Pub Date : 2022-01-01DOI: 10.4236/ojms.2022.124010
François Désiré Owona Edoa, G. E. Takem, Pascale Banga Medjo, A. Mama, Gabriel Bertrand Zambo, Joselly Éric Kouedeum Kueppo, Tahir Safia Mahamat, S. Z. Togouet
{"title":"Spatio-Temporal Variation of Dinoflagellates of the Genera <i>Ceratium</i> (Schrank 1793) and <i>Protoperidinium</i> (Bergh 1881) in Relationship with Some Abiotic Variables in the Atlantic Coast of Kribi (South Region—Cameroon)","authors":"François Désiré Owona Edoa, G. E. Takem, Pascale Banga Medjo, A. Mama, Gabriel Bertrand Zambo, Joselly Éric Kouedeum Kueppo, Tahir Safia Mahamat, S. Z. Togouet","doi":"10.4236/ojms.2022.124010","DOIUrl":"https://doi.org/10.4236/ojms.2022.124010","url":null,"abstract":"","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70368050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.4236/ojms.2022.124009
Barbilina Pam, P. M. Mohan
{"title":"Distribution of Larger Benthic Foraminifera (LBF) in Selected Islands of Marine National Park, Port Blair, South Andaman, India","authors":"Barbilina Pam, P. M. Mohan","doi":"10.4236/ojms.2022.124009","DOIUrl":"https://doi.org/10.4236/ojms.2022.124009","url":null,"abstract":"","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70367982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.4236/ojms.2022.122003
M. A. Malto, Antonino B. Mendoza
Marine microplastic pollution is becoming more visible and pervasive in various aquatic environments and species, including those intended for human consumption. The present study evaluated the occurrence of suspended microplastics in surface waters, the water column, and bivalves, such as Perna viridis and Atrina pectinata in Sorsogon bay. Microplastics were detected in all sampling sites and bivalve tissue samples. Surface water (0 m) and water column (5 m) samples taken from six sampling stations representing spatial consideration of the bay showed an average of 5.55 ± 1.74 items/m 3 (range: 2.27 - 1.66 items/m 3 ) and 5.80 ± 1.94 items/m 3 (range: 1.93 - 14.55 items/m 3 ), respectively. The mean microplastic number in farmed mussels and wild pen shells collected around the bay varied from 0.31 - 2.50 items/individual for mussels and 0.93 - 4.27 items/individual for pen shells. FTIR spectroscopy revealed that microplastics made up 55% of the debris analyzed, with an additional 45% natural materials, including aluminum silicate, cellulose, and chitin. It is becoming increasingly evident that Sorsogon Bay is not exempt from this paradigm. Hopefully, this will drive the community to support measures to address this issue, such as social perception and behavioral change.
{"title":"Suspended Microplastic in Sorsogon Bay Attributing <i>Perna viridis</i> and <i>Atrina pectinata</i> Contamination","authors":"M. A. Malto, Antonino B. Mendoza","doi":"10.4236/ojms.2022.122003","DOIUrl":"https://doi.org/10.4236/ojms.2022.122003","url":null,"abstract":"Marine microplastic pollution is becoming more visible and pervasive in various aquatic environments and species, including those intended for human consumption. The present study evaluated the occurrence of suspended microplastics in surface waters, the water column, and bivalves, such as Perna viridis and Atrina pectinata in Sorsogon bay. Microplastics were detected in all sampling sites and bivalve tissue samples. Surface water (0 m) and water column (5 m) samples taken from six sampling stations representing spatial consideration of the bay showed an average of 5.55 ± 1.74 items/m 3 (range: 2.27 - 1.66 items/m 3 ) and 5.80 ± 1.94 items/m 3 (range: 1.93 - 14.55 items/m 3 ), respectively. The mean microplastic