeffries-Matusita (J-M) statistical test confirmed a significant gap for 28S rRNA. Compared to COI, 28S rRNA is more effective in delineating genera and higher taxonomic levels such as families revealed by phylogenetic analyses. Additionally, 28S rRNA demonstrated higher amplification success rates and comparable species-level identification performance to COI.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102581"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2025-05-26DOI: 10.1016/j.seares.2025.102595
Nadine Jacques , Bent Herrmann , Manu Sistiaga , Jesse Brinkhof
Rigid sorting grids are used in demersal trawl fisheries globally. However, in some fisheries, such as the Barents Sea demersal trawl fishery, they have been found to release large quantities of target-sized catch while simultaneously retaining too many undersized fish. Several studies have documented this issue but an in-depth understanding regarding the exact reasons for these results is still lacking. Thus, the present study investigated whether so-called fall-through experiments conducted in the laboratory for cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and redfish (Sebastes spp.) could shed light on this matter. Predictive models based on these results, enabled a more detailed understanding of the size selection pattern from fishing trials for these species. The models revealed that the unintended release of target-sized cod and haddock occurs because a significant fraction of the fish entering the trawl squeezes themselves between the sorting grid bars to escape. For redfish, approximately 85 % of the contribution on the selectivity curve could be attributed to redfish squeezing themselves through the grid bar spacings to escape compared to when we considered that they do not squeeze (approximately 15 %). The unintended retention of undersized cod and haddock could be explained by the fact that many fish made contact with the grid with a suboptimal body orientation. The method applied enabled us to gain detailed insight into the interaction between fish and sorting grids and could potentially be applied to gain an understanding of the performance of other selectivity devices used in trawl fisheries.
{"title":"From behind bars to freedom: understanding the size selection of fish sorting grids","authors":"Nadine Jacques , Bent Herrmann , Manu Sistiaga , Jesse Brinkhof","doi":"10.1016/j.seares.2025.102595","DOIUrl":"10.1016/j.seares.2025.102595","url":null,"abstract":"<div><div>Rigid sorting grids are used in demersal trawl fisheries globally. However, in some fisheries, such as the Barents Sea demersal trawl fishery, they have been found to release large quantities of target-sized catch while simultaneously retaining too many undersized fish. Several studies have documented this issue but an in-depth understanding regarding the exact reasons for these results is still lacking. Thus, the present study investigated whether so-called fall-through experiments conducted in the laboratory for cod (<em>Gadus morhua</em>), haddock (<em>Melanogrammus aeglefinus</em>) and redfish (<em>Sebastes</em> spp.) could shed light on this matter. Predictive models based on these results, enabled a more detailed understanding of the size selection pattern from fishing trials for these species. The models revealed that the unintended release of target-sized cod and haddock occurs because a significant fraction of the fish entering the trawl squeezes themselves between the sorting grid bars to escape. For redfish, approximately 85 % of the contribution on the selectivity curve could be attributed to redfish squeezing themselves through the grid bar spacings to escape compared to when we considered that they do not squeeze (approximately 15 %). The unintended retention of undersized cod and haddock could be explained by the fact that many fish made contact with the grid with a suboptimal body orientation. The method applied enabled us to gain detailed insight into the interaction between fish and sorting grids and could potentially be applied to gain an understanding of the performance of other selectivity devices used in trawl fisheries.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102595"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-06-01Epub Date: 2025-05-11DOI: 10.1016/j.seares.2025.102591
Bibiana Américo Fernando Nassongole , Lene Buhl-Mortensen , Ana Hilário , Victor Quintino , Isabel Marques da Silva
Research on coral reef ecosystems highlights ongoing degradation driven by local and global factors, leading to biodiversity loss and a shift from hard coral to macroalgae communities. However, other reef components, such as soft corals, receive less attention. This study examines the temporal dynamics of benthic communities and the impact of fisheries closures on sessile reef organisms after a protected area was established. We aimed to assess benthic community changes, particularly a potential shift toward soft corals, before and after protection. Photo-quadrat transects were conducted at four sites, two inside and two outside the protected area, with surveys in 2006, 2012, 2014, and 2022 by SCUBA divers. Results showed no statistically significant differences between protected and unprotected areas but revealed site-specific fluctuations over time. Protection did not significantly alter the overall benthic composition, likely due to initial site heterogeneity and the limited timeframe for detecting changes. The lack of a shift from hard to soft corals outside of the protected area suggests nutrient availability may influence coral dynamics more than overfishing. Alternatively, unprotected sites may have avoided degradation due to increased public awareness and local conservation efforts. These findings emphasize the need for long-term monitoring to evaluate the effectiveness of implementing protected areas and inform conservation strategies for reef ecosystems.
