Pub Date : 2024-04-14DOI: 10.1016/j.seares.2024.102500
Paulo Roberto Camponez de Almeida , Marcus Rodrigues da Costa , Ana Tereza Rodrigues Ribeiro , Agostinho Almeida , Rui Azevedo , Cassiano Monteiro-Neto , Alberto Teodorico Correia
The delimitation of fish stocks and how species use habitats are essential keys to develop and to implement fishery resources management and rational sustainable programs. Otolith shape and microchemistry analyses can provide helpful information for defining population units and solving ecological connectivity issues. The black drum, Pogonias courbina, is an important fishery resource in the southeastern Brazil lagoon systems, and is considered a vulnerable fish according to the IUCN Red List of Threatened Species. Thus, the present study aimed to understand the population structure and habitat connectivity of P. courbina in two lagoon systems in the south-east coast of Rio de Janeiro, Brazil. A total of 60 individuals were collected from the lagoons of Saquarema (SQ) and Araruama (AR), between November 2019 and April 2020. Thirty individuals from each location, all estimated to be two years old based on the counting of the annual growth increments, were used. The composition (multi-elemental signatures – MES) and shape (elliptic Fourier descriptors – EFD) of the sagittal otoliths were integrated to evaluate the population structure and the habitat connectivity of the fish inside these lagoon systems. EFD showed differences between lagoon systems, with an overall reclassification rate of 97%. The MES exhibited distinct patterns between lagoon systems, mainly driven by differences in Ba/Ca, Co/Ca, Li/Ca, Mg/Ca, Ni/Ca, Sr/Ca, and Zn/Ca ratios. The overall reclassification rate for MES was also 97% (93% and 100% for SQ and ARA, respectively). The overall reclassification rate obtained using both EFD and MES was 98%. The results suggest a clear spatial discrimination and low connectivity between these groups of two years old P. coubina individuals living in the studied lagoon systems. These findings imply that small-scale artisanal fisheries in the lagoon systems require more attention, aiming to maximize local management strategies for commercially exploited species.
鱼类种群的划分以及物种如何利用栖息地是制定和实施渔业资源管理和合理可持续计划的关键。耳石形状和微化学分析可为界定种群单位和解决生态连接问题提供有用信息。黑鼓(Pogonias courbina)是巴西东南部泻湖系统的重要渔业资源,被世界自然保护联盟(IUCN)列入濒危物种红色名录,属于易危鱼类。因此,本研究旨在了解巴西里约热内卢东南海岸两个泻湖系统中 P. courbina 的种群结构和栖息地连通性。在2019年11月至2020年4月期间,研究人员从Saquarema泻湖(SQ)和Alaruama泻湖(AR)共采集了60个个体。每个地点各采集 30 只,根据年生长增量的计算,估计年龄均为两年。综合矢状耳石的成分(多元素特征--MES)和形状(椭圆傅立叶描述符--EFD)来评估这些泻湖系统内鱼类的种群结构和栖息地的连通性。EFD 显示了不同泻湖系统之间的差异,总体重新分类率为 97%。MES 在不同泻湖系统之间表现出不同的模式,主要由 Ba/Ca、Co/Ca、Li/Ca、Mg/Ca、Ni/Ca、Sr/Ca 和 Zn/Ca 比率的差异所驱动。MES 的总体重新分类率也达到了 97%(SQ 和 ARA 分别为 93% 和 100%)。使用 EFD 和 MES 的总体重新分类率为 98%。这些结果表明,生活在所研究泻湖系统中的两岁库比纳鱼个体群体之间存在明显的空间差异和较低的连通性。这些研究结果表明,需要对泻湖系统中的小型个体渔业给予更多关注,以便最大限度地利用当地的商业开发物种管理策略。
{"title":"Population structure and habitat connectivity of Pogonias courbina (Perciformes, Sciaenidae) in two Brazilian lagoon systems on south-east coast of Rio de Janeiro, Brazil, inferred from otolith shape and elemental signatures","authors":"Paulo Roberto Camponez de Almeida , Marcus Rodrigues da Costa , Ana Tereza Rodrigues Ribeiro , Agostinho Almeida , Rui Azevedo , Cassiano Monteiro-Neto , Alberto Teodorico Correia","doi":"10.1016/j.seares.2024.102500","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102500","url":null,"abstract":"<div><p>The delimitation of fish stocks and how species use habitats are essential keys to develop and to implement fishery resources management and rational sustainable programs. Otolith shape and microchemistry analyses can provide helpful information for defining population units and solving ecological connectivity issues. The black drum, <em>Pogonias courbina</em>, is an important fishery resource in the southeastern Brazil lagoon systems, and is considered a vulnerable fish according to the IUCN Red List of Threatened Species. Thus, the present study aimed to understand the population structure and habitat connectivity of <em>P. courbina</em> in two lagoon systems in the south-east coast of Rio de Janeiro, Brazil. A total of 60 individuals were collected from the lagoons of Saquarema (SQ) and Araruama (AR), between November 2019 and April 2020. Thirty individuals from each location, all estimated to be two years old based on the counting of the annual growth increments, were used. The composition (multi-elemental signatures – MES) and shape (elliptic Fourier descriptors – EFD) of the sagittal otoliths were integrated to evaluate the population structure and the habitat connectivity of the fish inside these lagoon systems. EFD showed differences between lagoon systems, with an overall reclassification rate of 97%. The MES exhibited distinct patterns between lagoon systems, mainly driven by differences in Ba/Ca, Co/Ca, Li/Ca, Mg/Ca, Ni/Ca, Sr/Ca, and Zn/Ca ratios. The overall reclassification rate for MES was also 97% (93% and 100% for SQ and ARA, respectively). The overall reclassification rate obtained using both EFD and MES was 98%. The results suggest a clear spatial discrimination and low connectivity between these groups of two years old <em>P. coubina</em> individuals living in the studied lagoon systems. These findings imply that small-scale artisanal fisheries in the lagoon systems require more attention, aiming to maximize local management strategies for commercially exploited species.