S. Cobarrubia-Russo, Sawyer I., M. Gómez-Alceste, A. Molero-Lizarraga
This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua, Venezuela, over a multi-year period. Using photo-identification, the most recent study (2019-2020) identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting. Site Fidelity (SF) and Residence (RES) indices were calculated and Agglomerative Hierarchical Clustering (AHC) modeling was performed, with three patterns of residence obtained: resident (25%), semiresident (17.86%) and transient (57.14%). These results were contrasted with remodeled data from a previous study (2006-2007), showing similar patterns: resident (24.44%), semi-resident (28.89%) and transient (46.67%). Importantly, two individuals were found to have been resident over the extended period. A breeding female sighted for the first time in 2004 and again in 2020 (16 years) and the other from 2005 to 2020 (15 years). This region is an important area for marine mammals, known to support a resident reproductive population over many years, as well seabirds, sea turtles, whale sharks and fishermen. We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.
{"title":"Site Fidelity and Residency of Tursiops truncatus off the Aragua Coast, Venezuela-First Records of Long Residency","authors":"S. Cobarrubia-Russo, Sawyer I., M. Gómez-Alceste, A. Molero-Lizarraga","doi":"10.30564/jms.v3i4.3811","DOIUrl":"https://doi.org/10.30564/jms.v3i4.3811","url":null,"abstract":"This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua, Venezuela, over a multi-year period. Using photo-identification, the most recent study (2019-2020) identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting. Site Fidelity (SF) and Residence (RES) indices were calculated and Agglomerative Hierarchical Clustering (AHC) modeling was performed, with three patterns of residence obtained: resident (25%), semiresident (17.86%) and transient (57.14%). These results were contrasted with remodeled data from a previous study (2006-2007), showing similar patterns: resident (24.44%), semi-resident (28.89%) and transient (46.67%). Importantly, two individuals were found to have been resident over the extended period. A breeding female sighted for the first time in 2004 and again in 2020 (16 years) and the other from 2005 to 2020 (15 years). This region is an important area for marine mammals, known to support a resident reproductive population over many years, as well seabirds, sea turtles, whale sharks and fishermen. We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80980418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Present short communication reports about beach stranding of Porpita porpita (Linnaeus 1758) from the Coast of Mandvi, Kutch during August 2021. Also, this is the first record of the blue button jellyfishes for the northern Gulf of Kutch region. A study was carried out by primary observation and measurements of common environmental parameters such as Sea Surface Temperature (SST), Wind Direction & Wind Speed. Aboral and oral parts were observed and described. It is assumed that the large biomass of blue button jellyfish on the beach is due to strong shoreward Monsoon winds.
{"title":"Mass Beach Stranding of Blue Button Jellyfishes, Porpita porpita (Linnaeus 1758) from the Coast of Mandvi, Kutch, India during August, 2021","authors":"Niki Shah, Yashesh Shah","doi":"10.30564/jms.v3i4.3851","DOIUrl":"https://doi.org/10.30564/jms.v3i4.3851","url":null,"abstract":"Present short communication reports about beach stranding of Porpita porpita (Linnaeus 1758) from the Coast of Mandvi, Kutch during August 2021. Also, this is the first record of the blue button jellyfishes for the northern Gulf of Kutch region. A study was carried out by primary observation and measurements of common environmental parameters such as Sea Surface Temperature (SST), Wind Direction & Wind Speed. Aboral and oral parts were observed and described. It is assumed that the large biomass of blue button jellyfish on the beach is due to strong shoreward Monsoon winds.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91304412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Humans rely on the sea for food and mineral resources; hence it is vital to their economic survival. Nations all throughout the world rely on the water for trade and commerce. This article looks at the present condition of marine security in the Gulf of Guinea. The Gulf of Guinea has a total shoreline of about 5,000 nautical miles and several natural harbours with dangerous weather. It has a significant crude oil reservoir, as well as fish and other natural resources. These traits provide huge prospects for marine trade and transportation, but the Gulf of Guinea is also riddled with maritime crimes of all types, including piracy and smuggling. Maritime piracy has presented a threat to coastal states’ stability and economic viability all across the world, not only in Africa. The study examines sea piracy in general, the Geographic Information System, and the impact of maritime piracy on the world socioeconomic development using secondary data. It then goes on to provide a number of recommendations aimed at addressing the problems caused by maritime piracy in the Gulf of Guinea in order to improve maritime security.
