Deep-sea Research Part Ii-topical Studies in Oceanography最新文献_第3页

A prior-knowledge-integrated downscaling approach for subsurface thermal structure reconstruction in the tropical Indian Ocean 热带印度洋地下热结构重建的先验知识集成降尺度方法

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2026-02-01 Epub Date: 2025-12-31 DOI: 10.1016/j.dsr2.2025.105589

Zhongkun Feng , Jifeng Qi , Bowen Xie , Yuan Cao , Delei Li , Chuanyu Liu , Baoshu Yin

Accurately obtaining high-resolution ocean subsurface thermal structure (OSTS) is essential for resolving mesoscale dynamics in the tropical Indian Ocean (TIO), yet observations remain sparse and uneven. We present a Transformer-based neural network model, the Downscaling Vision Transformer (DSVIT), which integrates prior knowledge to reconstruct high-resolution OSTS in the TIO. Inputs include sea surface temperature (SST), absolute dynamic topography (ADT), and wind stress curl (WSC), as well as temporal, geographic, and climatological information. DSVIT enhances a standard Vision Transformer (ViT) with a geographic positional prior and a physics-aware loss that emphasizes thermocline and surface variability. On an independent test set, DSVIT achieves a Root Mean Square Error (RMSE) of 0.29 °C and a Coefficient of Determination (R²) of 0.9962 for reconstructed subsurface temperature, outperforming traditional recurrent neural network (RNN) and convolutional neural network (CNN) models. Moreover, a key innovation of this study lies in its novel downscaling strategy, which effectively improves the EN4 subsurface temperature resolution from 1° to 1/4° by altering the input segmentation. Compared with traditional interpolation and assessed against independent high-resolution products, the downscaled outputs exhibit lower RMSE and higher R², indicating enhanced physical consistency and mesoscale representation. SHapley Additive exPlanations (SHAP) analysis further reveals that climatology and SST are the dominant predictors, followed by ADT. This study provides a novel approach for downscaling OSTS and offers valuable insights for advancing oceanic and climatic research.

准确获取高分辨率海洋地下热结构（OSTS）对于解析热带印度洋（TIO）中尺度动力学至关重要，但观测数据仍然稀疏且不均匀。我们提出了一种基于变压器的神经网络模型，即降尺度视觉变压器（DSVIT），它集成了先验知识来重建TIO中的高分辨率OSTS。输入包括海温（SST）、绝对动力地形（ADT）、风应力旋度（WSC）以及时间、地理和气候信息。DSVIT增强了标准视觉变压器（ViT）的地理位置先验和强调温跃层和地表变化的物理感知损失。在独立测试集上，DSVIT重建地下温度的均方根误差（RMSE）为0.29°C，决定系数（R2）为0.9962，优于传统的递归神经网络（RNN）和卷积神经网络（CNN）模型。此外，本研究的一个关键创新在于其新颖的降尺度策略，通过改变输入分割，有效地将EN4地下温度分辨率从1°提高到1/4°。与传统插值方法相比，并通过独立的高分辨率产品进行评估，缩小后的输出显示出更低的RMSE和更高的R2，表明物理一致性和中尺度代表性增强。SHapley加性解释（SHAP）进一步揭示了气候和海温是主要的预测因子，其次是ADT。该研究为降低OSTS的尺度提供了一种新的方法，为推进海洋和气候研究提供了有价值的见解。

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引用次数: 0

Primary productivity and N2-fixation in the eastern Indian ocean: Bottom-up support for an ecologically and economically important ecosystem 东印度洋的初级生产力和氮固定：对生态和经济重要生态系统的自下而上支持

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2026-02-01 Epub Date: 2025-11-25 DOI: 10.1016/j.dsr2.2025.105570

Sven A. Kranz , Jared M. Rose , Michael R. Stukel , Karen E. Selph , Natalia Yingling , Michael R. Landry

