Pub Date : 2024-11-14DOI: 10.3389/fmars.2024.1382153
Ryan Rubino, Anthony R. Lima, Joe M. Fox
Competing uses for nearshore coastal space, such as aquaculture, have complex environmental and ecological interactions with surrounding seagrass meadows. Oyster aquaculture is among the fastest-growing aquaculture segments in the United States, and it brings concerns such as increased sedimentation from farm maintenance operations and altered water quality through oyster filtration. Changes in seagrass coverage and growth are common indicators of ecological health used to determine anthropogenic impacts on nearshore environments. This study characterized the effects of a research-scale adjustable long-line oyster aquaculture system on the health of adjacent seagrass meadows in Copano Bay, TX. Four Halodule wrightii meadows were identified at various distances from the research site: 100 m upstream (upstream), directly adjacent (0 m), 30 m downstream (30 m), and 60 m downstream (60 m). Sites were monitored for 1) seagrass health, 2) water quality parameters, and 3) sediment deposition. Over the 18-week sampling period, no significant differences (p>0.05) were found for water quality variables or sediment grain-size analysis using a one-way ANOVA. A linear mixed-effects model was used for repeated measures of seagrass data, with no effect of the site found on mean seagrass length, coverage, or maximum length (p>0.05). These results suggest that seagrass health indicators were unaffected by proximity to the oyster system. It was concluded that an oyster research aquaculture system of the type and size at the project location had no major negative or positive impact on seagrass meadow health due to high background variability and the overall minor footprint of the oyster farm across a comparatively large spatial extent.
{"title":"Short-term effects of a research-scale oyster cage aquaculture system on sediment transport, water quality, and seagrass meadow health in Copano Bay, TX, USA","authors":"Ryan Rubino, Anthony R. Lima, Joe M. Fox","doi":"10.3389/fmars.2024.1382153","DOIUrl":"https://doi.org/10.3389/fmars.2024.1382153","url":null,"abstract":"Competing uses for nearshore coastal space, such as aquaculture, have complex environmental and ecological interactions with surrounding seagrass meadows. Oyster aquaculture is among the fastest-growing aquaculture segments in the United States, and it brings concerns such as increased sedimentation from farm maintenance operations and altered water quality through oyster filtration. Changes in seagrass coverage and growth are common indicators of ecological health used to determine anthropogenic impacts on nearshore environments. This study characterized the effects of a research-scale adjustable long-line oyster aquaculture system on the health of adjacent seagrass meadows in Copano Bay, TX. Four <jats:italic>Halodule wrightii</jats:italic> meadows were identified at various distances from the research site: 100 m upstream (upstream), directly adjacent (0 m), 30 m downstream (30 m), and 60 m downstream (60 m). Sites were monitored for 1) seagrass health, 2) water quality parameters, and 3) sediment deposition. Over the 18-week sampling period, no significant differences (<jats:italic>p</jats:italic>&gt;0.05) were found for water quality variables or sediment grain-size analysis using a one-way ANOVA. A linear mixed-effects model was used for repeated measures of seagrass data, with no effect of the site found on mean seagrass length, coverage, or maximum length (<jats:italic>p</jats:italic>&gt;0.05). These results suggest that seagrass health indicators were unaffected by proximity to the oyster system. It was concluded that an oyster research aquaculture system of the type and size at the project location had no major negative or positive impact on seagrass meadow health due to high background variability and the overall minor footprint of the oyster farm across a comparatively large spatial extent.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.3389/fmars.2024.1461696
Raheema Rahman, Hasibur Rahaman
Ocean and sea ice reanalyses (ORAs or ocean syntheses) are reconstructions of the ocean and sea ice states using an ocean model integration constrained by atmospheric surface forcing and ocean observations via a data assimilation method. Ocean reanalyses are a valuable tool for monitoring and understanding long-term ocean variability at depth, mainly because this part of the ocean is still largely unobserved. Sea surface temperature (SST) is the key variable that drives the air–sea interaction process on different time scales. Despite improvements in model and reanalysis schemes, ocean reanalyses show errors when evaluated with independent observations. The independent evaluation studies of SST from ocean reanalysis over the Indian Ocean are limited. In this study, we evaluated the SST from 10 reanalysis products (ECCO, BRAN, SODA, NCEP-GODAS, GODAS-MOM4p1, ORAS5, CGLORS, GLORYS2V4, GLOSEA, and GREP) and five synthetic observation products (COBE, ERSST, OISST, OSTIA, and HadISST) and from the pure observation-based product AMSR2 for 2012–2017 with 12 in-situ buoy observations (OMNI) over the Arabian Sea and Bay of Bengal. Even though the reanalysis and observational products perform very well in the open ocean, the performance is poorer near the coast and islands. The reanalysis products perform comparatively better than most of the observational products. COBE and OISST perform better among the synthetic observational products in the northern Indian Ocean. GODAS-MOM4p1 and GREP performs best among the reanalysis products, often surpassing the observational products. ECCO shows poorer performance and higher bias in the Bay of Bengal. Comparing the BRAN daily and monthly SST, the monthly SST performance of reanalysis is better than the daily time scale.