{"title":"The spatiotemporal dynamics of reef benthic communities in local marine protected areas: A case study of Vamizi Island","authors":"Bibiana Américo Fernando Nassongole , Lene Buhl-Mortensen , Ana Hilário , Victor Quintino , Isabel Marques da Silva","doi":"10.1016/j.seares.2025.102591","DOIUrl":"10.1016/j.seares.2025.102591","url":null,"abstract":"<div><div>Research on coral reef ecosystems highlights ongoing degradation driven by local and global factors, leading to biodiversity loss and a shift from hard coral to macroalgae communities. However, other reef components, such as soft corals, receive less attention. This study examines the temporal dynamics of benthic communities and the impact of fisheries closures on sessile reef organisms after a protected area was established. We aimed to assess benthic community changes, particularly a potential shift toward soft corals, before and after protection. Photo-quadrat transects were conducted at four sites, two inside and two outside the protected area, with surveys in 2006, 2012, 2014, and 2022 by SCUBA divers. Results showed no statistically significant differences between protected and unprotected areas but revealed site-specific fluctuations over time. Protection did not significantly alter the overall benthic composition, likely due to initial site heterogeneity and the limited timeframe for detecting changes. The lack of a shift from hard to soft corals outside of the protected area suggests nutrient availability may influence coral dynamics more than overfishing. Alternatively, unprotected sites may have avoided degradation due to increased public awareness and local conservation efforts. These findings emphasize the need for long-term monitoring to evaluate the effectiveness of implementing protected areas and inform conservation strategies for reef ecosystems.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"205 ","pages":"Article 102591"},"PeriodicalIF":2.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-04-01Epub Date: 2025-02-02DOI: 10.1016/j.seares.2025.102569
Fan Zeng, Chuan Pang, Huajun Tang
Currently, global warming leads to a notable increase in natural marine disasters. It is imperative that the academic community undertake a quantitative assessment of the impacts of natural marine disasters on shipping industry in China. The event study revealed that natural marine disasters lead to negative abnormal trading volume and abnormal stock returns for the Chinese shipping industry. Moreover, the findings of the regression analysis indicated that abnormal trading volume was positively related to abnormal stock return. Overall, natural marine disasters may lower investors' expectation on the development of the shipping firms, which would adversely affect shipping firms' market value. The findings of our paper highlighted the importance of disaster management in the shipping industry, which suggests managers in shipping industry should improve disaster management. Our research contributes to the research area of the economic effects of natural disasters and the effects of uncertainty on firms' investments.
{"title":"The impacts of natural marine disasters on shipping industry in China: An event study","authors":"Fan Zeng, Chuan Pang, Huajun Tang","doi":"10.1016/j.seares.2025.102569","DOIUrl":"10.1016/j.seares.2025.102569","url":null,"abstract":"<div><div>Currently, global warming leads to a notable increase in natural marine disasters. It is imperative that the academic community undertake a quantitative assessment of the impacts of natural marine disasters on shipping industry in China. The event study revealed that natural marine disasters lead to negative abnormal trading volume and abnormal stock returns for the Chinese shipping industry. Moreover, the findings of the regression analysis indicated that abnormal trading volume was positively related to abnormal stock return. Overall, natural marine disasters may lower investors' expectation on the development of the shipping firms, which would adversely affect shipping firms' market value. The findings of our paper highlighted the importance of disaster management in the shipping industry, which suggests managers in shipping industry should improve disaster management. Our research contributes to the research area of the economic effects of natural disasters and the effects of uncertainty on firms' investments.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"204 ","pages":"Article 102569"},"PeriodicalIF":2.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143386872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}