Deep-Sea Research Part I-Oceanographic Research Papers最新文献_第9页

Modeling of the isotope (δ18O, δ2H) composition and salinity of the seawater surface layer in polar regions: Application for the East and European arctic 极地海水表层同位素（δ18O, δ2H）组成和盐度的模拟：在东欧和欧洲北极的应用

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-06-18 DOI: 10.1016/j.dsr.2025.104547

E.O. Dubinina, S.A. Kossova, Yu.N. Chizhova, A.S. Avdeenko

The surface sea water salinity and isotope (δ¹⁸O, δ²H) composition in polar regions are determined by the balance between freshening and freezing-related processes. Due to sea ice formation and its melting, the relation between the salinity and δ¹⁸O(δ²H) values does not correspond entirely to an additive process. We propose the dynamic model of surface layer (DMSL), which considers the fluxes corresponding to the freshening, freezing, and sea ice melting in order to describe the δ¹⁸O(δ²H)–salinity and δ¹⁸O–δ²H relations in Arctic seawater. The DMSL shows that the slope in the δ–salinity space is a complex function of melting and freezing fluxes, freshwater flux, salinity, and isotope composition of marine and freshwater endmembers. The model can be applied to salinity and isotope signatures both for any whole water region and for single water samples. The testing of the DMSL was done for water areas covered with different freezing–melting activity, located both in shelf areas influenced of continental runoff and in areas isolated from it. The data used for test calculations were obtained for surface (0–15 m) seawater collected in the Eastern and European Arctic in 2017, 2018, and 2021 (70°–82.7° N, and −4° W to 168° E) at the end of ice-free seasons. The calculations show that the model is capable of adequately estimating both the isotope signature of fresh water and the ratio of the main fluxes that form the surface layer: freshening, modification, and the contribution from melting sea ice.

极地地区表层海水盐度和同位素（δ18O, δ2H）组成由与新鲜和冻结有关的过程之间的平衡决定。由于海冰的形成和融化，盐度与δ18O（δ2H）值之间的关系并不完全符合加性过程。为了描述北极海水的δ18O(δ2H) -盐度关系和δ18O -δ2H关系，提出了考虑海冰新鲜、冻结和融化对应通量的表层动力学模型（DMSL）。DMSL表明，δ -盐度空间的斜率是融化和冻结通量、淡水通量、盐度以及海洋和淡水端元同位素组成的复杂函数。该模型可以应用于任何整个水域和单个水样的盐度和同位素特征。对DMSL的测试是在不同冻融活动覆盖的水域进行的，这些水域既位于受大陆径流影响的大陆架地区，也位于与大陆径流隔绝的地区。用于测试计算的数据是在2017年、2018年和2021年（70°-82.7°N， - 4°W至168°E）无冰季节结束时，在北极东部和欧洲收集的表面（0-15 m）海水中获得的。计算表明，该模式能够充分估计淡水的同位素特征和形成表层的主要通量的比率：新鲜、变质和海冰融化的贡献。

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引用次数: 0

Bacterial community characterization and relationship in the gut of deep-sea holothurians and sediment from the Northern Indian Ocean 北印度洋深海海棠肠道细菌群落特征及其与沉积物的关系

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-06-18 DOI: 10.1016/j.dsr.2025.104546

Xinlong Li , Anning Mou , Yue Dong , Jing Mo , Xiaomei Liao , Xiao Wang , Zongling Wang , Xuelei Zhang , Qinzeng Xu

Sea cucumbers, widely distributed benthic invertebrates in diverse deep-sea habitats, rely on their gut bacterial communities for essential functions including energy metabolism, biological adaptation, and health. However, the gut bacterial community of deep-sea holothurians in the Indian Ocean remains poorly understood. We used 16S rRNA gene sequencing to characterize bacterial communities in the guts of sea cucumbers and surrounding sediments from two distinct regions of the northern Indian Ocean: the Ninety-East Ridge and the Arabian Sea Basin. This study investigates the composition, diversity, predicted functions, co-occurrence networks, and assembly processes of gut bacterial communities. Alpha diversity of gut bacterial communities did not differ significantly between the two regions. Based on principal coordinate analysis, the bacterial communities of gut formed a distinct cluster from the sediment communities. Actinobacteriota, Proteobacteria, Firmicutes, Chloroflexi, and Bacteroidota were the dominant phyla in both gut and sediment bacterial communities. In the Ninety-East Ridge, the gut microbial network exhibited a higher proportion of positive correlation than the sediment network, suggesting a greater potential for cooperative interactions. Compared to sediment communities, functional predictions indicated that gut communities were enriched in metabolic pathways, including those for amino acid, glycan, vitamin, and lipid metabolism. Stochastic processes were predominant in gut bacterial community assembly, whereas deterministic processes dominated in sediment bacterial communities. This study provides critical insights into the gut microbiota of deep-sea holothurians, advancing our understanding of microbial ecology in extreme marine environments.

