Pub Date : 2024-10-17DOI: 10.1016/j.rsma.2024.103872
Shanshan Fu , Jihan Lu , Xiangwei Liu , Andrew Lipman
Deep-sea mining is an emerging interdisciplinary and cross-domain research topic. As commercialization of deep-sea mining advances, economic analysis of the maritime transportation of minerals is critical to forming sound commercial plans. This paper proposes an approach for the economic analysis of shipping route planning in deep-sea mining operations, considering the varying capacities of the proposed mobile offshore minerals units (MOMUs) and the limited capacity. Capital expense (CAPEX), operational expense (OPEX), and voyage expense (VOYEX) are taken into account according to the arrangement of mineral transportation vessels (MTVs) with different capacities of MOMUs and fluctuating shipping prices. Monte Carlo Simulation is used to analyze the uncertainties of the total cost for MTVs with respect to CAPEX, OPEX, and VOYEX. A case study of the shipping route from the Chinese contract area in the Clarion-Clipperton Zone to Ningbo-Zhoushan Port is presented to interpret the proposed approach. The derived results demonstrate that 120,000 tons is the most economically viable MOMU size, saving at least 1.9 % of the total cost. These savings are mainly due to better scheduling, speed, and resilience to market prices. The proposed approach can support economic feasibility for deep-sea mining projects and provide investors with more specific operational measures to make well-informed decisions.
深海采矿是一个新兴的跨学科、跨领域研究课题。随着深海采矿商业化的推进，矿物海上运输的经济分析对于制定合理的商业计划至关重要。本文提出了深海采矿作业中航运路线规划的经济分析方法，考虑了拟议的移动式近海采矿装置（MOMU）的不同容量和有限容量。根据矿物运输船（MTVs）的安排，考虑了资本支出（CAPEX）、运营支出（OPEX）和航程支出（VOYEX），以及不同容量的 MOMUs 和波动的航运价格。采用蒙特卡洛模拟法分析 MTV 在资本支出（CAPEX）、运营支出（OPEX）和航程支出（VOYEX）方面总成本的不确定性。通过对克拉里昂-克利珀顿区中国合同区至宁波-舟山港航运路线的案例研究，对所提出的方法进行了解释。得出的结果表明，120,000 吨是最经济可行的 MOMU 规格，可节省至少 1.9% 的总成本。这些节省主要归功于更好的调度、速度和对市场价格的适应能力。所提出的方法可为深海采矿项目的经济可行性提供支持，并为投资者提供更具体的运营措施，以便其做出明智的决策。
{"title":"Economic analysis of shipping route planning in deep-sea mining operations under uncertain shipping market","authors":"Shanshan Fu , Jihan Lu , Xiangwei Liu , Andrew Lipman","doi":"10.1016/j.rsma.2024.103872","DOIUrl":"10.1016/j.rsma.2024.103872","url":null,"abstract":"<div><div>Deep-sea mining is an emerging interdisciplinary and cross-domain research topic. As commercialization of deep-sea mining advances, economic analysis of the maritime transportation of minerals is critical to forming sound commercial plans. This paper proposes an approach for the economic analysis of shipping route planning in deep-sea mining operations, considering the varying capacities of the proposed mobile offshore minerals units (MOMUs) and the limited capacity. Capital expense (CAPEX), operational expense (OPEX), and voyage expense (VOYEX) are taken into account according to the arrangement of mineral transportation vessels (MTVs) with different capacities of MOMUs and fluctuating shipping prices. Monte Carlo Simulation is used to analyze the uncertainties of the total cost for MTVs with respect to CAPEX, OPEX, and VOYEX. A case study of the shipping route from the Chinese contract area in the Clarion-Clipperton Zone to Ningbo-Zhoushan Port is presented to interpret the proposed approach. The derived results demonstrate that 120,000 tons is the most economically viable MOMU size, saving at least 1.9 % of the total cost. These savings are mainly due to better scheduling, speed, and resilience to market prices. The proposed approach can support economic feasibility for deep-sea mining projects and provide investors with more specific operational measures to make well-informed decisions.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.rsma.2024.103859
Loc Nguyen-Xuan , Tuan Nguyen-Le , Quan Tran-Anh , Long Trinh-Tuan
This study assesses the tidal energy potential in the Vietnam East Sea (VES), a region with complex hydrodynamics and significant interactions with the Western Pacific Ocean. A rigorous validation of six prominent semi-empirical global ocean tide models (FES2014, DTU16, EOT20, GOT4.10c, HAMTIDE12, OSU12.V1) was conducted against an extensive network of 34 tide gauge stations in the VES region. The validation identified FES2014 as the superior model, exhibiting the closest agreement with observations due to its advanced data assimilation techniques, high-resolution grids, and robust hydrodynamic representation influenced by the complex VES bathymetry. Leveraging the FES2014 model, the influential role of the semi-diurnal component (M2) in dictating energy distribution is prominently evident. Evaluation results of tidal amplitudes revealed three emerging hotspots: the Batang Lupar estuary (Malaysia), Anpu Gang (China), and Bac Lieu (Vietnam), with tidal amplitudes up to 326.2 cm. The Anpu Gang exhibited the highest theoretical potential tidal energy of 14.90 Wh/m2, making it the most promising site for localized tidal power development. Although moderate compared to globally renowned sites, the identified VES hotspots merit consideration for small-to-medium scale projects tailored to local conditions. While limited to potential energy assessments, this study provides a crucial baseline for the VES region, highlighting opportunities for sustainable tidal energy exploitation.
