This study assesses the impact of climate change on mean annual wave agitation and berth downtime at two major Eastern Mediterranean ports: Port of Piraeus, Greece, and Port of Limassol, Cyprus. Using high-fidelity numerical modeling under two climate scenarios (RCP4.5 and RCP8.5) up to 2100, changes in port basin wave agitation are evaluated, with and without accounting for Sea Level Rise (SLR). Results indicate that climate change will not uniformly increase wave agitation; outcomes vary depending on the adopted RCP scenario, time period, and berth location. Regarding mean annual berth downtime, more exposed berths in both ports are projected to face significant increases. The influence of SLR on downtime is inconsistent, especially at Port of Piraeus, where it may increase, decrease, or have negligible effects depending on location. These findings highlight the complex interplay between wave dynamics, local geomorphology, and port infrastructure, emphasizing the importance of port-specific climate resilience assessments.
{"title":"Assessing the impact of climate change on mean annual wave agitation and berth downtime at two major ports of the eastern Mediterranean Sea: Port of Piraeus, Greece and Port of Limassol, Cyprus","authors":"Michalis Chondros , Andreas Papadimitriou , Anastasios Metallinos , Vasiliki Chalastani , Conrad Landis , Dimitris Spyrou , Chrysi Laspidou , Phoebe Koundouri , Vasiliki Tsoukala","doi":"10.1016/j.seares.2025.102641","DOIUrl":"10.1016/j.seares.2025.102641","url":null,"abstract":"<div><div>This study assesses the impact of climate change on mean annual wave agitation and berth downtime at two major Eastern Mediterranean ports: Port of Piraeus, Greece, and Port of Limassol, Cyprus. Using high-fidelity numerical modeling under two climate scenarios (RCP4.5 and RCP8.5) up to 2100, changes in port basin wave agitation are evaluated, with and without accounting for Sea Level Rise (SLR). Results indicate that climate change will not uniformly increase wave agitation; outcomes vary depending on the adopted RCP scenario, time period, and berth location. Regarding mean annual berth downtime, more exposed berths in both ports are projected to face significant increases. The influence of SLR on downtime is inconsistent, especially at Port of Piraeus, where it may increase, decrease, or have negligible effects depending on location. These findings highlight the complex interplay between wave dynamics, local geomorphology, and port infrastructure, emphasizing the importance of port-specific climate resilience assessments.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102641"},"PeriodicalIF":2.9,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-04DOI: 10.1016/j.seares.2025.102640
Grete E. Dinesen , Kurt W. Ockelmann , Anders Nielsen
Larval settlement in response to conspecific adult pheromonal cues guides population connectivity and recruitment in many benthic invertebrates. However, evidence for this mechanism in bivalves, except for oysters and dreissenids, is limited. The evolution of such functional behaviour would have strengthened formation and maintenance of marine mussel aggregations of which several species and habitats are now considered threatened and in need of restoration. The two modioline bivalves, Modiolus modiolus and Modiolula phaseolina, form biogenic habitats in the subtidal. Experiments were conducted in vitro to test competent larval phototaxis, sinking rates, swimming behaviour and settlement responses to conspecific adult conditioned seawater (ACS) with pheromonal cues. Larvae of both species were maintained in ambient, aged seawater (ASW). Prior to settlement, the larvae became photonegative. Modiolus modiolus larvae sinking rates varied between 4.75 and 6.75 mm sec−1, depending on larval size and seawater temperature. Competent pediveliger larvae initially required higher concentrations of ACS to induce settlement completed by metamorphosis. The odds of larval settlement were 8 to 85 times higher with exposure to higher ACS concentrations compared to lower concentrations or absence of ACS. Low concentrations of ACS altered larval swimming behaviour but did not induce settlement completed by metamorphosis, and this is thus a threshold response. This first documentation of mytiloidean larval settlement in response to conspecific adult pheromonal cues, may play an integral role in the metapopulation dynamics of these species. Population declines could weaken plumes of pheromonal cues excreated from adults and, thereby, larval settlement and recruitment. This may explain, in part, the low recoverability of previously long-standing M. modiolus habitats after cessation of anthropogenic physical disturbance, such as bottom trawling. Application of these results may enable high metamorphosis and juvenile survival rates in aquaculture production and guide restocking efforts to enhance in situ recruitment and, thereby, support horse mussel habitat restoration in coastal waters.
