A total 5849 individuals of ostracods constituting twenty species were collected from five shallow marine sites along the area from El-Quseir to Marsa Alam on the West Coast of the Red Sea. The twenty ostracod species belonging to sixteen genera and ten different families. The three genera; Loxoconcha, Neonesidea and Xestoleberis have high species diversity. Furthermore, the species Loxoconcha ghardaqensis, Xestoleberis rotunda, Paranesidea fracticorallicola, Tanella gracilis and Neonesidea schulzi were the best recognized in the collecting region. Otherwise, the distribution of the collected ostracod species in relation to environmental variables and plants were discussed in detail here. Based on this, it is concluded that, vegetation type appears to be the most important factor controlling the distribution of ostracod species in the investigated area. Also, other factors such as, water temperature, salinity, dissolved oxygen, pH and electrical conductivity play an important role. Scanning electron microscope images of valves are delivered of the recorded taxa. These fauna displays close affinities to those of the Red Sea and the Indo- Pacific region.
{"title":"Distribution and Taxonomy of Shallow Marine Ostracods from the Western Coast of the Red Sea, Egypt","authors":"Ebtesam A. Yousef","doi":"10.4236/OJMS.2018.81004","DOIUrl":"https://doi.org/10.4236/OJMS.2018.81004","url":null,"abstract":"A total 5849 individuals of ostracods constituting twenty species were collected from five shallow marine sites along the area from El-Quseir to Marsa Alam on the West Coast of the Red Sea. The twenty ostracod species belonging to sixteen genera and ten different families. The three genera; Loxoconcha, Neonesidea and Xestoleberis have high species diversity. Furthermore, the species Loxoconcha ghardaqensis, Xestoleberis rotunda, Paranesidea fracticorallicola, Tanella gracilis and Neonesidea schulzi were the best recognized in the collecting region. Otherwise, the distribution of the collected ostracod species in relation to environmental variables and plants were discussed in detail here. Based on this, it is concluded that, vegetation type appears to be the most important factor controlling the distribution of ostracod species in the investigated area. Also, other factors such as, water temperature, salinity, dissolved oxygen, pH and electrical conductivity play an important role. Scanning electron microscope images of valves are delivered of the recorded taxa. These fauna displays close affinities to those of the Red Sea and the Indo- Pacific region.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41564061","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}
Limited information still exists on the movements of bottlenose dolphins in South Australian coastal waters. There is, however, a need to overcome this paucity of information for an effective development and implementation of conservation and management initiatives in these waters that are increasingly threatened by anthropogenic activities. This study infers potential movements of bottlenose dolphins (Tursiops spp.) between Kangaroo Island that separate and shelter South Australian coastal waters from the Southern Ocean swell, and the South Australian mainland (The Fleurieu Peninsula and The Adelaide Dolphin Sanctuary). Bottlenose dolphins were identified from three separate photo-identification catalogues collated from around the South Australian coastline. Of the 3518, 654 and 181 dolphins sighted in Kangaroo Island, Fleurieu Peninsula and the Adelaide Dolphin Sanctuary, 233, 74 and 40 individuals were recognizable, respectively. Resighting rates were similar in Kangaroo Island (70.4%) and Fleurieu Peninsula (75.7%), but much lower in the Adelaide Dolphin Sanctuary (35%). Ten individuals were resighted between Kangaroo Island and the Fleurieu Peninsula, whilst no matches were made between these two locations and the Adelaide Dolphin Sanctuary catalogue. This suggests a longitudinal connectivity between Kangaroo Island and South Australian mainland waters, but a lack of latitudinal connectivity that may result from the physical stratification processes that separate northern and southern South Australian waters. Our results also demonstrate the highly mobile nature of this species within South Australian waters as well as establish photo-identification as an effective non-invasive tool in which to monitor long-term movement patterns).