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102500"},"PeriodicalIF":2.0,"publicationDate":"2024-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000339/pdfft?md5=f7934999ed3237af4a04b86b2bec8a0d&pid=1-s2.0-S1385110124000339-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140619412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-12DOI: 10.1016/j.seares.2024.102497
Laura Leiva , Luis Giménez , Maarten Boersma
Biological monitoring of planktonic animals is greatly dependent on the deployment of traps. A variety of specialized traps have been designed for surface plankton and vertebrates. However, certain groups, such as planktonic larvae of benthic marine invertebrates remain underrepresented in sampling efforts. Catching them has proven to be more challenging because of their size, swimming ability, location, and abundance. In the present study a successful light trap for sampling American lobster larvae in New Brunswick, Canada, is evaluated on the island of Helgoland (German Bight, North Sea). Our results showed the traps were successful in catching larvae in laboratory experiments but were unable to catch European lobster larvae in the field. Traps deployed in the field were successful in capturing other benthic and pelagic zooplankton predominantly consisting of crustaceans from the orders: Cumacea, Amphipoda, Mysida and Isopoda. The low density of lobster larvae, the island's topography, and their unique photactic response possibly limited the success rate of the light traps. Future research is needed to construct a specialized trap to sample Helgoland's lobster larvae and provide information on the current larval fitness and population numbers.
{"title":"Evaluation of light traps for sampling lobster larvae in the German Bight, North Sea","authors":"Laura Leiva , Luis Giménez , Maarten Boersma","doi":"10.1016/j.seares.2024.102497","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102497","url":null,"abstract":"<div><p>Biological monitoring of planktonic animals is greatly dependent on the deployment of traps. A variety of specialized traps have been designed for surface plankton and vertebrates. However, certain groups, such as planktonic larvae of benthic marine invertebrates remain underrepresented in sampling efforts. Catching them has proven to be more challenging because of their size, swimming ability, location, and abundance. In the present study a successful light trap for sampling American lobster larvae in New Brunswick, Canada, is evaluated on the island of Helgoland (German Bight, North Sea). Our results showed the traps were successful in catching larvae in laboratory experiments but were unable to catch European lobster larvae in the field. Traps deployed in the field were successful in capturing other benthic and pelagic zooplankton predominantly consisting of crustaceans from the orders: Cumacea, Amphipoda, Mysida and Isopoda. The low density of lobster larvae, the island's topography, and their unique photactic response possibly limited the success rate of the light traps. Future research is needed to construct a specialized trap to sample Helgoland's lobster larvae and provide information on the current larval fitness and population numbers.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102497"},"PeriodicalIF":2.0,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000303/pdfft?md5=c47e4414fc28c4c09c166f4825ee61d2&pid=1-s2.0-S1385110124000303-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1016/j.seares.2024.102498
Joop W.P. Coolen , Babeth van der Weide , Oliver Bittner , Ninon Mavraki , Mandy Rus , Johan van der Molen , Rob Witbaard
The number of offshore artificial structures in the North Sea is continuously increasing. Apart from the structures that have been added to the marine environment accidentally (e.g., shipwrecks), structures are also deliberately developed to meet the increasing needs for renewable energy. These structures provide habitat for fouling organisms. The fouling communities vary in abundance and composition based on location, depth, and structure age. Most fouling species filter particles from the water column, changing phytoplankton production and affecting larval settlement success, while releasing ammonium that can fuel phytoplankton growth as well as (pseudo)faeces that enriches the seabed, changing local biogeochemical cycles.