海参是广泛分布于不同深海栖息地的底栖无脊椎动物，它们依靠肠道细菌群落来实现能量代谢、生物适应和健康等基本功能。然而，人们对印度洋深海全息鱼的肠道细菌群落知之甚少。我们使用16S rRNA基因测序来表征来自北印度洋两个不同区域的海参内脏和周围沉积物中的细菌群落：九十东脊和阿拉伯海盆地。本研究探讨了肠道细菌群落的组成、多样性、预测功能、共生网络和组装过程。两个地区肠道细菌群落的α多样性无显著差异。基于主坐标分析，肠道细菌群落与沉积物群落形成了明显的集群。放线菌门、变形菌门、厚壁菌门、绿菌门和拟杆菌门是肠道和沉积物细菌群落的优势门。在90 east Ridge，肠道微生物网络表现出比沉积物网络更高的正相关比例，表明更大的合作相互作用潜力。与沉积物群落相比，功能预测表明肠道群落在代谢途径中丰富，包括氨基酸、聚糖、维生素和脂质代谢途径。随机过程在肠道细菌群落组装中占主导地位，而确定性过程在沉积物细菌群落中占主导地位。这项研究为深海全息鱼的肠道微生物群提供了重要的见解，促进了我们对极端海洋环境下微生物生态的理解。

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引用次数: 0

Decadal change in deep-ocean dissolved oxygen in the North Atlantic Ocean and North Pacific Ocean 北大西洋和北太平洋深海溶解氧的年代际变化

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-06-16 DOI: 10.1016/j.dsr.2025.104534

Henry A. Ruhl , Christine L. Huffard , Monique Messié , Thomas P. Connolly , Thomas Soltwedel , Frank Wenzhöfer , Rodney J. Johnson , Nicholas R. Bates , Susan Hartman , Anita Flohr , Edward W. Mawji , David M. Karl , James Potemra , Fernando Santiago-Mandujano , Tetjana Ross , Kenneth L. Smith

Declining dissolved oxygen concentrations are documented at upper and mid ocean depths, but less is known about the deep ocean. Long time-series measurements of dissolved oxygen analyzed with Winkler titration over several decades reveal regional differences at six stations in the abyssal North Atlantic Ocean and North Pacific Ocean. A significant decline in dissolved oxygen was evident at two stations in the northeast Pacific Ocean at 4000–4200 m depth (Stations PAPA and M). A similar decreasing but insignificant trend was recorded in the Arctic region of the North Atlantic Ocean (HAUSGARTEN). However, there was no significant decrease in dissolved oxygen at two temperate stations in the North Atlantic Ocean (PAP, BATS) and at one tropical station in the central North Pacific Ocean (ALOHA) all at similar depths >4000 m over similar time periods. Continued long time-series observations will be needed to monitor global deep ocean processes and the impact of changing climate. We compare these rare long-term observations with model estimations from historical (1850–2014) and projected (2015–2100) forcing under a continued high greenhouse gas emission scenario.

在海洋上部和中部的深度有溶解氧浓度下降的记录，但对深海的了解较少。用温克勒滴定法分析了几十年来溶解氧的长时间序列测量结果，揭示了北大西洋和北太平洋深海六个站点的区域差异。东北太平洋4000 ~ 4200 m深度两个站（PAPA站和m站）溶解氧明显下降。在北大西洋的北极地区也有类似的下降趋势，但并不明显（HAUSGARTEN）。然而，北大西洋的两个温带站（PAP， BATS）和北太平洋中部的一个热带站（ALOHA）在相似的时间段内，在相似的深度>；4000 m处，溶解氧没有显著减少。为了监测全球深海过程和气候变化的影响，将需要持续的长时间序列观测。我们将这些罕见的长期观测结果与持续高温室气体排放情景下的历史（1850-2014）和预估（2015-2100）强迫模式估算值进行了比较。