{"title":"Evaluation of sea surface temperature from ocean reanalysis products over the North Indian Ocean","authors":"Raheema Rahman, Hasibur Rahaman","doi":"10.3389/fmars.2024.1461696","DOIUrl":"https://doi.org/10.3389/fmars.2024.1461696","url":null,"abstract":"Ocean and sea ice reanalyses (ORAs or ocean syntheses) are reconstructions of the ocean and sea ice states using an ocean model integration constrained by atmospheric surface forcing and ocean observations via a data assimilation method. Ocean reanalyses are a valuable tool for monitoring and understanding long-term ocean variability at depth, mainly because this part of the ocean is still largely unobserved. Sea surface temperature (SST) is the key variable that drives the air–sea interaction process on different time scales. Despite improvements in model and reanalysis schemes, ocean reanalyses show errors when evaluated with independent observations. The independent evaluation studies of SST from ocean reanalysis over the Indian Ocean are limited. In this study, we evaluated the SST from 10 reanalysis products (ECCO, BRAN, SODA, NCEP-GODAS, GODAS-MOM4p1, ORAS5, CGLORS, GLORYS2V4, GLOSEA, and GREP) and five synthetic observation products (COBE, ERSST, OISST, OSTIA, and HadISST) and from the pure observation-based product AMSR2 for 2012–2017 with 12 <jats:italic>in-situ</jats:italic> buoy observations (OMNI) over the Arabian Sea and Bay of Bengal. Even though the reanalysis and observational products perform very well in the open ocean, the performance is poorer near the coast and islands. The reanalysis products perform comparatively better than most of the observational products. COBE and OISST perform better among the synthetic observational products in the northern Indian Ocean. GODAS-MOM4p1 and GREP performs best among the reanalysis products, often surpassing the observational products. ECCO shows poorer performance and higher bias in the Bay of Bengal. Comparing the BRAN daily and monthly SST, the monthly SST performance of reanalysis is better than the daily time scale.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.3389/fmars.2024.1438955
Muhammad Farrukh Nisar, Mingxi Li, Jialin Xu, Chunpeng Wan
Diabetes mellitus (DM), a major global health concern, is a chronic metabolic disorder. Bioactive compounds sourced from numerous marine natural products recently have drawn attention as novel therapeutic approaches. Considering these chemicals and their role in cellular redox modulation by involving the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway, the current study attempts to highlight their anti-diabetic effects and the molecular mechanisms involved. Reactive oxygen species (ROS)-mediated oxidative stress, inflammation, and cellular damage are linked to most human pathologies specifically DM. The Nrf2/HO-1 pathway is a key defense mechanism developed by the cells to combat ROS burst. Marine natural compounds have strong pharmacological potential in triggering cellular antioxidant defense mechanisms by declining oxidative damage and inflammation linked to DM. How marine natural products potentially alleviate DM specifically type 2 diabetes (T2D) and its related issues is especially focused on. The literature was thoroughly analyzed to open a discussion about specific marine compounds and their well-established anti-diabetic effects to elucidate possible therapeutic applications. Furthermore, opportunities and the pros and cons of using these marine bioactive compounds as complementary treatment for DM are also discussed. The diverse characteristics of marine natural products, specifically with regard to redox control, offer promising opportunities for drug discovery and therapeutic interventions in clinical trials.