{"title":"New Evidence for Bottlenose Dolphin (Tursiops spp.) Population Connectivity between Kangaroo Island and South Australian Mainland Waters","authors":"Nardi Cribb, P. Bartram, Tony Bartram, L. Seuront","doi":"10.4236/OJMS.2018.81003","DOIUrl":"https://doi.org/10.4236/OJMS.2018.81003","url":null,"abstract":"Limited information still exists on the movements of bottlenose dolphins in \u0000South Australian coastal waters. There is, however, a need to overcome this \u0000paucity of information for an effective development and implementation of \u0000conservation and management initiatives in these waters that are increasingly \u0000threatened by anthropogenic activities. This study infers potential movements \u0000of bottlenose dolphins (Tursiops spp.) between Kangaroo Island that separate \u0000and shelter South Australian coastal waters from the Southern Ocean swell, \u0000and the South Australian mainland (The Fleurieu Peninsula and The Adelaide \u0000Dolphin Sanctuary). Bottlenose dolphins were identified from three separate \u0000photo-identification catalogues collated from around the South Australian \u0000coastline. Of the 3518, 654 and 181 dolphins sighted in Kangaroo Island, \u0000Fleurieu Peninsula and the Adelaide Dolphin Sanctuary, 233, 74 and 40 individuals \u0000were recognizable, respectively. Resighting rates were similar in Kangaroo \u0000Island (70.4%) and Fleurieu Peninsula (75.7%), but much lower in the \u0000Adelaide Dolphin Sanctuary (35%). Ten individuals were resighted between \u0000Kangaroo Island and the Fleurieu Peninsula, whilst no matches were made \u0000between these two locations and the Adelaide Dolphin Sanctuary catalogue. \u0000This suggests a longitudinal connectivity between Kangaroo Island and South \u0000Australian mainland waters, but a lack of latitudinal connectivity that may \u0000result from the physical stratification processes that separate northern and \u0000southern South Australian waters. Our results also demonstrate the highly \u0000mobile nature of this species within South Australian waters as well as establish photo-identification as an effective non-invasive tool in which to monitor \u0000long-term movement patterns).","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47331451","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}
Study was conducted with the aim to understand the temporal and spatial variations of water quality parameters (temperature, salinity, pH, DO, TSS, NO3-, NO2-, NH3-N and PO4-P, and phytoplankton cell density) in Ambong Bay, Sabah, Malaysia in order to provide reference for future mariculture development in the bay. Samplings were carried out once a month in two stations (coastal and open sea) within the bay for 12 months period from September 2015 to August 2016. Results showed that there were significant differences in pH and NO2- when compared spatially, whereas salinity, DO, TSS, phytoplankton cell density, NO3-, NH3-N, and PO4-P were temporally significant. The fermentation processes by anaerobic bacteria, organic acids from decaying vegetation and acidic clays in the mangrove soils might explain the significant spatial differences in pH and NO2-. The bay was dominated by dinoflagellate, Prorocentrum spp. (mean abundance of 16.23% and 24.44%, respectively) a potentially toxic algae species. Correlation matrix showed that NH3-N was positively correlated with PO4-P (r = 0.475, p < 0.05) but negatively correlated with salinity (r = –0.517, p < 0.01). Besides, salinity was positively correlated with DO (r = 0.505, p < 0.05) and TSS (r = 0.408, p < 0.05). In addition, DO and TSS were also positively correlated (r = 0.451, p < 0.05). Phytoplankton cell density was positively correlated with TSS (r = 0.644, p < 0.01). In general, the water quality in Ambong Bay is within the standard values permitted by the Malaysia Marine Water Quality standard for marine life, fisheries, coral reefs, recreational and mariculture (Class 2), except for NO3-. In conclusion, any mariculture operation to take place in Ambong Bay in the near future should take the temporal variation of the water quality into account. Moreover, effects of toxic phytoplankton to culture fishes should also be taken care and monitored frequently.
