Blue mussels, Mytilus edulis , form dense beds of both commercial and ecological importance, and many attempts have been made to determine their filtration rate. The total time in which mussels actually utilise their filtration capacity in nature varies greatly, making in situ methods for filtration rate measurements relevant. Further, it is being debated to what extend filtration rates measured in the laboratory using cultivated algal cells may apply for mussels in nature. In the present study, we have used an open-top chamber setup in order to allow repeated in situ filtration rate measurements of M. edulis using ambient natural phytoplankton and free-living bacteria. We found that the in situ measured filtration rates are comparable to filtration rates obtained in laboratory studies using different methods and controlled diets of cultivated algal cells. Further, we found that the retention efficiency of free-living bacteria was between 22.2% and 29.9%, in good agreement with values from laboratory studies. Our findings support the assumption that mussels in nature tend to use their filtration capacity when the phytoplankton concentration is above a certain lower trigger level.
{"title":"In Situ Filtration Rates of Blue Mussels ( Mytilus edulis ) Measured by an Open-Top Chamber Method","authors":"F. Lüskow, H. U. Riisgård","doi":"10.4236/OJMS.2018.84022","DOIUrl":"https://doi.org/10.4236/OJMS.2018.84022","url":null,"abstract":"Blue mussels, Mytilus edulis , form dense beds of both commercial and ecological importance, and many attempts have been made to determine their filtration rate. The total time in which mussels actually utilise their filtration capacity in nature varies greatly, making in situ methods for filtration rate measurements relevant. Further, it is being debated to what extend filtration rates measured in the laboratory using cultivated algal cells may apply for mussels in nature. In the present study, we have used an open-top chamber setup in order to allow repeated in situ filtration rate measurements of M. edulis using ambient natural phytoplankton and free-living bacteria. We found that the in situ measured filtration rates are comparable to filtration rates obtained in laboratory studies using different methods and controlled diets of cultivated algal cells. Further, we found that the retention efficiency of free-living bacteria was between 22.2% and 29.9%, in good agreement with values from laboratory studies. Our findings support the assumption that mussels in nature tend to use their filtration capacity when the phytoplankton concentration is above a certain lower trigger level.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48694930","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}
Ana Redondo Rodriguez, E. King, M. Doubell, P. V. Ruth
Satellite remote sensing data can produce global environmental data and is easily accessible and widely used by the scientific and non-scientific community. However, to use satellite data, it is important to know its limitations and how it validates against in situ measurements for the different regions. Here, field measurements of chlorophyll-a concentration and euphotic depth within the Great Australian Bight, Gulf St Vincent and Spencer Gulf were used to validate ocean colour products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite. The field data include in situ and in vivo chlorophyll-a concentration, which were compared against MODIS chlorophyll-a products derived from three algorithms (OC3M, Carder, and Garver-Siegel-Maritorena (GSM)), as well as euphotic depth measurements derived from photosynthetically active radiation (PAR) profiles, which were compared against two MODIS euphotic depth products (derived semi-analytically and from surface chlorophyll-a). The OC3M product performed well in open waters, with errors below the 35% NASA accepted limit, but it overestimated chlorophyll-a values in shallow (<50 m) waters. The GSM product produced the lowest errors, but also showed a smaller dynamic range, while the Carder product produced higher errors than GSM and it also showed small dynamic range. The relationships between the MODIS and in situ euphotic depth were robust, with errors lower than 20%. MODIS products showed weaker or no significant relationships to in situ measurements in the Eastern Great Australian Bight. This is thought to be due to the summertime subsurface upwelling pool that is characteristic of the area. Based on these results, the OC3M product provides the most reliable estimates of chlorophyll-a, and is recommended for further applications of MODIS imagery, if the limitations in shallow waters are taken into account. Alternatively, the GSM product could be a better option if the algorithm were locally adjusted. Changes in the sampling methodology to improve the algorithms are discussed. Derived euphotic depth products can be used with confidence in applying MODIS products for monitoring water clarity, ecosystem health or primary productivity in the region.