{"title":"Anti-diabetic effects of marine natural products through redox modulation via Nrf2/HO-1 cytoprotective pathways","authors":"Muhammad Farrukh Nisar, Mingxi Li, Jialin Xu, Chunpeng Wan","doi":"10.3389/fmars.2024.1438955","DOIUrl":"https://doi.org/10.3389/fmars.2024.1438955","url":null,"abstract":"Diabetes mellitus (DM), a major global health concern, is a chronic metabolic disorder. Bioactive compounds sourced from numerous marine natural products recently have drawn attention as novel therapeutic approaches. Considering these chemicals and their role in cellular redox modulation by involving the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway, the current study attempts to highlight their anti-diabetic effects and the molecular mechanisms involved. Reactive oxygen species (ROS)-mediated oxidative stress, inflammation, and cellular damage are linked to most human pathologies specifically DM. The Nrf2/HO-1 pathway is a key defense mechanism developed by the cells to combat ROS burst. Marine natural compounds have strong pharmacological potential in triggering cellular antioxidant defense mechanisms by declining oxidative damage and inflammation linked to DM. How marine natural products potentially alleviate DM specifically type 2 diabetes (T2D) and its related issues is especially focused on. The literature was thoroughly analyzed to open a discussion about specific marine compounds and their well-established anti-diabetic effects to elucidate possible therapeutic applications. Furthermore, opportunities and the pros and cons of using these marine bioactive compounds as complementary treatment for DM are also discussed. The diverse characteristics of marine natural products, specifically with regard to redox control, offer promising opportunities for drug discovery and therapeutic interventions in clinical trials.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.3389/fmars.2024.1426906
Gemma Portlock, Hannah Whitby, Pascal Salaün
Reduced sulfur species (RSS) are involved in essential biological and chemical processes, including metal complexation, yet little is known about their occurrence and behaviour in marine systems. Here, we present a quantitative and qualitative data set of species-specific RSS in open ocean samples collected during the GEOTRACES Tonga GPpr14 cruise. The cruise traversed differing biogeochemical provinces, from the mesotrophic Melanesian waters and the North Fiji Basin, through the hydrothermally active Lau Basin, eastward to the oligotrophic South Pacific Gyre. Using cathodic stripping voltammetry in acidified samples (pH 2), we measured the concentration of two RSS, with peak potentials of -0.18 and -0.09 V in equivalents of thioacetamide (TA) and glutathione (GSH) respectively. GSH-like compounds were only present in the upper 200 m at concentrations up to 6.2 nM eq. GSH, consistent with other cathodic stripping voltammetry as well as chromatography-based studies. In contrast, <jats:inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>R</mml:mi><mml:mi>S</mml:mi><mml:msubsup><mml:mi>S</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>0.18</mml:mn><mml:mo> </mml:mo><mml:mi>V</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></jats:inline-formula> compounds were detected at all depths at concentrations ranging from 48 nM to 980 nM eq. TA. Both <jats:inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>R</mml:mi><mml:mi>S</mml:mi><mml:msubsup><mml:mi>S</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>0.18</mml:mn><mml:mo> </mml:mo><mml:mi>V</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></jats:inline-formula> and GSH-like compounds were present at higher levels in the hydrothermally-impacted region of the Lau Basin relative to other stations. The highest levels, along with high sulfide concentrations, were detected in a hydrothermal plume sample, indicating that hydrothermal vents are a direct or indirect source of these compounds. Elevated levels of <jats:inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>R</mml:mi><mml:mi>S</mml:mi><mml:msubsup><mml:mi>S</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>0.18</mml:mn><mml:mo> </mml:mo><mml:mi>V</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></jats:inline-formula> compounds were detected throughout almost the entire water column at a station located in the North Fiji Basin. We also employed the qualitative technique of cathodic pseudopolarography on unbuffered samples (pH ~ 8.5). Pseudopolarograms of marine RSS were compared to sulfide, GSH and TA standards. Pseudopolarography supports the presence of GSH in marine samples. However, while a compound that is electrochemically similar to TA is often detected in marine samples, TA itself is not thought to be naturally present. This i
{"title":"Distribution and behaviour of reduced sulfur substances in the oligotrophic and hydrothermal waters of the Western Tropical South Pacific","authors":"Gemma Portlock, Hannah Whitby, Pascal Salaün","doi":"10.3389/fmars.2024.1426906","DOIUrl":"https://doi.org/10.3389/fmars.2024.1426906","url":null,"abstract":"Reduced sulfur species (RSS) are involved in essential biological and chemical processes, including metal complexation, yet little is known about their occurrence and behaviour in marine systems. Here, we present a quantitative and qualitative data set of species-specific RSS in open ocean samples collected during the GEOTRACES Tonga GPpr14 cruise. The cruise traversed differing biogeochemical provinces, from the mesotrophic Melanesian waters and the North Fiji Basin, through the hydrothermally active Lau Basin, eastward to the oligotrophic South Pacific Gyre. Using cathodic stripping voltammetry in acidified samples (pH 2), we measured the concentration of two RSS, with peak potentials of -0.18 and -0.09 V in equivalents of thioacetamide (TA) and glutathione (GSH) respectively. GSH-like compounds were only present in the upper 200 m at concentrations up to 6.2 nM eq. GSH, consistent with other cathodic stripping voltammetry as well as chromatography-based studies. In contrast, <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><mml:mrow><mml:mi>R</mml:mi><mml:mi>S</mml:mi><mml:msubsup><mml:mi>S</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>0.18</mml:mn><mml:mo> </mml:mo><mml:mi>V</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></jats:inline-formula> compounds were