Deep-sea Research Part Ii-topical Studies in Oceanography最新文献

Unveiling marine heatwave dynamics in the Persian /Arabian Gulf and the Gulf of Oman: A spatio-temporal analysis and future projections 揭示波斯湾/阿拉伯湾和阿曼湾的海洋热浪动态：时空分析和未来预测

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-11-08 DOI: 10.1016/j.dsr2.2024.105435

Mohamed Shaltout , Ahmed Eladawy

{"title":"Unveiling marine heatwave dynamics in the Persian /Arabian Gulf and the Gulf of Oman: A spatio-temporal analysis and future projections","authors":"Mohamed Shaltout , Ahmed Eladawy","doi":"10.1016/j.dsr2.2024.105435","DOIUrl":"10.1016/j.dsr2.2024.105435","url":null,"abstract":"<div><div>Amid escalating global marine heat waves, the Arabian Gulf is critical due to its shallow depths, high temperatures, and vulnerability to climate change impacts. This study provides a detailed spatio-temporal analysis of marine heatwave events from 1982 to 2022 across the Arabian Gulf and the adjacent Gulf of Oman. The study delineates regions of heightened vulnerability within these water bodies by comprehensively analyzing seasonal and annual variabilities and trend assessments. Moreover, an exploration of prevailing surface circulation patterns, underpinned by an extensive study of global circulation model outputs, elucidates the oceanographic mechanisms contributing to temperature dynamics. Identifying 25 significant heat wave events, with a focused examination of the six most protracted episodes, is noteworthy among the findings. Strikingly, the analysis reveals that the Gulf of Oman surpasses the Arabian Gulf in heatwave intensity. Looking forward, the investigation extends to future surface water temperature projections up to the close of the current century. The collective results underscore the region's acute susceptibility to the climate change perturbations of climate change, emphasizing the urgency of targeted interventions to mitigate these effects and address concurrent local stressors.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105435"},"PeriodicalIF":2.3,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657495","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}

引用次数: 0

Ecophenotypic variation in a cosmopolitan reef-building coral suggests reduced deep-sea reef growth under ocean change 一种世界性造礁珊瑚的生态表型变异表明，海洋变化导致深海珊瑚礁生长减少

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-11-01 DOI: 10.1016/j.dsr2.2024.105434

Giovanni Sanna , André Freiwald

{"title":"Ecophenotypic variation in a cosmopolitan reef-building coral suggests reduced deep-sea reef growth under ocean change","authors":"Giovanni Sanna , André Freiwald","doi":"10.1016/j.dsr2.2024.105434","DOIUrl":"10.1016/j.dsr2.2024.105434","url":null,"abstract":"<div><div>Sensitivity of reef-building corals to environmental factors has far-reaching ecosystem implications, especially in the limited number of cold-water coral (CWC) species that form reefs in the deep sea. Understanding CWC responses to large-scale oceanographic variation in their natural habitat can elucidate their sensitivity to global anthropogenic stressors. Here, we use skeletal samples to analyse fine-scale phenotypic variation in the widespread reef-building CWC <em>Desmophyllum pertusum</em> (<em>Lophelia pertusa</em>) in relation to broad physicochemical gradients in different sites across the Atlantic Ocean and Mediterranean Sea. We find evidence, amidst local and regional differentiation, of species-wide growth responses to physicochemical factors, mainly affecting corallite length, width and their ratio (slenderness). Our results suggest that higher temperature and lower oxygen levels negatively affect skeletal linear extension and budding rate of polyps. As also hinted by the reduced corallite length and slenderness in less developed reefs, these widespread responses may lead to a general decline in CWC reef growth rates as a long-term consequence of ocean warming and deoxygenation. Given this relevance, such responses can be used to model reef growth in a changing ocean.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105434"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Siliceous microfossil assemblages in the southern Emperor Seamount Chain sediments and their biogeographical and paleoceanographical implications 皇帝海山链南部沉积物中的硅质微化石组合及其生物地理学和古海洋学意义

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-10-22 DOI: 10.1016/j.dsr2.2024.105433