在许多底栖无脊椎动物中,响应同种成虫信息素线索的幼虫定居指导种群连通性和招募。然而,这种机制在双壳类动物中的证据,除了牡蛎和双壳类,是有限的。这种功能行为的进化将加强海洋贻贝群体的形成和维持,其中一些物种和栖息地现在被认为受到威胁,需要恢复。这两种双壳类生物,modolus Modiolus和phaseolina Modiolula,在潮下形成了生物栖息地。通过体外实验,研究了在信息素提示下,适能幼虫对同种成虫条件海水(ACS)的趋光性、下沉率、游泳行为和沉降反应。将两种幼虫置于环境老化海水(ASW)中。在定居之前,幼虫具有光负性。根据幼虫的大小和海水温度的不同,莫索线虫幼虫的下沉率在4.75 ~ 6.75 mm sec−1之间变化。正常的小叶虫幼虫最初需要较高浓度的ACS来诱导沉降完成变态。与暴露于较低浓度或没有ACS相比,暴露于较高浓度的ACS的幼虫沉降几率高出8至85倍。低浓度的ACS改变了幼虫的游泳行为,但没有诱导通过变态完成的沉降,因此这是一个阈值反应。这是对同种成虫信息素线索的首次记录,可能在这些物种的超种群动态中起着不可或缺的作用。种群数量的减少可能会削弱成虫产生的信息素线索,从而影响幼虫的定居和招募。这可能在一定程度上解释了在人为物理干扰(如海底拖网捕捞)停止后,以前长期存在的毛藻栖息地的恢复能力较低。这些结果的应用可以在水产养殖生产中实现高的蜕变率和幼鱼存活率,并指导重新放养工作,加强原地补充,从而支持沿海水域马贻贝栖息地的恢复。
{"title":"Competent larval behaviour and settlement responses to adult conspecific cues of the horse mussels Modiolus modiolus and Modiolula phaseolina (Mytiloidea)","authors":"Grete E. Dinesen , Kurt W. Ockelmann , Anders Nielsen","doi":"10.1016/j.seares.2025.102640","DOIUrl":"10.1016/j.seares.2025.102640","url":null,"abstract":"<div><div>Larval settlement in response to conspecific adult pheromonal cues guides population connectivity and recruitment in many benthic invertebrates. However, evidence for this mechanism in bivalves, except for oysters and dreissenids, is limited. The evolution of such functional behaviour would have strengthened formation and maintenance of marine mussel aggregations of which several species and habitats are now considered threatened and in need of restoration. The two modioline bivalves, <em>Modiolus modiolus</em> and <em>Modiolula phaseolina</em>, form biogenic habitats in the subtidal. Experiments were conducted in vitro to test competent larval phototaxis, sinking rates, swimming behaviour and settlement responses to conspecific adult conditioned seawater (ACS) with pheromonal cues. Larvae of both species were maintained in ambient, aged seawater (ASW). Prior to settlement, the larvae became photonegative. <em>Modiolus modiolus</em> larvae sinking rates varied between 4.75 and 6.75 mm sec<sup>−1</sup>, depending on larval size and seawater temperature. Competent pediveliger larvae initially required higher concentrations of ACS to induce settlement completed by metamorphosis. The odds of larval settlement were 8 to 85 times higher with exposure to higher ACS concentrations compared to lower concentrations or absence of ACS. Low concentrations of ACS altered larval swimming behaviour but did not induce settlement completed by metamorphosis, and this is thus a threshold response. This first documentation of mytiloidean larval settlement in response to conspecific adult pheromonal cues, may play an integral role in the metapopulation dynamics of these species. Population declines could weaken plumes of pheromonal cues excreated from adults and, thereby, larval settlement and recruitment. This may explain, in part, the low recoverability of previously long-standing <em>M. modiolus</em> habitats after cessation of anthropogenic physical disturbance, such as bottom trawling. Application of these results may enable high metamorphosis and juvenile survival rates in aquaculture production and guide restocking efforts to enhance in situ recruitment and, thereby, support horse mussel habitat restoration in coastal waters.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102640"},"PeriodicalIF":2.9,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145519702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-04DOI: 10.1016/j.seares.2025.102642
Henk de Haas , Veit Hühnerbach , Martin Laungaard , Carsten Skaarup , Antoon Kuijpers
Detailed multibeam bathymetric mapping in combination with 3.5 kHz sub-bottom profiling, seabed video observations, sediment coring and hydrographic (CTD) measurements were performed in a deep-water area south of the Azores, Eastern North Atlantic Ocean. The study site is located immediately north of an UN-designated large marine protection area including the Atlantis-Meteor Seamount Complex. This seamount area represents a deep-sea benthic environment characterized by a vulnerable marine ecosystem with a large, partly unknown, biodiversity. Spatial distribution of deep-sea biodiversity is mainly driven by seabed topography and bottom water conditions, which are the main topics addressed in the present study. The seabed data collected during two cruises with RV’Pelagia’ (Royal NIOZ) provides evidence of significant (retrogressive) erosion patterns and local tectonic activity. A variety of larger and smaller erosional and sedimentary structures and the limited distribution of fine-grained bedded sediments are interpreted to have resulted from a combination of local hydrodynamic processes and tectonic activity. This new seabed information acquired in our study will thus contribute to a better understanding of the role of (near) seabed dynamics and topography in controlling deep-water biodiversity south of the Azores.