Our study used in-situ incubation chambers to investigate oxygen, nitrogen, and phosphate fluxes associated with fouling organisms to improve understanding of these changes in biogeochemical cycles. Divers used incubation chambers (domes) on shipwrecks in the southern North Sea where over 55 years mature fouling communities have established. A series of water samples was collected from each dome during deployment to measure the change in concentration of ammonium, nitrite, nitrate, and phosphate. All fauna enclosed in the domes was collected after each measurement for further analysis.
The full macrofauna dataset contained 65 unique species on 4 shipwrecks (25 to 50 species per sample). Abundance ranged from 2187 to 59,427 individuals per sample (683 cm2). On average, a decrease in oxygen concentration of 126 μmol/g ash free dry weight/h was found. The sequential water samples also showed clear changes in nutrient concentration with time in all incubations. The largest changes were observed with high fouling community abundances and biomass. Ammonium, nitrite, and phosphate always increased, with 1.5-to-5-fold increases from start to end of the incubation, while for nitrate both an efflux and influx were measured. Oxygen decreased in all incubations. Mean fluxes (all in μmol per m2 per hour with standard error) were significant for ammonium (945 ± 300), nitrite (80 ± 30), phosphate (61 ± 8), and oxygen (−11,794 ± 3289), but not for nitrate (−206 ± 122). Per gram AFDW, only ammonium (12.7 ± 3.5) and oxygen (−126 ± 48) had fluxes that differed significantly from zero.
Compared to average seabed (sandy bottom) oxygen demand and community fluxes from previous studies, the observed fluxes were high. Our findings resembled those from temperate biogenic reef studies. Further data collection across a larger spatial and temporal scale is needed to fully understand offshore structure effects on marine environments.
{"title":"Fluxes of nitrogen and phosphorus in fouling communities on artificial offshore structures","authors":"Joop W.P. Coolen , Babeth van der Weide , Oliver Bittner , Ninon Mavraki , Mandy Rus , Johan van der Molen , Rob Witbaard","doi":"10.1016/j.seares.2024.102498","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102498","url":null,"abstract":"<div><p>The number of offshore artificial structures in the North Sea is continuously increasing. Apart from the structures that have been added to the marine environment accidentally (e.g., shipwrecks), structures are also deliberately developed to meet the increasing needs for renewable energy. These structures provide habitat for fouling organisms. The fouling communities vary in abundance and composition based on location, depth, and structure age. Most fouling species filter particles from the water column, changing phytoplankton production and affecting larval settlement success, while releasing ammonium that can fuel phytoplankton growth as well as (pseudo)faeces that enriches the seabed, changing local biogeochemical cycles.</p><p>Our study used in-situ incubation chambers to investigate oxygen, nitrogen, and phosphate fluxes associated with fouling organisms to improve understanding of these changes in biogeochemical cycles. Divers used incubation chambers (domes) on shipwrecks in the southern North Sea where over 55 years mature fouling communities have established. A series of water samples was collected from each dome during deployment to measure the change in concentration of ammonium, nitrite, nitrate, and phosphate. All fauna enclosed in the domes was collected after each measurement for further analysis.</p><p>The full macrofauna dataset contained 65 unique species on 4 shipwrecks (25 to 50 species per sample). Abundance ranged from 2187 to 59,427 individuals per sample (683 cm<sup>2</sup>). On average, a decrease in oxygen concentration of 126 μmol/g ash free dry weight/h was found. The sequential water samples also showed clear changes in nutrient concentration with time in all incubations. The largest changes were observed with high fouling community abundances and biomass. Ammonium, nitrite, and phosphate always increased, with 1.5-to-5-fold increases from start to end of the incubation, while for nitrate both an efflux and influx were measured. Oxygen decreased in all incubations. Mean fluxes (all in μmol per m<sup>2</sup> per hour with standard error) were significant for ammonium (945 ± 300), nitrite (80 ± 30), phosphate (61 ± 8), and oxygen (−11,794 ± 3289), but not for nitrate (−206 ± 122). Per gram AFDW, only ammonium (12.7 ± 3.5) and oxygen (−126 ± 48) had fluxes that differed significantly from zero.</p><p>Compared to average seabed (sandy bottom) oxygen demand and community fluxes from previous studies, the observed fluxes were high. Our findings resembled those from temperate biogenic reef studies. Further data collection across a larger spatial and temporal scale is needed to fully understand offshore structure effects on marine environments.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102498"},"PeriodicalIF":2.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000315/pdfft?md5=af4bc04ed88afbb1752a3608f18a024a&pid=1-s2.0-S1385110124000315-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140605910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1016/j.seares.2024.102499