number in farmed mussels and wild pen shells collected around the bay varied from 0.31 - 2.50 items/individual for mussels and 0.93 - 4.27 items/individual for pen shells. FTIR spectroscopy revealed that microplastics made up 55% of the debris analyzed, with an additional 45% natural materials, including aluminum silicate, cellulose, and chitin. It is becoming increasingly evident that Sorsogon Bay is not exempt from this paradigm. Hopefully, this will drive the community to support measures to address this issue, such as social perception and behavioral change.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70367347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.4236/ojms.2022.123007
O. A. Njoh, Naomi Sama, Y. Sali
{"title":"Shallow Marine Cenomanian-Turonian Benthic Foraminifera and Kerogen Type from Mangoule, Logbadjeck Formation, Douala/Kribi-Campo Basin, Cameroon, West Africa","authors":"O. A. Njoh, Naomi Sama, Y. Sali","doi":"10.4236/ojms.2022.123007","DOIUrl":"https://doi.org/10.4236/ojms.2022.123007","url":null,"abstract":"","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70367657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.4236/ojms.2022.123005
R. Riad
{"title":"Comparative Taxonomical Studies on the Egyptian Red Sea Cephalopods (Cephalopoda: Mollusca)","authors":"R. Riad","doi":"10.4236/ojms.2022.123005","DOIUrl":"https://doi.org/10.4236/ojms.2022.123005","url":null,"abstract":"","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70367025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-06DOI: 10.4236/ojms.2021.114009
F. Besack, Ebonji Seth Rodrigue, Ajonina Gordon Nwutih, Edikin Roland Dieudonné, Sone Essoh Willy, Nguekeu Brice, Mbang Essome Junior, Hamadou Toume Michel-Remi, O. Raphael, T. Minette
This study aimed to provide relevant knowledge about the dynamics of the hydrological parameters in the river-estuary continuum of the Wouri-Nkam river estuary for a sustainable management program. The hydrological parameters were recorded in eleven stations spanned out on the basis of population density and human activities. Water quality parameters (Temperature, salinity, dissolved oxygen, pH, Total dissolved solutes, Redox potential and conductivity) were collected in subsurface water using a multiple parameter. Surface currents and morphometric (depth and width) parameters were recorded using a drifter, sonar depth and GPS. The field measurements took placed between 18/05/2019 to 08/09/2020 and were divided into six (06) cruises. The data were later subjected to an analysis of variance (ANOVA) and Principle Component Analysis using XLSTAT 2017 (2.7 version) software. Results obtained revealed that, the water quality parameters were spatially more stable notsignficant at (df = 9, p 0.05) with a relatively low temperature (25.5°C - 27°C) during the wet period. The limit of the frontal zone extended to S5 (Bonalokan, 8.25 km from S1) during the snapshot of the dry period, spring phase and flood tide conditions. Inversely, during wet period, this extension reduced to S1 (Bridge) and relatively increases slightly to S3 (Bonangang) during the neap phase and ebb tides of this season. This result revealed a change in the axial gradient of about eight (08) and four (04) kilometers during the seasonal and tidal scales (lunar and diurnal periods) respectively. These changes were also accompanied by changes in the water quality signatures, that may affect the fishery distribution and compositions. However, futures studies to buttress the results of this investigation should focus on longer time series sampling methods and model developments.