{"title":"Seabed topography of a deep-water channel and nearby abyssal mount area south of the Azores, Eastern North Atlantic: Evidence of tectonic activity, erosion, and bottom current action","authors":"Henk de Haas , Veit Hühnerbach , Martin Laungaard , Carsten Skaarup , Antoon Kuijpers","doi":"10.1016/j.seares.2025.102642","DOIUrl":"10.1016/j.seares.2025.102642","url":null,"abstract":"<div><div>Detailed multibeam bathymetric mapping in combination with 3.5 kHz sub-bottom profiling, seabed video observations, sediment coring and hydrographic (CTD) measurements were performed in a deep-water area south of the Azores, Eastern North Atlantic Ocean. The study site is located immediately north of an UN-designated large marine protection area including the Atlantis-Meteor Seamount Complex. This seamount area represents a deep-sea benthic environment characterized by a vulnerable marine ecosystem with a large, partly unknown, biodiversity. Spatial distribution of deep-sea biodiversity is mainly driven by seabed topography and bottom water conditions, which are the main topics addressed in the present study. The seabed data collected during two cruises with RV’Pelagia’ (Royal NIOZ) provides evidence of significant (retrogressive) erosion patterns and local tectonic activity. A variety of larger and smaller erosional and sedimentary structures and the limited distribution of fine-grained bedded sediments are interpreted to have resulted from a combination of local hydrodynamic processes and tectonic activity. This new seabed information acquired in our study will thus contribute to a better understanding of the role of (near) seabed dynamics and topography in controlling deep-water biodiversity south of the Azores.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102642"},"PeriodicalIF":2.9,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.seares.2025.102639
Beatrice Coda , Asami Suzuki Mashio , Tenyu Tamura , Aya Mamorita , Kuo Hong Wong , Nozomu Iwasaki , Hiroshi Hasegawa
The phylum Cnidaria is a vast taxonomic group that includes corals, sea anemones, and jellyfish. This study focuses on corals within the class Octocorallia, order Scleralcyonacea, and family Coralliidae, specifically Corallium japonicum and Pleurocorallium konojoi, which are of ecological and scientific significance in Japan. We evaluated cleaning protocols using sodium hypochlorite and sodium hydroxide to remove organic matter from the biomineralized structures of coral species. The objective was to improve structural integrity preservation, to enable more accurate chemical and structural analyses and contribute to coral restoration efforts. Our findings demonstrated that the most effective cleaning approach for the axial skeleton was the use of 0.4 M sodium hypochlorite (NaClO) solution, immersing the skeleton for 100 min at room temperature (approximately 20 °C). Meanwhile, for the sclerites, the experimental results indicated that the preferred cleaning technique was the use of either 0.1 M or 0.2 M sodium hypochlorite (NaClO) solution for 100 min at room temperature (approximately 20 °C). Additionally, centrifugation of the precious coral sclerites resulted in the clear separation of red and white sclerites. Lastly, we performed chemical analyses on both the skeletons and the sclerites, utilizing ICP-MS and ICP-AES technologies to gain an overview on the concentrations of the major and minor chemical elements that were present in both structures.