detected at all depths at concentrations ranging from 48 nM to 980 nM eq. TA. Both <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><mml:mrow><mml:mi>R</mml:mi><mml:mi>S</mml:mi><mml:msubsup><mml:mi>S</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>0.18</mml:mn><mml:mo> </mml:mo><mml:mi>V</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></jats:inline-formula> and GSH-like compounds were present at higher levels in the hydrothermally-impacted region of the Lau Basin relative to other stations. The highest levels, along with high sulfide concentrations, were detected in a hydrothermal plume sample, indicating that hydrothermal vents are a direct or indirect source of these compounds. Elevated levels of <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><mml:mrow><mml:mi>R</mml:mi><mml:mi>S</mml:mi><mml:msubsup><mml:mi>S</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>0.18</mml:mn><mml:mo> </mml:mo><mml:mi>V</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></jats:inline-formula> compounds were detected throughout almost the entire water column at a station located in the North Fiji Basin. We also employed the qualitative technique of cathodic pseudopolarography on unbuffered samples (pH ~ 8.5). Pseudopolarograms of marine RSS were compared to sulfide, GSH and TA standards. Pseudopolarography supports the presence of GSH in marine samples. However, while a compound that is electrochemically similar to TA is often detected in marine samples, TA itself is not thought to be naturally present. This i","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vibrio disease is a prevalent bacterial infection in aquaculture, and using bacteria with antagonistic properties against Vibrio species as probiotics has emerged as a promising method for disease prevention. Additionally, low biomass productivity of microalgae feed remains a significant bottleneck in bivalve aquaculture. Therefore, it is essential to screen for bacteria that both enhance microalgae growth and inhibit Vibrio pathogens. In this study, seven bacterial strains capable of promoting microalgae growth were screened for their ability to inhibit three Vibrio pathogens, i.e., Vibrio vulnificus, Vibrio parahaemolyticus and Vibrio cholerae, and thus serve as a dual-functional probiotic for aquaculture. The antagonistic mechanism of these bacteria was further investigated by analyzing the inhibitory effects of their extracellular products (ECP) on Vibrio species. Results indicated that Pseudoalteromonas flavipulchra exhibited antagonistic effects against all three Vibrio species tested. The ECP of P. flavipulchra displayed stable antibacterial activity, though this ability was lost after the ECP was treated with heat, alkali, or proteinase K. The proteinaceous fraction isolated from the ECP by precipitation with 90% saturated ammonium sulfate demonstrated concentration-dependent antibacterial activity. These findings suggest that P. flavipulchra could serve as a promising dual-functional probiotic for aquaculture, warranting further research to optimize its application in this field.
{"title":"Pseudoalteromonas flavipulchra as a dual-functional probiotic for aquaculture: enhancing microalgae growth and antagonizing Vibrio pathogens","authors":"Min-nan Wu, Yi-jun Xu, Meng-meng Shao, Zi-yue Wang, Jia-yi Cao, Ji-lin Xu","doi":"10.3389/fmars.2024.1492142","DOIUrl":"https://doi.org/10.3389/fmars.2024.1492142","url":null,"abstract":"<jats:italic>Vibrio</jats:italic> disease is a prevalent bacterial infection in aquaculture, and using bacteria with antagonistic properties against <jats:italic>Vibrio</jats:italic> species as probiotics has emerged as a promising method for disease prevention. Additionally, low biomass productivity of microalgae feed remains a significant bottleneck in bivalve aquaculture. Therefore, it is essential to screen for bacteria that both enhance microalgae growth and inhibit <jats:italic>Vibrio</jats:italic> pathogens. In this study, seven bacterial strains capable of promoting microalgae growth were screened for their ability to inhibit three <jats:italic>Vibrio</jats:italic> pathogens, i.e., <jats:italic>Vibrio vulnificus, Vibrio parahaemolyticus</jats:italic> and <jats:italic>Vibrio cholerae</jats:italic>, and thus serve as a dual-functional probiotic for aquaculture. The antagonistic mechanism of these bacteria was further investigated by analyzing the inhibitory effects of their extracellular products (ECP) on <jats:italic>Vibrio</jats:italic> species. Results indicated that <jats:italic>Pseudoalteromonas flavipulchra</jats:italic> exhibited antagonistic effects against all three <jats:italic>Vibrio</jats:italic> species tested. The ECP of <jats:italic>P. flavipulchra</jats:italic> displayed stable antibacterial activity, though this ability was lost after the ECP was treated with heat, alkali, or proteinase K. The proteinaceous fraction isolated from the ECP by precipitation with 90% saturated ammonium sulfate demonstrated concentration-dependent antibacterial activity. These findings suggest that <jats:italic>P. flavipulchra</jats:italic> could serve as a promising dual-functional probiotic for aquaculture, warranting further research to optimize its application in this field.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.3389/fmars.2024.1474610
Fatemeh Shokri Alikhanlou, Mohsen Soltanpour, Farzin Samsami, S. Abbas Haghshenas, Maryam Hajibaba
Sediments containing more than 10% clay particles by mass can exhibit cohesive properties. Cohesive sediments are commonly found in coastal areas worldwide, including the southern shore of the Caspian Sea and the northern/northwestern beaches of the Persian Gulf. These cohesive sediments can form a layer of soft to extremely soft mud, known as fluid mud, covering the seabed. The study examined the properties of natural mud samples collected from different depths and locations within three Iranian ports: Anzali Port (Caspian Sea), and Khorramshahr and Bushehr Ports (Persian Gulf). The laboratory analyses included determining the sediment grain-size distribution, density, carbonate content, organic matter content, and rheological properties at different water content ratios. Disregarding the impact of variations in organic matter and carbonate contents in the samples, water content ratio was the main factor affecting the rheological properties of sediments.