本研究对越南东海（VES）的潮汐能潜力进行了评估，该地区水动力复杂，与西太平洋相互作用密切。根据越南东海地区 34 个验潮站组成的广泛网络，对六个著名的半经验全球海洋潮汐模型（FES2014、DTU16、EOT20、GOT4.10c、HAMTIDE12、OSU12.V1）进行了严格验证。验证结果表明，FES2014 是更优越的模型，由于其先进的数据同化技术、高分辨率网格以及受 VES 复杂水深影响的强大流体动力表现，该模型与观测结果的吻合度最高。利用 FES2014 模型，半昼夜分量（M2）在决定能量分布方面的影响作用非常明显。潮汐振幅的评估结果显示了三个新出现的热点地区：Batang Lupar 河口（马来西亚）、安埔岗（中国）和Bac Lieu（越南），潮汐振幅高达 326.2 厘米。安埔港的理论潜在潮汐能量最高，达到 14.90 Wh/m2，是最有希望进行本地化潮汐发电开发的地点。虽然与全球知名的地点相比，这些已确定的 VES 热点并不突出，但仍值得考虑根据当地条件开展中小型项目。虽然这项研究仅限于潜在的能源评估，但它为 VES 地区提供了一个重要的基线，凸显了可持续潮汐能开发的机遇。
{"title":"Estimation of tidal energy potential in the Vietnam East Sea: A comprehensive analysis using semi-empirical tide models","authors":"Loc Nguyen-Xuan , Tuan Nguyen-Le , Quan Tran-Anh , Long Trinh-Tuan","doi":"10.1016/j.rsma.2024.103859","DOIUrl":"10.1016/j.rsma.2024.103859","url":null,"abstract":"<div><div>This study assesses the tidal energy potential in the Vietnam East Sea (VES), a region with complex hydrodynamics and significant interactions with the Western Pacific Ocean. A rigorous validation of six prominent semi-empirical global ocean tide models (FES2014, DTU16, EOT20, GOT4.10c, HAMTIDE12, OSU12.V1) was conducted against an extensive network of 34 tide gauge stations in the VES region. The validation identified FES2014 as the superior model, exhibiting the closest agreement with observations due to its advanced data assimilation techniques, high-resolution grids, and robust hydrodynamic representation influenced by the complex VES bathymetry. Leveraging the FES2014 model, the influential role of the semi-diurnal component (M<sub>2</sub>) in dictating energy distribution is prominently evident. Evaluation results of tidal amplitudes revealed three emerging hotspots: the Batang Lupar estuary (Malaysia), Anpu Gang (China), and Bac Lieu (Vietnam), with tidal amplitudes up to 326.2 cm. The Anpu Gang exhibited the highest theoretical potential tidal energy of 14.90 Wh/m<sup>2</sup>, making it the most promising site for localized tidal power development. Although moderate compared to globally renowned sites, the identified VES hotspots merit consideration for small-to-medium scale projects tailored to local conditions. While limited to potential energy assessments, this study provides a crucial baseline for the VES region, highlighting opportunities for sustainable tidal energy exploitation.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tropical cyclone (TC) disturbances can cause changes in ocean dynamics before, during, and afterwards. We employed an Argo data and ocean model product of Copernicus Marine Environment Monitoring Service (CMEMS) to address the gap in observations of the ocean response from the severe TC Seroja and its interactions with the tropical low TC Odette, known as the rare Fujiwhara effect phenomenon. Our study in southern Indonesia seawater was conducted between March and April 2021, beginning with reconciling the deviation of the CMEMS ocean model product by assessing the model accuracy to the Argo float data to build confidence in using the model for further analysis. Comparison revealed that the temperature model datasets have a higher correlation coefficient (∼0.95) with the Argo observation than the salinity model datasets. Further, we investigated the temporal evolution of vertical profiles and upper ocean responses both inside and beyond the TCs route zone. We discovered that the upper ocean response results in a colder and saltier surface with a recovery time of more than 15 days. Furthermore, as a result of the strong surface cooling, mixed layers inside the Seroja track were rapidly thickening following the passage of TC. Our findings provide insights into how the TCs Seroja and Odette affect the ocean layers, especially the primary ocean features and behaviours (temperature and salinity), using the Argo and model datasets.