{"title":"Optimized cleaning and centrifugation of Japanese precious corals for enhanced sclerite classification and chemical profiling","authors":"Beatrice Coda , Asami Suzuki Mashio , Tenyu Tamura , Aya Mamorita , Kuo Hong Wong , Nozomu Iwasaki , Hiroshi Hasegawa","doi":"10.1016/j.seares.2025.102639","DOIUrl":"10.1016/j.seares.2025.102639","url":null,"abstract":"<div><div>The phylum Cnidaria is a vast taxonomic group that includes corals, sea anemones, and jellyfish. This study focuses on corals within the class Octocorallia, order Scleralcyonacea, and family Coralliidae, specifically <em>Corallium japonicum</em> and <em>Pleurocorallium konojoi</em>, which are of ecological and scientific significance in Japan. We evaluated cleaning protocols using sodium hypochlorite and sodium hydroxide to remove organic matter from the biomineralized structures of coral species. The objective was to improve structural integrity preservation, to enable more accurate chemical and structural analyses and contribute to coral restoration efforts. Our findings demonstrated that the most effective cleaning approach for the axial skeleton was the use of 0.4 M sodium hypochlorite (NaClO) solution, immersing the skeleton for 100 min at room temperature (approximately 20 °C). Meanwhile, for the sclerites, the experimental results indicated that the preferred cleaning technique was the use of either 0.1 M or 0.2 M sodium hypochlorite (NaClO) solution for 100 min at room temperature (approximately 20 °C). Additionally, centrifugation of the precious coral sclerites resulted in the clear separation of red and white sclerites. Lastly, we performed chemical analyses on both the skeletons and the sclerites, utilizing ICP-MS and ICP-AES technologies to gain an overview on the concentrations of the major and minor chemical elements that were present in both structures.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102639"},"PeriodicalIF":2.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-30DOI: 10.1016/j.seares.2025.102638
Qingxia Li , Zhonghua Ren , Yanli Lei , Qingyuan Hu , Shuaishuai Dong , Junfeng Shi
As a coastal semi-enclosed bay, Laizhou Bay has experienced significant ecological impacts due to intensified human influence. Benthic foraminifera, known for their sensitivity to environmental change, serve as excellent bioindicators for monitoring marine pollution and assessing ecological disturbances. In this study, we collected sediment samples from nineteen sites in Laizhou Bay, at water depths ranging from 3.76 to 16.88 m, and assessed foraminiferal diversity using eDNA metabarcoding. A total of 75 foraminiferal species were identified, nearly double the number reported in previous morphology-based studies. Among the 712 operational taxonomic units (OTUs) detected, 416 (∼58 % of the total) were classified as soft-shelled monothalamiids, which represented the highest proportion of OTUs across all sampling sites. This finding contrasts sharply with morphological surveys, which have typically reported multi-chambered hyaline taxa as the dominant component of benthic foraminifera in Laizhou Bay. The lack of significant Spearman correlations between alpha diversity and individual environmental parameters (depth, temperature, salinity, pH) suggested that foraminiferal diversity in this dynamic coastal setting was not governed by a single dominant factor. This implies that the community structure is more likely a result of the complex interplay of multiple environmental stressors and/or biological interactions. Furthermore, we used PICRUSt2 to predict metabolic functions of the benthic foraminiferal community, providing initial insights into its potential ecological roles. This study reveals the community structure and functional diversity of benthic foraminifera in Laizhou Bay and highlights the utility of eDNA metabarcoding as a highly sensitive tool in foraminiferal ecology.
