Pub Date : 2026-01-01Epub Date: 2025-11-19DOI: 10.1016/j.pocean.2025.103622
Xinyu Cao , Bangyi Tao , Chunli Liu , Libo Ai , Changpeng Li , Shiji Li , Xiaolong Li , Yize Zhang
The coastal waters in the northern Shandong Peninsula experienced a significant and persistent harmful algal bloom (HAB) event during the winter of 2021. This study aims to investigate the persistence and extent mechanisms of this large-scale HAB using the satellite-derived and reanalysis datasets, with a focus on the role of sea surface temperature (SST) fronts, known to influence nutrient accumulation and act as physical barriers that prevent the dispersion of algal blooms. The results showed the HAB in the winter of 2021 began in the coastal waters of the northern Dongying on October 27th near the Yellow River estuary and expanded southeastward, reaching the Yantai-Weihai coastal waters before subsiding by December 28. The anomalous intensification and early onset of the Yantai-Weihai Coastal Front (YWCF) played a crucial role in sustaining the HAB by creating a stable marine environment with enhanced nutrient concentrations. The HAB was first detected near the Yellow River estuary and subsequently spread along the coast, influenced by prevailing northwesterly winds, southeastward currents, and the impact of the YWCF. Our findings highlight the significant impact of the front on the development and persistence of HAB, suggesting that such oceanographic features could serve as key indicators for predicting future algal blooms in this region.
{"title":"Association of abnormal Yantai-Weihai coastal front with large-scale algal bloom in winter in the northern Shandong peninsula coastal waters","authors":"Xinyu Cao , Bangyi Tao , Chunli Liu , Libo Ai , Changpeng Li , Shiji Li , Xiaolong Li , Yize Zhang","doi":"10.1016/j.pocean.2025.103622","DOIUrl":"10.1016/j.pocean.2025.103622","url":null,"abstract":"<div><div>The coastal waters in the northern Shandong Peninsula experienced a significant and persistent harmful algal bloom (HAB) event during the winter of 2021. This study aims to investigate the persistence and extent mechanisms of this large-scale HAB using the satellite-derived and reanalysis datasets, with a focus on the role of sea surface temperature (SST) fronts, known to influence nutrient accumulation and act as physical barriers that prevent the dispersion of algal blooms. The results showed the HAB in the winter of 2021 began in the coastal waters of the northern Dongying on October 27th near the Yellow River estuary and expanded southeastward, reaching the Yantai-Weihai coastal waters before subsiding by December 28. The anomalous intensification and early onset of the Yantai-Weihai Coastal Front (YWCF) played a crucial role in sustaining the HAB by creating a stable marine environment with enhanced nutrient concentrations. The HAB was first detected near the Yellow River estuary and subsequently spread along the coast, influenced by prevailing northwesterly winds, southeastward currents, and the impact of the YWCF. Our findings highlight the significant impact of the front on the development and persistence of HAB, suggesting that such oceanographic features could serve as key indicators for predicting future algal blooms in this region.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103622"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-11-10DOI: 10.1016/j.pocean.2025.103618
Juan Cruz Carbajal , Jacobo Martin , Maité P. Latorre , Facundo Barrera , Julieta Kaminsky , Andreana M. Cadaillón , Martin Saraceno
The continental margin south of Tierra del Fuego and the adjacent northwest Scotia Sea serves as a transition area between the Southern Chilean and the Southern Argentinian Patagonian ecosystems. Bounded by the Northern Boundary and the Sub-Antarctic Front of the Antarctic Circumpolar Current, circulation in this area transports water and properties from the Pacific to the Atlantic Ocean, influencing the ecology of southern ecosystems. The narrow continental margin hosts a network of submarine canyons, including the deeply incised Sloggett Canyon, which intercepts and likely modifies the along-shelf-break current. Combining in-situ hydrographic measurements from a multidisciplinary cruise conducted in November 2022 with coincident global atmospheric and oceanic reanalysis, we investigate the water masses and dynamics in this understudied area. Analysis of upper ocean variability exhibited two distinct phases associated with Ekman dynamics: a relaxation phase characterized by calm wind conditions, a weak along-shelf-break current (45 cm s−1), and well-defined mesoscale activity along the Sub-Antarctic Front, and an intensification phase marked by strong wind conditions, an intense along-shelf-break current (over 80 cm s−1), and increased meander activity offshore. Despite limited field data, we document a remarkable wind-driven upwelling episode in the upper portion of the Sloggett Canyon during the intensification phase, highlighting the role of wind stress and canyon geomorphology as possible mechanisms driving upwelling events. This episode was also coincident with near-surface chlorophyll-a maxima, emphasizing the canyon’s relevance as a biological hotspot. Our findings raise new questions, highlighting the need for longer time-series studies and more dedicated multidisciplinary research efforts.