本研究旨在了解马来西亚沙巴州Ambong湾水质参数(温度、盐度、pH、DO、TSS、NO3-、NO2-、NH3-N和PO4-P以及浮游植物细胞密度)的时空变化，为该湾未来的海水养殖发展提供参考。2015年9月至2016年8月，在海湾内两个站点(沿海和远海)每月进行一次采样，为期12个月。结果表明，pH和NO2-在空间上存在显著差异，而盐度、DO、TSS、浮游植物细胞密度、NO3-、NH3-N和PO4-P在时间上存在显著差异。红树林土壤中厌氧细菌、腐烂植被有机酸和酸性粘土的发酵过程可能解释了pH和NO2-的显著空间差异。甲藻(dinoflagellate)、原心藻(proorocentrum spp.)是具有潜在毒性的藻类，平均丰度分别为16.23%和24.44%。相关矩阵显示，NH3-N与PO4-P呈正相关(r = 0.475, p < 0.05)，与盐度呈负相关(r = -0.517, p < 0.01)。盐度与DO (r = 0.505, p < 0.05)、TSS (r = 0.408, p < 0.05)呈正相关。此外，DO与TSS也呈正相关(r = 0.451, p < 0.05)。浮游植物细胞密度与TSS呈正相关(r = 0.644, p < 0.01)。除了NO3-外，安奉湾的水质一般都在马来西亚海洋水质标准所允许的用于海洋生物、渔业、珊瑚礁、娱乐和海水养殖(第二类)的标准值之内。综上所述，近期在安峰湾进行的任何海水养殖作业都应考虑到水质的时间变化。此外，有毒浮游植物对养殖鱼类的影响也应引起重视和经常监测。
{"title":"Assessment of Spatial and Temporal Variations of Water Quality for Future Mariculture Operation in Ambong Bay, Sabah, Malaysia","authors":"F. S. Ong, J. Ransangan","doi":"10.4236/OJMS.2017.81001","DOIUrl":"https://doi.org/10.4236/OJMS.2017.81001","url":null,"abstract":"Study was conducted with the aim to understand the temporal and spatial variations of water quality parameters (temperature, salinity, pH, DO, TSS, NO3-, NO2-, NH3-N and PO4-P, and phytoplankton cell density) in Ambong Bay, Sabah, Malaysia in order to provide reference for future mariculture development in the bay. Samplings were carried out once a month in two stations (coastal and open sea) within the bay for 12 months period from September 2015 to August 2016. Results showed that there were significant differences in pH and NO2- when compared spatially, whereas salinity, DO, TSS, phytoplankton cell density, NO3-, NH3-N, and PO4-P were temporally significant. The fermentation processes by anaerobic bacteria, organic acids from decaying vegetation and acidic clays in the mangrove soils might explain the significant spatial differences in pH and NO2-. The bay was dominated by dinoflagellate, Prorocentrum spp. (mean abundance of 16.23% and 24.44%, respectively) a potentially toxic algae species. Correlation matrix showed that NH3-N was positively correlated with PO4-P (r = 0.475, p < 0.05) but negatively correlated with salinity (r = –0.517, p < 0.01). Besides, salinity was positively correlated with DO (r = 0.505, p < 0.05) and TSS (r = 0.408, p < 0.05). In addition, DO and TSS were also positively correlated (r = 0.451, p < 0.05). Phytoplankton cell density was positively correlated with TSS (r = 0.644, p < 0.01). In general, the water quality in Ambong Bay is within the standard values permitted by the Malaysia Marine Water Quality standard for marine life, fisheries, coral reefs, recreational and mariculture (Class 2), except for NO3-. In conclusion, any mariculture operation to take place in Ambong Bay in the near future should take the temporal variation of the water quality into account. Moreover, effects of toxic phytoplankton to culture fishes should also be taken care and monitored frequently.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70365211","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}
Stella Patricia Betancur-Turizo, A. González-Silvera, E. Santamaría-del-Ángel, R. Millán-Núñez, E. Millán-Núñez, H. García-Nava, V. Godínez, L. Sánchez‐Velasco
Variability of the optical properties of the northern Gulf of California (Mexico) were analyzed for the first time based on six cruises performed from spring to summer (March to September) between 2008 and 2013. The changes observed in the absorption by three seawater components (phytoplankton, detritus and chromophoric dissolved organic matter or CDOM) were analyzed in relation to changes in bio-optical regions and composition of the phytoplankton community (determined based on phytoplankton pigments). Two regions with unique bio-optical characteristics were identified separated by a narrow transition zone: the Upper Gulf of California (UGC) and Northern Gulf of California (NGC). Despite the temporal changes in their spatial distribution they maintained particular characteristic. UGC is characterized by an average Chla of 1.78 mg/m3, the dominance of microphytoplankton (diatoms and dinoflagellates) and a stronger contribution of detritus to total light absorption. NGC is characterized by an average Chla of 0.7 mg/m3 and the predominance of picophytoplankton, characterized by the dominance of zeaxanthin (marker pigment for cyanobacteria) and/or chlorophyll b (marker pigment for green algae), along with a co-dominium by CDOM and phytoplankton to light absorption. Results indicate that Case II waters can be very different when evaluating the individual contribution by phytoplankton, detritus and CDOM to total light absorption what has to be considered for the selection of bio-optical models for each specific region what can also help to a better definition of the related uncertainties.