Oligotrophic ocean regions are characterized by strong nutrient limitation, low standing phytoplankton biomass, and highly efficient nutrient recycling. During the BLOOFINZ-IO expedition (February 2022), we quantified nutrient inventories, primary productivity and N₂ fixation in the Argo Basin of the eastern Indian Ocean, the sole known spawning ground for Southern Bluefin Tuna. Low concentrations of surface nitrate (<0.02 μmol L⁻¹) and persistent residual phosphate indicated N as the limiting macronutrient, with photophysiological indices consistent with iron colimitation. Depth-integrated net primary production (NPP), from ¹⁴C-based in-situ incubations during 4 Lagrangian experiments, averaged ∼460 mg C m⁻²d⁻¹, generally agreeing with mean satellite-based NPP estimates (459 mg C m⁻²d⁻¹) but with spatial discrepancies. Nitrogen fixation provided a consistent new nitrogen source, contributing ∼16 % to local NPP in the upper euphotic zone. Gross primary production (GPP), from fast-repetition-rate-fluorometry-based estimates of electron transport, revealed significant autotrophic respiration losses, with mean GPP:NPP ratios of ∼1.8 consistent with metabolic costs under nutrient limitation. Net community production (NCP) from O₂/Ar ratios averaged ∼20 % of NPP in the upper 30 m. This result, in combination with N₂ fixation measurement, indicates that N₂ fixation supports most of the export production in the region. Together, the multi-method approach revealed a recycling-dominated ecosystem affected by episodic mixing events, where primary productivity is maintained primarily through efficient nitrogen recycling and physiological photoacclimation. These results provide a comprehensive baseline of bottom-up support of ecosystem productivity for the Argo Basin for assessing future climate-driven changes in stratification, nutrient cycling, and food-web dynamics.

低营养海洋区具有养分限制强、浮游植物生物量低、养分循环效率高的特点。在BLOOFINZ-IO考察期间（2022年2月），我们量化了东印度洋Argo盆地（已知唯一的南蓝鳍金枪鱼产卵地）的营养库存、初级生产力和N2固定。低浓度的表面硝酸盐（<0.02 μmol L−1）和持久残留的磷酸盐表明N是限制性常量养分，其光生理指标与铁共生一致。在4次拉格朗日实验中，基于14c的原位孵育的深度综合净初级产量（NPP）平均为~ 460 mg C m−2d−1，与基于卫星的平均NPP估算值（459 mg C m−2d−1）大致一致，但存在空间差异。固氮提供了一致的新氮源，对高光区局部NPP贡献约16%。根据基于快速重复率荧光测量的电子传递估计，总初级产量（GPP）显示了显著的自养呼吸损失，GPP:NPP的平均比率为1.8，与营养限制下的代谢成本一致。O2/Ar比值产生的群落净产量（NCP）平均为30米上游NPP的20%。这一结果与N2固定测量相结合，表明N2固定支持该地区的大部分出口生产。总之，多方法方法揭示了一个以循环为主的生态系统，受偶发性混合事件的影响，其中初级生产力主要通过有效的氮循环和生理光驯化来维持。这些结果为Argo盆地生态系统生产力自下而上的支持提供了一个全面的基线，用于评估未来气候驱动的分层、养分循环和食物网动态变化。

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引用次数: 0

Vertical distribution and environmental drivers of meiofaunal communities in the Persian Gulf: insights into biodiversity and sediment dynamics 波斯湾小型动物群落的垂直分布和环境驱动因素：对生物多样性和沉积物动力学的见解

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2026-02-01 Epub Date: 2025-11-24 DOI: 10.1016/j.dsr2.2025.105571

Narges Badri , Behrooz Abtahi , Abolfazl Saleh , Homira Agah , Hans-Peter Grossart