{"title":"Assessing foraminiferal diversity in Laizhou Bay, Bohai Sea: Insights from eDNA metabarcoding","authors":"Qingxia Li , Zhonghua Ren , Yanli Lei , Qingyuan Hu , Shuaishuai Dong , Junfeng Shi","doi":"10.1016/j.seares.2025.102638","DOIUrl":"10.1016/j.seares.2025.102638","url":null,"abstract":"<div><div>As a coastal semi-enclosed bay, Laizhou Bay has experienced significant ecological impacts due to intensified human influence. Benthic foraminifera, known for their sensitivity to environmental change, serve as excellent bioindicators for monitoring marine pollution and assessing ecological disturbances. In this study, we collected sediment samples from nineteen sites in Laizhou Bay, at water depths ranging from 3.76 to 16.88 m, and assessed foraminiferal diversity using eDNA metabarcoding. A total of 75 foraminiferal species were identified, nearly double the number reported in previous morphology-based studies. Among the 712 operational taxonomic units (OTUs) detected, 416 (∼58 % of the total) were classified as soft-shelled monothalamiids, which represented the highest proportion of OTUs across all sampling sites. This finding contrasts sharply with morphological surveys, which have typically reported multi-chambered hyaline taxa as the dominant component of benthic foraminifera in Laizhou Bay. The lack of significant Spearman correlations between alpha diversity and individual environmental parameters (depth, temperature, salinity, pH) suggested that foraminiferal diversity in this dynamic coastal setting was not governed by a single dominant factor. This implies that the community structure is more likely a result of the complex interplay of multiple environmental stressors and/or biological interactions. Furthermore, we used PICRUSt2 to predict metabolic functions of the benthic foraminiferal community, providing initial insights into its potential ecological roles. This study reveals the community structure and functional diversity of benthic foraminifera in Laizhou Bay and highlights the utility of eDNA metabarcoding as a highly sensitive tool in foraminiferal ecology.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102638"},"PeriodicalIF":2.9,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1016/j.seares.2025.102636
Khadem Hussain Saeedi , Manjulatha Chapara , Jane Polyn P. Bejoc , S.K.K.A. Perera
Maintaining optimal water parameters in a biofloc technology system is essential for ensuring the healthy growth, development, and survival of cultured aquatic organisms. Fluctuations in these parameters can negatively impact their health, growth performance, and overall survival rate. This study compares the effects of two biofloc-producing bacteria, Bacillus cereus and Klebsiella pneumoniae, on water quality. The study was conducted under sterile laboratory conditions using water with 10 ppt salinity, and water quality parameters were assessed at 24-h intervals. Both bacterial strains were capable of forming bioflocs, though their performance varied over time. Bacillus cereus showed fluctuations in pH (6.5–8.9), whereas Klebsiella pneumoniae maintained relative stability (6–7.4). Both treatments elevated total alkalinity, but K. pneumoniae caused a sharp increase from 150 ppm to 310 ppm, differing from previous observations. B. cereus maintained stable total hardness and dissolved oxygen (2–5 mg/L) but caused elevated turbidity (819 NTU) after floc disintegration. Overall, bioflocs produced by B. cereus were more consistent and exhibited properties better suited for sustainable aquaculture under controlled conditions compared to those formed by K. pneumoniae.
{"title":"Boosting aquaculture resilience through biofloc-forming Bacteria: A comparative approach","authors":"Khadem Hussain Saeedi , Manjulatha Chapara , Jane Polyn P. Bejoc , S.K.K.A. Perera","doi":"10.1016/j.seares.2025.102636","DOIUrl":"10.1016/j.seares.2025.102636","url":null,"abstract":"<div><div>Maintaining optimal water parameters in a biofloc technology system is essential for ensuring the healthy growth, development, and survival of cultured aquatic organisms. Fluctuations in these parameters can negatively impact their health, growth performance, and overall survival rate. This study compares the effects of two biofloc-producing bacteria<em>, Bacillus cereus</em> and <em>Klebsiella pneumoniae</em>, on water quality. The study was conducted under sterile laboratory conditions using water with 10 ppt salinity, and water quality parameters were assessed at 24-h intervals. Both bacterial strains were capable of forming bioflocs, though their performance varied over time. <em>Bacillus cereus</em> showed fluctuations in pH (6.5–8.9), whereas <em>Klebsiella pneumoniae</em> maintained relative stability (6–7.4). Both treatments elevated total alkalinity, but <em>K. pneumoniae</em> caused a sharp increase from 150 ppm to 310 ppm, differing from previous observations. <em>B. cereus</em> maintained stable total hardness and dissolved oxygen (2–5 mg/L) but caused elevated turbidity (819 NTU) after floc disintegration. Overall, bioflocs produced by <em>B. cereus</em> were more consistent and exhibited properties better suited for sustainable aquaculture under controlled conditions compared to those formed by <em>K. pneumoniae.</em></div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102636"},"PeriodicalIF":2.9,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-15DOI: 10.1016/j.seares.2025.102637
Qin Xin , Zhaoyang Yang , Zhi Chen , Kenneth Lee
Recent offshore oil spill incidents have raised public concern over subsea blowouts in oil and gas operations. To improve and validate the accuracy of current oil spill models the scientific community has identified the need for additional experimental data under deepwater environmental conditions. This study intends to address this challenge through laboratory experiments simulating oil blowouts under various high-pressure subsea conditions. Results of critical constituents such as benzene, toluene, ethylbenzene, and xylenes (BTEX), total polycyclic aromatic hydrocarbons (PAHs), and total oil content in water columns improved our understanding of the chemical composition of deepwater oil spills. Microscopy analysis revealed that most oil droplets suspended in the water had diameters of less than 20 μm, constituting over 98 % of the total extractable oil mass. Dissolved BTEX and total PAHs accounted for less than 2 % of the total extractable oil. Our findings showed that as the blowout depth increased, the resulting oil concentration in water also increased. Water temperature and pressure significantly affected the retention of small oil droplets in the water at near-blowout locations. These results provide key insights into deepwater oil behavior and offer valuable data for testing and validation of developed and developing oil spill models.