{"title":"Spatial and Temporal Variation of the Hydrological Parameters in the Wouri-Nkam Section of the Cameroon Estuary, Central African Atlantic Coast","authors":"F. Besack, Ebonji Seth Rodrigue, Ajonina Gordon Nwutih, Edikin Roland Dieudonné, Sone Essoh Willy, Nguekeu Brice, Mbang Essome Junior, Hamadou Toume Michel-Remi, O. Raphael, T. Minette","doi":"10.4236/ojms.2021.114009","DOIUrl":"https://doi.org/10.4236/ojms.2021.114009","url":null,"abstract":"This study aimed to provide relevant knowledge about the dynamics of the hydrological parameters in the river-estuary continuum of the Wouri-Nkam river estuary for a sustainable management program. The hydrological parameters were recorded in eleven stations spanned out on the basis of population density and human activities. Water quality parameters (Temperature, salinity, dissolved oxygen, pH, Total dissolved solutes, Redox potential and conductivity) were collected in subsurface water using a multiple parameter. Surface currents and morphometric (depth and width) parameters were recorded using a drifter, sonar depth and GPS. The field measurements took placed between 18/05/2019 to 08/09/2020 and were divided into six (06) cruises. The data were later subjected to an analysis of variance (ANOVA) and Principle Component Analysis using XLSTAT 2017 (2.7 version) software. Results obtained revealed that, the water quality parameters were spatially more stable notsignficant at (df = 9, p 0.05) with a relatively low temperature (25.5°C - 27°C) during the wet period. The limit of the frontal zone extended to S5 (Bonalokan, 8.25 km from S1) during the snapshot of the dry period, spring phase and flood tide conditions. Inversely, during wet period, this extension reduced to S1 (Bridge) and relatively increases slightly to S3 (Bonangang) during the neap phase and ebb tides of this season. This result revealed a change in the axial gradient of about eight (08) and four (04) kilometers during the seasonal and tidal scales (lunar and diurnal periods) respectively. These changes were also accompanied by changes in the water quality signatures, that may affect the fishery distribution and compositions. However, futures studies to buttress the results of this investigation should focus on longer time series sampling methods and model developments.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42286091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-06DOI: 10.4236/ojms.2021.114010
Juhong Tao, Y. Pei, Jianyi Zhu, Qinqin Lu, Hongxia Jiang, Tao Zhang
The cytological characteristics of major green-tide-forming green algae Ulva prolifera collected from Yellow Sea were studied through cutting segments, long time low temperature or dark treatments. After being dried in the shade and preserved at -20°C for 30 days, the U. prolifera was cultured at 4°C in sterilized seawater under 40 μmol photons m-2·s-1 light intensity for 120 days, results indicated that the plastid of U. prolifera continuously shrank with the extension of treatment, and most cells turned white and died, only a small amount of cells still contained a few of visible inclusions at the 120d of treatment. Then those samples were transferred to 20°C and 40 μmol photons m-2·s-1 condition for recovery cultivation, after about 10 days, some recovery cells were observed in the thallus, and those cells developed to young thallus gradually and released germ cells almost in the same time. After about 60 days of recovery cultivation, the newly-grown green thallus broke through the original dead thallus, and the germ cells also grew to new individual thallus. Before dark treatment, the U. prolifera cells were filled with plastid, contained visible starch grain and discernible cell outlines, while after 120 days of dark treatment, the plastid shrank and degraded together with the disappearance of cell inclusions, and the cell outlines also blurred, then those samples were transferred to optimal culture conditions at 20°C in 40 μmol photons m-2·s-1 light intensity, and 15 days later, newly-grown cells appeared on the almost dead thallus, these cells divided continuously and grew to young thallus, and those newly-grown thallus also generated active germ cells, which developed to new thallus that cytologically identical to the original thallus. Observation of chopped tissue of U. prolifera cultivated at 20°C, 40 μmol m-2·s-1 showed that the morphological upper part cells turned to germ cells first, those germ cells including gametophyte and sporophyte, which released later and grew to new individual thallus. These findings provided cytological evidences for how U. prolifera live through stress conditions such as low temperature, darkness, and also useful for understanding the mechanism of the occurrence of green tide.