Gonasageran Naidoo, Krishnaveni Naidoo
The effects of oil pollution on nematode assemblages were investigated in a mangrove sediment. Microcosms comprised 350 mL plastic jars filled with 250 g sediment. In the oiled treatments (O), 15 mL oil were added to the soil. In the oil and fertiliser treatments (O + F), oil and fertiliser (N: P: K: 3: 2: 5) were added to the soil. After four weeks, nematodes were extracted and identified. The number of nematode taxa was highest in the C (61), intermediate in the O + F (59) and significantly lower in the O (25) treatment. Taxa present in the C but absent in the O treatment were oil-intolerant. Taxa present in the O treatments were oil-tolerant. Five taxa survived oiling probably due to fertiliser amendment. Oiling eliminated oil-intolerant taxa and favoured those that were resistant. In the O+ F treatment, the number and species of nematodes increased significantly.
研究了红树林沉积物中石油污染对线虫群落的影响。微生态系统由装有 250 克沉积物的 350 毫升塑料瓶组成。在涂油处理(O)中,向土壤中添加 15 mL 油。在油和肥料处理(O + F)中,向土壤中添加油和肥料(氮:磷:钾:3:2:5)。四周后,提取线虫并进行鉴定。线虫类群的数量在 C 处理中最高(61 个),在 O + F 处理中居中(59 个),在 O 处理中明显较低(25 个)。在 C 处理中存在但在 O 处理中不存在的类群不耐油。在 O 处理中出现的分类群耐油。有 5 个分类群在涂油后存活了下来,这可能是由于肥料改良的缘故。涂油消除了不耐油的分类群,有利于耐油的分类群。在 O+ F 处理中,线虫的数量和种类显著增加。
{"title":"Responses of nematodes to oil contamination in a mangrove sediment: A microcosm study","authors":"Gonasageran Naidoo, Krishnaveni Naidoo","doi":"10.1016/j.seares.2024.102499","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102499","url":null,"abstract":"<div><p>The effects of oil pollution on nematode assemblages were investigated in a mangrove sediment. Microcosms comprised 350 mL plastic jars filled with 250 g sediment. In the oiled treatments (O), 15 mL oil were added to the soil. In the oil and fertiliser treatments (O + F), oil and fertiliser (N: P: K: 3: 2: 5) were added to the soil. After four weeks, nematodes were extracted and identified. The number of nematode taxa was highest in the C (61), intermediate in the O + F (59) and significantly lower in the O (25) treatment. Taxa present in the C but absent in the O treatment were oil-intolerant. Taxa present in the O treatments were oil-tolerant. Five taxa survived oiling probably due to fertiliser amendment. Oiling eliminated oil-intolerant taxa and favoured those that were resistant. In the O+ F treatment, the number and species of nematodes increased significantly.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102499"},"PeriodicalIF":2.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000327/pdfft?md5=242baf1f26c97d5ab2a76a7861fb8a56&pid=1-s2.0-S1385110124000327-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140550840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-04DOI: 10.1016/j.seares.2024.102496
Nana Tang
In the era of economic globalization and heightened international competition, the emergence of free trade zones has significantly increased regional openness, introducing both new opportunities and challenges for ports. This paper proposes the enhancement of intelligent design in the maritime landscapes of smart ports, with a focus on optimizing internal pathways and developing a predictive model to gauge the impact of smart port landscapes. Furthermore, the study delves into the assessment of risks in smart port supply chains, employing an innovative approach that integrates rough set theory and neural networks. This novel model significantly improves the accuracy of risk evaluation in port supply chains, thereby providing crucial decision support for port management. Additionally, the economic efficiency of smart ports is scrutinized using the Data Envelopment Analysis (DEA) Malmquist index method. Through meticulous selection of research subjects, port efficiency indicators, and the DEA Malmquist index, this analysis offers a comprehensive insight into the economic operations of smart ports. This research not only offers guidance for port economic management but also establishes a framework for the sustainable development of smart ports, thereby ensuring their long-term viability.