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引用次数: 0

Evolutionary affinity of a novel deep-sea coral from the Central Indian Ridge seamount, and its links to Pacific Ocean species 中印度脊海山一种新型深海珊瑚的进化亲缘性及其与太平洋物种的联系

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-06-16 DOI: 10.1016/j.dsr.2025.104543

Rengaiyan Periasamy , Baban Ingole

The family Victorgorgiidae Moore et al., 2017 comprises deep-sea gorgonian corals typically characterized by purple colonies and distinctive josephinae clubs in their polyp tentacles. Despite this, the family exhibits low species diversity and the ones from the deep Indian Ocean remain poorly unknown, remarking the need for more research to better understand their ecological role and evolutionary history. A new species, Victorgorgia indica sp. nov., was discovered on a seamount along the Central Indian Ridge (CIR) at depths of 1917–2053 m, representing the first record of Victorgorgiidae in the Indian Ocean. Among the nine known species of Victorgorgia López-González and Briand, 2002), V. indica sp. nov. is morphologically most similar to V. flabellata Li et al., 2020 and V. iocasica Li et al., 2020, particularly in the arrangement of the calyx, which is mainly isolated in three sides of the branches. However, this arrangement can vary in different parts of a colony and may be influenced by local habitat conditions. V. indica sp. nov. differs from these species by having tuberculate rods, a thorn club in the tentacle rachis, and curved rodlets with tall tubercules along their edges in the pinnules. Phylogenetic analysis at the family level using the MutS-like protein (MutS) gene supports Victorgorgiidae as a monophyletic group. The evolutionary relationships of the new CIR species suggest a close affinity with its Pacific Ocean congeners, including V. flabellata, V. iocasica and V. eminens Moore et al., 2017. This points to the CIR seamount system potentially acting as a link for gene flow between the Indian and Pacific Oceans. Analyses of the reproductions of these species showed that V. indica sp. nov. is a brooder, with planula larvae developing within clumped autozooids—the only mature polyps—and settling on dead deep-sea coral. Here we presented also the complete mitochondrial genome of V. indica sp. nov., which is 18,715 base pairs in size, and includes 14 protein-coding genes (PCGs), two ribosomal RNA genes (rrnS and rrnL), and one transfer RNA gene. The gene order of the mitogenome is identical to that of other sequenced Victorgorgiidae species.

victororggiidae Moore等人，2017包括深海柳珊瑚，其典型特征是紫色的群落和在其水螅触须上独特的josephinae棒。尽管如此，这个家族的物种多样性很低，来自印度洋深处的物种仍然鲜为人知，这表明需要更多的研究来更好地了解它们的生态作用和进化历史。一新种victororggia indica sp. nov.在印度洋中部山脊（CIR）深处1917-2053米的海底山上被发现，这是在印度洋首次记录到victororgorgiidae。在已知的9个victorgorggia （López-González and Briand, 2002）种中，V. indica sp. nov.在形态上与V. flabellata Li et al.， 2020和V. iocasica Li et al.， 2020最相似，特别是花萼的排列方式，花萼主要分离在枝的三面。然而，这种安排在一个群体的不同部分可能会有所不同，并可能受到当地栖息地条件的影响。与这些种的不同之处在于在触手轴上有有结核的茎，刺棒和弯曲的小茎，在小叶尖的边缘有高的结节。利用MutS样蛋白（MutS -like protein, MutS）基因在家族水平上进行系统发育分析，支持vicorgorgiidae为单系类群。新的CIR物种的进化关系表明其与太平洋同系物（包括V. flabellata， V. iocasica和V. eminens Moore等，2017）有密切的亲缘关系。这表明CIR海底山系统可能作为印度洋和太平洋之间基因流动的纽带。对这些物种繁殖的分析表明，印度浮藻是一种孵卵动物，浮藻幼虫在成团的自生动物（唯一成熟的珊瑚虫）中发育，并定居在死的深海珊瑚上。本文还报道了印度血吸虫线粒体基因组全长18715个碱基对，包括14个蛋白质编码基因（PCGs）、2个核糖体RNA基因（rrnS和rrnL）和1个转移RNA基因。有丝分裂基因组的基因顺序与其他有丝分裂科物种相同。

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引用次数: 0

Megafauna of the RMS Titanic shipwreck and a nearby seamount ridge in the deep sea of the western North Atlantic 泰坦尼克号沉船上的巨型动物和北大西洋西部深海附近的海底山脊