{"title":"Impact of the Fujiwhara effect from tropical cyclones Seroja and Odette on ocean dynamic in Southern Indonesia: Insights from argo data and model analysis","authors":"Mukti Trenggono , Dessy Berlianty , Bayu Priyono , Zexun Wei , Shujiang Li , Tengfei Xu","doi":"10.1016/j.rsma.2024.103877","DOIUrl":"10.1016/j.rsma.2024.103877","url":null,"abstract":"<div><div>Tropical cyclone (TC) disturbances can cause changes in ocean dynamics before, during, and afterwards. We employed an Argo data and ocean model product of Copernicus Marine Environment Monitoring Service (CMEMS) to address the gap in observations of the ocean response from the severe TC Seroja and its interactions with the tropical low TC Odette, known as the rare <em>Fujiwhara</em> effect phenomenon. Our study in southern Indonesia seawater was conducted between March and April 2021, beginning with reconciling the deviation of the CMEMS ocean model product by assessing the model accuracy to the Argo float data to build confidence in using the model for further analysis. Comparison revealed that the temperature model datasets have a higher correlation coefficient (∼0.95) with the Argo observation than the salinity model datasets. Further, we investigated the temporal evolution of vertical profiles and upper ocean responses both inside and beyond the TCs route zone. We discovered that the upper ocean response results in a colder and saltier surface with a recovery time of more than 15 days. Furthermore, as a result of the strong surface cooling, mixed layers inside the Seroja track were rapidly thickening following the passage of TC. Our findings provide insights into how the TCs Seroja and Odette affect the ocean layers, especially the primary ocean features and behaviours (temperature and salinity), using the Argo and model datasets.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.rsma.2024.103871
Britta Katharina Fiedler , Anthony David Montgomery , Fiona Chong , Hiromu Miyagi , Marilyn Carletti , Rocktim Ramen Das , Yoko Shintani , Timothy Ravasi , James Davis Reimer
Outbreaks of the cyanobacteriosponge Terpios hoshinota are one of the many issues contributing to coral reef decline in the Indo-Pacific. This species occasionally undergoes local outbreaks, becoming an aggressive space competitor and overgrowing and killing zooxanthellate corals. Large outbreaks have been observed in Taiwan and the Ryukyu Islands in southern Japan. Many questions regarding the characteristics and chronology of T. hoshinota outbreaks remain unsolved. Therefore, the aim of this research was to identify outbreak stages at an outbreak site (Ogimi) on the west coast of northern Okinawa Island, Japan. We developed a novel approach to understand the chronology of outbreaks. Distinct outbreak stages were defined based on observations, in which Terpios: 1) starts overgrowing coral colonies, 2) covers a whole coral colony, 3) in the case of branching corals, causes the coral colony to collapse, and 4) the sponge is eventually overgrown by other organisms including turf algae and other sponges. Analyses were done based on photographic transects and the relative proportions of each stage were calculated. Results showed Ogimi is likely in final outbreak stages as overgrown Terpios had the highest share of all stages (57.9 % and 44.9 % at two outbreak sites), while smaller patches of Terpios, marking the starting point of the successional process, made up less than 1.5 % of all observations. We suggest collecting such stage information during Terpios monitoring as it can allow identification of outbreaks at early stages, and potentially identify global patterns.