{"title":"Spatial Analysis of Maritime Piracy in the Gulf of Guinea","authors":"Jonathan Ejuvweyere Okpuvwie","doi":"10.30564/jms.v3i4.3810","DOIUrl":"https://doi.org/10.30564/jms.v3i4.3810","url":null,"abstract":"Humans rely on the sea for food and mineral resources; hence it is vital to their economic survival. Nations all throughout the world rely on the water for trade and commerce. This article looks at the present condition of marine security in the Gulf of Guinea. The Gulf of Guinea has a total shoreline of about 5,000 nautical miles and several natural harbours with dangerous weather. It has a significant crude oil reservoir, as well as fish and other natural resources. These traits provide huge prospects for marine trade and transportation, but the Gulf of Guinea is also riddled with maritime crimes of all types, including piracy and smuggling. Maritime piracy has presented a threat to coastal states’ stability and economic viability all across the world, not only in Africa. The study examines sea piracy in general, the Geographic Information System, and the impact of maritime piracy on the world socioeconomic development using secondary data. It then goes on to provide a number of recommendations aimed at addressing the problems caused by maritime piracy in the Gulf of Guinea in order to improve maritime security.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86894647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Severe weather systems can generate large waves and storm surges which can cause many fatalities in coastal areas. In extreme circumstances a single cyclone caused up to 500,000 fatalities in the Bay of Bengal in 1970. Adaption by authorities in that region from evacuations and construction of storm shelters have significantly reduced the number of such fatalities there. The effects of Hurricane Sandy in 2012 in New York City and surrounding areas is examined to show how ocean effects can cause many casualties. Scrutiny of a European storm shows how a slight error in analysis can fail to detect a deadly increase in intensity which caused many fatalities. World record wave height events are examined, and the historical Australian east coast events are investigated. The impacts from long period waves emanating from distant storms are shown to be a forecasting problem.
{"title":"Ocean Affects from Severe Weather Systems in Coastal Areas","authors":"J. Callaghan","doi":"10.30564/jms.v3i4.3772","DOIUrl":"https://doi.org/10.30564/jms.v3i4.3772","url":null,"abstract":"Severe weather systems can generate large waves and storm surges which can cause many fatalities in coastal areas. In extreme circumstances a single cyclone caused up to 500,000 fatalities in the Bay of Bengal in 1970. Adaption by authorities in that region from evacuations and construction of storm shelters have significantly reduced the number of such fatalities there. The effects of Hurricane Sandy in 2012 in New York City and surrounding areas is examined to show how ocean effects can cause many casualties. Scrutiny of a European storm shows how a slight error in analysis can fail to detect a deadly increase in intensity which caused many fatalities. World record wave height events are examined, and the historical Australian east coast events are investigated. The impacts from long period waves emanating from distant storms are shown to be a forecasting problem.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72725697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Cabrera, J. Díaz‐Larrea, Arsenio J. Areces, L. Ñúñez García, J. Cruz-Aviña, Gabriela Vázquez Silva
Recent advances in molecular biology make it possible to sequence not only genes or genomes, but also to understand codon dynamics. For the organelle genes of these organisms, a small set of preferred codons are used for encoding proteins. For the first time, this paper treats the divergence of synonymous codon usage and its bias in the rbcL gene within the Laurencia complex of red algae. We observed that the synonymous codon preference biases in rbcL are large and differ among species. A clear distinction in codon usage between genera is evident: the genera Dasya and Delesseria use a set that fluctuated between 53 and 58 codons. Whereas, in the genera Ceramium, Chondrophycus, Chlamydomonas, Chlorella, Laurencia s.s, Osmundea, and Palisada codon usage indicates a higher restriction fluctuating between 40 to 51 codons. Laurencia complex genera and other representative algae showed a defined composition pattern, with lower percentage values of NNC/G (7-24.9%). Dasya and Delesseria showed a selective pattern tendency because of high percentage values of NNC/G (54-55%). The estimated codon bias parameters were tested to infer systematic relationships and match suitable codons with the NNC / G codon percentages. Cluster analysis based on Codon Usage supports phylogenetic relationships between Chondrophycus, Palisada, Laurencia, Osmundea, and Yuzurua species.