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-06-15 DOI: 10.1016/j.dsr.2025.104544

Jason Cleland , Anna Gebruk , J. Murray Roberts , Dmitry Aleynik , Beverly McClenaghan , Rod Mather , Bridget Buxton , Steve W. Ross

The biology of shipwrecks and hard substrata in the deep sea remains poorly explored. These complex habitats alter biodiversity on the deep seafloor and facilitate connecting populations over large distances. We analysed biological and environmental data collected at the RMS Titanic wreck site (3800 m) and a seamount ridge (2900 m) during the 2022 Titanic Expedition (15 June–25 July). The ridge is part of Seamount U, approximately 40 km southeast of the Titanic, and was explored for the first time on July 23, 2022. We analysed megafaunal occurrence across 920 images of the wreck site and 169 images of the ridge site, from digital video. The most common megafauna overall were Ophiuroidea, Munidopsis sp., Cushion-Encrusting Porifera, Geodia spp., and cold-water corals including Keratoisididae and Pennatuloidea. We describe the patterns in community composition across five benthic habitats, likely controlled by substrate type, local hydrodynamics, and food availability. The ridge yielded a higher number of observed megafauna and higher Shannon diversity (n = 73; H = 2.89) than the wreck (n = 21; H = 1.39). The communities associated with the ridge showed high dissimilarity to those at the wreck. We also explored the temporal variability of biofouling organisms on the Titanic using video from 1986 to 2022. We observed a net increase in Chrysogorgia sp. and Lepidisis sp. coral colonies over time with estimated average linear growth rates of up to 10 mm/yr and linear rusticle extensions of up to 14 mm/yr, raising questions about the wreck's ecological succession as it deteriorates.

沉船和深海中坚硬基质的生物学研究仍然很少。这些复杂的栖息地改变了深海海底的生物多样性，并促进了远距离种群之间的联系。我们分析了2022年泰坦尼克号探险（6月15日至7月25日）期间在泰坦尼克号沉船遗址（3800米）和海山脊（2900米）收集的生物和环境数据。该山脊是U号海山的一部分，位于泰坦尼克号东南约40公里处，于2022年7月23日首次被探索。我们分析了920张沉船现场的图像和169张山脊现场的图像，这些图像来自数字视频。总体而言，最常见的巨型动物是蛇科、Munidopsis、垫壳Porifera、Geodia和冷水珊瑚，包括Keratoisididae和Pennatuloidea。我们描述了五种底栖生物栖息地的群落组成模式，可能受基质类型、当地流体动力学和食物供应的控制。脊区有较多的巨型动物和较多的Shannon多样性(n = 73；H = 2.89)大于沉船(n = 21；h = 1.39)。与山脊相关的群落与沉船处的群落表现出高度的差异。我们还利用1986年至2022年的视频，探索了泰坦尼克号上生物污染生物的时间变化。随着时间的推移，我们观察到Chrysogorgia sp.和Lepidisis sp.珊瑚群落的净增长，估计平均线性增长率高达10毫米/年，线性锈迹延伸高达14毫米/年，这引发了对沉船生态演替的质疑。

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引用次数: 0

Functional and microbial insights into the gill symbiosis and metal tolerance of the cold seep mussel Gigantidas haimaensis 海马巨鲷（Gigantidas haimaensis）鳃共生和金属耐受性的功能和微生物研究

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-06-11 DOI: 10.1016/j.dsr.2025.104545

Xuanguang Liang , Mingmin Du , Yuxin Qin , Wenlong Cai , Junrou Huang , Genmei Lin , Jianguo Lu

Deep-sea cold seeps that discharge fluids rich in methane, hydrogen sulfide, and heavy metals present extreme conditions under which only a few organisms, such as deep-sea mussels, can survive. Deep-sea mussels exploit chemosynthetic energy via symbiotic microorganisms. This study compared environmental sensing and stress responses in different tissues of Gigantidas haimaensis from the Haima cold seep through transcriptome and microbiome sequencing, biochemistry index measurements and metal content assessments to decipher its adaptive mechanisms. Transcriptomic analysis revealed distinct expression patterns among three tissues, with more genes expressed in the gill. Compared to the mantle and adductor muscle, the gill had 2519 and 4508 differentially expressed genes (DEGs), respectively, while 1453 DEGs were identified between the mantle and the adductor muscle. Up-regulated DEGs in the gill were associated with symbiont acquisition, pathogen recognition, pathogen removal, symbiotic substance exchange, and oxidative stress response. Meanwhile, the gill microbiota was dominated by methanotrophic Methylomonaceae (>85 % relative abundance). Of the 13 metals analyzed, Zn, Fe, and Cu exhibited the highest concentrations. Genes associated with distinct metal-binding pathways were expressed in different tissues. The gill also showed heightened antioxidant capacity and metal accumulation, underscoring its role in the stress response. The up-regulated genes in the adductor muscle were related to muscle contraction, while in the mantle, the up-regulated protease inhibitors were linked to humoral immunity. This study demonstrates the gill's crucial functions in symbiont and pathogen regulation as well as metal stress response, thus extending our understanding of the adaptive mechanism of G. haimaensis inhabiting cold seeps.