{"title":"Study of the rheological properties and nautical depth assessment of fine sediments in Iranian ports","authors":"Fatemeh Shokri Alikhanlou, Mohsen Soltanpour, Farzin Samsami, S. Abbas Haghshenas, Maryam Hajibaba","doi":"10.3389/fmars.2024.1474610","DOIUrl":"https://doi.org/10.3389/fmars.2024.1474610","url":null,"abstract":"Sediments containing more than 10% clay particles by mass can exhibit cohesive properties. Cohesive sediments are commonly found in coastal areas worldwide, including the southern shore of the Caspian Sea and the northern/northwestern beaches of the Persian Gulf. These cohesive sediments can form a layer of soft to extremely soft mud, known as fluid mud, covering the seabed. The study examined the properties of natural mud samples collected from different depths and locations within three Iranian ports: Anzali Port (Caspian Sea), and Khorramshahr and Bushehr Ports (Persian Gulf). The laboratory analyses included determining the sediment grain-size distribution, density, carbonate content, organic matter content, and rheological properties at different water content ratios. Disregarding the impact of variations in organic matter and carbonate contents in the samples, water content ratio was the main factor affecting the rheological properties of sediments.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.3389/fmars.2024.1438129
Nayan Patel, Krupal J. Patel, Ashish Patel, Daoud Ali, Saud Alarifi, Jigneshkumar N. Trivedi
The present study focused on investigating the population structure and breeding biology of a species of Porcellanid crab, Petrolisthes boscii (Audouin, 1826). Evaluating the population ecology of the species is essential considering its crucial role in ecological functions including the nutrition cycle and its potential vulnerability to environmental stressors. The samples were collected over a period of 12 consecutive months (from March 2019 to February 2020) in an area of 500 m2 during low tide, utilizing the catch-per-unit-effort (CPUE) method when the water receded. The collected specimens (859 individuals) were categorized into males (407 individuals), non-ovigerous females (452 individuals), and ovigerous females (303 individuals). The assessment of fecundity was conducted by measuring the egg characteristics, including the total number, size, and weight of the eggs, as well as the carapace width of the ovigerous females. There was an evident difference in size, with males (8.60 ± 2.76) being significantly larger compared to females (8.39 ± 2.46) (p < 0.001). The overall and monthly sex ratios were female-biased (1:1.17). Moreover, the size frequency distribution revealed a bimodal distribution in male as well as female individuals. Ovigerous females occurred in all the months, which shows that the species breeds continuously throughout the year, with peaks in the months of March to May and August to October. There was a significant positive relationship observed among the size of ovigerous females and their total number of eggs (130.39 ± 83.31), egg mass weight (150 ± 110 mg). The study may provide baseline information for future studies on the impacts of a continuously altering environment and the consequences of increasing anthropogenic pressure on coastal areas.