{"title":"Unraveling deepwater oil blowouts at different depths: A coupled experimental and modeling study","authors":"Qin Xin , Zhaoyang Yang , Zhi Chen , Kenneth Lee","doi":"10.1016/j.seares.2025.102637","DOIUrl":"10.1016/j.seares.2025.102637","url":null,"abstract":"<div><div>Recent offshore oil spill incidents have raised public concern over subsea blowouts in oil and gas operations. To improve and validate the accuracy of current oil spill models the scientific community has identified the need for additional experimental data under deepwater environmental conditions. This study intends to address this challenge through laboratory experiments simulating oil blowouts under various high-pressure subsea conditions. Results of critical constituents such as benzene, toluene, ethylbenzene, and xylenes (BTEX), total polycyclic aromatic hydrocarbons (PAHs), and total oil content in water columns improved our understanding of the chemical composition of deepwater oil spills. Microscopy analysis revealed that most oil droplets suspended in the water had diameters of less than 20 μm, constituting over 98 % of the total extractable oil mass. Dissolved BTEX and total PAHs accounted for less than 2 % of the total extractable oil. Our findings showed that as the blowout depth increased, the resulting oil concentration in water also increased. Water temperature and pressure significantly affected the retention of small oil droplets in the water at near-blowout locations. These results provide key insights into deepwater oil behavior and offer valuable data for testing and validation of developed and developing oil spill models.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102637"},"PeriodicalIF":2.9,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-29DOI: 10.1016/j.seares.2025.102635
Wenyao Ma , Anzhou Cao , Zheng Guo , Jicai Zhang , Jinbao Song
Cold waves are a common meteorological phenomenon in the winter seasons, which often induce water surges that further threaten offshore safety. Zhejiang offshore is a typical region that frequently suffers from cold waves. Hence, understanding the characteristics and mechanisms of cold wave-induced surges in Zhejiang offshore is of great importance. Based on the Regional Ocean Modeling System, we simulate a total of 35 cold wave events and analyze their associated surges in Zhejiang offshore in the winter seasons from 2013 to 2023. The regional maximum surges induced by these cold wave events range between 0.23 and 1.02 m. According to the spatial pattern, the surges induced by the 35 cold wave events can be classified into three categories, which are characterized by high values in Hangzhou Bay, Taizhou-Wenzhou offshore, and nearly the entire coastal region of Zhejiang, respectively. Moreover, both the Kelvin wave and Ekman transport contribute to the surges induced by cold waves. Through a comparison with control experiments, it is found that the Kelvin wave is the dominant factor, which contributes more than 75 % to the surges, whereas the contribution of Ekman transport is less than 25 %.