Unlike earlier studies conducted in shallow coastal areas, this study is the first to examine the vertical distribution of meiofaunal communities at depths ranging from 10 to 93 m at five stations in the northern semi-enclosed Persian Gulf. Among the sampled stations, the highest meiofauna density was observed at Station 2, with an average of 2398 ± 921.4 individuals per 10 cm², while the lowest abundance was recorded at Station 4, amounting to 444.3 ± 96.2 individuals per 10 cm². A comprehensive analysis of 20311 meiofauna individuals representing 29 taxa revealed several dominant groups. Free-living nematodes (51.98 %), foraminifera (27.88 %), copepods (4.9 %), juvenile bivalves (2.79 %), polychaetes (2.76 %), and oligochaetes (2.39 %) comprised together 93 % of the community. The vertical distribution profile indicated that 91 % of the Persian Gulf meiofauna were concentrated in the top 2–3 cm sediment layer, although some were found at depths exceeding 5 cm. The nematode complex exhibited a diverse composition, with 90 genera from 30 families and 7 orders identified across the study sites. Environmental parameters, including sediment characteristics, i.e., dissolved oxygen (DO) as the strongest driver, total organic matter (TOM), grain size, and water depth, emerged as critical factors influencing meiofaunal abundance and diversity. Based on the Environmental Quality Standards (EQS) classification, the sampling stations demonstrated high to good EQS compliance.

与之前在浅海地区进行的研究不同，这项研究是第一次在波斯湾北部半封闭的五个站点，在深度从10米到93米的范围内检查小型动物群落的垂直分布。其中，2号站的数量最多，平均为2398±921.4只/ 10 cm2； 4号站的数量最少，平均为444.3±96.2只/ 10 cm2。对29个分类群的20311个珍稀动物个体进行综合分析，发现了几个优势群。线虫（51.98%）、有孔虫（27.88%）、桡足类（4.9%）、双壳类幼体（2.79%）、多毛类（2.76%）和寡毛类（2.39%）共占群落的93%。垂直分布剖面表明，91%的波斯湾小型动物集中在2 ~ 3 cm的沉积物层上，尽管在深度超过5 cm的地方也发现了一些。线虫复合体显示出多样化的组成，在整个研究地点鉴定出30科7目90属。环境参数，包括沉积物特征，即溶解氧（DO）是最强的驱动因素，总有机质（TOM），粒度和水深是影响微量动物丰度和多样性的关键因素。根据环境质量标准（EQS）分类，采样站符合环境质量标准（EQS）。

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引用次数: 0

Subsurface mixing and ventilation of oxygen minimum zone waters in the southern Bay of Bengal during summer monsoon 夏季风期间孟加拉湾南部氧最小带水域的地下混合和通气

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2026-02-01 Epub Date: 2025-12-15 DOI: 10.1016/j.dsr2.2025.105584

Rajdeep Roy , P.N. Vinayachandran , Jenson George , Amit Sarkar , Chandanlal Parida

During the summer monsoon, the influence of the cyclonic curl of local wind forcing around Sri Lanka causes the formation of a cold dome called the Sri Lanka Dome (SLD), which upwells subsurface water. To the east of SLD, the summer monsoon Current (SMC) flows into the Bay of Bengal (BoB), transporting Arabian Sea high salinity water. We show that SMC, alongside the upwelled waters of SLD, is ventilated episodically during the summer monsoon in the southern BoB, leading to a net exchange of low oxygen subsurface waters with the oxygen-saturated surface mixed layers. We observed the presence of a hypoxic boundary <63 μmol kg⁻¹ very close to the surface. Within the SLD, it shoaled between 35 and 40 m with oxygen concentrations reaching as low as 6 μmol kg⁻¹ at the bottom of the thermocline. Negative fluxes representing the in-gassing rates ranged between (-0.33 to - 9.43 μmol m⁻² sec⁻¹) within SLD and SMC. We emphasize that episodic ventilation observed during this investigation may lead to disequilibrium in the surface mixed layers and can contribute to mid-depth oxygen enrichment. Our present study possibly illustrates a likely mechanism that contributes to preventing denitrification in this region.