火地岛南部的大陆边缘和邻近的西北斯科舍海是智利南部和阿根廷南部巴塔哥尼亚生态系统之间的过渡区域。受南极环极流的北部边界和亚南极锋的限制，该地区的环流将水和物质从太平洋输送到大西洋，影响了南部生态系统的生态。狭窄的大陆边缘拥有海底峡谷网络，包括深切的斯洛格特峡谷，它拦截并可能改变沿大陆架断裂的水流。结合2022年11月进行的多学科巡航的现场水文测量和同步的全球大气和海洋再分析，我们研究了这一研究不足地区的水团和动力学。上层海洋变率分析显示了与Ekman动力学相关的两个不同阶段：以平静风条件为特征的松弛阶段，弱的沿大陆架断裂流（45 cm s - 1），以及沿亚南极锋明确的中尺度活动；以及以强风条件为特征的强化阶段，强的沿大陆架断裂流（超过80 cm s - 1），以及近海蜿蜒活动的增加。尽管野外资料有限，但我们在加剧阶段记录了一个显著的风驱动上升流事件，突出了风应力和峡谷地貌作为驱动上升流事件的可能机制的作用。这一事件也与近地表叶绿素a的最大值一致，强调了峡谷作为生物热点的相关性。我们的发现提出了新的问题，强调需要更长的时间序列研究和更专注的多学科研究努力。
{"title":"Circulation and wind-driven processes in the Yaganes area","authors":"Juan Cruz Carbajal , Jacobo Martin , Maité P. Latorre , Facundo Barrera , Julieta Kaminsky , Andreana M. Cadaillón , Martin Saraceno","doi":"10.1016/j.pocean.2025.103618","DOIUrl":"10.1016/j.pocean.2025.103618","url":null,"abstract":"<div><div>The continental margin south of Tierra del Fuego and the adjacent northwest Scotia Sea serves as a transition area between the Southern Chilean and the Southern Argentinian Patagonian ecosystems. Bounded by the Northern Boundary and the Sub-Antarctic Front of the Antarctic Circumpolar Current, circulation in this area transports water and properties from the Pacific to the Atlantic Ocean, influencing the ecology of southern ecosystems. The narrow continental margin hosts a network of submarine canyons, including the deeply incised Sloggett Canyon, which intercepts and likely modifies the along-shelf-break current. Combining <em>in-situ</em> hydrographic measurements from a multidisciplinary cruise conducted in November 2022 with coincident global atmospheric and oceanic reanalysis, we investigate the water masses and dynamics in this understudied area. Analysis of upper ocean variability exhibited two distinct phases associated with Ekman dynamics: a relaxation phase characterized by calm wind conditions, a weak along-shelf-break current (45 cm s<sup>−1</sup>), and well-defined mesoscale activity along the Sub-Antarctic Front, and an intensification phase marked by strong wind conditions, an intense along-shelf-break current (over 80 cm s<sup>−1</sup>), and increased meander activity offshore. Despite limited field data, we document a remarkable wind-driven upwelling episode in the upper portion of the Sloggett Canyon during the intensification phase, highlighting the role of wind stress and canyon geomorphology as possible mechanisms driving upwelling events. This episode was also coincident with near-surface chlorophyll-a maxima, emphasizing the canyon’s relevance as a biological hotspot. Our findings raise new questions, highlighting the need for longer time-series studies and more dedicated multidisciplinary research efforts.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103618"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145485316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-11-17DOI: 10.1016/j.pocean.2025.103623
Henry Knauber, Angelika Brandt, Torben Riehl
The vast extent of the deep-sea floor raises questions about the connectivity and extent of benthic biodiversity, while simultaneously rendering studies on biogeographic distribution patterns and population genetics difficult due to underexploration. This study investigates the biodiversity, connectivity and biogeography of janiroidean isopods from the relatively well-studied North Pacific (NP), a taxon often considered to mostly comprise poor dispersers. This contribution focuses on janiroidean species recorded from the NP abyssal plains interconnecting the regions surrounding the eastern Aleutian Trench (AT), the Kuril-Kamchatka Trench (KKT), and the Japan Trench (JT). It has the goal to investigate faunal connectivity and to infer potential influences of Isolation by Distance. The study is centered around the epibenthic Haploniscidae Hansen, 1916 and the endobenthic Macrostylidae Hansen, 1916, analyzing their distributional ranges as well as molecular structuring and differentiation patterns using an extensive dataset of 16S rRNA sequences and COI barcodes. Species delimitation analyses revealed the existence of multiple new “cryptic” species amongst established taxa in both families, resulting in much more diverse biodiversity patterns across the whole NP than initially assumed based on morphology alone. While only a single macrostylid species showed a distribution spanning from the abyssal plains of the AT region to the ones of the JT/KKT regions, multiple haploniscid species reportedly possess ranges of several thousand kilometers across the abyssal plains of the NP. Isolation by Distance was inferred within most species appearing in at least two of the three greater trench regions investigated. These observed differences in biogeography and the inferred molecular variation patterns can be explained by different life-history strategies.