{"title":"Evaluation of MODIS Products in the Great Australian Bight and Adjacent Coastal Waters","authors":"Ana Redondo Rodriguez, E. King, M. Doubell, P. V. Ruth","doi":"10.4236/ojms.2018.84024","DOIUrl":"https://doi.org/10.4236/ojms.2018.84024","url":null,"abstract":"Satellite remote sensing data can produce global environmental data and is easily accessible and widely used by the scientific and non-scientific community. However, to use satellite data, it is important to know its limitations and how it validates against in situ measurements for the different regions. Here, field measurements of chlorophyll-a concentration and euphotic depth within the Great Australian Bight, Gulf St Vincent and Spencer Gulf were used to validate ocean colour products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite. The field data include in situ and in vivo chlorophyll-a concentration, which were compared against MODIS chlorophyll-a products derived from three algorithms (OC3M, Carder, and Garver-Siegel-Maritorena (GSM)), as well as euphotic depth measurements derived from photosynthetically active radiation (PAR) profiles, which were compared against two MODIS euphotic depth products (derived semi-analytically and from surface chlorophyll-a). The OC3M product performed well in open waters, with errors below the 35% NASA accepted limit, but it overestimated chlorophyll-a values in shallow (<50 m) waters. The GSM product produced the lowest errors, but also showed a smaller dynamic range, while the Carder product produced higher errors than GSM and it also showed small dynamic range. The relationships between the MODIS and in situ euphotic depth were robust, with errors lower than 20%. MODIS products showed weaker or no significant relationships to in situ measurements in the Eastern Great Australian Bight. This is thought to be due to the summertime subsurface upwelling pool that is characteristic of the area. Based on these results, the OC3M product provides the most reliable estimates of chlorophyll-a, and is recommended for further applications of MODIS imagery, if the limitations in shallow waters are taken into account. Alternatively, the GSM product could be a better option if the algorithm were locally adjusted. Changes in the sampling methodology to improve the algorithms are discussed. Derived euphotic depth products can be used with confidence in applying MODIS products for monitoring water clarity, ecosystem health or primary productivity in the region.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48014471","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}
Pipelines are system of pipes designed to transport liquids, gases or solid/ liquid mixtures over long distances. Some are used for domestic, household and sewage purposes. Others are buried underground or submerged in water for transportation of natural oil and gas (O & G) products. In this work, the specimens had to be kept in a workable state and steps were taken to prepare each specimen: all cuts and sheared edges were ground out to prevent them from becoming sites for preferential attack. The finishing of the specimen surface with grit abrasive paper (sand paper) and rinsing of the specimens in distilled water were done. Then degreasing of specimen in acetone and air-dried were carried out. Upon drying, the specimens were immediately weighed to obtain their initial weights. Twelve specimens were used for the test as follows: 6 Aluminum (Al); and 6 mild steel (MS) samples. With a 2 M concentration of Vernomia Amydalina (VA) extract solution, the MS and Al samples were immersed in different plastic containers containing 400 ml of seawater with pH value of 7.25 with no (0%) inhibitor added to it. A 5% (400 ml) of the VA solution was poured into the measuring cylinder for each sample-Al and MS. The specimens were suspended by the strings and completely immersed in the different percentage test media. The same procedure was carried out for each of the different percentages, 10%, 15%, 20%, and 25% and a total of 12 solutions were set up. The experimental procedure used was that seawater of 7.25 pH was obtained from Abonnema water front of Rivers State. At the end of every week (168 hours), the specimens were removed from the corrosive media. Observation and recording of appearance of the specimen noting sites were done. Cleanings of specimen with white handkerchief or tissue paper were carried out and washing of specimen with distilled water, scrubbing of specimen with a soft brush and dipping the specimen into acetone after washing, it was removed to air-dry and weighed. It is observed that optimum inhibition of coupons was obtained between 15% - 25% of VA solution during the first four weeks of testing. At the fifth week the inhibitor was gradually losing its effectiveness. This means that more inhibitor need be added at regular intervals to sustain the effectiveness of the inhibitor.