在夏季季风期间，斯里兰卡周围的气旋旋度的影响导致了一个被称为斯里兰卡圆顶（SLD）的冷圆顶的形成，该圆顶使地下水上升。在SLD以东，夏季风流（SMC）流入孟加拉湾（BoB），输送阿拉伯海高盐度水。研究表明，在夏季风期间，南太平洋的SMC与SLD上升水一起偶尔通风，导致低氧地下水与含氧饱和的地表混合层的净交换。我们观察到非常接近表面的低氧边界<；63 μmol kg−1的存在。在SLD内，它在35 ~ 40 m之间浅滩，在温跃层底部氧浓度低至6 μmol kg−1。负通量表示SLD和SMC的入气速率在（-0.33 ~ - 9.43 μmol m−2 sec−1）之间。我们强调，在本研究中观察到的间歇性通气可能导致表层混合层的不平衡，并有助于中深度的氧富集。我们目前的研究可能说明了一种可能的机制，有助于防止该地区的反硝化。

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引用次数: 0

Trophic specialization enhances growth performance in larvae of southern bluefin, albacore, and skipjack tunas from the eastern Indian ocean 营养特化提高了东印度洋南部蓝鳍金枪鱼、长鳍金枪鱼和鲣鱼幼虫的生长性能

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2026-02-01 Epub Date: 2025-12-19 DOI: 10.1016/j.dsr2.2025.105585

Raúl Laiz-Carrión , Ricardo Borrego-Santos , José María Quintanilla , Claudio Quezada- Romegialli , Estrella Malca , Rasmus Swalethorp , Francisco Abascal , María Grazia Pennino , Manuel Vargas-Yáñez , Carolina Johnstone , Miguel Ángel Godoy-Bermúdez , David Die , Michael R. Landry

We examined trophic ecology and its influence on larval growth variability for three scombrids, southern bluefin (Thunnus maccoyii, SBT), albacore (T. alalunga, ALB), and skipjack tunas (Katsuwonus pelamis, SKJ), that share a common spawning ground in the eastern Indian Ocean. We combined otolith-based ageing with bulk nitrogen and carbon stable isotope analysis (SIA) of individual larva. Significant interspecific differences in δ¹⁵N and δ¹³C indicate adaptive resource partitioning that allows these tunas to coexist during early ontogeny. Trophic position and isotopic niche were estimated with both frequentist and Bayesian approaches, enabling the evaluation of ontogenetic isotope shifts, niche overlap, and resource use in relation to growth. ALB grew fastest, had the highest trophic position, and the broadest isotopic niche. Optimally growing tuna larvae occupied the narrowest trophic niche and had lower trophic positions for all three species, supporting the hypothesis that strong trophic specialization supports better growth performance and that feeding on more efficient shorter food chains (e.g., microbial loop via appendicularians) can enhance larval fitness. Using lower C:N ratio as a proxy of larval condition found in optimal growing groups supports the broader hypothesis that growth potential is closely tied to energy allocation strategies during early ontogeny. A detailed understanding of how larval trophodynamics, niche breadth, and resource partitioning interact with growth and survival during these vulnerable stages is essential for ecosystem-based management, particularly in systems where growth rate modulates predation risk and competitive fitness.