{"title":"Traversing the North Pacific: Biogeography and connectivity patterns of deep-sea isopods across three trench systems","authors":"Henry Knauber, Angelika Brandt, Torben Riehl","doi":"10.1016/j.pocean.2025.103623","DOIUrl":"10.1016/j.pocean.2025.103623","url":null,"abstract":"<div><div>The vast extent of the deep-sea floor raises questions about the connectivity and extent of benthic biodiversity, while simultaneously rendering studies on biogeographic distribution patterns and population genetics difficult due to underexploration. This study investigates the biodiversity, connectivity and biogeography of janiroidean isopods from the relatively well-studied North Pacific (NP), a taxon often considered to mostly comprise poor dispersers. This contribution focuses on janiroidean species recorded from the NP abyssal plains interconnecting the regions surrounding the eastern Aleutian Trench (AT), the Kuril-Kamchatka Trench (KKT), and the Japan Trench (JT). It has the goal to investigate faunal connectivity and to infer potential influences of Isolation by Distance. The study is centered around the epibenthic Haploniscidae <span><span>Hansen, 1916</span></span> and the endobenthic Macrostylidae <span><span>Hansen, 1916</span></span>, analyzing their distributional ranges as well as molecular structuring and differentiation patterns using an extensive dataset of 16S rRNA sequences and COI barcodes. Species delimitation analyses revealed the existence of multiple new “cryptic” species amongst established taxa in both families, resulting in much more diverse biodiversity patterns across the whole NP than initially assumed based on morphology alone. While only a single macrostylid species showed a distribution spanning from the abyssal plains of the AT region to the ones of the JT/KKT regions, multiple haploniscid species reportedly possess ranges of several thousand kilometers across the abyssal plains of the NP. Isolation by Distance was inferred within most species appearing in at least two of the three greater trench regions investigated. These observed differences in biogeography and the inferred molecular variation patterns can be explained by different life-history strategies.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103623"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145554315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-10-27DOI: 10.1016/j.pocean.2025.103601
Joanna Zanker , Emma F. Young , Paul Brickle , Ivan Haigh
Climate change is impacting high-latitude fjord circulation with consequences for the transport of marine biota essential for supporting local ecosystems. Currently, little is understood about oceanographic variability in sub-Antarctic island fjords such as Cumberland Bay, the largest fjord on the island of South Georgia in the Southern Ocean. Cumberland Bay is split into two arms, West Bay and East Bay, and is a key spawning site for the ecologically and commercially important mackerel icefish. Through the use of a high-resolution three-dimensional hydrodynamic model, the seasonal cycle in Cumberland Bay is found to be driven by a combination of boundary forcing influencing shelf exchange and deep inflow, atmospheric forcing influencing near surface temperatures and flows and freshwater forcing via subglacial discharge driving upwelling and strong outflow. There is a complex three-dimensional flow structure with a high degree of variability on short timescales due to wind forcing. Using model flow fields to drive an individual-based model parameterised for mackerel icefish larvae spawned in Cumberland Bay, we identify West Bay as a key retention zone. Successful retention of mackerel icefish larvae is found to be sensitive to complex circulation patterns driven by winds, freshwater and fjord-shelf exchanges and to changes in physical processes linked to climate change such as meltwater runoff and föhn wind events. This study highlights the importance of oceanographic variability in influencing ecological processes in fjords in our changing climate.