深海冷渗漏会释放出富含甲烷、硫化氢和重金属的液体，在这种极端条件下，只有少数生物（如深海贻贝）能够生存。深海贻贝通过共生微生物利用化学合成能量。本研究通过转录组测序、微生物组测序、生物化学指标测定和金属含量测定等方法，比较了海马巨鲷不同组织对环境的感知和胁迫反应，以揭示其适应机制。转录组学分析揭示了三种组织中不同的表达模式，在鳃中表达的基因更多。与地幔和内收肌相比，鳃分别有2519个和4508个差异表达基因（deg），而在地幔和内收肌之间鉴定出1453个差异表达基因。鳃中deg的上调与共生体获取、病原体识别、病原体去除、共生物质交换和氧化应激反应有关。与此同时，鳃微生物群以甲烷营养甲基藻科（>； 85%的相对丰度）为主。在分析的13种金属中，锌、铁和铜的浓度最高。与不同的金属结合途径相关的基因在不同的组织中表达。鳃也显示出更高的抗氧化能力和金属积累，强调其在应激反应中的作用。内收肌中上调的基因与肌肉收缩有关，而在套膜中上调的蛋白酶抑制剂与体液免疫有关。本研究揭示了鳃在共生体和病原菌调控以及金属胁迫响应中的重要功能，从而拓展了我们对海参在冷渗环境中的适应机制的认识。

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引用次数: 0

The role of eddy merging in maintaining the quasi-permanent Ulleung Eddy 涡旋合并在维持准永久郁陵涡旋中的作用

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-06-09 DOI: 10.1016/j.dsr.2025.104542

Guoqing Han , Wang Zhu , Yaofeng Wang , Xiayan Lin , Juncheng Xie , Yu Liu

Eddy merging plays a crucial role in maintaining the lifetimes of quasi-permanent eddies. This study used satellite observations and 3D reanalysis data to investigate the eddy merging process of a quasi-permanent eddy, known as the Ulleung Eddy, in the Ulleung Basin (UB) of the Sea of Japan. The results showed that the number of cyclonic eddies in the Sea of Japan was greater than that of anticyclonic eddies. However, regarding long-lived eddies (>360 days), which were mostly distributed in UB, the number of anticyclonic eddies was greater than that of cyclonic eddies. The eddy merging process is beneficial for strengthening the Ulleung Eddy and maintaining its quasi-permanent state. Through a case analysis of 3D reanalysis data, considerable instability was observed during the merging of the Ulleung Eddy. During the eddy merging process, energy conversion associated with baroclinic instability is dominant. In particular, 95.8 % of the eddy merging processes exhibited a conversion from mean potential energy to eddy potential energy, whereas 83.3 % of the eddy merging processes demonstrated a conversion from mean kinetic energy to eddy kinetic energy. The merging of the Ulleung Eddy is conducive to its maintenance and development.

涡旋合并对维持准永久涡旋的寿命起着至关重要的作用。本研究利用卫星观测和三维再分析资料，研究了日本海郁陵盆地（UB）准永久涡旋郁陵涡旋的涡旋合并过程。结果表明：日本海的气旋涡旋数量大于反气旋涡旋数量；而长寿命涡旋（>；360天）多分布在UB，反气旋涡旋数量多于气旋涡旋数量。涡旋合并过程有利于郁陵涡旋的强化和准永久状态的维持。通过对三维再分析数据的实例分析，发现郁陵涡旋合并过程中存在相当大的不稳定性。在涡旋合并过程中，与斜压不稳定相关的能量转换占主导地位。其中，95.8%的涡旋合并过程表现出平均势能向涡旋势能的转化，而83.3%的涡旋合并过程表现出平均动能向涡旋动能的转化。郁陵涡旋的合并有利于郁陵涡旋的维护和发展。