{"title":"Combating Corrosion in Transmission Pipelines in Marine Environment Using Vernomia Amydalina as Inhibitor","authors":"S. Nitonye, U. Emmanuel, A. O. Ezenwa","doi":"10.4236/OJMS.2018.84025","DOIUrl":"https://doi.org/10.4236/OJMS.2018.84025","url":null,"abstract":"Pipelines are system of pipes designed to transport liquids, gases or solid/ liquid mixtures over long distances. Some are used for domestic, household and sewage purposes. Others are buried underground or submerged in water for transportation of natural oil and gas (O & G) products. In this work, the specimens had to be kept in a workable state and steps were taken to prepare each specimen: all cuts and sheared edges were ground out to prevent them from becoming sites for preferential attack. The finishing of the specimen surface with grit abrasive paper (sand paper) and rinsing of the specimens in distilled water were done. Then degreasing of specimen in acetone and air-dried were carried out. Upon drying, the specimens were immediately weighed to obtain their initial weights. Twelve specimens were used for the test as follows: 6 Aluminum (Al); and 6 mild steel (MS) samples. With a 2 M concentration of Vernomia Amydalina (VA) extract solution, the MS and Al samples were immersed in different plastic containers containing 400 ml of seawater with pH value of 7.25 with no (0%) inhibitor added to it. A 5% (400 ml) of the VA solution was poured into the measuring cylinder for each sample-Al and MS. The specimens were suspended by the strings and completely immersed in the different percentage test media. The same procedure was carried out for each of the different percentages, 10%, 15%, 20%, and 25% and a total of 12 solutions were set up. The experimental procedure used was that seawater of 7.25 pH was obtained from Abonnema water front of Rivers State. At the end of every week (168 hours), the specimens were removed from the corrosive media. Observation and recording of appearance of the specimen noting sites were done. Cleanings of specimen with white handkerchief or tissue paper were carried out and washing of specimen with distilled water, scrubbing of specimen with a soft brush and dipping the specimen into acetone after washing, it was removed to air-dry and weighed. It is observed that optimum inhibition of coupons was obtained between 15% - 25% of VA solution during the first four weeks of testing. At the fifth week the inhibitor was gradually losing its effectiveness. This means that more inhibitor need be added at regular intervals to sustain the effectiveness of the inhibitor.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41903933","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}
M. P. Garcia, A. M. Paz-Alberto, T. Abella, C. Sace, E. G. Claudio, Arneil G. Gabriel
Little is known about the diversity and status of endemic freshwater fishes which are valuable bio-indicators of ecosystem health and an integral part of a country’s natural heritage. Some of the less studied areas in the Philippines are the river systems in the Cordillera which are equally important as that of the other freshwater systems in the country. Amburayan River in Kapangan, Benguet is one of the rivers in the said region. Thus assessment study of the diversity of macro aquatic species was conducted to provide a baseline data in the formulation of resource management strategies and polices. By using a mixture of qualitative and quantitative research methods, the study determined and identified the presence of macro species in the study area. It applied the National Stock Assessment Program (NSAP) procedures in the gathering of samples while identification and determination of fish stocks were done by morphometric analysis of the catch with the help of available references and assistance of experts. This is later verified through submission of samples to the National Fisheries Research Development Institute (NFRDI) as part of the NSAP areas for DNA analysis. The measurement of the impacts of human activities to the river systems was done using the checklist method by Smith and Smith. The study found that there is low biodiversity of macro aquatic species in the area because of the presence of introduced species, illegal fishing practices, quarrying and mining activities. There are also no indigenous or traditional management measures conducted to conserve the river ecosystem biodiversity. The study recommended that similar study be done in other areas of the river and that the government agencies to undertake fisheries programs which would regulate the exploitation and utilization and allow regeneration of macro aquatic species in the river system.