{"title":"Research on Growth Characteristics of Green-Tide-Forming Green Algae under Stress Conditions","authors":"Juhong Tao, Y. Pei, Jianyi Zhu, Qinqin Lu, Hongxia Jiang, Tao Zhang","doi":"10.4236/ojms.2021.114010","DOIUrl":"https://doi.org/10.4236/ojms.2021.114010","url":null,"abstract":"The cytological characteristics of major green-tide-forming green algae Ulva prolifera collected from Yellow Sea were studied through cutting segments, long time low temperature or dark treatments. After being dried in the shade and preserved at -20°C for 30 days, the U. prolifera was cultured at 4°C in sterilized seawater under 40 μmol photons m-2·s-1 light intensity for 120 days, results indicated that the plastid of U. prolifera continuously shrank with the extension of treatment, and most cells turned white and died, only a small amount of cells still contained a few of visible inclusions at the 120d of treatment. Then those samples were transferred to 20°C and 40 μmol photons m-2·s-1 condition for recovery cultivation, after about 10 days, some recovery cells were observed in the thallus, and those cells developed to young thallus gradually and released germ cells almost in the same time. After about 60 days of recovery cultivation, the newly-grown green thallus broke through the original dead thallus, and the germ cells also grew to new individual thallus. Before dark treatment, the U. prolifera cells were filled with plastid, contained visible starch grain and discernible cell outlines, while after 120 days of dark treatment, the plastid shrank and degraded together with the disappearance of cell inclusions, and the cell outlines also blurred, then those samples were transferred to optimal culture conditions at 20°C in 40 μmol photons m-2·s-1 light intensity, and 15 days later, newly-grown cells appeared on the almost dead thallus, these cells divided continuously and grew to young thallus, and those newly-grown thallus also generated active germ cells, which developed to new thallus that cytologically identical to the original thallus. Observation of chopped tissue of U. prolifera cultivated at 20°C, 40 μmol m-2·s-1 showed that the morphological upper part cells turned to germ cells first, those germ cells including gametophyte and sporophyte, which released later and grew to new individual thallus. These findings provided cytological evidences for how U. prolifera live through stress conditions such as low temperature, darkness, and also useful for understanding the mechanism of the occurrence of green tide.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42839567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-30DOI: 10.4236/ojms.2021.113008
A. Mama, Willy Karol Abouga Bodo, Gisèle Flodore Youbouni Ghepdeu, G. Ajonina, Jules Rémi Ngoupayou Ndam
To evaluate the actual status of water quality and conclude on the mains source of pollution in the Nyong estuary River, seasonal and spatial variation of water quality parameters was interpreted by multivariate statistical techniques (Principal Component analysis). Nine (09) environmental variables were monitored at four surface stations in the estuary for two seasonal cycles. The fieldwork was conducted from 2018 to 2019 during high tide and low tide for each survey. In situ physical parameters were measured for a total of 64 samples (32 samples for each tide). The laboratory works consisted of some physicochemical analyses and processing of these data by descriptive and multidimensional statistical analyses. Temperature, suspended particle matter, nitrate, nitrite and phosphate change significantly in the estuary with season (p p > 0.05). Principal Component analysis found temperature, salinity, pH, ammonium to be the most important parameters contributing to the fluctuations of surface water quality in the Nyong estuary during the dry seasons whereas suspended particle matter, nitrate, and phosphate are the most important parameters contributing to the fluctuation of surface water quality in the Nyong estuary during the rainy seasons. Based on spatial variation, the Principal Component analysis found that, suspended particle matter, nitrate and phosphate contribute to the fluctuation of surface water quality parameters upstream of the estuary while downstream salinity, pH, and ammonium contribute the most to the fluctuation of surface water quality. This study shows us the usefulness of multivariate statistical techniques used in assessing water quality data sets that would help us in understanding seasonal and spatial variations of water quality parameters to manage estuarine systems.