{"title":"Unveiling the population structure and breeding patterns of Petrolisthes boscii (Audouin, 1826) a common intertidal inhabitant of Shivrajpur, Saurashtra Coast, Gujarat","authors":"Nayan Patel, Krupal J. Patel, Ashish Patel, Daoud Ali, Saud Alarifi, Jigneshkumar N. Trivedi","doi":"10.3389/fmars.2024.1438129","DOIUrl":"https://doi.org/10.3389/fmars.2024.1438129","url":null,"abstract":"The present study focused on investigating the population structure and breeding biology of a species of Porcellanid crab, <jats:italic>Petrolisthes boscii</jats:italic> (Audouin, 1826). Evaluating the population ecology of the species is essential considering its crucial role in ecological functions including the nutrition cycle and its potential vulnerability to environmental stressors. The samples were collected over a period of 12 consecutive months (from March 2019 to February 2020) in an area of 500 m<jats:sup>2</jats:sup> during low tide, utilizing the catch-per-unit-effort (CPUE) method when the water receded. The collected specimens (859 individuals) were categorized into males (407 individuals), non-ovigerous females (452 individuals), and ovigerous females (303 individuals). The assessment of fecundity was conducted by measuring the egg characteristics, including the total number, size, and weight of the eggs, as well as the carapace width of the ovigerous females. There was an evident difference in size, with males (8.60 ± 2.76) being significantly larger compared to females (8.39 ± 2.46) (p &lt; 0.001). The overall and monthly sex ratios were female-biased (1:1.17). Moreover, the size frequency distribution revealed a bimodal distribution in male as well as female individuals. Ovigerous females occurred in all the months, which shows that the species breeds continuously throughout the year, with peaks in the months of March to May and August to October. There was a significant positive relationship observed among the size of ovigerous females and their total number of eggs (130.39 ± 83.31), egg mass weight (150 ± 110 mg). The study may provide baseline information for future studies on the impacts of a continuously altering environment and the consequences of increasing anthropogenic pressure on coastal areas.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The West Kallaallit Nunaat (Greenland) coast, characterized by a variety of fjords, bays, and channels influenced by glacier melting and Atlantic and Arctic waters, is one of the most affected ecosystems by climate change. Here, we combine oceanography, optics, microscopy, high throughput sequencing, microalgal strain establishments, and state-of-the-art analytical methods to fully characterize the diversity, community composition, and toxin repertoire of the eukaryotic plankton members of the coast of the West Kalaallit Nunaat (Greenland). Results indicate that the West Kalaallit Nunaat (Greenland) coast is a complex and oceanographically challenging system, where the superimposition of water masses of different origins, the penetration of light and its repercussions, generate mainly vertical, rather than horizontal heterogeneity in nutrient concentration and plankton biomass. Nevertheless, our molecular data reveal a strong homogeneity and a high diversity in the plankton community along the Greenland coast. We confirmed the presence of five phycotoxin groups: domoic acid and paralytic shellfish toxins were most abundant along the transect from Qeqertarsuup Tunua (Disko Bay) to the northern Baffin Bay, while spirolides, yessotoxins and pectenotoxins were predominant in Nuup Kangerlua (GodthaabFjord) and Qeqertarsuup Tunua (Disko Bay). Concentrations of these phycotoxins correlate differently to temperature, salinity and nutrients, reflecting the ecological differences of their producers. Patterns of paralytic shellfish and spirolide toxins suggest the presence of genetically distinct populations of Alexandrium along the Western Kalaallit Nunaat (Greenland). Phytoplankton strains isolated during this oceanographic campaign resemble, in most cases, the toxin profiles of the respective field stations. Overall, this work shows the diversity and community composition of the plankton at the Western Kalaallit Nunaat coast and reveals a distinct spatial distribution of phycotoxins, with certain toxin groups restricted to specific areas.