在经济全球化和国际竞争加剧的时代,自由贸易区的出现大大提高了区域开放度,为港口带来了新的机遇和挑战。本文提出在智能港口的海洋景观中加强智能设计,重点是优化内部路径和开发预测模型,以衡量智能港口景观的影响。此外,该研究还深入探讨了智能港口供应链中的风险评估,采用了一种融合粗糙集理论和神经网络的创新方法。这一新型模型大大提高了港口供应链风险评估的准确性,从而为港口管理提供了重要的决策支持。此外,还利用数据包络分析(DEA)的 Malmquist 指数法对智能港口的经济效益进行了研究。通过对研究对象、港口效率指标和 DEA Malmquist 指数的精心选择,本分析报告对智能港口的经济运行情况进行了全面深入的分析。这项研究不仅为港口经济管理提供了指导,还为智能港口的可持续发展建立了框架,从而确保了智能港口的长期生命力。
{"title":"Multi-element integrated design of marine landscape in sustainable smart ports","authors":"Nana Tang","doi":"10.1016/j.seares.2024.102496","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102496","url":null,"abstract":"<div><p>In the era of economic globalization and heightened international competition, the emergence of free trade zones has significantly increased regional openness, introducing both new opportunities and challenges for ports. This paper proposes the enhancement of intelligent design in the maritime landscapes of smart ports, with a focus on optimizing internal pathways and developing a predictive model to gauge the impact of smart port landscapes. Furthermore, the study delves into the assessment of risks in smart port supply chains, employing an innovative approach that integrates rough set theory and neural networks. This novel model significantly improves the accuracy of risk evaluation in port supply chains, thereby providing crucial decision support for port management. Additionally, the economic efficiency of smart ports is scrutinized using the Data Envelopment Analysis (DEA) Malmquist index method. Through meticulous selection of research subjects, port efficiency indicators, and the DEA Malmquist index, this analysis offers a comprehensive insight into the economic operations of smart ports. This research not only offers guidance for port economic management but also establishes a framework for the sustainable development of smart ports, thereby ensuring their long-term viability.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102496"},"PeriodicalIF":2.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000297/pdfft?md5=f8cc8e9aef8be3d6d44087bed7f19a75&pid=1-s2.0-S1385110124000297-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140605775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.1016/j.seares.2024.102495
Bingzhong Yang , Bent Herrmann , Rong Wan
The size selectivity and exploitation patterns of two T0 (diamond mesh) codends were tested and compared with T90 (diamond mesh turned by 90°) codends in demersal trawl fishery targeting white croaker (Pennahia argentata) of the northern South China Sea. The four experimental codends involved two mesh sizes, 30 and 35 mm, respectively. The size selectivity of the T0 codend with mesh size of 30 mm, T0_30, was used as a starting point to compare with the rest codends. The results showed that compared with the T0_30 codend increasing the mesh size to 35 mm or applying the T90 codends would result in significantly larger L50 values, and the retention risk (probability) of undersized white croaker with length < 8.5 cm would significantly reduce. These codends, however, had no effect on improving the size selectivity of undersized white croaker with the length ranging between 10 and 15 cm. The results of our study will have relevant implications for fishing gears management and future direction of codend selectivity research.