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引用次数: 0

A video dataset for hadal snailfish along with the benchmark hadal蜗牛鱼的视频数据集以及基准

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-05-27 DOI: 10.1016/j.dsr.2025.104517

Jiushuang Zhang, Yong Wang

Application of deep learning technology for deep-sea ecological studies is still in its infancy stage especially in the field of automatic taxonomic identification and statistics. In this study, we created a novel dataset containing annotated videos for the rare species of hadal snailfish inhabiting in depth below 6000 meters, and conducted control experiments by combining models of different specifications and adding different attention mechanisms. We successfully generated a set of benchmark test data from a quantitative perspective. In addition, based on out of set data with completely different data distributions from the training and validation sets, the generalization ability of the model trained on the new dataset in real-world scenarios was qualitatively analyzed. Other researchers can continue to expand and supplement the dataset based on our benchmarks, or directly apply our results to actual deep-sea videos collected, and accurately identify and capture deep-sea snailfish in the videos. With this deep learning video processing technology, distribution pattern and biodiversity of the deep-sea organisms will be accomplished efficiently.

深度学习技术在深海生态研究中的应用还处于起步阶段，特别是在自动分类识别和统计领域。本研究对生活在6000米以下的稀有物种hadal蜗牛鱼创建了一个全新的包含注释视频的数据集，并通过组合不同规格的模型和添加不同的注意机制进行了对照实验。我们成功地从定量的角度生成了一组基准测试数据。此外，基于与训练集和验证集数据分布完全不同的集外数据，定性分析了在新数据集上训练的模型在真实场景下的泛化能力。其他研究人员可以在我们的基准基础上继续扩展和补充数据集，或者直接将我们的结果应用到实际收集的深海视频中，准确识别和捕获视频中的深海蜗牛鱼。利用这种深度学习视频处理技术，可以有效地完成深海生物的分布格局和生物多样性。

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引用次数: 0

Spatial variation of micrometeorite abundance in global ocean 全球海洋微陨石丰度的空间变化

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-05-26 DOI: 10.1016/j.dsr.2025.104533

V.P. Singh , N.G. Rudraswami

Annually, Earth accumulates ∼40,000 tons of cosmic dust, with ∼4000–6000 tons reaching the surface as micrometeorites (MMs). This study analyzes ∼3 tons of wet sediments and ∼5000 MMs from the Central Indian Ocean Basin, using a machine learning algorithm based on terrestrial sedimentation rate (TSR) and MM abundance to identify optimal collection regions. Deep-sea sediments (TSR <0.01 cm/kyr) contain ∼50 MM/kg of dry sediments, yet remain largely unexplored. Moderately deep-sea sediments (0.01 < TSR <0.1 cm/kyr), like those in this study, average ∼15 MM/kg, while shallow-sea sediments yield far fewer. Modelling indicates that ocean regions between 45° N and 45° S latitude are ideal for MM collection. The eastern Pacific Ocean (10-40° N and 10-30° S) and the Central Indian Ocean (0-45° S) are particularly suitable. Apart from deep-sea collection, ancient rocks deposited in calm environments with low TSR (e.g. shale, claystone, mudstone, chert, and limestone) are promising for collecting fossil MMs. Overall, this research enhances micrometeorite collection strategies, enabling more accurate flux estimation and providing a foundation for researchers to effectively target specific ocean areas and ancient rock formations, thereby facilitating investigations into extraterrestrial activities and their impacts on Earth's processes.

地球每年积累4万吨宇宙尘埃，其中有4000 ~ 6000吨以微陨石（mm）的形式到达地球表面。本研究分析了来自中印度洋盆地的~ 3吨湿沉积物和~ 5000 MM，使用基于陆地沉积速率（TSR）和MM丰度的机器学习算法来确定最佳收集区域。深海沉积物（TSR <0.01 cm/kyr）含有约50 MM/kg的干沉积物，但大部分尚未开发。中深海沉积物(0.01 <；与本研究一样，TSR （0.1 cm/kyr）平均为~ 15 MM/kg，而浅海沉积物的产量要少得多。模拟表明，北纬45°至南纬45°之间的海洋区域是收集MM的理想区域。东太平洋（北纬10-40°和南纬10-30°）和印度洋中部（南纬0-45°）特别适合。除深海收集外，沉积在低TSR平静环境中的古岩石（如页岩、粘土岩、泥岩、燧石和石灰岩）也有可能收集化石mm。总体而言，本研究增强了微陨石收集策略，使通量估算更加精确，为研究人员有效瞄准特定海洋区域和古岩层提供了基础，从而促进了对地外活动及其对地球过程影响的研究。