{"title":"Delineation of outbreak stages of the coral-killing sponge Terpios hoshinota","authors":"Britta Katharina Fiedler , Anthony David Montgomery , Fiona Chong , Hiromu Miyagi , Marilyn Carletti , Rocktim Ramen Das , Yoko Shintani , Timothy Ravasi , James Davis Reimer","doi":"10.1016/j.rsma.2024.103871","DOIUrl":"10.1016/j.rsma.2024.103871","url":null,"abstract":"<div><div>Outbreaks of the cyanobacteriosponge <em>Terpios hoshinota</em> are one of the many issues contributing to coral reef decline in the Indo-Pacific. This species occasionally undergoes local outbreaks, becoming an aggressive space competitor and overgrowing and killing zooxanthellate corals. Large outbreaks have been observed in Taiwan and the Ryukyu Islands in southern Japan. Many questions regarding the characteristics and chronology of <em>T. hoshinota</em> outbreaks remain unsolved. Therefore, the aim of this research was to identify outbreak stages at an outbreak site (Ogimi) on the west coast of northern Okinawa Island, Japan. We developed a novel approach to understand the chronology of outbreaks. Distinct outbreak stages were defined based on observations, in which <em>Terpios</em>: 1) starts overgrowing coral colonies, 2) covers a whole coral colony, 3) in the case of branching corals, causes the coral colony to collapse, and 4) the sponge is eventually overgrown by other organisms including turf algae and other sponges. Analyses were done based on photographic transects and the relative proportions of each stage were calculated. Results showed Ogimi is likely in final outbreak stages as overgrown <em>Terpios</em> had the highest share of all stages (57.9 % and 44.9 % at two outbreak sites), while smaller patches of <em>Terpios</em>, marking the starting point of the successional process, made up less than 1.5 % of all observations. We suggest collecting such stage information during <em>Terpios</em> monitoring as it can allow identification of outbreaks at early stages, and potentially identify global patterns.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.rsma.2024.103870
Gideon Binobo , Ben Bradshaw , Ataharul Chowdhury
Effective fisheries governance has long been a challenge to achieve across the globe with critical implications for food security and livelihoods in coastal zones. This is especially true for the Philippines, an archipelagic country with abundant coastal biodiversity. While scholars have investigated specific elements of fisheries governance in the Philippines, none has sought to make holistic sense in terms of the coherence of its goals, instruments, actions, opportunities, and challenges. To address this gap, a scoping review was conducted based upon 160 published articles. Results of the study reveal that marine fisheries governance in the Philippines is primarily dominated by participatory governance, specifically co-management, which encourages public-private partnerships. This collaborative arrangement is legally empowered by legislation that provides the mandate for the decentralization of fisheries governance – the Local Government Code of 1991 and the Philippine Fisheries Code of 1998. Marine fisheries governance is primarily oriented towards biodiversity conservation, an overarching goal necessary to achieve other social, economic, and cultural goals. In order to achieve these goals, a combination of hard and soft instruments is typically employed in governance operations in tandem with, predominantly, surveillance and enforcement actions. Opportunities in fisheries governance are principally institutional factors (i.e. institutional linkages), whereas challenges are mostly resource-oriented factors (i.e. illegal fishing). More broadly, marine fisheries governance in the Philippines has evolved in response to historical political processes and especially the dynamics of power relations among key actors – the state, market and civil society - and the struggle for decolonization.
{"title":"Scoping review of marine fisheries governance in the Philippines: Goals, instruments, actions, opportunities and challenges","authors":"Gideon Binobo , Ben Bradshaw , Ataharul Chowdhury","doi":"10.1016/j.rsma.2024.103870","DOIUrl":"10.1016/j.rsma.2024.103870","url":null,"abstract":"<div><div>Effective fisheries governance has long been a challenge to achieve across the globe with critical implications for food security and livelihoods in coastal zones. This is especially true for the Philippines, an archipelagic country with abundant coastal biodiversity. While scholars have investigated specific elements of fisheries governance in the Philippines, none has sought to make holistic sense in terms of the coherence of its goals, instruments, actions, opportunities, and challenges. To address this gap, a scoping review was conducted based upon 160 published articles. Results of the study reveal that marine fisheries governance in the Philippines is primarily dominated by participatory governance, specifically co-management, which encourages public-private partnerships. This collaborative arrangement is legally empowered by legislation that provides the mandate for the decentralization of fisheries