{"title":"Assessment of the Diversity of Macro Aquatic Species in Amburayan River in Kapangan, Benguet in the Philippines","authors":"M. P. Garcia, A. M. Paz-Alberto, T. Abella, C. Sace, E. G. Claudio, Arneil G. Gabriel","doi":"10.4236/OJMS.2018.83018","DOIUrl":"https://doi.org/10.4236/OJMS.2018.83018","url":null,"abstract":"Little is known about the diversity and status of endemic freshwater fishes which are valuable bio-indicators of ecosystem health and an integral part of a country’s natural heritage. Some of the less studied areas in the Philippines are the river systems in the Cordillera which are equally important as that of the other freshwater systems in the country. Amburayan River in Kapangan, Benguet is one of the rivers in the said region. Thus assessment study of the diversity of macro aquatic species was conducted to provide a baseline data in the formulation of resource management strategies and polices. By using a mixture of qualitative and quantitative research methods, the study determined and identified the presence of macro species in the study area. It applied the National Stock Assessment Program (NSAP) procedures in the gathering of samples while identification and determination of fish stocks were done by morphometric analysis of the catch with the help of available references and assistance of experts. This is later verified through submission of samples to the National Fisheries Research Development Institute (NFRDI) as part of the NSAP areas for DNA analysis. The measurement of the impacts of human activities to the river systems was done using the checklist method by Smith and Smith. The study found that there is low biodiversity of macro aquatic species in the area because of the presence of introduced species, illegal fishing practices, quarrying and mining activities. There are also no indigenous or traditional management measures conducted to conserve the river ecosystem biodiversity. The study recommended that similar study be done in other areas of the river and that the government agencies to undertake fisheries programs which would regulate the exploitation and utilization and allow regeneration of macro aquatic species in the river system.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44215307","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}
M. Hasan, B. S. Hossain, M. J. Alam, K. Chowdhury, A. Karim, Nuruddin Md. Khaled Chowdhury
This paper draws attention to the prospects of sea-based economy to promote Bangladesh in a middle-income country through the sustainable use of marine resources. About three-fourths of the earth is covered by the seas. It plays the vital role in two important functions from ancient time known as the means of communication and the source of huge living and non-living natural resources. At present, the countries are becoming very much concerned about their marine resources to resolve many of the present and future challenges of their economies. Generally for Bangladesh, ocean is contributing a significant role to its overall socio-economic progress through rising up the economic activities across the country and especially to the coastal zone at southern part. This paper investigates how much Bangladesh is capable to take of or handle the challenges to become a middle income country through the Sustainable Development Goals (SDGs). In addition, it has attempted with a closer-look to find out the barriers or limitations of these activities from different angles if exist.
{"title":"The Prospects of Blue Economy to Promote Bangladesh into a Middle-Income Country","authors":"M. Hasan, B. S. Hossain, M. J. Alam, K. Chowdhury, A. Karim, Nuruddin Md. Khaled Chowdhury","doi":"10.4236/OJMS.2018.83019","DOIUrl":"https://doi.org/10.4236/OJMS.2018.83019","url":null,"abstract":"This paper draws attention to the prospects of sea-based economy to promote Bangladesh in a middle-income country through the sustainable use of marine resources. About three-fourths of the earth is covered by the seas. It plays the vital role in two important functions from ancient time known as the means of communication and the source of huge living and non-living natural resources. At present, the countries are becoming very much concerned about their marine resources to resolve many of the present and future challenges of their economies. Generally for Bangladesh, ocean is contributing a significant role to its overall socio-economic progress through rising up the economic activities across the country and especially to the coastal zone at southern part. This paper investigates how much Bangladesh is capable to take of or handle the challenges to become a middle income country through the Sustainable Development Goals (SDGs). In addition, it has attempted with a closer-look to find out the barriers or limitations of these activities from different angles if exist.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43784970","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 Thin Plate Regression Spline (TPRS) was introduced as a means of smoothing off the differences between the satellite and in-situ observations during the two dimensional (2D) blending process in an attempt to calibrate ocean chlorophyll. The result was a remarkable improvement on the predictive capabilities of the penalized model making use of the satellite observation. In addition, the blending process has been extended to three dimensions (3D) since it is believed that most physical systems exist in the three dimensions (3D). In this article, an attempt to obtain more reliable and accurate predictions of ocean chlorophyll by extending the penalization process to three dimensional (3D) blending is presented. Penalty matrices were computed using the integrated least squares (ILS) and integrated squared derivative (ISD). Results obtained using the integrated least squares were not encouraging, but those obtained using the integrated squared derivative showed a reasonable improvement in predicting ocean chlorophyll especially where the validation datum was surrounded by available data from the satellite data set, however, the process appeared computationally expensive and the results matched the other methods on a general scale. In both case, the procedure for implementing the penalization process in three dimensional blending when penalty matrices were calculated using the two techniques has been well established and can be used in any similar three dimensional problem when it becomes necessary.