{"title":"Variability in the Light Absorption Coefficient by Phytoplankton, Non-Algal Particles and Colored Dissolved Organic Matter in the Northern Gulf of California","authors":"Stella Patricia Betancur-Turizo, A. González-Silvera, E. Santamaría-del-Ángel, R. Millán-Núñez, E. Millán-Núñez, H. García-Nava, V. Godínez, L. Sánchez‐Velasco","doi":"10.4236/OJMS.2018.81002","DOIUrl":"https://doi.org/10.4236/OJMS.2018.81002","url":null,"abstract":"Variability of the optical properties of the northern Gulf of California (Mexico) were analyzed for the first time based on six cruises performed from spring to summer (March to September) between 2008 and 2013. The changes observed in the absorption by three seawater components (phytoplankton, detritus and chromophoric dissolved organic matter or CDOM) were analyzed in relation to changes in bio-optical regions and composition of the phytoplankton community (determined based on phytoplankton pigments). Two regions with unique bio-optical characteristics were identified separated by a narrow transition zone: the Upper Gulf of California (UGC) and Northern Gulf of California (NGC). Despite the temporal changes in their spatial distribution they maintained particular characteristic. UGC is characterized by an average Chla of 1.78 mg/m3, the dominance of microphytoplankton (diatoms and dinoflagellates) and a stronger contribution of detritus to total light absorption. NGC is characterized by an average Chla of 0.7 mg/m3 and the predominance of picophytoplankton, characterized by the dominance of zeaxanthin (marker pigment for cyanobacteria) and/or chlorophyll b (marker pigment for green algae), along with a co-dominium by CDOM and phytoplankton to light absorption. Results indicate that Case II waters can be very different when evaluating the individual contribution by phytoplankton, detritus and CDOM to total light absorption what has to be considered for the selection of bio-optical models for each specific region what can also help to a better definition of the related uncertainties.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70365391","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}
G. Mojgan, Mohammad Mehdizadeh Mehdi, Bannazadeh Mohammad Reza
Knowing the pattern of surface winds on the seas and oceans and how it changes over time is of great importance. In this research, the monthly surface wind fields on the Indian Ocean have been studied and analyzed for a 35-year period (1981-2015), using NCEP/NCAR data reanalysis. The results show that transition from cold to warm pattern happens in May and that the summer monsoon pattern begins in June and continues until August. The wind speed pattern tends to the winter monsoon from November on. The maximum average wind speed in June is 13 m/s and its minimum is 2 m/s in October. Direction of prevailing winds is the southwest in the summer. The highest wind speed happens in the latitude of 10 - 15 degrees. Analysis of the wind distribution shows that the wind speed of 2 - 5 m/s happens in about 60% of the cases. There is probability of blowing 0.5 - 4 m/s wind for all months; but this probability is higher in the autumn (October and November) than that in the summer (July and August). Probability of the monthly over 5 m/s winds shows a definitely opposite distribution; that is, wind speed in July and August is higher than that in October. A long-term survey on the speed of surface water wind and sea surface temperature shows an opposite changing trend in wind speed and sea surface temperature during a 55-year statistical period. Wind speed reduced, while the sea surface temperature was increasing. The wind speed gradient in the upper levels of atmosphere graph has been increasing; this phenomenon confirms the effects of global warming and ocean warming on the monsoon system patterns in the Indian Ocean. Keywords North
{"title":"The Trend of Changes in Surface Wind in the Indian Ocean, in the Period from 1981 to 2015, Using Reanalysis Data, NCEP/NCAR","authors":"G. Mojgan, Mohammad Mehdizadeh Mehdi, Bannazadeh Mohammad Reza","doi":"10.4236/OJMS.2017.74031","DOIUrl":"https://doi.org/10.4236/OJMS.2017.74031","url":null,"abstract":"Knowing the pattern of surface winds on the seas and oceans and how it changes over time is of great importance. In this research, the monthly surface wind fields on the Indian Ocean have been studied and analyzed for a 35-year period (1981-2015), using NCEP/NCAR data reanalysis. The results show that transition from cold to warm pattern happens in May and that the summer monsoon pattern begins in June and continues until August. The wind speed pattern tends to the winter monsoon from November on. The maximum average wind speed in June is 13 m/s and