{"title":"Comparing the size selectivity and exploitation patterns of two T0 codends with T90 codends in demersal trawl fishery targeting white croaker (Pennahia argentata) of the northern South China Sea","authors":"Bingzhong Yang , Bent Herrmann , Rong Wan","doi":"10.1016/j.seares.2024.102495","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102495","url":null,"abstract":"<div><p>The size selectivity and exploitation patterns of two T0 (diamond mesh) codends were tested and compared with T90 (diamond mesh turned by 90°) codends in demersal trawl fishery targeting white croaker (<em>Pennahia argentata</em>) of the northern South China Sea. The four experimental codends involved two mesh sizes, 30 and 35 mm, respectively. The size selectivity of the T0 codend with mesh size of 30 mm, T0_30, was used as a starting point to compare with the rest codends. The results showed that compared with the T0_30 codend increasing the mesh size to 35 mm or applying the T90 codends would result in significantly larger L50 values, and the retention risk (probability) of undersized white croaker with length < 8.5 cm would significantly reduce. These codends, however, had no effect on improving the size selectivity of undersized white croaker with the length ranging between 10 and 15 cm. The results of our study will have relevant implications for fishing gears management and future direction of codend selectivity research.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102495"},"PeriodicalIF":2.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000285/pdfft?md5=401c49644efddf0c8d81f0c0bb62079b&pid=1-s2.0-S1385110124000285-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140330818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-27DOI: 10.1016/j.seares.2024.102494
Tianxiang Chang
The vertical structure of internal tidal currents in the Jailolo Strait of the Indonesian seas is studied using the year-long mooring observations with two Acoustic Doppler Current Profiler instruments looking upward and downward, respectively, coving the full depth of the strait. The barotropic tides are extracted from the full-depth current profile measurements, showing the dominant M2, K1, and O1 tidal currents with amplitudes of 13.5 cm s−1, 11.0 cm s−1 and 7.6 cm s−1, in nearly reciprocating movement in the direction of 34.5°, 63.1°, and 75.2° clockwise from due north. The internal tidal currents in the Jailolo Strait contributing to about 50% of the total kinetic energy are found to be dominated by the low baroclinic modes, with M2 tide as the most dominant tidal constituent. High-frequency internal tides of D3 and D4 are observed, with baroclinic structure similar to that of M2 tides, and are suggested to be stimulated by nonlinear processes. The complicated vertical structure of tidal currents in the Jailolo Strait is disclosed for the first time in history. Its potential impact on vertical turbulent mixing suggests its importance in global ocean circulation and climate.
{"title":"Mooring observations of tidal currents in the Jailolo Strait of the Indonesian seas","authors":"Tianxiang Chang","doi":"10.1016/j.seares.2024.102494","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102494","url":null,"abstract":"<div><p>The vertical structure of internal tidal currents in the Jailolo Strait of the Indonesian seas is studied using the year-long mooring observations with two Acoustic Doppler Current Profiler instruments looking upward and downward, respectively, coving the full depth of the strait. The barotropic tides are extracted from the full-depth current profile measurements, showing the dominant M<sub>2</sub>, K<sub>1</sub>, and O<sub>1</sub> tidal currents with amplitudes of 13.5 cm s<sup>−1</sup>, 11.0 cm s<sup>−1</sup> and 7.6 cm s<sup>−1</sup>, in nearly reciprocating movement in the direction of 34.5°, 63.1°, and 75.2° clockwise from due north. The internal tidal currents in the Jailolo Strait contributing to about 50% of the total kinetic energy are found to be dominated by the low baroclinic modes, with M<sub>2</sub> tide as the most dominant tidal constituent. High-frequency internal tides of D<sub>3</sub> and D<sub>4</sub> are observed, with baroclinic structure similar to that of M<sub>2</sub> tides, and are suggested to be stimulated by nonlinear processes. The complicated vertical structure of tidal currents in the Jailolo Strait is disclosed for the first time in history. Its potential impact on vertical turbulent mixing suggests its importance in global ocean circulation and climate.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102494"},"PeriodicalIF":2.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000273/pdfft?md5=826844b76997f5e9a960037293e4ffa6&pid=1-s2.0-S1385110124000273-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140327678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-26DOI: 10.1016/j.seares.2024.102493
Lei Zhang , Weishuai Xu , Maolin Li
Ocean fronts, as typical marine phenomena, significantly impact the marine environment and the distribution of organisms. However, the research on their tilted structure is limited. This study considered the frontal slope as a key parameter for describing the tilting characteristics of ocean fronts. A novel method, based on high-resolution in situ observations and reanalysis data, was proposed to extract global frontal slopes using contour lines and surfaces. To validate this approach, a mathematical model was developed for the oceanic front slope and verified through in situ observations. The frontal slope equation produced reliable results, indicating that the front tilting primarily arises from shear flow and density differences. Furthermore, a modified oceanic front gradient parameter was proposed based on the frontal slope, and its significance in understanding the impacts of ocean fronts on underwater acoustic propagation was validated through numerical simulation and statistical analysis. The distribution characteristics of frontal slope for ocean fronts on a global scale were analyzed for the first time. Marginal ice zone fronts had the highest slope (>1.5 m/km), followed by tidal mixing fronts, western boundary current fronts, and water mass convergence fronts (1–1.5 m/km). In contrast, upwelling fronts and estuarine plume fronts generally had slopes below 1 m/km. This parameter provides a new perspective on ocean front systems and their influence on dynamic structures and ecological resource distributions. This study helps in a comprehensive understanding of the tilting characteristics of the ocean front and their implications.