{"title":"Numerical simulation of cold wave-induced surges in Zhejiang offshore from 2013 to 2023","authors":"Wenyao Ma , Anzhou Cao , Zheng Guo , Jicai Zhang , Jinbao Song","doi":"10.1016/j.seares.2025.102635","DOIUrl":"10.1016/j.seares.2025.102635","url":null,"abstract":"<div><div>Cold waves are a common meteorological phenomenon in the winter seasons, which often induce water surges that further threaten offshore safety. Zhejiang offshore is a typical region that frequently suffers from cold waves. Hence, understanding the characteristics and mechanisms of cold wave-induced surges in Zhejiang offshore is of great importance. Based on the Regional Ocean Modeling System, we simulate a total of 35 cold wave events and analyze their associated surges in Zhejiang offshore in the winter seasons from 2013 to 2023. The regional maximum surges induced by these cold wave events range between 0.23 and 1.02 m. According to the spatial pattern, the surges induced by the 35 cold wave events can be classified into three categories, which are characterized by high values in Hangzhou Bay, Taizhou-Wenzhou offshore, and nearly the entire coastal region of Zhejiang, respectively. Moreover, both the Kelvin wave and Ekman transport contribute to the surges induced by cold waves. Through a comparison with control experiments, it is found that the Kelvin wave is the dominant factor, which contributes more than 75 % to the surges, whereas the contribution of Ekman transport is less than 25 %.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102635"},"PeriodicalIF":2.9,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-26DOI: 10.1016/j.seares.2025.102634
Hannah Charan-Dixon , Patricia S. Lamker , Annika S. Arvin-Blaauw , Fetuao Nokise , Jolanda K. Brons , Ann-Christin Ziebell , Margot A.M. Maathuis , Ingrid Tulp , Britas Klemens Eriksson
Coastal marshes are an important habitat for many juvenile and small fishes, providing refuge and feeding opportunities. Understanding their diets can reveal more about the food web and the underlying factors impacting fish in these threatened habitats. We compared the diets of common goby (Pomatoschistus microps), three-spined stickleback (Gasterosteus aculeatus), Atlantic herring (Clupea harengus), European flounder (Platichthys flesus), European seabass (Dicentrarchus labrax), and European smelt (Osmerus eperlanus). These fish were collected seasonally from Dutch Wadden Sea salt marshes using fyke nets set at fixed stations from three locations with varying degrees of habitat modification. Comparing visual identification and DNA metabarcoding (CO1 region) of stomach contents revealed that DNA (relative read abundance) could be used semi-quantitatively for the dominant prey classes, but failed to detect some prey groups identified visually. The dominant prey of most fish species were the harpacticoid copepod Tachidius discipes, the amphipod Corophium volutator, and other crustaceans including Crangon crangon and Neomysis integer. Diets were affected by season, abiotic conditions, predator length, sampling location, and predator species. Gobies and stickleback shared similar diets, while the four other species displayed distinct diets. Flounder diets were characterised by benthic prey, herring diets consisted predominantly of copepods, smelt were generalists, while seabass diets predominantly contained Malacostraca. Fish diets at the least modified sampling location exhibited the greatest prey diversity. Our findings indicate that salt marshes provide a feeding habitat for the resident and migrant fish species studied, where the degree of marsh habitat modification may affect the marine food web.
{"title":"The molecularly and visually identified prey of fish in Dutch salt marshes","authors":"Hannah Charan-Dixon , Patricia S. Lamker , Annika S. Arvin-Blaauw , Fetuao Nokise , Jolanda K. Brons , Ann-Christin Ziebell , Margot A.M. Maathuis , Ingrid Tulp , Britas Klemens Eriksson","doi":"10.1016/j.seares.2025.102634","DOIUrl":"10.1016/j.seares.2025.102634","url":null,"abstract":"<div><div>Coastal marshes are an important habitat for many juvenile and small fishes, providing refuge and feeding opportunities. Understanding their diets can reveal more about the food web and the underlying factors impacting fish in these threatened habitats. We compared the diets of common goby (<em>Pomatoschistus microps</em>), three-spined stickleback (<em>Gasterosteus aculeatus</em>), Atlantic herring (<em>Clupea harengus</em>), European flounder (<em>Platichthys flesus</em>), European seabass (<em>Dicentrarchus labrax</em>), and European smelt (<em>Osmerus eperlanus</em>). These fish were collected seasonally from Dutch Wadden Sea salt marshes using fyke nets set at fixed stations from three locations with varying degrees of habitat modification. Comparing visual identification and DNA metabarcoding (CO1 region) of stomach contents revealed that DNA (relative read abundance) could be used semi-quantitatively for the dominant prey classes, but failed to detect some prey groups identified visually. The dominant prey of most fish species were the harpacticoid copepod <em>Tachidius discipes</em>, the amphipod <em>Corophium volutator</em>, and other crustaceans including <em>Crangon crangon</em> and <em>Neomysis integer.