its minimum is 2 m/s in October. Direction of prevailing winds is the southwest in the summer. The highest wind speed happens in the latitude of 10 - 15 degrees. Analysis of the wind distribution shows that the wind speed of 2 - 5 m/s happens in about 60% of the cases. There is probability of blowing 0.5 - 4 m/s wind for all months; but this probability is higher in the autumn (October and November) than that in the summer (July and August). Probability of the monthly over 5 m/s winds shows a definitely opposite distribution; that is, wind speed in July and August is higher than that in October. A long-term survey on the speed of surface water wind and sea surface temperature shows an opposite changing trend in wind speed and sea surface temperature during a 55-year statistical period. Wind speed reduced, while the sea surface temperature was increasing. The wind speed gradient in the upper levels of atmosphere graph has been increasing; this phenomenon confirms the effects of global warming and ocean warming on the monsoon system patterns in the Indian Ocean. Keywords North","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45124705","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}
The invasive ctenophore Mnemiopsis leidyi, which comes from North America’s east coast, was observed in Danish waters for the first time in 2007. Since then, the new invader has every summer spread in Danish and adjacent waters (i.e. North Sea, Limfjorden, Skagerrak, Kattegat, Belt Sea, Baltic Sea). The invasive comb jelly has apparently come to stay, as it has no effective enemies. Possible harmful effects of M. leidyi which feeds voraciously on zooplankton, fish eggs and larvae, have so far not been thoroughly studied in Danish waters, although dedicated attempts have been made in Limfjorden and in the central Baltic Sea. Over the last 10 years, the Danish national environmental monitoring program did not include gelatinous zooplankton, but new initiatives have been recently taken. A brief overview of our current knowledge on the impact of M. leidyi in Danish waters is given here.
{"title":"Invasion of Danish and adjacent Waters by the comb jelly Mnemiopsis leidyi - 10 years after","authors":"H. U. Riisgård","doi":"10.4236/OJMS.2017.74032","DOIUrl":"https://doi.org/10.4236/OJMS.2017.74032","url":null,"abstract":"The invasive ctenophore Mnemiopsis leidyi, which comes from North America’s \u0000east coast, was observed in Danish waters for the first time in 2007. Since \u0000then, the new invader has every summer spread in Danish and adjacent waters \u0000(i.e. North Sea, Limfjorden, Skagerrak, Kattegat, Belt Sea, Baltic Sea). The invasive \u0000comb jelly has apparently come to stay, as it has no effective enemies. \u0000Possible harmful effects of M. leidyi which feeds voraciously on zooplankton, \u0000fish eggs and larvae, have so far not been thoroughly studied in Danish waters, \u0000although dedicated attempts have been made in Limfjorden and in the central \u0000Baltic Sea. Over the last 10 years, the Danish national environmental monitoring \u0000program did not include gelatinous zooplankton, but new initiatives \u0000have been recently taken. A brief overview of our current knowledge on the \u0000impact of M. leidyi in Danish waters is given here.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42759553","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}
As the Armor shape has a significant effect on the reduction of wave overtopping, this study compares the performance of various shapes of concrete armored blocks of X block and Tetrapod as the most suitable armors. In this study, a three-dimensional numerical model was used for simulation of the effects of waves on the armors of Tetrapod and X Block breakwaters. In this regard, in order to calibrate the numerical model, a sample of conventional stone armor has been selected and using available experimental data on the design of armor such as wave overtopping, wave height, period of waves and energy density of the required spectral range of wave verification was conducted on a numerical model. In this regard, it is necessary to calibrate all the conditions of the model including boundary conditions, numerical modeling, initial conditions, numerical solvers and other parameters in the numerical model and simulation error rate is determined. The maximum error of the numerical model for the relative height values of the impact waves on the structure of breakwater is 7.87% for different conditions. Accordingly, the maximum error of the numerical model in determining overtopping values is 7.81%. The average fluctuation value of overtopping in the X block armor has dropped by about 31% compared to the tetrapod armor.