{"title":"Frontal slope: A new measure of ocean fronts","authors":"Lei Zhang , Weishuai Xu , Maolin Li","doi":"10.1016/j.seares.2024.102493","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102493","url":null,"abstract":"<div><p>Ocean fronts, as typical marine phenomena, significantly impact the marine environment and the distribution of organisms. However, the research on their tilted structure is limited. This study considered the frontal slope as a key parameter for describing the tilting characteristics of ocean fronts. A novel method, based on high-resolution in situ observations and reanalysis data, was proposed to extract global frontal slopes using contour lines and surfaces. To validate this approach, a mathematical model was developed for the oceanic front slope and verified through in situ observations. The frontal slope equation produced reliable results, indicating that the front tilting primarily arises from shear flow and density differences. Furthermore, a modified oceanic front gradient parameter was proposed based on the frontal slope, and its significance in understanding the impacts of ocean fronts on underwater acoustic propagation was validated through numerical simulation and statistical analysis. The distribution characteristics of frontal slope for ocean fronts on a global scale were analyzed for the first time. Marginal ice zone fronts had the highest slope (>1.5 m/km), followed by tidal mixing fronts, western boundary current fronts, and water mass convergence fronts (1–1.5 m/km). In contrast, upwelling fronts and estuarine plume fronts generally had slopes below 1 m/km. This parameter provides a new perspective on ocean front systems and their influence on dynamic structures and ecological resource distributions. This study helps in a comprehensive understanding of the tilting characteristics of the ocean front and their implications.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102493"},"PeriodicalIF":2.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000261/pdfft?md5=093ea23753a8e4a0a7766a9fcbf58894&pid=1-s2.0-S1385110124000261-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140320583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-12DOI: 10.1016/j.seares.2024.102491
Jiao Li, Jialin Jin
This study investigates the impact of digital innovation on the growth of the marine economy by optimizing the structure of the new media communication culture industry. Through the simulation of the particle swarm optimization (PSO) and Back Propagation (BP) computational network model, the Gross Domestic Production (GDP) of the marine economic zone is predicted, and the prediction effect of the PSO-BP computational network model on multivariate spatiotemporal transitions is further verified. The results show that the PSO-BP model has less prediction variance and a better fit than the BP model. The analysis of the joint prediction model reveals that there are differences in the publicity effects of different self-media modes in various types of sea areas. In terms of the economic peak of the overall data, Bilibili has the best publicity effect, followed by WeChat, Weibo, and Shake. The results show that the trend of macroeconomic indicators and the size of values in different regions affect the prediction effect. Region A has a higher annual average rate of change of macroeconomic indicators and has a better prediction effect. Region B has a faster macroeconomic development and has a more fluctuating prediction effect. Regions C and D have their advantages and disadvantages of the prediction effect under the self-media model.