Lidiya N. Vasilenko , Ira B. Tsoy , Tatyana N. Dautova

{"title":"Siliceous microfossil assemblages in the southern Emperor Seamount Chain sediments and their biogeographical and paleoceanographical implications","authors":"Lidiya N. Vasilenko , Ira B. Tsoy , Tatyana N. Dautova","doi":"10.1016/j.dsr2.2024.105433","DOIUrl":"10.1016/j.dsr2.2024.105433","url":null,"abstract":"<div><div>The taxonomic composition and abundance of siliceous microfossils in sediments is a valuable source of information about environmental changes at the sea surface today and in the geological past. This paper presents the results of a study of siliceous microplankton (radiolaria, diatoms, and silicoflagellates) in the surface calcareous sediments (silty foraminiferal oozes and sands) of the Nintoku, Jingu, Ojin, Koko, and Yuryaku guyots at the southern end of the Emperor Seamount Chain (ESC). Bottom sediments were collected using an underwater remote-operated vehicle (ROV) Comanche-18. The study revealed the taxonomic diversity and relatively high abundance of siliceous microplankton. Radiolarians are represented by 237 taxa (104 taxa from 68 genera of Spumellaria, 120 taxa from 61 genera of Nassellaria, and 13 taxa from 7 genera of Collodaria). Diatoms are represented by 60 species from 29 genera, and silicoflagellates by 5 species from 3 genera. Differences in siliceous microplankton reflect the northern boundary of warm water in the ESC, passing at approximately 38°N, between the Jingu and Ojin guyots, which coincides with the boundary of the Kuroshio Bifurcation Current, confirmed by the corals and the bathyal fauna of brittle stars (<em>Ophiura</em>). The absence of remains of siliceous microplankton in some sediments is probably due to dissolution, and the presence of extinct taxa from older sedimentary rocks and neritic species is due to process of reworking caused by active hydrodynamics on ESC guyots and transport by currents.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105433"},"PeriodicalIF":2.3,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593800","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}

引用次数: 0

The first Mud Dragons (Kinorhyncha) from the Emperor Seamount Chain (Northwestern Pacific) with notes on their biogeography and distribution patterns in the Pacific Deep-Sea 来自皇帝海山链（西北太平洋）的第一条泥龙（Kinorhyncha），以及关于其生物地理学和太平洋深海分布模式的说明

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-10-18 DOI: 10.1016/j.dsr2.2024.105430

Andrey V. Adrianov , Anastassya S. Maiorova

{"title":"The first Mud Dragons (Kinorhyncha) from the Emperor Seamount Chain (Northwestern Pacific) with notes on their biogeography and distribution patterns in the Pacific Deep-Sea","authors":"Andrey V. Adrianov , Anastassya S. Maiorova","doi":"10.1016/j.dsr2.2024.105430","DOIUrl":"10.1016/j.dsr2.2024.105430","url":null,"abstract":"<div><div>Seamounts and oceanic currents play crucial roles in shaping the genetic diversity of species by either acting as barriers or pathways for species dispersal. In the meiofaunal samples collected using ROV facilities at the slope of the Koko Guyot (2172 m) in the southernmost part of the Emperor Seamount Chain in the Northwestern Pacific, we found representatives of three kinorhynch genera, <em>Echinoderes</em> cf. <em>lupherorum</em> Sørensen et al. 2018, <em>Campyloderes</em> cf. <em>vanhoeffeni</em> Zelinka, 1913 and <em>Sphenoderes</em> sp. 1., previously known from other locations in the Pacific. Kinorhynchs were studied and illustrated using light (LM) and scanning electron (SEM) microscopy to prove the species identity and to compare morphological variations with representatives of these species collected from other, very distant localities in the Pacific. We illustrate the pan-oceanic distribution of the collected species with a system of abyssal currents in the Pacific. The probable distribution pattern corresponds with the northward pathway of Antarctic Bottom Water out of the Southern Ocean in the Pacific through the deep-sea area off New Zealand. <em>Echinoderes lupherorum</em> appears to be the first representative of the Echinoderidae with the pan-Pacific distribution. Discussions on the biogeography of <em>Campyloderes</em> cf. <em>vanhoeffeni</em> Zelinka, 1913 and <em>Sphenoderes</em> in the Pacific are also provided.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105430"},"PeriodicalIF":2.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534936","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}