{"title":"Estimating Ocean Chlorophyll Using the Penalized Three Dimensional (3D) Blending Technique","authors":"M. Onabid, S. Wood","doi":"10.4236/OJMS.2018.83021","DOIUrl":"https://doi.org/10.4236/OJMS.2018.83021","url":null,"abstract":"The Thin Plate Regression Spline (TPRS) was introduced as a means of smoothing off the differences between the satellite and in-situ observations during the two dimensional (2D) blending process in an attempt to calibrate ocean chlorophyll. The result was a remarkable improvement on the predictive capabilities of the penalized model making use of the satellite observation. In addition, the blending process has been extended to three dimensions (3D) since it is believed that most physical systems exist in the three dimensions (3D). In this article, an attempt to obtain more reliable and accurate predictions of ocean chlorophyll by extending the penalization process to three dimensional (3D) blending is presented. Penalty matrices were computed using the integrated least squares (ILS) and integrated squared derivative (ISD). Results obtained using the integrated least squares were not encouraging, but those obtained using the integrated squared derivative showed a reasonable improvement in predicting ocean chlorophyll especially where the validation datum was surrounded by available data from the satellite data set, however, the process appeared computationally expensive and the results matched the other methods on a general scale. In both case, the procedure for implementing the penalization process in three dimensional blending when penalty matrices were calculated using the two techniques has been well established and can be used in any similar three dimensional problem when it becomes necessary.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46192302","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}
Based on core and casting slice observation, well drilling and logging data, the source of carbonate materials, lithology together with electric properties, types, genesis mechanism and distribution of calcareous interbeds in Songtao uplift and its periphery of Qiongdongnan Basin have been thoroughly analyzed. Results show that typical features have been appeared from well logging curves, containing low gamma-ray, low acoustic travel time, low neutron value, high density, as well as bright white calcium nodules or bands in electrical imaging well-logging curves. Drilling results reveal that calcareous interbeds developed mostly in high position of paleostructures and their distribution was controlled by the combined effects of macroscopic and microscopic factors. Macroscopically, calcareous interbeds relate to paleogeomorphology together with the combination of sandstone and mudstone. They are also controlled microscopically by the source of carbonate cements and pore space. Under normal circumstances, with regard to the same sand, the closer to the mudstone and the thicker of mudstone, the more conducive to the formation of calcareous interlayer. Low compaction strength, high content of rigid particles, coarse grain size, well-sorted sandstone and large pore space during carbonate cementation are favorable for the development of calcareous interbeds.
{"title":"Mechanism and Distribution of Calcareous Interbeds in Songtao Uplift and Its Periphery of Qiongdongnan Basin","authors":"P. Zhu, L. You, Q. Yuan, Jia Zhong, Aiqun Liu","doi":"10.4236/OJMS.2018.83020","DOIUrl":"https://doi.org/10.4236/OJMS.2018.83020","url":null,"abstract":"Based on core and casting slice observation, well drilling and logging data, the source of carbonate materials, lithology together with electric properties, types, genesis mechanism and distribution of calcareous interbeds in Songtao uplift and its periphery of Qiongdongnan Basin have been thoroughly analyzed. Results show that typical features have been appeared from well logging curves, containing low gamma-ray, low acoustic travel time, low neutron value, high density, as well as bright white calcium nodules or bands in electrical imaging well-logging curves. Drilling results reveal that calcareous interbeds developed mostly in high position of paleostructures and their distribution was controlled by the combined effects of macroscopic and microscopic factors. Macroscopically, calcareous interbeds relate to paleogeomorphology together with the combination of sandstone and mudstone. They are also controlled microscopically by the source of carbonate cements and pore space. Under normal circumstances, with regard to the same sand, the closer to the mudstone and the thicker of mudstone, the more conducive to the formation of calcareous interlayer. Low compaction strength, high content of rigid particles, coarse grain size, well-sorted sandstone and large pore space during carbonate cementation are favorable for the development of calcareous interbeds.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42149206","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 island of Jamaica is often cited as an example of how overfishing has dramatically reduced the sizes of coral reef fishes. To examine the change in fish sizes over a 36-year period, we analyzed data from systematic surveys conducted in 1977 and 2013/14 of the sizes and relative abundances of four common algae-grazing fishes in the shallow backreef habitats of Jamaica and Grand Cayman. The four species are: striped parrotfish (Scarus iseri), stoplight parrotfish (Sparisoma viride), ocean surgeon (Acanthurus tractus) and the blue tang (Acanthurus coeruleus). We predicted that all four species would be larger in Grand Cayman than in Jamaica in 1977 as well as in 2013/14, because Grand Cayman has been cited as having less fishing pressure than Jamaica. For the same reason, we expected all four species would have declined in size over the 36 years in Jamaica but not in Grand Cayman. Furthermore, we predicted that the compressed body shape of the ocean surgeon and the blue tang would have made them especially vulnerable to net and trap fishing compared to the two parrotfishes, and that accordingly the effects of overfishing would be greater in these two species. We rejected this hypothesis. The size distributions of the laterally compressed species changed significantly on both islands over the 36-year time span, although not as predicted. At both islands, the blue tangs shifted toward smaller sizes and the ocean surgeons shifted toward larger sizes. There were no size distribution changes detected in the two fusiform species. There was also no support for the prediction that the sizes of these four species were larger in Grand Cayman than in Jamaica during either time period.