governance – the Local Government Code of 1991 and the Philippine Fisheries Code of 1998. Marine fisheries governance is primarily oriented towards biodiversity conservation, an overarching goal necessary to achieve other social, economic, and cultural goals. In order to achieve these goals, a combination of hard and soft instruments is typically employed in governance operations in tandem with, predominantly, surveillance and enforcement actions. Opportunities in fisheries governance are principally institutional factors (i.e. institutional linkages), whereas challenges are mostly resource-oriented factors (i.e. illegal fishing). More broadly, marine fisheries governance in the Philippines has evolved in response to historical political processes and especially the dynamics of power relations among key actors – the state, market and civil society - and the struggle for decolonization.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.rsma.2024.103863
A’an Johan Wahyudi , Febty Febriani
Conducting in-depth studies of carbon dynamics in the Southeast Asia’s Sunda Shelf waters is challenging. Particulate organic carbon (POC) is a key component that can be monitored in the region, but ocean assessment requires advanced research and POC monitoring, especially in relation to ocean dynamics and forecasts. Accurate forecasting of POC in marine environments is difficult due to the complexity of oceanic processes and the influence of various environmental factors. Statistical forecasting models such as Seasonal Autoregressive Integrated Moving Average (SARIMA) or SARIMA with Exogenous Factors (SARIMAX) are useful for this purpose. This study compares these two time-series forecasting models to assess the role of exogenous factors in predicting POC variability in Indonesian seas. The models were specified as SARIMA (3, 1, 3)x(2, 0, 0, 60) and SARIMAX (3, 1, 3)x(2, 0, 0, 60). We obtained Akaike Information Criterion (AIC) values of 1237.767 for the SARIMA model and 1207.341 for SARIMAX[exog=SST]. The SARIMA model's validation metrics were 6.94 % for MAPE, 10.80 for RMSE, and 0.65 for the correlation coefficient, outperforming the SARIMAX model. While SARIMAX incorporates additional environmental variables, SARIMA outperforms it based on MAPE, RMSE, and correlation coefficients. Our findings reveal that only sea surface temperature can significantly influence POC forecasts, thus providing a new perspective on oceanic carbon dynamics. From 2022–2030, POC levels are expected to range between 108.3 and 135.9 mg/m³, with a mean value of 120.9±5.4 mg/m³, lower than that observed from 2002 to 2022, which was 118.8±11.9 mg/m³. The highest peak in POC is predicted for the end of 2026 and 2027. The annual trend shows that the highest POC values correspond to the northwest monsoon season, with the lowest during the intermonsoon period.
{"title":"Time-series forecasting of particulate organic carbon on the Sunda Shelf: Comparative performance of the SARIMA and SARIMAX models","authors":"A’an Johan Wahyudi , Febty Febriani","doi":"10.1016/j.rsma.2024.103863","DOIUrl":"10.1016/j.rsma.2024.103863","url":null,"abstract":"<div><div>Conducting in-depth studies of carbon dynamics in the Southeast Asia’s Sunda Shelf waters is challenging. Particulate organic carbon (POC) is a key component that can be monitored in the region, but ocean assessment requires advanced research and POC monitoring, especially in relation to ocean dynamics and forecasts. Accurate forecasting of POC in marine environments is difficult due to the complexity of oceanic processes and the influence of various environmental factors. Statistical forecasting models such as Seasonal Autoregressive Integrated Moving Average (SARIMA) or SARIMA with Exogenous Factors (SARIMAX) are useful for this purpose. This study compares these two time-series forecasting models to assess the role of exogenous factors in predicting POC variability in Indonesian seas. The models were specified as SARIMA (3, 1, 3)x(2, 0, 0, 60) and SARIMAX (3, 1, 3)x(2, 0, 0, 60). We obtained Akaike Information Criterion (AIC) values of 1237.767 for the SARIMA model and 1207.341 for SARIMAX[exog=SST]. The SARIMA model's validation metrics were 6.94 % for MAPE, 10.80 for RMSE, and 0.65 for the correlation coefficient, outperforming the SARIMAX model. While SARIMAX incorporates additional environmental variables, SARIMA outperforms it based on MAPE, RMSE, and correlation coefficients. Our findings reveal that only sea surface temperature can significantly influence POC forecasts, thus providing a new perspective on oceanic carbon dynamics. From 2022–2030, POC levels are expected to range between 108.3 and 135.9 mg/m³, with a mean value of 120.9±5.4 mg/m³, lower than that observed from 2002 to 2022, which was 118.8±11.9 mg/m³. The highest peak in POC is predicted for the end of 2026 and 2027. The annual trend shows that the highest POC values correspond to the northwest monsoon season, with the lowest during the intermonsoon period.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.rsma.2024.103869
Liya V. Benjamin , Ratheesh Kumar R , Shelton Padua , Vineetha G , Sajna V.H , Parvathy R.