引用次数: 0

Latitudinal variation in zooplankton over the Emperor Seamounts (34°–44° N, 170°–171° E) during the summer of 2019 2019 年夏季皇帝海山（北纬 34°-44°，东经 170°-171°）浮游动物的纬度变化

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-10-18 DOI: 10.1016/j.dsr2.2024.105432

Valentina V. Kasyan

{"title":"Latitudinal variation in zooplankton over the Emperor Seamounts (34°–44° N, 170°–171° E) during the summer of 2019","authors":"Valentina V. Kasyan","doi":"10.1016/j.dsr2.2024.105432","DOIUrl":"10.1016/j.dsr2.2024.105432","url":null,"abstract":"<div><div>The horizontal and vertical distributions of zooplankton over the Emperor Seamounts (Koko, Jingu, Nintoku, and Suiko guyots) were analyzed. The zooplankton was represented by four genera of amphipods, seven genera of pteropods, 39 genera of copepods, and larvae of benthic invertebrates and fish. The abundance and biomass of zooplankton increased towards higher latitudes along the series Koko < Jingu < Nintoku < Suiko guyots. The highest index of diversity was recorded over the Koko and Jingu guyots; the highest species richness occurred over the Jingu and Nintoku guyots. Small-sized copepods, appendicularians, chaetognaths, euphausiids, and fish eggs and larvae concentrated in the epipelagic; large copepods and ostracods were concentrated in the mesopelagic. We identified three types of zooplankton assemblages: a Subtropical assemblage between 34°–35°N characterized by tropical/subtropical forms; a Transition assemblage characterized by subtropical, subarctic, and widespread species between 38°–41°N; and a Subarctic assemblage characterized by subarctic and widespread species between 43°–44°N. The spatial distribution of zooplankton was a function of environmental variables such as surface salinity, temperature at 200 m, and, to a certain extent, by surface Chl-<em>a</em> concentrations.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105432"},"PeriodicalIF":2.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534937","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}

引用次数: 0

Methane distribution above the Emperor Seamount chain 皇帝海山链上方的甲烷分布情况

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-10-16 DOI: 10.1016/j.dsr2.2024.105431

Nikita S. Polonik, Alexey A. Legkodimov

{"title":"Methane distribution above the Emperor Seamount chain","authors":"Nikita S. Polonik, Alexey A. Legkodimov","doi":"10.1016/j.dsr2.2024.105431","DOIUrl":"10.1016/j.dsr2.2024.105431","url":null,"abstract":"<div><div>Dissolved methane (CH<sub>4</sub>) concentrations were measured in the water column at 25 stations along the four sections above Koko and Jingu guyots (the southern part of Emperor Seamount chain). The measured methane concentrations were relatively low (1–6.5 nM). The patterns of CH<sub>4</sub> vertical distributions over Koko and Jingu were different. The greatest dissolved methane concentrations (6.5 nM) were found in the near-bottom layer (357 m) above the Koko summit. For Koko guyot, the greatest CH<sub>4</sub> content (3.9–6.5 nM) was mainly associated with the subsurface (10–300 m) layer above the summit. However, another methane plume (6 nM) was detected at 1000 m on the western slope of the guyot. We propose that methane maximum was caused by the influence of the Kuroshio Extension or deep eddies. The CH<sub>4</sub> distribution over Jingu gyuot was similar to that in open ocean waters. The greatest methane concentrations (3.8–6 nM) were found in the subsurface layers above the summit. Methane exceeded atmospheric equilibrium concentration in the surface (5–52 % supersaturation) layer for both Koko and Jingu. The methane content and supersaturation level in the subsurface layer was at least two times higher than previously measured values for the open ocean. We believe that the high methane and supersaturation level was caused by enhanced methanogenesis in the water column above the seamounts. The estimated methane flux to the atmosphere varied from 1.4 to 16.3 μmol m<sup>−2</sup> day<sup>−1</sup> for Koko and from 0.5 to 6.5 μmol m<sup>−2</sup> day<sup>−1</sup> for Jingu, respectively. The average fluxes calculated for Koko (8.37 μmol m<sup>−2</sup> day<sup>−1</sup>) and Jingu (2.8 μmol m<sup>−2</sup> day<sup>−1</sup>) were significantly greater than the average flux for open and coastal oceans. Given the substantial methane atmospheric contributions, the global methane budget should be reconsidered.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105431"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534938","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}