{"title":"Comparison of the Effect of Tetrapod Block and Armor X block on Reducing Wave Overtopping in Breakwaters","authors":"Omid Nourani, M. Askar","doi":"10.4236/OJMS.2017.74033","DOIUrl":"https://doi.org/10.4236/OJMS.2017.74033","url":null,"abstract":"As the Armor shape has a significant effect on the reduction of wave overtopping, \u0000this study compares the performance of various shapes of concrete armored \u0000blocks of X block and Tetrapod as the most suitable armors. In this \u0000study, a three-dimensional numerical model was used for simulation of the \u0000effects of waves on the armors of Tetrapod and X Block breakwaters. In this \u0000regard, in order to calibrate the numerical model, a sample of conventional \u0000stone armor has been selected and using available experimental data on the \u0000design of armor such as wave overtopping, wave height, period of waves and \u0000energy density of the required spectral range of wave verification was conducted \u0000on a numerical model. In this regard, it is necessary to calibrate all the \u0000conditions of the model including boundary conditions, numerical modeling, \u0000initial conditions, numerical solvers and other parameters in the numerical \u0000model and simulation error rate is determined. The maximum error of the \u0000numerical model for the relative height values of the impact waves on the \u0000structure of breakwater is 7.87% for different conditions. Accordingly, the \u0000maximum error of the numerical model in determining overtopping values is \u00007.81%. The average fluctuation value of overtopping in the X block armor has \u0000dropped by about 31% compared to the tetrapod armor.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49100303","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}
At present, the fishery of Litopenaeus vannamei continues overexploited in the Gulf of Tehuantepec (GT), Mexico. From the available literature it was demonstrated that marine closure systems implemented in GT have not worked adequately since 1993, because these are completely protecting marine recruitment seasons, and reproductive seasons were only partially considered to protect. Due to these problems, new marine closure systems were proposed in the literature, but they were not accepted by fishermen from GT because they did not include marine and lagoon recruitment information. For this reason, in this study both recruitment types were analyzed with estimations on the recruitment age (RA), and its relationship with total length and weight. To the Cabeza de Toro la Joya Buenavista lagoon system (CTJB-LS), it was concluded that young recruits migration toward outside CTJB-LS elapsed between 3 and 5-m-olds, with the highest recruit flow in 4-m-olds. Thus, this last age was called the RA of L. vannamei (at 106 mm). Maximum marine recruitment ranked from June to July, and maximum reproductive seasons were in October. In both recruitment seasons it was observed that biomass production was different. In marine season RA recorded 8.4 g more than lagoon season at the same size. Results were used in order to discus about atarraya nets uses, and to propose the implementation of a lagoon closure during July inside lagoon systems located in GT. With this proposal artisanal fishermen will be allowed to use atarraya nets with mesh opening of 25.4 mm during June, and they will obtain a good biomass production level as economic support.Additionally, with new marine closure systems shrimp reproductive seasons will be protected (from July to November).
目前，在墨西哥的特万特佩克湾(GT)，凡纳滨对虾的渔业继续被过度开发。从现有文献中可以看出，自1993年以来，GT实施的海洋封闭系统没有充分发挥作用，因为这些系统完全保护海洋招募季节，而生殖季节只被认为是部分保护。由于这些问题，文献中提出了新的海洋封闭系统，但由于没有包括海洋和泻湖的招募信息，因此没有被GT渔民接受。因此，本研究对两种招募类型进行了分析，并估计了招募年龄(RA)及其与总长度和体重的关系。对于Cabeza de Toro la Joya Buenavista泻湖系统(CTJB-LS)，得出的结论是，年轻新兵向CTJB-LS外部迁移的时间为3至5米，其中4米的新兵流量最高。因此，这最后的年龄被称为L. vanamei的RA(在106毫米)。6 ~ 7月是海洋生物最多的季节，10月是海洋生物最多的繁殖季节。在两个招聘季节，观察到生物量产量不同。在海洋季节，RA比相同大小的泻湖季节多记录8.4 g。研究结果用于讨论atarraya网的使用，并建议在7月份在GT的泻湖系统内实施泻湖关闭。根据该建议，手工渔民将被允许在6月份使用网孔为25.4 mm的atarraya网，他们将获得良好的生物质生产水平作为经济支持。此外，新的海洋封闭系统将保护虾的繁殖季节(从7月到11月)。