{"title":"Diversity of eukaryote plankton and phycotoxins along the West Kalaallit Nunaat (Greenland) coast","authors":"Susana Rodríguez-Marconi, Bernd Krock, Urban Tillmann, Anette Tillmann, Daniela Voss, Oliver Zielinski, Mónica Vásquez, Nicole Trefault","doi":"10.3389/fmars.2024.1443389","DOIUrl":"https://doi.org/10.3389/fmars.2024.1443389","url":null,"abstract":"The West Kallaallit Nunaat (Greenland) coast, characterized by a variety of fjords, bays, and channels influenced by glacier melting and Atlantic and Arctic waters, is one of the most affected ecosystems by climate change. Here, we combine oceanography, optics, microscopy, high throughput sequencing, microalgal strain establishments, and state-of-the-art analytical methods to fully characterize the diversity, community composition, and toxin repertoire of the eukaryotic plankton members of the coast of the West Kalaallit Nunaat (Greenland). Results indicate that the West Kalaallit Nunaat (Greenland) coast is a complex and oceanographically challenging system, where the superimposition of water masses of different origins, the penetration of light and its repercussions, generate mainly vertical, rather than horizontal heterogeneity in nutrient concentration and plankton biomass. Nevertheless, our molecular data reveal a strong homogeneity and a high diversity in the plankton community along the Greenland coast. We confirmed the presence of five phycotoxin groups: domoic acid and paralytic shellfish toxins were most abundant along the transect from Qeqertarsuup Tunua (Disko Bay) to the northern Baffin Bay, while spirolides, yessotoxins and pectenotoxins were predominant in Nuup Kangerlua (GodthaabFjord) and Qeqertarsuup Tunua (Disko Bay). Concentrations of these phycotoxins correlate differently to temperature, salinity and nutrients, reflecting the ecological differences of their producers. Patterns of paralytic shellfish and spirolide toxins suggest the presence of genetically distinct populations of Alexandrium along the Western Kalaallit Nunaat (Greenland). Phytoplankton strains isolated during this oceanographic campaign resemble, in most cases, the toxin profiles of the respective field stations. Overall, this work shows the diversity and community composition of the plankton at the Western Kalaallit Nunaat coast and reveals a distinct spatial distribution of phycotoxins, with certain toxin groups restricted to specific areas.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.3389/fmars.2024.1488610
Kang Li, Yi Hao, Nan Wang, Yingming Feng, Dehai Song, Yanyu Chen, Hao Zhang, Zhaopeng Ren, Xianwen Bao
Stricter controls on destructive human activities in recent years have improved the protection and management of sandy coasts in China. Marine-driven geomorphic changes have become the predominant process influencing future beach evolution. However, in the complex geomorphic conditions of mixed artificial and natural coastlines, the mechanisms and contributions of various marine-driven factors to beach changes remain unclear. Using methods of field observations and numerical simulations by FVCOM model, this study reveals the sedimentary dynamic mechanism of straight sandy beach in the southern Shandong Peninsula (Wanpingkou beach, WPK beach). From 2005 to 2016, the northern section of WPK Beach eroded at a rate of approximately 2-3 m/year, the middle section at about 0.5-1.5 m/year, and the southern section accrued at an average rate of about 1-2 m/year, demonstrating an overall pattern of “northern erosion and southern accretion.” During winter, the average grain size of beach sediments is about 0.5 mm with minimal variations, indicating an onshore transport trend; in summer, the average grain size is about 0.7 mm with larger variations, indicating an offshore transport trend. Offshore sediment transport correlates mainly with seasonal changes in wind direction, while alongshore sediment transport is influenced by tidal currents, wind-induced currents, and wave-induced currents. Wave-induced currents are the primary force in alongshore sediment transport with a velocity of 0.1-0.3 m/s toward southwest. Followed by tidal currents with a velocity of 0.05-0.1 m/s, and wind-induced currents with a velocity of 0-0.1 m/s, which have a relatively minor impact. Therefore, seasonal changes in beach morphology are primarily controlled by waves, while interannual variations is mainly influenced by a combination of wave-induced currents and tidal currents. With increasing efforts in beach maintenance and coastal ecological restoration in recent years, understanding the sedimentary dynamics of beaches remains of vital theoretical and practical value.
{"title":"Hydrodynamic mechanisms of topographic evolution in straight sandy beach: a case study of Wanpingkou beach, China","authors":"Kang Li, Yi Hao, Nan Wang, Yingming Feng, Dehai Song, Yanyu Chen, Hao Zhang, Zhaopeng Ren, Xianwen Bao","doi":"10.3389/fmars.2024.1488610","DOIUrl":"https://doi.org/10.3389/fmars.2024.1488610","url":null,"abstract":"Stricter controls on destructive human activities in recent years have improved the protection and management of sandy coasts in China. Marine-driven geomorphic changes have become the predominant process influencing future beach evolution. However, in the complex geomorphic conditions of mixed artificial and natural coastlines, the mechanisms and contributions of various marine-driven factors to beach changes remain unclear. Using methods of field observations and numerical simulations by FVCOM model, this study reveals the sedimentary dynamic mechanism of straight sandy beach in the southern Shandong Peninsula (Wanpingkou beach, WPK beach). From 2005 to 2016, the northern section of WPK Beach eroded at a rate of approximately 2-3 m/year, the middle section at about 0.5-1.5 m/year, and the southern section accrued at an average rate of about 1-2 m/year, demonstrating an overall pattern of “northern erosion and southern accretion.” During winter, the average grain size of beach