利用多元统计技术(主成分分析)对宁戎河口水质参数的季节和空间变化规律进行了分析，以评价宁戎河口水质的实际状况，明确主要污染源。在河口4个地面站对9个环境变量进行了2个季节周期的监测。实地调查于2018年至2019年进行，每次调查均在涨潮和退潮期间进行。共测量了64个样本的原位物理参数(每个潮汐32个样本)。实验室工作包括一些物理化学分析，并通过描述性和多维统计分析处理这些数据。温度、悬浮颗粒物、硝酸盐、亚硝酸盐和磷酸盐随季节变化显著(p p > 0.05)。主成分分析结果表明，温度、盐度、pH、铵态氮是枯水期尼龙口表层水质波动的最主要影响因子，而悬浮颗粒物、硝酸盐和磷酸盐是雨季尼龙口表层水质波动的最主要影响因子。基于空间变异，主成分分析发现，悬浮物、硝酸盐和磷酸盐对河口上游地表水水质参数波动的影响最大，而下游盐度、pH和铵对地表水水质参数波动的影响最大。这项研究向我们展示了用于评估水质数据集的多元统计技术的有用性，这将有助于我们了解水质参数的季节和空间变化，以管理河口系统。
{"title":"Understanding Seasonal and Spatial Variation of Water Quality Parameters in Mangrove Estuary of the Nyong River Using Multivariate Analysis (Cameroon Southern Atlantic Coast)","authors":"A. Mama, Willy Karol Abouga Bodo, Gisèle Flodore Youbouni Ghepdeu, G. Ajonina, Jules Rémi Ngoupayou Ndam","doi":"10.4236/ojms.2021.113008","DOIUrl":"https://doi.org/10.4236/ojms.2021.113008","url":null,"abstract":"To evaluate the actual status of water quality and conclude on the mains source of pollution in the Nyong estuary River, seasonal and spatial variation of water quality parameters was interpreted by multivariate statistical techniques (Principal Component analysis). Nine (09) environmental variables were monitored at four surface stations in the estuary for two seasonal cycles. The fieldwork was conducted from 2018 to 2019 during high tide and low tide for each survey. In situ physical parameters were measured for a total of 64 samples (32 samples for each tide). The laboratory works consisted of some physicochemical analyses and processing of these data by descriptive and multidimensional statistical analyses. Temperature, suspended particle matter, nitrate, nitrite and phosphate change significantly in the estuary with season (p p > 0.05). Principal Component analysis found temperature, salinity, pH, ammonium to be the most important parameters contributing to the fluctuations of surface water quality in the Nyong estuary during the dry seasons whereas suspended particle matter, nitrate, and phosphate are the most important parameters contributing to the fluctuation of surface water quality in the Nyong estuary during the rainy seasons. Based on spatial variation, the Principal Component analysis found that, suspended particle matter, nitrate and phosphate contribute to the fluctuation of surface water quality parameters upstream of the estuary while downstream salinity, pH, and ammonium contribute the most to the fluctuation of surface water quality. This study shows us the usefulness of multivariate statistical techniques used in assessing water quality data sets that would help us in understanding seasonal and spatial variations of water quality parameters to manage estuarine systems.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48267728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-06DOI: 10.4236/OJMS.2021.112007
T. Mohanraj, M. Sheeba, Siluvai Regi Thomas Sherly Cross, Thangaraj Jebarani Rajathy
Heavy metals are considered to be the most common environmental pollutants in waters and biota; that indicate presence of effluents associated with industrial and domestic sources. The present study aimed to evaluate the trace metal accumulation (Fe, Mn, Zn, Cu, Cd, Pd and Ni) in the tissue of radiate top shell, the sediment and water samples collected from the Hare Island, Tuticorin, during May 2015 to April 2016. During the study, the metal accumulation in the Water, Sediment and Tissue were in the order of Zn > Pb > Cu > Cd; Fe > Mn > Zn > Cu > Cd; Fe > Zn > Mn > Cu > Cd > Pb > Ni respectively. The concentration of Fe dominated in the sediment and tissue sample throughout the study period. Elevated levels of trace metals especially Fe, Mn, Cu, Pb and Zn was observed during October to December, i.e., during the northeast monsoon in all the samples. One way ANOVA indicated statistically no significant difference (p > 0.01) in the variation of Fe, Mn and Ni within the samples.