</em> Diets were affected by season, abiotic conditions, predator length, sampling location, and predator species. Gobies and stickleback shared similar diets, while the four other species displayed distinct diets. Flounder diets were characterised by benthic prey, herring diets consisted predominantly of copepods, smelt were generalists, while seabass diets predominantly contained Malacostraca. Fish diets at the least modified sampling location exhibited the greatest prey diversity. Our findings indicate that salt marshes provide a feeding habitat for the resident and migrant fish species studied, where the degree of marsh habitat modification may affect the marine food web.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102634"},"PeriodicalIF":2.9,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brown algae (Phaeophyceae) are the largest and most ecologically important group of marine algae, serving as habitat-forming organisms shaping coastal ecosystems. Understanding the feeding pressure exerted by herbivorous fishes on brown algae is essential for elucidating the dynamics of both coral reefs and algal forests. This study focused on the unique ability of brown algae to accumulate strontium (Sr) and tested the hypothesis that frequent consumption of brown algae elevates otolith Sr:calcium (Ca) ratios in herbivorous fishes. We analysed stomach contents and otolith Sr:Ca ratios in four sympatric species collected in southwestern Japan. Among three Kyphosus species, higher Sr:Ca ratios were associated with the frequency of brown-algae consumption. Notably, K. bigibbus, a brown-algae specialist, exhibited an exceptionally high otolith Sr:Ca ratio (0.12), far exceeding the common range of marine fishes (0.004–0.02). In K. vaigiensis, Sr:Ca ratios were high in areas where brown algae were frequently consumed, whereas they were moderate in areas where red algae were predominantly consumed. In K. cinerascens, only the latter pattern was observed. Both patterns are consistent with our hypothesis. Furthermore, the results suggest that K. bigibbus begin feeding on brown algae at approximately 1 year of age. By contrast, Siganus fuscescens exhibited Sr:Ca ratios within the common range, despite frequent feeding on brown algae, deviating from this hypothesis. Therefore, otolith Sr:Ca ratios may serve as a species-specific proxy for reconstructing feeding histories on brown algae, providing a novel tool for investigating herbivory over several decades in long-lived species.
{"title":"Potential application of otolith Sr:Ca ratios as indicators of brown-algae feeding histories in herbivorous fishes","authors":"Yoshimi Ogino , Keisuke Furumitsu , Takanari Kiriyama , Atsuko Yamaguchi","doi":"10.1016/j.seares.2025.102633","DOIUrl":"10.1016/j.seares.2025.102633","url":null,"abstract":"<div><div>Brown algae (Phaeophyceae) are the largest and most ecologically important group of marine algae, serving as habitat-forming organisms shaping coastal ecosystems. Understanding the feeding pressure exerted by herbivorous fishes on brown algae is essential for elucidating the dynamics of both coral reefs and algal forests. This study focused on the unique ability of brown algae to accumulate strontium (Sr) and tested the hypothesis that frequent consumption of brown algae elevates otolith Sr:calcium (Ca) ratios in herbivorous fishes. We analysed stomach contents and otolith Sr:Ca ratios in four sympatric species collected in southwestern Japan. Among three <em>Kyphosus</em> species, higher Sr:Ca ratios were associated with the frequency of brown-algae consumption. Notably, <em>K. bigibbus</em>, a brown-algae specialist, exhibited an exceptionally high otolith Sr:Ca ratio (0.12), far exceeding the common range of marine fishes (0.004–0.02). In <em>K. vaigiensis</em>, Sr:Ca ratios were high in areas where brown algae were frequently consumed, whereas they were moderate in areas where red algae were predominantly consumed. In <em>K. cinerascens</em>, only the latter pattern was observed. Both patterns are consistent with our hypothesis. Furthermore, the results suggest that <em>K. bigibbus</em> begin feeding on brown algae at approximately 1 year of age. By contrast, <em>Siganus fuscescens</em> exhibited Sr:Ca ratios within the common range, despite frequent feeding on brown algae, deviating from this hypothesis. Therefore, otolith Sr:Ca ratios may serve as a species-specific proxy for reconstructing feeding histories on brown algae, providing a novel tool for investigating herbivory over several decades in long-lived species.</div></div>","PeriodicalId":50056,"journal":{"name":"Journal of Sea Research","volume":"208 ","pages":"Article 102633"},"PeriodicalIF":2.9,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}