The study elucidates the inter-annual and seasonal variability in the phytoplankton abundance and community structure concurrent to variable rainfall patterns in Chettuva, a tropical monsoonal estuary along the southwest coast of India. The phytoplankton community exhibited statistically significant inter-annual variation with a 1.2-fold increase in abundance (av. 19.44 ×104cellsL−1) in 2021 in comparison with 2019 (av. 15.30 ×104cellsL−1). A total of 87 phytoplankton species were observed during the study, among which Bacillariophyceae dominated with 52 species, followed by Dinophyceae (20 species), and to a lesser extent by Chlorophyceae (11 species) and Cyanophyceae (2 species). Phytoplankton community structure also showed variation, with 71 species contributing to the diversity in 2021 and 62 species in 2019. Though Bacillariophycea dominated during both years, the community was more diverse in 2021comparatively a more saline year Biddulphia sp. Coscinodiscus sp., Cyclotella striata, Melosira sulcata, Pleurosigma sp., and Skeletonema costatum were the diatoms common to both the years, though with varied abundance. Dinophyceae did not show a conspicuous change in community structure in both years, with mostly the same species contributing to the total phytoplankton population but showed slight variation in abundance. Cyanophycea was observed exclusively during the year 2021. The abundance and community structure of the species varied from year to year, but they also changed seasonally, with lower numbers observed during the monsoon compared to the post-monsoon period in both years. CCA analysis identified two groups of phytoplankton assemblages in relation to the prevailing environmental conditions. The Group I species preferred lower temperature and salinity and elevated nutrient concentrations and they dominated during the monsoon season. Group II species preferred high saline well oxygenated, nutrient-poor waters and they dominated during the post-monsoon. Furthermore, the trophic state index analysis indicated mesotrophic conditions during the monsoon, while eutrophic conditions were observed in the post-monsoon period.
{"title":"Inter-annual variability in the phytoplankton abundance and community structure of a tropical monsoonal estuary in response to variable monsoonal patterns","authors":"Liya V. Benjamin , Ratheesh Kumar R , Shelton Padua , Vineetha G , Sajna V.H , Parvathy R.","doi":"10.1016/j.rsma.2024.103869","DOIUrl":"10.1016/j.rsma.2024.103869","url":null,"abstract":"<div><div>The study elucidates the inter-annual and seasonal variability in the phytoplankton abundance and community structure concurrent to variable rainfall patterns in Chettuva, a tropical monsoonal estuary along the southwest coast of India. The phytoplankton community exhibited statistically significant inter-annual variation with a 1.2-fold increase in abundance (av. 19.44 ×10<sup>4</sup>cellsL<sup>−1</sup>) in 2021 in comparison with 2019 (av. 15.30 ×10<sup>4</sup>cellsL<sup>−1</sup>). A total of 87 phytoplankton species were observed during the study, among which Bacillariophyceae dominated with 52 species, followed by Dinophyceae (20 species), and to a lesser extent by Chlorophyceae (11 species) and Cyanophyceae (2 species). Phytoplankton community structure also showed variation, with 71 species contributing to the diversity in 2021 and 62 species in 2019. Though Bacillariophycea dominated during both years, the community was more diverse in 2021comparatively a more saline year <em>Biddulphia</em> sp. <em>Coscinodiscus</em> sp.<em>, Cyclotella striata, Melosira sulcata, Pleurosigma</em> sp.<em>,</em> and <em>Skeletonema costatum</em> were the diatoms common to both the years, though with varied abundance. Dinophyceae did not show a conspicuous change in community structure in both years, with mostly the same species contributing to the total phytoplankton population but showed slight variation in abundance. Cyanophycea was observed exclusively during the year 2021. The abundance and community structure of the species varied from year to year, but they also changed seasonally, with lower numbers observed during the monsoon compared to the post-monsoon period in both years. CCA analysis identified two groups of phytoplankton assemblages in relation to the prevailing environmental conditions. The Group I species preferred lower temperature and salinity and elevated nutrient concentrations and they dominated during the monsoon season. Group II species preferred high saline well oxygenated, nutrient-poor waters and they dominated during the post-monsoon. Furthermore, the trophic state index analysis indicated mesotrophic conditions during the monsoon, while eutrophic conditions were observed in the post-monsoon period.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-12DOI: 10.1016/j.rsma.2024.103867
Fulin Sun , Hongqiang Yang , Xingyu Song , Zhiyuan Ouyang
The microbial composition of surrounding waters is crucial for the health of coral reefs and holds significant value for understanding the complexity and environmental adaptability of coral reef ecosystems. This study reveals the spatial heterogeneity and diversity characteristics of bacterial and eukaryotic communities in different coral reef regions of the South China Sea. Chao and Shannon indices showed significant differences (p < 0.05) in diversity of bacterial and eukaryotic communities across different coral reefs. PCoA (principal coordinate analysis) indicates significant differences in community composition among regions, highlighting the crucial role of coral reef environmental heterogeneity on microbial community. NST (normalized stochasticity ratio) analysis indicates that community assembly in coral reef areas is more influenced by ecological stochastic processes. Major bacterial groups include Proteobacteria, Cyanobacteria, and Bacteroidota, while dominant eukaryotic groups include Dinophyceae, Apicomplexa, Bacillariophyta, Florideophyceae, Mamiellophyceae, Syndiniales, Prasino-Clade-VII, and Ascomycota, each showing significant abundance differences across coral reef regions (p < 0.05). High abundance of Rhodobacterales and Flavobacteriales are detected in all coral reef waters. Correlation analysis indicates that temperature, pH, and salinity are important factors affecting the bacterial and eukaryotic communities. This study reveals the spatial heterogeneity of microbial communities in coral reef regions of South China Sea and underscores the significant impact of marine environmental heterogeneity on community structure.