{"title":"Codon Usage of Chloroplast Gene rbcL in Laurencia sensu lato (Rhodophyta) species","authors":"R. Cabrera, J. Díaz‐Larrea, Arsenio J. Areces, L. Ñúñez García, J. Cruz-Aviña, Gabriela Vázquez Silva","doi":"10.30564/jms.v3i4.3542","DOIUrl":"https://doi.org/10.30564/jms.v3i4.3542","url":null,"abstract":"Recent advances in molecular biology make it possible to sequence not only genes or genomes, but also to understand codon dynamics. For the organelle genes of these organisms, a small set of preferred codons are used for encoding proteins. For the first time, this paper treats the divergence of synonymous codon usage and its bias in the rbcL gene within the Laurencia complex of red algae. We observed that the synonymous codon preference biases in rbcL are large and differ among species. A clear distinction in codon usage between genera is evident: the genera Dasya and Delesseria use a set that fluctuated between 53 and 58 codons. Whereas, in the genera Ceramium, Chondrophycus, Chlamydomonas, Chlorella, Laurencia s.s, Osmundea, and Palisada codon usage indicates a higher restriction fluctuating between 40 to 51 codons. Laurencia complex genera and other representative algae showed a defined composition pattern, with lower percentage values of NNC/G (7-24.9%). Dasya and Delesseria showed a selective pattern tendency because of high percentage values of NNC/G (54-55%). The estimated codon bias parameters were tested to infer systematic relationships and match suitable codons with the NNC / G codon percentages. Cluster analysis based on Codon Usage supports phylogenetic relationships between Chondrophycus, Palisada, Laurencia, Osmundea, and Yuzurua species.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83139186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01Epub Date: 2021-01-19DOI: 10.1007/s00773-020-00794-7
Antonio Sánchez-Caja, Jussi Martio, Ville M Viitanen, Timo Siikonen
This paper presents a procedure for the estimation of propeller effective wakes in oblique flows. It shows how a recently developed method for controlling coupling errors can be applied to analyze propellers operating in off-design conditions. The approach allows the use of fast potential flow methods for the representation of the propeller in the context of viscous flow solvers and works accurately for a wide range of advance numbers and incidence angles with a minimum computational cost. The new method makes it possible to disclose flow phenomena on the effective wake that were hidden in conventional approaches of effective wake simulation. Different application cases are analyzed, such as a propeller-shaft configuration in inclined flow, a pod propulsor in an oblique inflow, and a ship hull advancing at a yaw angle. A dipole-like distortion on the effective wake is unmasked for a uniform flow incident to a propeller mounted on an inclined shaft. The flow component perpendicular to the axis is found to be responsible for the distortion. The effect of the direction of propeller rotation on the effective wake is illustrated for a single-shaft ship moving at a yaw angle. In particular, keel vortices are either attracted to or repelled from the propeller disk depending on the sign of the yaw angle or alternatively on that of the propeller rotation.
{"title":"Simulation of turbulent effective wakes for propellers in off-design conditions by a correction factor approach.","authors":"Antonio Sánchez-Caja, Jussi Martio, Ville M Viitanen, Timo Siikonen","doi":"10.1007/s00773-020-00794-7","DOIUrl":"10.1007/s00773-020-00794-7","url":null,"abstract":"<p><p>This paper presents a procedure for the estimation of propeller effective wakes in oblique flows. It shows how a recently developed method for controlling coupling errors can be applied to analyze propellers operating in off-design conditions. The approach allows the use of fast potential flow methods for the representation of the propeller in the context of viscous flow solvers and works accurately for a wide range of advance numbers and incidence angles with a minimum computational cost. The new method makes it possible to disclose flow phenomena on the effective wake that were hidden in conventional approaches of effective wake simulation. Different application cases are analyzed, such as a propeller-shaft configuration in inclined flow, a pod propulsor in an oblique inflow, and a ship hull advancing at a yaw angle. A dipole-like distortion on the effective wake is unmasked for a uniform flow incident to a propeller mounted on an inclined shaft. The flow component perpendicular to the axis is found to be responsible for the distortion. The effect of the direction of propeller rotation on the effective wake is illustrated for a single-shaft ship moving at a yaw angle. In particular, keel vortices are either attracted to or repelled from the propeller disk depending on the sign of the yaw angle or alternatively on that of the propeller rotation.</p>","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7813973/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38853165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine environment represents a very important and actual topic. Water bodies cover more than two thirds of the earth’s surface and even after thousands of years, scientists have yet to fully uncover their mysteries. At the same time climate, change has visible effects with a growing dynamics in the last decades and the marine environment is very sensitive to these changes. In order to mitigate the effects of the climate change there is an increasing need of reducing the CO2 emissions and from this perspective the marine environment represents an important source of clean renewable energy. In this respect, the Journal of Marine Science represented even from the beginning an open framework dedicated to the presentation of the discoveries and insights in marine science research.