sediments is about 0.5 mm with minimal variations, indicating an onshore transport trend; in summer, the average grain size is about 0.7 mm with larger variations, indicating an offshore transport trend. Offshore sediment transport correlates mainly with seasonal changes in wind direction, while alongshore sediment transport is influenced by tidal currents, wind-induced currents, and wave-induced currents. Wave-induced currents are the primary force in alongshore sediment transport with a velocity of 0.1-0.3 m/s toward southwest. Followed by tidal currents with a velocity of 0.05-0.1 m/s, and wind-induced currents with a velocity of 0-0.1 m/s, which have a relatively minor impact. Therefore, seasonal changes in beach morphology are primarily controlled by waves, while interannual variations is mainly influenced by a combination of wave-induced currents and tidal currents. With increasing efforts in beach maintenance and coastal ecological restoration in recent years, understanding the sedimentary dynamics of beaches remains of vital theoretical and practical value.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.3389/fmars.2024.1459187
Dandan Liu, Jingmei Li, Jingzhu Shan, Fangyuan Shi
Management policies are crucial for safeguarding sustained and stable marine biodiversity amidst ongoing pressures such as land use change, pollution, resource overexploitation, invasive alien species and climate change. China established a nature’s contributions to people value realization policy (NCPVR) in 2021, aiming to encourage stakeholders to prioritize environmentally beneficial production and consumption choices, thereby stimulating intrinsic public motivation for ecological conservation. Biodiversity conservation is an integral component of the NCPVR policy. A choice experiment method was employed to investigate the changes in public preferences for marine biodiversity conservation in Jiaozhou Bay before and after the enactment of the NCPVR policy (in 2017 and 2023, respectively), aiming to evaluate the effectiveness of the policy on marine biodiversity conservation. The results indicate that two years after the implementation of the NCPVR, the public’s overall breadth and depth of awareness regarding marine biodiversity increased. Additionally, public preferences for marine biodiversity conservation increased, expanding from two categories in 2017 (shallow-water swimming organisms and marine plants) to five categories in 2023 (with the addition of seabirds, plankton, and intertidal and benthic organisms). The willingness to pay (WTP) for seabirds, plankton, and intertidal and benthic organisms, as well as shallow-water swimming organisms, increased from 32.21~85.77 CNY/person·year to 98.21~140.49 CNY/person·year. China’s NCPVR policy effectively conveyed important information about biodiversity conservation in the short term, enhancing public awareness and preferences for marine biodiversity conservation. The study also revealed that economic incentive policies for NCPVR remain at the conceptual propaganda level and lack operational incentives for biodiversity conservation. It is recommended that the government deepen the design of value realization pathways and market trading arrangements to stimulate the intrinsic motivation of the public for marine biodiversity conservation and ensure the long-term effectiveness of policies.
{"title":"Does nature’s contributions to people value realization policy in China improve public awareness and preferences for marine biodiversity conservation? A temporal stability analysis","authors":"Dandan Liu, Jingmei Li, Jingzhu Shan, Fangyuan Shi","doi":"10.3389/fmars.2024.1459187","DOIUrl":"https://doi.org/10.3389/fmars.2024.1459187","url":null,"abstract":"Management policies are crucial for safeguarding sustained and stable marine biodiversity amidst ongoing pressures such as land use change, pollution, resource overexploitation, invasive alien species and climate change. China established a nature’s contributions to people value realization policy (NCPVR) in 2021, aiming to encourage stakeholders to prioritize environmentally beneficial production and consumption choices, thereby stimulating intrinsic public motivation for ecological conservation. Biodiversity conservation is an integral component of the NCPVR policy. A choice experiment method was employed to investigate the changes in public preferences for marine biodiversity conservation in Jiaozhou Bay before and after the enactment of the NCPVR policy (in 2017 and 2023, respectively), aiming to evaluate the effectiveness of the policy on marine biodiversity conservation. The results indicate that two years after the implementation of the NCPVR, the public’s overall breadth and depth of awareness regarding marine biodiversity increased. Additionally, public preferences for marine biodiversity conservation increased, expanding from two categories in 2017 (shallow-water swimming organisms and marine plants) to five categories in 2023 (with the addition of seabirds, plankton, and intertidal and benthic organisms). The willingness to pay (WTP) for seabirds, plankton, and intertidal and benthic organisms, as well as shallow-water swimming organisms, increased from 32.21~85.77 CNY/person·year to 98.21~140.49 CNY/person·year. China’s NCPVR policy effectively conveyed important information about biodiversity conservation in the short term, enhancing public awareness and preferences for marine biodiversity conservation. The study also revealed that economic incentive policies for NCPVR remain at the conceptual propaganda level and lack operational incentives for biodiversity conservation. It is recommended that the government deepen the design of value realization pathways and market trading arrangements to stimulate the intrinsic motivation of the public for marine biodiversity conservation and ensure the long-term effectiveness of policies.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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