本研究通过优化新媒体传播文化产业结构,探讨数字创新对海洋经济增长的影响。通过粒子群优化(PSO)和反向传播(BP)计算网络模型的仿真,预测了海洋经济区的国内生产总值(GDP),并进一步验证了PSO-BP计算网络模型对多变量时空转换的预测效果。结果表明,与 BP 模型相比,PSO-BP 模型的预测方差更小,拟合效果更好。通过对联合预测模型的分析发现,不同自媒体模式在各类海域的宣传效果存在差异。从整体数据的经济峰值来看,Bilibili 的宣传效果最好,其次是微信、微博、抖音。结果表明,不同地区的宏观经济指标走势和数值大小会影响预测效果。A 地区宏观经济指标年均变化率较高,预测效果较好。B 地区宏观经济发展较快,预测效果波动较大。C 区和 D 区在自媒体模式下的预测效果各有优劣。
{"title":"Structural optimization of new media communication culture industry on the impact of digital innovation on marine economic growth","authors":"Jiao Li, Jialin Jin","doi":"10.1016/j.seares.2024.102491","DOIUrl":"10.1016/j.seares.2024.102491","url":null,"abstract":"<div><p>This study investigates the impact of digital innovation on the growth of the marine economy by optimizing the structure of the new media communication culture industry. Through the simulation of the particle swarm optimization (PSO) and Back Propagation (BP) computational network model, the Gross Domestic Production (GDP) of the marine economic zone is predicted, and the prediction effect of the PSO-BP computational network model on multivariate spatiotemporal transitions is further verified. The results show that the PSO-BP model has less prediction variance and a better fit than the BP model. The analysis of the joint prediction model reveals that there are differences in the publicity effects of different self-media modes in various types of sea areas. In terms of the economic peak of the overall data, Bilibili has the best publicity effect, followed by WeChat, Weibo, and Shake. The results show that the trend of macroeconomic indicators and the size of values in different regions affect the prediction effect. Region A has a higher annual average rate of change of macroeconomic indicators and has a better prediction effect. Region B has a faster macroeconomic development and has a more fluctuating prediction effect. Regions C and D have their advantages and disadvantages of the prediction effect under the self-media model.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"199 ","pages":"Article 102491"},"PeriodicalIF":2.0,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000248/pdfft?md5=80883d336a37f3e1020e51b4dbeb7786&pid=1-s2.0-S1385110124000248-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-11DOI: 10.1016/j.seares.2024.102490
Huichao Jiang , Jianlong He , Ling Cheng , Ning Liu , Ping Fu , Ning Wang , Xiaoyu Jiang , Shan Sun , Juan Zhang
Nutrient reductions are considered effective methods to control eutrophication; however, our understanding of how plankton assemblages respond to nutrient reductions is limited. In the present study, we used a long-term dataset between 2004 and 2018 from Laizhou Bay, China, to describe the main characteristics of plankton assemblage response to nutrient reduction, and to compare the differences in plankton response between the different nutrient reduction regions. The results showed that plankton abundance showed obvious decreasing trends in response to nutrient reductions. The phytoplankton abundance decline rate was directly proportional to the magnitude of nutrient reductions. The large-scale shellfish culture may disrupt the response of mesozooplankton to nutrient reductions. Positive recovery signs in the plankton community were observed with species dominance decreasing for small individuals and increasing for large ones. The results suggested that the reduction in nitrogen and phosphorus positively affected plankton abundance and community recovery in Laizhou Bay.
{"title":"Long-term response of plankton assemblage to differentiated nutrient reductions in Laizhou Bay, China","authors":"Huichao Jiang , Jianlong He , Ling Cheng , Ning Liu , Ping Fu , Ning Wang , Xiaoyu Jiang , Shan Sun , Juan Zhang","doi":"10.1016/j.seares.2024.102490","DOIUrl":"https://doi.org/10.1016/j.seares.2024.102490","url":null,"abstract":"<div><p>Nutrient reductions are considered effective methods to control eutrophication; however, our understanding of how plankton assemblages respond to nutrient reductions is limited. In the present study, we used a long-term dataset between 2004 and 2018 from Laizhou Bay, China, to describe the main characteristics of plankton assemblage response to nutrient reduction, and to compare the differences in plankton response between the different nutrient reduction regions. The results showed that plankton abundance showed obvious decreasing trends in response to nutrient reductions. The phytoplankton abundance decline rate was directly proportional to the magnitude of nutrient reductions. The large-scale shellfish culture may disrupt the response of mesozooplankton to nutrient reductions. Positive recovery signs in the plankton community were observed with species dominance decreasing for small individuals and increasing for large ones. The results suggested that the reduction in nitrogen and phosphorus positively affected plankton abundance and community recovery in Laizhou Bay.</p></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"198 ","pages":"Article 102490"},"PeriodicalIF":2.0,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1385110124000236/pdfft?md5=936d2baeb515e8424b15d65a92e834ff&pid=1-s2.0-S1385110124000236-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140123020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}