{"title":"Sub-Antarctic fjord circulation and associated icefish larval retention in a changing climate","authors":"Joanna Zanker , Emma F. Young , Paul Brickle , Ivan Haigh","doi":"10.1016/j.pocean.2025.103601","DOIUrl":"10.1016/j.pocean.2025.103601","url":null,"abstract":"<div><div>Climate change is impacting high-latitude fjord circulation with consequences for the transport of marine biota essential for supporting local ecosystems. Currently, little is understood about oceanographic variability in sub-Antarctic island fjords such as Cumberland Bay, the largest fjord on the island of South Georgia in the Southern Ocean. Cumberland Bay is split into two arms, West Bay and East Bay, and is a key spawning site for the ecologically and commercially important mackerel icefish. Through the use of a high-resolution three-dimensional hydrodynamic model, the seasonal cycle in Cumberland Bay is found to be driven by a combination of boundary forcing influencing shelf exchange and deep inflow, atmospheric forcing influencing near surface temperatures and flows and freshwater forcing via subglacial discharge driving upwelling and strong outflow. There is a complex three-dimensional flow structure with a high degree of variability on short timescales due to wind forcing. Using model flow fields to drive an individual-based model parameterised for mackerel icefish larvae spawned in Cumberland Bay, we identify West Bay as a key retention zone. Successful retention of mackerel icefish larvae is found to be sensitive to complex circulation patterns driven by winds, freshwater and fjord-shelf exchanges and to changes in physical processes linked to climate change such as meltwater runoff and föhn wind events. This study highlights the importance of oceanographic variability in influencing ecological processes in fjords in our changing climate.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103601"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-10-05DOI: 10.1016/j.pocean.2025.103584
C. Tracy Shaw , Jennifer L. Fisher
Euphausiids are essential prey in the northeast Pacific, where changes in their distribution, biomass, and species composition can impact higher trophic levels. We used an 18-year (2001–2018) high-frequency time-series from the Newport Hydrographic Line (44.6°N) to investigate how temperature drives changes in cross-shelf distribution and how both temperature and productivity influence seasonal and interannual differences in euphausiid density, biomass, and length. Three species occurred throughout the study: Euphausia pacifica was most abundant (85%), followed by Thysanoessa spinifera (14 %), and Thysanoessa inspinata (1 %). E. pacifica were consistently associated with shelf break and slope habitats. T. spinifera abundances were generally similar at all stations but notably higher inshore during cool conditions. Temperature was inversely related to E. pacifica and T. spinifera density, biomass, and adult length, and adults of both species were nearly absent during anomalously warm ocean conditions. There were strong cross-shelf gradients in length for adult E. pacifica and T. spinifera, with consistently smaller individuals found at offshore stations and larger adults occurring at cooler more productive inshore stations. In warmer years, adults of both species were consistently smaller across all stations. Our results demonstrate euphausiid species-specific responses to climate variability suggesting reduced prey resources for higher trophic levels during warm ocean conditions.
{"title":"Climate variability drives species-specific changes in euphausiid biomass and length during a long-term study off Newport, Oregon, USA (2001–2018)","authors":"C. Tracy Shaw , Jennifer L. Fisher","doi":"10.1016/j.pocean.2025.103584","DOIUrl":"10.1016/j.pocean.2025.103584","url":null,"abstract":"<div><div>Euphausiids are essential prey in the northeast Pacific, where changes in their distribution, biomass, and species composition can impact higher trophic levels. We used an 18-year (2001–2018) high-frequency time-series from the Newport Hydrographic Line (44.6°N) to investigate how temperature drives changes in cross-shelf distribution and how both temperature and productivity influence seasonal and interannual differences in euphausiid density, biomass, and length. Three species occurred throughout the study: <em>Euphausia pacifica</em> was most abundant (85%), followed by <em>Thysanoessa spinifera</em> (14 %), and <em>Thysanoessa inspinata</em> (1 %). <em>E. pacifica</em> were consistently associated with shelf break and slope habitats. <em>T. spinifera</em> abundances were generally similar at all stations but notably higher inshore during cool conditions. Temperature was inversely related to <em>E. pacifica</em> and <em>T. spinifera</em> density, biomass, and adult length, and adults of both species were nearly absent during anomalously warm ocean conditions. There were strong cross-shelf gradients in length for adult <em>E. pacifica</em> and <em>T. spinifera,</em> with consistently smaller individuals found at offshore stations and larger adults occurring at cooler more productive inshore stations. In warmer years, adults of both species were consistently smaller across all stations. Our results demonstrate euphausiid species-specific responses to climate variability suggesting reduced prey resources for higher trophic levels during warm ocean conditions.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103584"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-11-03DOI: 10.1016/j.pocean.2025.103616
Katharine T. Bigham , Ashley A. Rowden , Daniel Leduc , David A. Bowden
Sediment density flows are complex events that contain multiple flow types which can transport massive amounts of sediment across large distances. Turbidity flows are believed to have profound and lasting impacts on benthic communities in the deep sea. A canyon-flushing event in Kaikōura Canyon, New Zealand, triggered by the 2016 Mw 7.8 Kaikōura Earthquake, included significant submarine mass wasting, debris, and turbidity flows, and provided an opportunity to investigate the effects of this disturbance. Previous studies have analysed the mega-, macro-, and meiofauna community structure, before and after the event using a time series of imagery and sediment cores. Additionally, community recovery was investigated in relation to changes in the physical characteristics of the habitat, using environmental variables from images and bathymetric variables and sediment cores. However, no attempt has been made to examine the overall community response to turbidity flow disturbance or to consider interactions between the different size classes. To address this gap, the data and results for each size class in Kaikōura Canyon were synthesised here with an emphasis on assessing the overall deep-sea benthic community response, and predicting time to recovery for the full community in Kaikōura Canyon. Overall, the benthic community in Kaikoura Canyon appears to be resilient to the disturbance with meiofauna showing the fastest recovery time followed by megafauna and then macrofauna. Differences in the life-history characteristics of mega-, macro- and meiofauna, as well as various interactions among the faunal size class communities, likely have influenced the recovery patterns observed.