引用次数: 0

Ocean-atmosphere-ice processes in the Ross Sea: A review 罗斯海的海洋-大气-冰过程：综述

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-10-11 DOI: 10.1016/j.dsr2.2024.105429

Pierpaolo Falco , Giuseppe Aulicino , Pasquale Castagno , Vincenzo Capozzi , Paola de Ruggiero , Angela Garzia , Antonino Ian Ferola , Yuri Cotroneo , Alessio Colella , Giannetta Fusco , Stefano Pierini , Giorgio Budillon , Enrico Zambianchi , Giancarlo Spezie

{"title":"Ocean-atmosphere-ice processes in the Ross Sea: A review","authors":"Pierpaolo Falco , Giuseppe Aulicino , Pasquale Castagno , Vincenzo Capozzi , Paola de Ruggiero , Angela Garzia , Antonino Ian Ferola , Yuri Cotroneo , Alessio Colella , Giannetta Fusco , Stefano Pierini , Giorgio Budillon , Enrico Zambianchi , Giancarlo Spezie","doi":"10.1016/j.dsr2.2024.105429","DOIUrl":"10.1016/j.dsr2.2024.105429","url":null,"abstract":"<div><div>The Ross Sea has been the site of extensive investigations since the earliest days of polar exploration. The International Geophysical Year of 1957-58 enhanced research activities with the establishment of scientific stations and the collection of oceanographic observations in the area. While many features of its oceanography, ecology, physics, glaciology, geology, and biogeochemistry are known, recent advances provide new insights into its structure and function, as well as into its relationship to global climate. We present a comprehensive review of the advances of understanding the main processes occurring in the area, such as the formation of dense shelf water and the production of Antarctic Bottom Water (AABW), as well as the main drivers (at both large and local scales) of local dynamics and water mass variability. We also summarize the main modeling applications, which are still limited and need to be improved using high-resolution models and, locally, limited-area models to explain processes driven mainly by thermodynamics and water-mass transformations. The Ross Sea forms the most saline AABW due to the activity of two polynyas in the western sector. A salinity gradient occurs on the shelf, with fresh Low Salinity Shelf Waters concentrated in the eastern Ross Sea, which is influenced by the inflow of fresh water from the Amundsen and Bellingshausen Seas. This freshwater inflow was thought to be the cause of a multi-decadal freshening of the High Salinity Shelf Water, precursor to the AABW, although a rebound in salinity in the Ross Sea has been observed since 2014. The increase in salinity has also affected the production of AABW, with the respective rebound occurring almost simultaneously.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105429"},"PeriodicalIF":2.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring sea ice transport dynamics at the eastern gate of the Ross Sea 探索罗斯海东门的海冰迁移动力学

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-10-11 DOI: 10.1016/j.dsr2.2024.105428