{"title":"Distinct bacterial and eukaryotic communities reflect the specificity of different coral reefs in the South China Sea","authors":"Fulin Sun , Hongqiang Yang , Xingyu Song , Zhiyuan Ouyang","doi":"10.1016/j.rsma.2024.103867","DOIUrl":"10.1016/j.rsma.2024.103867","url":null,"abstract":"<div><div>The microbial composition of surrounding waters is crucial for the health of coral reefs and holds significant value for understanding the complexity and environmental adaptability of coral reef ecosystems. This study reveals the spatial heterogeneity and diversity characteristics of bacterial and eukaryotic communities in different coral reef regions of the South China Sea. Chao and Shannon indices showed significant differences (<em>p</em> < 0.05) in diversity of bacterial and eukaryotic communities across different coral reefs. PCoA (principal coordinate analysis) indicates significant differences in community composition among regions, highlighting the crucial role of coral reef environmental heterogeneity on microbial community. NST (normalized stochasticity ratio) analysis indicates that community assembly in coral reef areas is more influenced by ecological stochastic processes. Major bacterial groups include Proteobacteria, Cyanobacteria, and Bacteroidota, while dominant eukaryotic groups include Dinophyceae, Apicomplexa, Bacillariophyta, Florideophyceae, Mamiellophyceae, Syndiniales, Prasino-Clade-VII, and Ascomycota, each showing significant abundance differences across coral reef regions (<em>p</em> < 0.05). High abundance of Rhodobacterales and Flavobacteriales are detected in all coral reef waters. Correlation analysis indicates that temperature, pH, and salinity are important factors affecting the bacterial and eukaryotic communities. This study reveals the spatial heterogeneity of microbial communities in coral reef regions of South China Sea and underscores the significant impact of marine environmental heterogeneity on community structure.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-12DOI: 10.1016/j.rsma.2024.103862
Andrea Tadić , Nino Krvavica , Čedomir Benac , Igor Ružić
The study explores the general vulnerability of the coastline, with a focus on assessing vulnerability using the coastal vulnerability index (CVI) along the highly indented coastline of Primorje-Gorski Kotar County (PGC), Croatia. Vulnerability was assessed every 25 m of the 1235 km long coastline by calculating the CVI based on five representative variables: geological setting, coastal slope in relation to terrain instabilities (rockfalls and landslides), significant wave height, coastal flooding, and beaches, which were also integrated into a single overall CVI. The length of the coastline, characterised by different relief forms, and the scale of available data required an adaptation of the commonly used methodology. The results show a low overall vulnerability, mainly due to the prevalence of relatively resistant carbonate sedimentary rocks along the coasts. However, almost a quarter of the investigated coastline is highly or very highly vulnerable to coastal flooding. Of particular concern is the fact that many of the most vulnerable areas are inhabited. Analyses at this scale are suitable for regional spatial planning. The results of the conducted research are available publicly online, which enables their practical application for planning and management of coastal areas. Adaptation to the impacts of climate change is highly dependent on the location itself, but overall, this assessment provides indications of the most vulnerable locations in the PGC, where it is necessary to limit interventions in the coastal area.