{"title":"Seasonal Variation of Heavy Metals in the Intertidal Gastropod Trochus radiatus of Gulf of Mannar","authors":"T. Mohanraj, M. Sheeba, Siluvai Regi Thomas Sherly Cross, Thangaraj Jebarani Rajathy","doi":"10.4236/OJMS.2021.112007","DOIUrl":"https://doi.org/10.4236/OJMS.2021.112007","url":null,"abstract":"Heavy metals are considered to be the most common environmental pollutants in waters and biota; that indicate presence of effluents associated with industrial and domestic sources. The present study aimed to evaluate the trace metal accumulation (Fe, Mn, Zn, Cu, Cd, Pd and Ni) in the tissue of radiate top shell, the sediment and water samples collected from the Hare Island, Tuticorin, during May 2015 to April 2016. During the study, the metal accumulation in the Water, Sediment and Tissue were in the order of Zn > Pb > Cu > Cd; Fe > Mn > Zn > Cu > Cd; Fe > Zn > Mn > Cu > Cd > Pb > Ni respectively. The concentration of Fe dominated in the sediment and tissue sample throughout the study period. Elevated levels of trace metals especially Fe, Mn, Cu, Pb and Zn was observed during October to December, i.e., during the northeast monsoon in all the samples. One way ANOVA indicated statistically no significant difference (p > 0.01) in the variation of Fe, Mn and Ni within the samples.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49027624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-06DOI: 10.4236/OJMS.2021.112005
Yu-ming Sheng
Wind load is a control load that affects the safety of structures in the design of ocean platforms. It has not only direct and powerful effects that may cause structure resonance but also has indirect effects causing waves or currents in the ocean. By analyzing the domestic and international norms, this study presents a review of calculation methods of wind load on ocean platforms, which belongs to large-scale non-entity structure used in the open sea while surrounding wind has no fixed direction. Current computations according to the norms are not accurate, which even not takes the force of the wind against the surface perpendicular to the structure into consideration. Additionally, this study also introduces and compares the lift model of platforms based on different theories, such as vortex-excitation and vibration, engineering structure dynamics, gas flow pressure theory, analyzing their applicability, advantages, and disadvantages. This paper analyzes the limitations and applicable conditions of the existing calculation method itself, such as the lift model is suitable for the existence of stable vortex wake; the calculation method of the structural dynamics of marine engineering must be combined with the wind tunnel test and consider the mistakes caused by the position relationship; the numerical simulation method is accurate but tedious. This study provides an insight into the calculation methods of lift in designing ocean platforms, including the finite element method for simulating fluid force and updating formulas in Chinese norms.
{"title":"A Review of the Calculation Methods of Lifting Capacity in Wind Loads on Ocean Platforms","authors":"Yu-ming Sheng","doi":"10.4236/OJMS.2021.112005","DOIUrl":"https://doi.org/10.4236/OJMS.2021.112005","url":null,"abstract":"Wind load is a control load that affects the safety of structures in the design of ocean platforms. It has not only direct and powerful effects that may cause structure resonance but also has indirect effects causing waves or currents in the ocean. By analyzing the domestic and international norms, this study presents a review of calculation methods of wind load on ocean platforms, which belongs to large-scale non-entity structure used in the open sea while surrounding wind has no fixed direction. Current computations according to the norms are not accurate, which even not takes the force of the wind against the surface perpendicular to the structure into consideration. Additionally, this study also introduces and compares the lift model of platforms based on different theories, such as vortex-excitation and vibration, engineering structure dynamics, gas flow pressure theory, analyzing their applicability, advantages, and disadvantages. This paper analyzes the limitations and applicable conditions of the existing calculation method itself, such as the lift model is suitable for the existence of stable vortex wake; the calculation method of the structural dynamics of marine engineering must be combined with the wind tunnel test and consider the mistakes caused by the position relationship; the numerical simulation method is accurate but tedious. This study provides an insight into the calculation methods of lift in designing ocean platforms, including the finite element method for simulating fluid force and updating formulas in Chinese norms.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48450639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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