Naomi Krauzig , Daniela Flocco , Stefan Kern , Enrico Zambianchi

{"title":"Exploring sea ice transport dynamics at the eastern gate of the Ross Sea","authors":"Naomi Krauzig , Daniela Flocco , Stefan Kern , Enrico Zambianchi","doi":"10.1016/j.dsr2.2024.105428","DOIUrl":"10.1016/j.dsr2.2024.105428","url":null,"abstract":"<div><div>As Antarctic sea ice extent continues to reach record lows, significant efforts have been directed towards understanding the underlying processes and their regional differences within the Southern Ocean. Here, we explore the dynamics of zonal sea ice transport at the eastern gate of the Ross Sea from 1988 to 2023 using GIOMAS-model and ERA5-reanalysis data. Our analysis reveals a modest overall increase in eastward sea ice transport (3.721 ± 0.672 km³/month per decade), with diverging trends in the coastal and open ocean zones. Driven by easterly winds and the Antarctic Slope Current, the predominant westward transport in the coastal region experienced a significant rise during the early 2000s, followed by a steep decline post-2011. Conversely, driven by the Antarctic Circumpolar Current, the strong open-ocean transport exhibited a moderate increase towards the Amundsen Sea until the late 1990s, which was interrupted by a reversal in 2007. The variability of zonal sea ice transport and its underlying conditions (sea ice concentration, thickness, and zonal drift) revealed considerable shifts throughout the different decades and on seasonal scales. During austral winter, approximately half of the zonal sea ice transport variability seems to be driven by large-scale teleconnections, including the Southern Annular Mode, Southern Oscillation Index, Amundsen Sea Low and the Zonal Wave 3 with considerable impacts on the wind stress field. Whereas during summer, the Southern Oscillation Index emerges as the dominant driver, exhibiting a significant positive correlation (r=0.55, p<0.001) that reflects the influence of the El Niño-Southern Oscillation, while other teleconnections play minimal roles. Our study highlights the complex nature of sea ice transport through the eastern gate of the Ross Sea towards the Amundsen Seas, where contrasting climatic conditions are known to occur.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105428"},"PeriodicalIF":2.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Second International Indian Ocean Expedition (IIOE-2): Motivating New Exploration in a Poorly Understood Ocean Basin (Volume 6) 第二次国际印度洋考察（IIOE-2）：激励在一个鲜为人知的大洋盆地进行新的探索（第 6 卷）

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-10-10 DOI: 10.1016/j.dsr2.2024.105427

Raleigh R. Hood, Lynnath E. Beckley, V.V.S.S. Sarma, P.N. Vinayachandran

引用次数: 0

Mesoscale cyclonic eddies born in an eastern boundary upwelling system enhance microbial eukaryote diversity in oligotrophic offshore waters 东部边界上升流系统中产生的中尺度气旋漩涡提高了寡营养近海水域微生物真核生物的多样性

IF 2.3 3区地球科学

Deep-sea Research Part Ii-topical Studies in Oceanography Pub Date : 2024-09-28 DOI: 10.1016/j.dsr2.2024.105425

Sven Nicolai Katzenmeier , Maren Nothof , Hans-Werner Breiner , Tim Fischer , Thorsten Stoeck

{"title":"Mesoscale cyclonic eddies born in an eastern boundary upwelling system enhance microbial eukaryote diversity in oligotrophic offshore waters","authors":"Sven Nicolai Katzenmeier , Maren Nothof , Hans-Werner Breiner , Tim Fischer , Thorsten Stoeck","doi":"10.1016/j.dsr2.2024.105425","DOIUrl":"10.1016/j.dsr2.2024.105425","url":null,"abstract":"<div><div>Mesoscale eddies which originate in Eastern Boundary Upwelling Systems (EBUS) such as the Canary Current System, entrap nutrient-rich coastal water and travel offshore while aging. We have analyzed the protistan plankton community structures in the deep chlorophyll maximum (DCM), sub-DCM, and oxygen minimum zone (OMZ) of three differently aged cyclonic EBUS eddies off Northwest Africa, as well as of non-eddy affected reference sites, using DNA metabarcoding. Throughout all water depths, we found that the investigated eddies generated local dispersal-driven hotspots of protistan plankton diversity in the naturally oligotrophic subtropical offshore waters off Northwest Africa. Based on the taxonomic composition of protistan plankton communities, these diversity hotspots are likely to play an important role in carbon sequestration and for regional food webs up to top predatory levels. Thereby, the life-span of an eddy emerged as an important criterion, how local offshore protistan plankton diversity is transformed quantitatively and qualitatively: each of the three eddies was characterized by notably distinct protistan plankton communities. This could be linked to the physicochemical water properties (predominantly macronutrients, temperature, and salinity) of the eddies' cores and rings, which experience pronounced changes during the eddies’ westward trajectories. Furthermore, we found evidence that eddy-specific deep-water protistan communities are relatively short-lived compared to the ones in the sunlit DCM. However, our results do not only witness from the importance of fine-scale physical ocean features for regional ecosystem processes, but they also show the complexity of these ocean features and that we are still far from understanding the biological processes and their driving forces in such features.</div></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"218 ","pages":"Article 105425"},"PeriodicalIF":2.3,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0