{"title":"Journal of Marine Science: An Open Framework Dedicated to the Presentation of the Discoveries and Insights in Marine Science Research","authors":"E. Rusu","doi":"10.30564/jms.v3i3.3511","DOIUrl":"https://doi.org/10.30564/jms.v3i3.3511","url":null,"abstract":"Marine environment represents a very important and actual topic. Water bodies cover more than two thirds of the earth’s surface and even after thousands of years, scientists have yet to fully uncover their mysteries. At the same time climate, change has visible effects with a growing dynamics in the last decades and the marine environment is very sensitive to these changes. In order to mitigate the effects of the climate change there is an increasing need of reducing the CO2 emissions and from this perspective the marine environment represents an important source of clean renewable energy. In this respect, the Journal of Marine Science represented even from the beginning an open framework dedicated to the presentation of the discoveries and insights in marine science research.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91211637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Purandara, Sudhir Kumar, N. Varadarajan, Sumit Kant, J. Tyagi
Submarine groundwater discharges to the coastal ecosystems have been recognised as a source of dissolved chemical substances that cause chemical and ecological effects on sea waters. Groundwater, in many coastal areas, becomes contaminated or at least enriched with a variety of chemical substances and can have higher concentrations of dissolved solids than river water. As a result SGD makes a larger contribution to the flux of dissolved chemical compounds than river run-off. Therefore, the present investigation has been carried out to understand the process of submarine groundwater discharge based on hydrological, hydrogeological and hydrochemical components. Accordingly water balance components were evaluated based on hydrological and hydrogeological investigations. Hydrochemical parameters were also evaluated to understand the impact of seawater intrusion during both pre-monsoon and post-monsoon seasons of 2019. Study revealed that, there are signatures of considerable quantity of submarine groundwater discharge in parts of Honnavara, Kumta, Ankola and Karwar talukas. The influence of seawater in coastal aquifers is quite rare all along the coast of Uttara kannada district which is attributed to high groundwater recharge(15-20%) occurring in catchment areas.
{"title":"Hydrogeological and Hydrochemical Characterization of Coastal aquifers with Special reference to Submarine Groundwater Discharge in Uttara kannada, Karnataka, India","authors":"B. Purandara, Sudhir Kumar, N. Varadarajan, Sumit Kant, J. Tyagi","doi":"10.30564/jms.v3i3.3476","DOIUrl":"https://doi.org/10.30564/jms.v3i3.3476","url":null,"abstract":"Submarine groundwater discharges to the coastal ecosystems have been recognised as a source of dissolved chemical substances that cause chemical and ecological effects on sea waters. Groundwater, in many coastal areas, becomes contaminated or at least enriched with a variety of chemical substances and can have higher concentrations of dissolved solids than river water. As a result SGD makes a larger contribution to the flux of dissolved chemical compounds than river run-off. Therefore, the present investigation has been carried out to understand the process of submarine groundwater discharge based on hydrological, hydrogeological and hydrochemical components. Accordingly water balance components were evaluated based on hydrological and hydrogeological investigations. Hydrochemical parameters were also evaluated to understand the impact of seawater intrusion during both pre-monsoon and post-monsoon seasons of 2019. Study revealed that, there are signatures of considerable quantity of submarine groundwater discharge in parts of Honnavara, Kumta, Ankola and Karwar talukas. The influence of seawater in coastal aquifers is quite rare all along the coast of Uttara kannada district which is attributed to high groundwater recharge(15-20%) occurring in catchment areas.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81034981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patrícia Pinheiro Beck Eichler, Christofer Paul Barker, M. Gomes, H. Vital
We use the excellent sediment recovery of International Ocean Discovery Program (IODP) Exp. 363, in the Western Pacific Warm Pool (WPWP) to assess down-core variations in the abundance of warm versus cool benthic foraminiferal species through a warm benthic foraminifers (WBF) curve. The total percentage of the “warm” shallower species group (Laticarinina pauperata, Cibicidoides kullenbergi, C. robertsonianus, Cibicidoides sp., Hoeglundina elegans, and Bulimina aculeata) and of the “cool” species group from deep waters (Pyrgo murrhina, Planulina wuellerstorfi, Uvigerina peregrina, and Globobulimina hoeglundi, Hopkinsina pacifica) at all sites is used to assess paleo temporal and spatial variations in preservation and marine temperature. Our study sites span water depths ranging from 875 m to 3421 m and our results indicate that well-preserved living and fossil foraminifera characterize mudline and core sediments at all water depths attesting the wide environmental tolerance of these species to temperature and pressure. Using magneto-and biostratigraphy datum, these sediments are of Oligocene age. Our low-resolution study showed that with the exception of core 1486B which the linear tendency of warmer species is toward cool sediments in old times, all of them show that older sediments indicate warmer periods than today, which is expected from Miocene to Recent. Our results provide evidence for the preservation potential of deeply buried sediments, which has implications on climate reconstructions based on the population dynamics of calcareous benthic foraminifera.