{"title":"Integrated understanding of benthic community response to disturbance from an earthquake-triggered turbidity flow event","authors":"Katharine T. Bigham , Ashley A. Rowden , Daniel Leduc , David A. Bowden","doi":"10.1016/j.pocean.2025.103616","DOIUrl":"10.1016/j.pocean.2025.103616","url":null,"abstract":"<div><div>Sediment density flows are complex events that contain multiple flow types which can transport massive amounts of sediment across large distances. Turbidity flows are believed to have profound and lasting impacts on benthic communities in the deep sea. A canyon-flushing event in Kaikōura Canyon, New Zealand, triggered by the 2016 M<sub>w</sub> 7.8 Kaikōura Earthquake, included significant submarine mass wasting, debris, and turbidity flows, and provided an opportunity to investigate the effects of this disturbance. Previous studies have analysed the mega-, macro-, and meiofauna community structure, before and after the event using a time series of imagery and sediment cores. Additionally, community recovery was investigated in relation to changes in the physical characteristics of the habitat, using environmental variables from images and bathymetric variables and sediment cores. However, no attempt has been made to examine the overall community response to turbidity flow disturbance or to consider interactions between the different size classes. To address this gap, the data and results for each size class in Kaikōura Canyon were synthesised here with an emphasis on assessing the overall deep-sea benthic community response, and predicting time to recovery for the full community in Kaikōura Canyon. Overall, the benthic community in Kaikoura Canyon appears to be resilient to the disturbance with meiofauna showing the fastest recovery time followed by megafauna and then macrofauna. Differences in the life-history characteristics of mega-, macro- and meiofauna, as well as various interactions among the faunal size class communities, likely have influenced the recovery patterns observed.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103616"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145427973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-12-11DOI: 10.1016/j.pocean.2025.103648
Yan Jia , Weifeng (Gordon) Zhang , Steven J. Lentz , Nathaniel R. Mollica , Gonzalo Pérez-Rosales , Anne L. Cohen
Majuro, a coral atoll in the Central Pacific, consists of rim reefs and low-lying islands surrounding a lagoon 40 km long, 10 km wide, and averaging 35 m deep. The lagoon is connected to the open ocean through shallow reef flats along the northwestern and western rims, and a 40 m deep channel in the northern rim. Spatiotemporal variability of lagoon hydrodynamics is characterized with a 15-year (2009–2023) simulation of a high-resolution ocean-wave coupled model. In winter, strong northeasterly winds generate high waves that approach the atoll from the northeast, breaking on the reef flats to the northwest of the lagoon, and driving strong flow across the reef flats into the lagoon. The wave- and wind-driven flows together forms a counterclockwise vortex pattern over the entire water column in the western lagoon, leading to a strong barotropic outflow through the deep channel. The lagoon circulation in winter is thus laterally sheared. In summer with weaker northeasterly winds, the wave-driven overflow across the northwestern reef flats weakens. In fall, episodic westerly winds drive open ocean water across the western reef flat into the lagoon. The weak winds in summer and fall allow the development of vertically sheared flows in the lagoon, with surface flows generally aligned with winds and subsurface flows opposing winds. This study demonstrates that lagoon circulation, varying over the scale of O(100 m-10 km), differ drastically from that in the surrounding ocean, can directly affect coral reef communities, and is thus critical for effective marine resource management.
Plain language summary.