{"title":"Have the Algae-Grazing Fish in the Back Reefs of Jamaica and Grand Cayman Changed in Size? A View across 36 Years","authors":"M. Draud, M. Itzkowitz","doi":"10.4236/OJMS.2018.82016","DOIUrl":"https://doi.org/10.4236/OJMS.2018.82016","url":null,"abstract":"The island of Jamaica is often cited as an example of how overfishing has dramatically reduced the sizes of coral reef fishes. To examine the change in fish sizes over a 36-year period, we analyzed data from systematic surveys conducted in 1977 and 2013/14 of the sizes and relative abundances of four common algae-grazing fishes in the shallow backreef habitats of Jamaica and Grand Cayman. The four species are: striped parrotfish (Scarus iseri), stoplight parrotfish (Sparisoma viride), ocean surgeon (Acanthurus tractus) and the blue tang (Acanthurus coeruleus). We predicted that all four species would be larger in Grand Cayman than in Jamaica in 1977 as well as in 2013/14, because Grand Cayman has been cited as having less fishing pressure than Jamaica. For the same reason, we expected all four species would have declined in size over the 36 years in Jamaica but not in Grand Cayman. Furthermore, we predicted that the compressed body shape of the ocean surgeon and the blue tang would have made them especially vulnerable to net and trap fishing compared to the two parrotfishes, and that accordingly the effects of overfishing would be greater in these two species. We rejected this hypothesis. The size distributions of the laterally compressed species changed significantly on both islands over the 36-year time span, although not as predicted. At both islands, the blue tangs shifted toward smaller sizes and the ocean surgeons shifted toward larger sizes. There were no size distribution changes detected in the two fusiform species. There was also no support for the prediction that the sizes of these four species were larger in Grand Cayman than in Jamaica during either time period.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42286931","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}
A. Mayfield, Yi-Jyun Chen, Chi-Yu Lu, Chii‐Shiarng Chen
Although reef-building corals are threatened by a number of anthropogenic impacts, certain scleractinian-dinoflagellate (genus Symbiodinium) endosymbioses have proven markedly resilient to environmental change. For instance, corals from upwelling habitats of Southern Taiwan withstand both short- and long-term increases in temperature, potentially due to their routine exposure to highly variable temperature regimes in situ. To gain a greater understanding of the proteomic basis for such acclimatization to unstable environmental conditions, specimens of the Indo-Pacific reef-building coral Seriatopora hystrix Dana 1846 were sampled during a period of stable temperature conditions from 1) a site characterized by frequent upwelling events in Southern Taiwan and 2) a nearby, non-upwelling control site in the Taiwan Strait. Two-dimensional gel electrophoresis followed by sequencing of differentially concentrated proteins with mass spectrometry unveiled significantly more proteins involved in the cellular stress response in coral hosts of the upwelling site. Although such stress protein signatures could be indicative of sub-lethal levels of cellular stress, especially given the relatively higher sediment loads characteristic of the upwelling site, these proteins may, in contrast, have been constitutively maintained at high levels in preparation for large fluctuations in temperature and other abiotic parameters (e.g., nutrient levels) brought upon by upwelling events.