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引用次数: 0

The roles of benthic diversity and environmental factors in nutrient and macrofaunal dynamics within the oxygen minimum zone of the British Columbia continental slope 不列颠哥伦比亚省陆坡最低氧带底栖生物多样性和环境因子在营养和大型动物动态中的作用

IF 2.3 3区地球科学 Q2 OCEANOGRAPHY

Deep-Sea Research Part I-Oceanographic Research Papers

Pub Date : 2025-05-22 DOI: 10.1016/j.dsr.2025.104530

Alessia C. Ciraolo , Paul V.R. Snelgrove , Marta M. Cecchetto , Andrew K. Sweetman

Global warming has expanded oxygen minimum zones (OMZs), or oceanic “dead zones”. Despite their ecological significance, the diversity, and functional roles of benthic organisms in nutrient cycling and carbon (C) uptake in OMZ remain understudied. In this study, we focused on the Northeast Pacific continental slope OMZ (600–1200 m depth) off Vancouver Island, Canada, along an oxygen and depth transect (∼77, 40, and 10 μmol ‧ l⁻¹ at 200-, 475-, 850-m depth, respectively). Using a multicorer we collected sediment cores and performed shipboard incubations to examine organic matter remineralization and nutrient flux rates. In parallel, we performed pulse-chase tracer incubations with isotopically labeled algae (Phaeodactylum sp.) at the 475- and 850-m sites, to assess macrofaunal C uptake and benthic nutrient flux responses to fresh phytodetritus. Our results revealed no clear influence of decreasing oxygen on macrofaunal abundances, nutrient regeneration, or on the role of infauna in organic matter remineralization. Nontheless, organic matter quantity and quality strongly influenced macrofaunal community structure. Despite differences in community composition among sites, we also observed no clear relationship between macrofaunal community composition and nutrient fluxes, with phytoplankton-based food as a key food source for oxygen-deficient-adapted infauna. The highest C uptake rate and highest net nutrient influxes at the 475 m site contrasted lower rates at 850 m site, where only one flabelligerid and one cirratulid polychaete species ingested the organic matter, followed by amphipods, cumaceans, unidentified crustaceans, and bivalves, all primarily in the upper 2 cm of sediment. Our findings highlight the complex interplay of oxygen, depth, and organic matter, suggesting that organic matter quality and quantity may obscure oxygen effects on benthic biodiversity and ecological processes.

全球变暖扩大了氧气最小带（OMZs），即海洋“死亡区”。尽管底栖生物具有重要的生态意义，但其多样性及其在OMZ养分循环和碳(C)吸收中的功能作用仍未得到充分研究。在这项研究中，我们重点研究了加拿大温哥华岛附近东北太平洋大陆坡OMZ （600-1200 m深度），沿着氧气和深度样带（分别在200-，475-，850-m深度为~ 77,40和10 μmol·l−1）。我们使用多层覆盖物收集沉积物岩心，并在船上进行孵育，以检查有机物再矿化和营养通量率。与此同时，我们在475米和850米的地点用同位素标记的藻类（Phaeodactylum sp.）进行了脉冲追踪示踪培养，以评估大型动物对C的吸收和底栖生物对新鲜植物碎屑的营养通量的反应。我们的研究结果显示，氧气减少对大型动物丰度、养分再生或动物在有机物再矿化中的作用没有明显的影响。然而，有机质的数量和质量对大型动物群落结构有强烈的影响。尽管不同地点的群落组成存在差异，但我们也观察到大型动物群落组成与营养通量之间没有明确的关系，以浮游植物为基础的食物是缺氧适应动物的主要食物来源。475 m位置的碳吸收率和净营养物流通量最高，而850 m位置的吸收率较低，只有一种软肋类和一种环状多毛类摄入有机物，其次是片脚类、cumac纲、未识别的甲壳类和双壳类，所有这些都主要在沉积物的上部2 cm。我们的研究结果强调了氧气、深度和有机质之间复杂的相互作用，表明有机质的质量和数量可能掩盖了氧气对底栖生物多样性和生态过程的影响。

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