Majuro Atoll, Republic of Marshall Islands, is located in the Central Pacific and is made up of rim reefs and islands surrounding lagoon of 40 km long and 10 km wide. The lagoon is separated from the open ocean by shallow rim reefs on its north and west sides and an island chain on its south and east sides. The deep part of the lagoon is connected to the open ocean by a 40-m deep channel in the north. This work uses a high-resolution computer model to simulate flows and temperature conditions in 2009–2023 and study how the lagoon flow conditions change in space and time. The model shows that the lagoon flows are influenced not only by winds throughout the year but also by high waves approaching the atoll from the northeast. As the waves break on the north shore of the atoll, they push a significant amount of water into the lagoon. Some of the lagoon water then flow out into the open ocean through the deep channel. Circulation in the lagoon changes dramatically with the winds. All these flow changes in the lagoon cause the lagoon environment to differ significantly from the open ocean. Such fine-scale changes in lagoon conditions likely affect coral health, influence their responses to climate change, and provide key information for effective coral reef conservation and protection.
{"title":"Fine-scale hydrodynamic variability at Majuro Atoll, Republic of the Marshall islands. Part I: Flow variability","authors":"Yan Jia , Weifeng (Gordon) Zhang , Steven J. Lentz , Nathaniel R. Mollica , Gonzalo Pérez-Rosales , Anne L. Cohen","doi":"10.1016/j.pocean.2025.103648","DOIUrl":"10.1016/j.pocean.2025.103648","url":null,"abstract":"<div><div>Majuro, a coral atoll in the Central Pacific, consists of rim reefs and low-lying islands surrounding a lagoon 40 km long, 10 km wide, and averaging 35 m deep. The lagoon is connected to the open ocean through shallow reef flats along the northwestern and western rims, and a 40 m deep channel in the northern rim. Spatiotemporal variability of lagoon hydrodynamics is characterized with a 15-year (2009–2023) simulation of a high-resolution ocean-wave coupled model. In winter, strong northeasterly winds generate high waves that approach the atoll from the northeast, breaking on the reef flats to the northwest of the lagoon, and driving strong flow across the reef flats into the lagoon. The wave- and wind-driven flows together forms a counterclockwise vortex pattern over the entire water column in the western lagoon, leading to a strong barotropic outflow through the deep channel. The lagoon circulation in winter is thus <em>laterally sheared</em>. In summer with weaker northeasterly winds, the wave-driven overflow across the northwestern reef flats weakens. In fall, episodic westerly winds drive open ocean water across the western reef flat into the lagoon. The weak winds in summer and fall allow the development of <em>vertically sheared</em> flows in the lagoon, with surface flows generally aligned with winds and subsurface flows opposing winds. This study demonstrates that lagoon circulation, varying over the scale of O(100 m-10 km), differ drastically from that in the surrounding ocean, can directly affect coral reef communities, and is thus critical for effective marine resource management.</div><div>Plain language summary.</div><div>Majuro Atoll, Republic of Marshall Islands, is located in the Central Pacific and is made up of rim reefs and islands surrounding lagoon of 40 km long and 10 km wide. The lagoon is separated from the open ocean by shallow rim reefs on its north and west sides and an island chain on its south and east sides. The deep part of the lagoon is connected to the open ocean by a 40-m deep channel in the north. This work uses a high-resolution computer model to simulate flows and temperature conditions in 2009–2023 and study how the lagoon flow conditions change in space and time. The model shows that the lagoon flows are influenced not only by winds throughout the year but also by high waves approaching the atoll from the northeast. As the waves break on the north shore of the atoll, they push a significant amount of water into the lagoon. Some of the lagoon water then flow out into the open ocean through the deep channel. Circulation in the lagoon changes dramatically with the winds. All these flow changes in the lagoon cause the lagoon environment to differ significantly from the open ocean. Such fine-scale changes in lagoon conditions likely affect coral health, influence their responses to climate change, and provide key information for effective coral reef conservation and protection.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103648"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145732113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-12-31DOI: 10.1016/j.pocean.2025.103663
Yifeng Shi , Wenzhe Xu , Rui Gu , Wenxin Zhou , Guicheng Zhang , Yu Guo , Yiyan Guo , Jun Sun
In coastal benthic ecosystems, bioturbation is one of the most important ecosystem functions. However, the understanding of how this function changes under anthropogenic and climatic stresses is still insufficient. In this study, we quantified the potential bioturbation capacity of macrobenthos in Bohai Bay based on their traits such as the type of sediment modification and motility. In terms of biodiversity, the nearshore biodiversity was low in the wet season and recovered rapidly in the dry season. The biodiversity of offshore communities was relatively stable. In terms of bioturbation potential, the functional stability of the nearshore community was significantly lower than that of the offshore community, as evidenced by the fact that the nearshore bioturbation potential was severely suppressed in the wet season and released in the dry season. Nearshore bioturbation potential rose from a mean of 51.2 to 231.9, whereas offshore values increased more modestly (88.3 to 124.2). The increase in polychaetes largely supported the restoration of diversity and function in the nearshore community in the dry season, especially for some potentially large-bodied species. Additionally, the species dominating the bioturbation in the nearshore community in the dry season were very similar to those in the offshore community, implying that the dispersal of functionally important species in adjacent waters is an important mechanism for the functional recovery of the local community. Although functional recovery in the nearshore region has been faster than expected. However, seasonal fluctuations in the huge bioturbation potential of this region raised our unease about seasonal impairment of benthic function. These findings provide insights into the resilience of benthic functions under eutrophication stress.