{"title":"Recruitment Age of Litopenaeus vannamei (Boone, 1931) (Decapoda: Penaeidae) in the Cabeza De Toro-La Joya Buenavista Lagoon System, Oaxaca-Chiapas, Mexico","authors":"P. C. Hernández, P. Hernández, M. A. G. Ponce","doi":"10.4236/OJMS.2017.74036","DOIUrl":"https://doi.org/10.4236/OJMS.2017.74036","url":null,"abstract":"At present, the fishery of Litopenaeus vannamei continues overexploited in \u0000the Gulf of Tehuantepec (GT), Mexico. From the available literature it was \u0000demonstrated that marine closure systems implemented in GT have not \u0000worked adequately since 1993, because these are completely protecting marine \u0000recruitment seasons, and reproductive seasons were only partially considered \u0000to protect. Due to these problems, new marine closure systems were proposed \u0000in the literature, but they were not accepted by fishermen from GT because \u0000they did not include marine and lagoon recruitment information. For this \u0000reason, in this study both recruitment types were analyzed with estimations \u0000on the recruitment age (RA), and its relationship with total length and weight. \u0000To the Cabeza de Toro la Joya Buenavista lagoon system (CTJB-LS), it was \u0000concluded that young recruits migration toward outside CTJB-LS elapsed between \u00003 and 5-m-olds, with the highest recruit flow in 4-m-olds. Thus, this \u0000last age was called the RA of L. vannamei (at 106 mm). Maximum marine recruitment \u0000ranked from June to July, and maximum reproductive seasons were \u0000in October. In both recruitment seasons it was observed that biomass production \u0000was different. In marine season RA recorded 8.4 g more than lagoon season \u0000at the same size. Results were used in order to discus about atarraya nets \u0000uses, and to propose the implementation of a lagoon closure during July inside \u0000lagoon systems located in GT. With this proposal artisanal fishermen will \u0000be allowed to use atarraya nets with mesh opening of 25.4 mm during June, \u0000and they will obtain a good biomass production level as economic support.Additionally, with new marine closure systems shrimp reproductive seasons \u0000will be protected (from July to November).","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41798536","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}
Concern over health risk from consumption of bivalves originating from Marudu Bay is escalating due to the rapid agricultural development surrounding the bay. This has motivated us to estimate the health risk index (HRI) of heavy metals from four commercially important and highly exploited bivalve species which are abundant in the bay. Samples (n = 30) of green mussel (Perna viridis), Asiatic hard clam (Meretrix meretrix), Pacific oyster (Crassosstrea gigas) and marsh clam (Polymesoda expans) were acquired from fishermen in Kg. Teritipan, Marudu Bay. These bivalves were analyzed for heavy metals content using the Inductively Couples Plasma-Optical Emission Spectroscopy (ICP-OES). The study found that the mean contents of Arsenic (As) and Manganese (Mn) in all analyzed bivalves exceeded the permissible limits as well as copper (Cu), lead (Pb) and zinc (Zn) in Pacific oyster, and Zn in marsh clam. It was also noticed that consumption of different bivalve species may bring about health risk from different metals as indicated by varied Total Hazard Index (THI) values. Consumption of the four bivalves was noticed to promote high health risk from As intoxication. Although metal pollution index (MPI) analysis revealed that the bivalves from the bay are currently not seriously impacted by heavy metal pollution, vigorous efforts should be taken to preserve the natural condition of the bay for years to come. There are several ways to minimize health issues from bivalve consumption which include keeping the bivalve natural habitat away from heavy metals pollution by strictly enforcing environmental laws and policies, establishing zones for bivalve fisheries, monitoring heavy metals concentration in bivalve on a regular basis and making depuration process a compulsory requirement in every seafood restaurant throughout the country.