{"title":"An Overview of Oligocene to Recent Sediments of the Western Pacific Warm Pool (WPWP) (International Ocean Discovery Program-IODP Exp. 363) Using Warm and Cool Foraminiferal Species","authors":"Patrícia Pinheiro Beck Eichler, Christofer Paul Barker, M. Gomes, H. Vital","doi":"10.30564/jms.v3i3.3516","DOIUrl":"https://doi.org/10.30564/jms.v3i3.3516","url":null,"abstract":"We use the excellent sediment recovery of International Ocean Discovery Program (IODP) Exp. 363, in the Western Pacific Warm Pool (WPWP) to assess down-core variations in the abundance of warm versus cool benthic foraminiferal species through a warm benthic foraminifers (WBF) curve. The total percentage of the “warm” shallower species group (Laticarinina pauperata, Cibicidoides kullenbergi, C. robertsonianus, Cibicidoides sp., Hoeglundina elegans, and Bulimina aculeata) and of the “cool” species group from deep waters (Pyrgo murrhina, Planulina wuellerstorfi, Uvigerina peregrina, and Globobulimina hoeglundi, Hopkinsina pacifica) at all sites is used to assess paleo temporal and spatial variations in preservation and marine temperature. Our study sites span water depths ranging from 875 m to 3421 m and our results indicate that well-preserved living and fossil foraminifera characterize mudline and core sediments at all water depths attesting the wide environmental tolerance of these species to temperature and pressure. Using magneto-and biostratigraphy datum, these sediments are of Oligocene age. Our low-resolution study showed that with the exception of core 1486B which the linear tendency of warmer species is toward cool sediments in old times, all of them show that older sediments indicate warmer periods than today, which is expected from Miocene to Recent. Our results provide evidence for the preservation potential of deeply buried sediments, which has implications on climate reconstructions based on the population dynamics of calcareous benthic foraminifera.","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79200162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reproductive biology of Leiognathus splendens was studied by using the samples collected from the catches of trawl fisheries in Myeik coastal waters during January to December 2014. Spawning takes place throughout the year, with a peak during April-May and September-December. The observed length at first maturity was 9.0 cm total length in males and 8.4 cm in females. The mean gonadosomatic index was more prominently in females (2.5) than males (1.5). Sex ratio (1 male: 1.1 females) also indicates the general dominant of females over males Fecundity varied from 6120 to 58412 eggs. Relationship of fecundity to fish length, fish weight and ovary weight showed that fecundity is more related to the gonad weight (r=0.9) than length (r=0.8) and weight of fish (r=0.7)
{"title":"Reproductive Biology of Splendid Ponyfish Leiognathus splendens (Cuvier, 1829) in Myeik Coastal Waters, Myanmar","authors":"K. Maung, Phan Minh-Thu, N. Tun","doi":"10.30564/jmsr.v1i2.923","DOIUrl":"https://doi.org/10.30564/jmsr.v1i2.923","url":null,"abstract":"Reproductive biology of Leiognathus splendens was studied by using the samples collected from the catches of trawl fisheries in Myeik coastal waters during January to December 2014. Spawning takes place throughout the year, with a peak during April-May and September-December. The observed length at first maturity was 9.0 cm total length in males and 8.4 cm in females. The mean gonadosomatic index was more prominently in females (2.5) than males (1.5). Sex ratio (1 male: 1.1 females) also indicates the general dominant of females over males Fecundity varied from 6120 to 58412 eggs. Relationship of fecundity to fish length, fish weight and ovary weight showed that fecundity is more related to the gonad weight (r=0.9) than length (r=0.8) and weight of fish (r=0.7)","PeriodicalId":16334,"journal":{"name":"Journal of Marine Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72986994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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