{"title":"Coastal vulnerability index for the indented coastline of Primorje-Gorski Kotar County, Croatia","authors":"Andrea Tadić , Nino Krvavica , Čedomir Benac , Igor Ružić","doi":"10.1016/j.rsma.2024.103862","DOIUrl":"10.1016/j.rsma.2024.103862","url":null,"abstract":"<div><div>The study explores the general vulnerability of the coastline, with a focus on assessing vulnerability using the coastal vulnerability index (CVI) along the highly indented coastline of Primorje-Gorski Kotar County (PGC), Croatia. Vulnerability was assessed every 25 m of the 1235 km long coastline by calculating the CVI based on five representative variables: geological setting, coastal slope in relation to terrain instabilities (rockfalls and landslides), significant wave height, coastal flooding, and beaches, which were also integrated into a single overall CVI. The length of the coastline, characterised by different relief forms, and the scale of available data required an adaptation of the commonly used methodology. The results show a low overall vulnerability, mainly due to the prevalence of relatively resistant carbonate sedimentary rocks along the coasts. However, almost a quarter of the investigated coastline is highly or very highly vulnerable to coastal flooding. Of particular concern is the fact that many of the most vulnerable areas are inhabited. Analyses at this scale are suitable for regional spatial planning. The results of the conducted research are available publicly online, which enables their practical application for planning and management of coastal areas. Adaptation to the impacts of climate change is highly dependent on the location itself, but overall, this assessment provides indications of the most vulnerable locations in the PGC, where it is necessary to limit interventions in the coastal area.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-11DOI: 10.1016/j.rsma.2024.103865
Retina I. Cleetus , C.V. Asha , S. Bijoy Nandan , P.S. Suson , P.R. Jayachandran
The Vembanad Lake (VL) is a brackish water lagoon, an integral part of Ramsar site, Vembanad Kol Wetland ecosystem on the southwestern coast of India. VL faces escalating anthropogenic impact, notably worsened by the establishment of the Thanneermukkom barrage (TMB) in 1976. This study hypothesizes that the TMB has led to significant ecological changes in VL, specifically altering the distribution and abundance of calanoid copepods, which are vital as a food source for higher trophic levels, particularly fish. To test this hypothesis, zooplankton samples were collected from various sites along the lake, and environmental parameters such as salinity and chlorophyll-a concentration were measured. This investigation reveals a distinct limnetic zone in the southern region, in contrast to the oligo-mesohaline zone in the north, attributed to the TMB. The study identifies the prevalence of calanoid copepod species such as Heliodiaptomus cinctus, Allodiaptomus mirabilipes, and Acartiella gravelyi in the TMB-South region, reflecting a freshwater-dominated ecosystem. The low salinity and high chlorophyll-a content in this area create an optimal environment for these species. In contrast, the dominance of Acartia (Odontacartia) spinicauda, Pseudodiaptomus serricadatus, and Paracalanus sp. in the TMB-North indicates higher salinity levels, with species in this region adapting to a different ecological niche. Thus, the installation of the TMB has significantly altered the ecological balance of VL by dividing the water body into two distinct salinity zones. This separation has led to changes in the distribution and abundance of calanoid copepods, which are essential for energy transfer to higher trophic levels in the VL food web, consequently affecting fish populations and overall biodiversity.
{"title":"Ecological impact of artificial barrage on calanoid copepods in the Vembanad Lake, Southwest Coast of India","authors":"Retina I. Cleetus , C.V. Asha , S. Bijoy Nandan , P.S. Suson , P.R. Jayachandran","doi":"10.1016/j.rsma.2024.103865","DOIUrl":"10.1016/j.rsma.2024.103865","url":null,"abstract":"<div><div>The Vembanad Lake (VL) is a brackish water lagoon, an integral part of Ramsar site, Vembanad Kol Wetland ecosystem on the southwestern coast of India. VL faces escalating anthropogenic impact, notably worsened by the establishment of the Thanneermukkom barrage (TMB) in 1976. This study hypothesizes that the TMB has led to significant ecological changes in VL, specifically altering the distribution and abundance of calanoid copepods, which are vital as a food source for higher trophic levels, particularly fish. To test this hypothesis, zooplankton samples were collected from various sites along the lake, and environmental parameters such as salinity and chlorophyll-a concentration were measured. This investigation reveals a distinct limnetic zone in the southern region, in contrast to the oligo-mesohaline zone in the north, attributed to the TMB. The study identifies the prevalence of calanoid copepod species such as <em>Heliodiaptomus cinctus</em>, <em>Allodiaptomus mirabilipes</em>, and <em>Acartiella gravelyi</em> in the TMB-South region, reflecting a freshwater-dominated ecosystem. The low salinity and high chlorophyll-a content in this area create an optimal environment for these species. In contrast, the dominance of <em>Acartia</em> (<em>Odontacartia</em>) <em>spinicauda</em>, <em>Pseudodiaptomus serricadatus</em>, and <em>Paracalanus</em> sp. in the TMB-North indicates higher salinity levels, with species in this region adapting to a different ecological niche. Thus, the installation of the TMB has significantly altered the ecological balance of VL by dividing the water body into two distinct salinity zones. This separation has led to changes in the distribution and abundance of calanoid copepods, which are essential for energy transfer to higher trophic levels in the VL food web, consequently affecting fish populations and overall biodiversity.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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