{"title":"Health Risk Assessment Due to Heavy Metals Exposure via Consumption of Bivalves Harvested from Marudu Bay, Malaysia","authors":"D. Denil, Ching Fui Fui, J. Ransangan","doi":"10.4236/OJMS.2017.74035","DOIUrl":"https://doi.org/10.4236/OJMS.2017.74035","url":null,"abstract":"Concern over health risk from consumption of bivalves originating from Marudu Bay is escalating due to the rapid agricultural development surrounding the bay. This has motivated us to estimate the health risk index (HRI) of heavy metals from four commercially important and highly exploited bivalve species which are abundant in the bay. Samples (n = 30) of green mussel (Perna viridis), Asiatic hard clam (Meretrix meretrix), Pacific oyster (Crassosstrea gigas) and marsh clam (Polymesoda expans) were acquired from fishermen in Kg. Teritipan, Marudu Bay. These bivalves were analyzed for heavy metals content using the Inductively Couples Plasma-Optical Emission Spectroscopy (ICP-OES). The study found that the mean contents of Arsenic (As) and Manganese (Mn) in all analyzed bivalves exceeded the permissible limits as well as copper (Cu), lead (Pb) and zinc (Zn) in Pacific oyster, and Zn in marsh clam. It was also noticed that consumption of different bivalve species may bring about health risk from different metals as indicated by varied Total Hazard Index (THI) values. Consumption of the four bivalves was noticed to promote high health risk from As intoxication. Although metal pollution index (MPI) analysis revealed that the bivalves from the bay are currently not seriously impacted by heavy metal pollution, vigorous efforts should be taken to preserve the natural condition of the bay for years to come. There are several ways to minimize health issues from bivalve consumption which include keeping the bivalve natural habitat away from heavy metals pollution by strictly enforcing environmental laws and policies, establishing zones for bivalve fisheries, monitoring heavy metals concentration in bivalve on a regular basis and making depuration process a compulsory requirement in every seafood restaurant throughout the country.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48127823","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}
Nowadays, shipping industry which is the backbone of economic development has affiliated to ship maintenance and repair industry. This industry provides technical maintenance services to ships in a way to enable them to meet the requirements and regulations of the International Maritime Organization and maintaining the vessels at high technical standard & continual seaworthiness condition. Maintaining the minimum requirement of classification societies on the ships is solely taken place with repairs. The research method is an applied study in sake of aim and a descriptive study in sake of nature. This research has been conducted to examine causes and factors contributed to failures repairing in dry docks in the country; using the obtained results, an approach has been presented to reduce obstacles existing in country and reach to standard international levels. The problems include lack of suitable strategy, lack of government support, governmental facet of the structure of this sector, cumbersome laws, customs problems, lack of specialized workshops, low levels of technology and lack of new technology etc. Thus, by taking amendment to the cumbersome rules, taking advantage of industry and modern technology experts, increasing productivity and competitiveness, centralizing active domestic and foreign workshops at private sector, facilitating timely supply of parts and accessories, using research and development sector, increasing quality, reducing costs and repair time, selecting secure industrial- trade partner and etc. can pave the way in this context.
{"title":"Study and Analysis of Obstacles and Challenges Facing Ship-Repair Industry in Iran","authors":"Reza Bozorgpour, B. Omaraee, Mohsen Asadi","doi":"10.4236/ojms.2017.74034","DOIUrl":"https://doi.org/10.4236/ojms.2017.74034","url":null,"abstract":"Nowadays, shipping industry which is the backbone of economic development \u0000has affiliated to ship maintenance and repair industry. This industry \u0000provides technical maintenance services to ships in a way to enable them to \u0000meet the requirements and regulations of the International Maritime Organization \u0000and maintaining the vessels at high technical standard & continual \u0000seaworthiness condition. Maintaining the minimum requirement of classification \u0000societies on the ships is solely taken place with repairs. The research method \u0000is an applied study in sake of aim and a descriptive study in sake of nature. \u0000This research has been conducted to examine causes and factors contributed \u0000to failures repairing in dry docks in the country; using the obtained results, \u0000an approach has been presented to reduce obstacles existing in country \u0000and reach to standard international levels. The problems include lack of suitable \u0000strategy, lack of government support, governmental facet of the structure \u0000of this sector, cumbersome laws, customs problems, lack of specialized workshops, \u0000low levels of technology and lack of new technology etc. Thus, by taking \u0000amendment to the cumbersome rules, taking advantage of industry and \u0000modern technology experts, increasing productivity and competitiveness, \u0000centralizing active domestic and foreign workshops at private sector, facilitating \u0000timely supply of parts and accessories, using research and development \u0000sector, increasing quality, reducing costs and repair time, selecting secure industrial- \u0000trade partner and etc. can pave the way in this context.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43918561","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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