{"title":"Spatial and seasonal variation in bioturbation potential of Macrobenthic communities in Bohai Bay","authors":"Yifeng Shi , Wenzhe Xu , Rui Gu , Wenxin Zhou , Guicheng Zhang , Yu Guo , Yiyan Guo , Jun Sun","doi":"10.1016/j.pocean.2025.103663","DOIUrl":"10.1016/j.pocean.2025.103663","url":null,"abstract":"<div><div>In coastal benthic ecosystems, bioturbation is one of the most important ecosystem functions. However, the understanding of how this function changes under anthropogenic and climatic stresses is still insufficient. In this study, we quantified the potential bioturbation capacity of macrobenthos in Bohai Bay based on their traits such as the type of sediment modification and motility. In terms of biodiversity, the nearshore biodiversity was low in the wet season and recovered rapidly in the dry season. The biodiversity of offshore communities was relatively stable. In terms of bioturbation potential, the functional stability of the nearshore community was significantly lower than that of the offshore community, as evidenced by the fact that the nearshore bioturbation potential was severely suppressed in the wet season and released in the dry season. Nearshore bioturbation potential rose from a mean of 51.2 to 231.9, whereas offshore values increased more modestly (88.3 to 124.2). The increase in polychaetes largely supported the restoration of diversity and function in the nearshore community in the dry season, especially for some potentially large-bodied species. Additionally, the species dominating the bioturbation in the nearshore community in the dry season were very similar to those in the offshore community, implying that the dispersal of functionally important species in adjacent waters is an important mechanism for the functional recovery of the local community. Although functional recovery in the nearshore region has been faster than expected. However, seasonal fluctuations in the huge bioturbation potential of this region raised our unease about seasonal impairment of benthic function. These findings provide insights into the resilience of benthic functions under eutrophication stress.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103663"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-10-01DOI: 10.1016/j.pocean.2025.103582
Zhen Lin , Shin-ichi Ito , Alan Baudron , Christine Stawitz , Takeshi Tomiyama , Kunihiro Fujiwara , Paul D. Spencer , John Morrongiello
Fish body size is a crucial biological trait that has implications for ecology, economics, and food security. In recent years, widespread reports of large-scale fish size reduction have been variously attributed to warming temperatures, shifts in density-dependent growth, changes in prey availability, and fishing pressure. Disentangling the relative importance of these factors is vital for understanding fluctuations in fish size in complex marine ecosystems. This study used a state-space approach to explore weight deviation dynamics of 16 stocks spanning over 35 years (1982–2018, six stocks) and over 20 years (∼1995–2018, 10 stocks) in the western North Pacific (WNP). Weight anomalies were calculated separately for the youngest age (age 0 for most stocks) and for the older ages (age ≥ 1 for most stocks). We explored combinations of covariates that tested whether weight anomalies were related to species competition, environmental factors and fishing mortality. We found that intra- and interspecies competition was particularly influential, affecting 75 % of stocks. The importance of intraspecific competition became more pronounced as fish aged. Though generally less influential than competition, stratification strength, which was primarily driven by surface water temperatures, affected weight deviations for approximately 50 % of stocks at older life stages. Fishing pressure exerted a negative impact for 25 % of stocks. Our findings highlight the critical role of species competition in shaping fish size anomalies in the wild, along with the influence of environmental conditions and fishing mortality, and emphasize the need to integrate these size-driving mechanisms into traditional stock assessments to improve fisheries management.