虽然造礁珊瑚受到许多人为影响的威胁，但某些硬核-甲藻(共生属)内共生已被证明对环境变化具有显著的弹性。例如，来自台湾南部上升流栖息地的珊瑚可以承受短期和长期的温度升高，这可能是由于它们经常暴露在高度变化的温度环境中。为了更好地了解这种对不稳定环境条件的适应的蛋白质组学基础，在稳定的温度条件下，从1)台湾南部一个以频繁上升流事件为特征的地点和2)台湾海峡附近一个非上升流的控制地点取样了印度太平洋造礁珊瑚Seriatopora hystrix Dana 1846的标本。二维凝胶电泳和质谱测序显示，上升流区珊瑚宿主的细胞应激反应中有更多的蛋白质参与。虽然这种应激蛋白特征可能表明细胞应激的亚致死水平，特别是考虑到上升流部位相对较高的沉积物负荷特征，但相反，这些蛋白质可能在组成上保持在高水平，以应对上升流事件带来的温度和其他非生物参数(例如营养水平)的大幅波动。
{"title":"Exploring the Environmental Physiology of the Indo-Pacific Reef Coral Seriatopora hystrix with Differential Proteomics","authors":"A. Mayfield, Yi-Jyun Chen, Chi-Yu Lu, Chii‐Shiarng Chen","doi":"10.4236/OJMS.2018.82012","DOIUrl":"https://doi.org/10.4236/OJMS.2018.82012","url":null,"abstract":"Although reef-building corals are threatened by a number of anthropogenic \u0000impacts, certain scleractinian-dinoflagellate (genus Symbiodinium) endosymbioses \u0000have proven markedly resilient to environmental change. For instance, \u0000corals from upwelling habitats of Southern Taiwan withstand both short- and \u0000long-term increases in temperature, potentially due to their routine exposure \u0000to highly variable temperature regimes in situ. To gain a greater understanding \u0000of the proteomic basis for such acclimatization to unstable environmental \u0000conditions, specimens of the Indo-Pacific reef-building coral Seriatopora hystrix Dana 1846 were sampled during a period of stable temperature conditions \u0000from 1) a site characterized by frequent upwelling events in Southern \u0000Taiwan and 2) a nearby, non-upwelling control site in the Taiwan Strait. \u0000Two-dimensional gel electrophoresis followed by sequencing of differentially \u0000concentrated proteins with mass spectrometry unveiled significantly more \u0000proteins involved in the cellular stress response in coral hosts of the upwelling \u0000site. Although such stress protein signatures could be indicative of sub-lethal \u0000levels of cellular stress, especially given the relatively higher sediment loads \u0000characteristic of the upwelling site, these proteins may, in contrast, have been \u0000constitutively maintained at high levels in preparation for large fluctuations in \u0000temperature and other abiotic parameters (e.g., nutrient levels) brought upon \u0000by upwelling events.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45069691","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}
Xiaoqing Tian, C. Fan, Zhidong Liu, Hongliang Huang, Ya-Nan Lu
Phospholipids are one of the major bioactive ingredients of Antarctic krill Euphausea superba. A feasible and effective extraction method of Antarctic krill oil was investigated and modified by orthogonal test which the ratio of solid to liquid was 1:2.5, extraction time was 5 min, ratio of ethyl acetate (EA) and n-butanol (BuOH) was 1:1. With this method, the extract of krill oil has a higher phospholipids content of 27.7% - 42.3%, together with total oil yields of 4.15% - 6.18%.
{"title":"An Effective Extract Method of Phospholipids from Antarctic Krill Euphausea superba","authors":"Xiaoqing Tian, C. Fan, Zhidong Liu, Hongliang Huang, Ya-Nan Lu","doi":"10.4236/ojms.2018.82015","DOIUrl":"https://doi.org/10.4236/ojms.2018.82015","url":null,"abstract":"Phospholipids are one of the major bioactive ingredients of Antarctic krill Euphausea superba. A feasible and effective extraction method of Antarctic krill oil was investigated and modified by orthogonal test which the ratio of solid to liquid was 1:2.5, extraction time was 5 min, ratio of ethyl acetate (EA) and n-butanol (BuOH) was 1:1. With this method, the extract of krill oil has a higher phospholipids content of 27.7% - 42.3%, together with total oil yields of 4.15% - 6.18%.","PeriodicalId":65849,"journal":{"name":"海洋科学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46097921","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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