{"title":"A state-space approach reveals that competition drives variation in fish body weight, with influences from environmental conditions and fishing pressure","authors":"Zhen Lin , Shin-ichi Ito , Alan Baudron , Christine Stawitz , Takeshi Tomiyama , Kunihiro Fujiwara , Paul D. Spencer , John Morrongiello","doi":"10.1016/j.pocean.2025.103582","DOIUrl":"10.1016/j.pocean.2025.103582","url":null,"abstract":"<div><div>Fish body size is a crucial biological trait that has implications for ecology, economics, and food security. In recent years, widespread reports of large-scale fish size reduction have been variously attributed to warming temperatures, shifts in density-dependent growth, changes in prey availability, and fishing pressure. Disentangling the relative importance of these factors is vital for understanding fluctuations in fish size in complex marine ecosystems. This study used a state-space approach to explore weight deviation dynamics of 16 stocks spanning over 35 years (1982–2018, six stocks) and over 20 years (∼1995–2018, 10 stocks) in the western North Pacific (WNP). Weight anomalies were calculated separately for the youngest age (age 0 for most stocks) and for the older ages (age ≥ 1 for most stocks). We explored combinations of covariates that tested whether weight anomalies were related to species competition, environmental factors and fishing mortality. We found that intra- and interspecies competition was particularly influential, affecting 75 % of stocks. The importance of intraspecific competition became more pronounced as fish aged. Though generally less influential than competition, stratification strength, which was primarily driven by surface water temperatures, affected weight deviations for approximately 50 % of stocks at older life stages. Fishing pressure exerted a negative impact for 25 % of stocks. Our findings highlight the critical role of species competition in shaping fish size anomalies in the wild, along with the influence of environmental conditions and fishing mortality, and emphasize the need to integrate these size-driving mechanisms into traditional stock assessments to improve fisheries management.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103582"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01Epub Date: 2025-12-11DOI: 10.1016/j.pocean.2025.103650
Y.R. Mu , Y.S. Xu , J.H. Park
Near-inertial internal waves (NIIWs) play a central role in ocean mixing and energy transfer, and understanding their local variability is essential for quantifying ocean energetics. This study investigates the local drivers of NIIW variability in the Kuroshio Extension System Study (KESS) region using observations from a Current-and Pressure-sensor-equipped Inverted Echo Sounder (CPIES) array deployed over a 600 km by 600 km area, assuming negligible net NIIW flux. We developed an empirical model to quantify the contributions of wind-induced near-inertial energy flux (WNEF), mixed layer depth (MLD), and relative vorticity (), which have dominant influences on NIIW variability, accounting for 39 %, 41 %, and 20 % of the variability, respectively. WNEF and MLD positively correlate with NIIW energy, while shows a negative correlation. These findings highlight the significance of local processes in modulating NIIW energy and improving our understanding of ocean mixing dynamics by transitioning from qualitative to quantitative analysis.
近惯性内波（NIIWs）在海洋混合和能量传递中起着核心作用，了解其局部变率对海洋能量学的量化至关重要。本文研究了黑潮延伸系统研究（KESS）区域NIIW变率的局部驱动因素，利用部署在600 km × 600 km区域的配备电流和压力传感器的反向回声测深仪（CPIES）阵列的观测数据，假设净NIIW通量可以忽略不计。我们建立了一个经验模型来量化风致近惯性能量通量（WNEF）、混合层深度（MLD）和相对涡度（ζ）对NIIW变率的贡献，它们对NIIW变率的影响占主导地位，分别占39%、41%和20%。WNEF和MLD与NIIW能量呈正相关，ζ呈负相关。这些发现强调了局部过程在调节NIIW能量方面的重要性，并通过从定性分析过渡到定量分析来提高我们对海洋混合动力学的理解。
{"title":"Variability of near-inertial internal wave energy in the Kuroshio extension from CPIES array observations","authors":"Y.R. Mu , Y.S. Xu , J.H. Park","doi":"10.1016/j.pocean.2025.103650","DOIUrl":"10.1016/j.pocean.2025.103650","url":null,"abstract":"<div><div>Near-inertial internal waves (NIIWs) play a central role in ocean mixing and energy transfer, and understanding their local variability is essential for quantifying ocean energetics. This study investigates the local drivers of NIIW variability in the Kuroshio Extension System Study (KESS) region using observations from a Current-and Pressure-sensor-equipped Inverted Echo Sounder (CPIES) array deployed over a 600 km by 600 km area, assuming negligible net NIIW flux. We developed an empirical model to quantify the contributions of wind-induced near-inertial energy flux (WNEF), mixed layer depth (MLD), and relative vorticity (<span><math><mrow><mi>ζ</mi></mrow></math></span>), which have dominant influences on NIIW variability, accounting for 39 %, 41 %, and 20 % of the variability, respectively. WNEF and MLD positively correlate with NIIW energy, while <span><math><mrow><mi>ζ</mi></mrow></math></span> shows a negative correlation. These findings highlight the significance of local processes in modulating NIIW energy and improving our understanding of ocean mixing dynamics by transitioning from qualitative to quantitative analysis.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103650"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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