我们研究了南蓝鳍金枪鱼（Thunnus maccoyii， SBT）、长鳍金枪鱼（T. alalunga， ALB）和鲣鱼（Katsuwonus pelamis， SKJ）这三种鲭鱼的营养生态学及其对幼虫生长变异的影响，这三种鲭鱼在东印度洋共享一个产卵地。我们将基于耳石的老化与个体幼虫的体积氮碳稳定同位素分析（SIA）相结合。δ15N和δ13C的显著种间差异表明，在个体发育早期，这些金枪鱼的适应性资源分配使其能够共存。利用频率和贝叶斯方法估算了营养位置和同位素生态位，从而评估了与生长相关的个体成因同位素变化、生态位重叠和资源利用。ALB生长最快，营养地位最高，同位素生态位最广。最佳生长的金枪鱼幼虫占据了最窄的营养生态位，并且在所有三个物种中都处于较低的营养位置，这支持了强营养专业化支持更好的生长性能的假设，以及更有效的短食物链（例如通过阑尾虫的微生物环）的摄食可以提高幼虫的适应性。利用较低的碳氮比作为最佳生长群体中幼虫状况的代表，支持了一个更广泛的假设，即生长潜力与个体发育早期的能量分配策略密切相关。在这些脆弱阶段，详细了解幼虫营养动力学、生态位宽度和资源分配如何与生长和生存相互作用，对于基于生态系统的管理至关重要，特别是在生长速度调节捕食风险和竞争适应性的系统中。

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引用次数: 0

Dissolved nitrogen in a tropical river-sea continuum: a seasonal view on the distribution and transformation 热带河海连续体中的溶解氮：分布和转变的季节性观点

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2026-02-01 Epub Date: 2025-12-08 DOI: 10.1016/j.dsr2.2025.105583

Longyun Lai , Moritz Müller , Rahayu Sukmaria Sukri , Changi Wong , Aazani Mujahid , Sumei Liu , Zhaomeng Xu , Tim Rixen , Thorsten Warneke , Justus Notholt , Shan Jiang

The Belait River is a typical blackwater river in Brunei, characterized by deep tea-brown water rich in dissolved organic matter (DOM) derived from surrounding peat swamps and rainforests. This study provides a systematic assessment of the chemical composition, transformation, and transport processes of dissolved nitrogen (N) in the Belait River during alternating wet and dry seasons by integrating nitrate (NO₃⁻) stable isotope techniques with microbial analyses. Results indicate that dissolved organic nitrogen (DON) constitutes the primary component of total dissolved nitrogen (TDN), with its seasonal dynamics significantly controlled by hydrological climate and microbial activity. Along the salinity gradient, DON decreases due to dilution and degradation, while ammonium (NH₄⁺) and NO₃⁻ accumulate significantly in densely populated areas owing to anthropogenic inputs. The extremely low dissolved inorganic phosphorus (DIP) concentrations in the Belait River highlight the crucial role of P limitation in maintaining the system's oligotrophic state. Through the investigation in this representative blackwater system, this study highlights complex N cycling mechanisms in blackwater and provides a critical gauge in land-ocean material fluxes at the Indo-Pacific Convergence Area.

Belait河是文莱典型的黑水河流，其特点是深茶色的水富含来自周围泥炭沼泽和雨林的溶解有机质（DOM）。本研究通过将硝酸盐（NO3−）稳定同位素技术与微生物分析相结合，系统地评估了干湿交替季节Belait河中溶解态氮(N)的化学组成、转化和运输过程。结果表明，溶解有机氮（DON）是总溶解氮（TDN）的主要组成部分，其季节动态受水文气候和微生物活动的显著控制。沿盐度梯度，DON因稀释和降解而减少，而在人口密集地区，铵（NH4+）和NO3−因人为输入而显著积累。Belait河中极低的溶解无机磷（DIP）浓度突出了P限制在维持系统寡营养状态中的关键作用。通过对这一具有代表性的黑水系统的调查，本研究突出了黑水中复杂的N循环机制，并为印太辐合区陆-海物质通量提供了一个关键指标。

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引用次数: 0

Temporal stability in genetic origin of juvenile green turtle recruits at remote western Indian Ocean islands 西印度洋偏远岛屿绿海龟幼崽遗传起源的时间稳定性

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-12-01 Epub Date: 2025-09-11 DOI: 10.1016/j.dsr2.2025.105545

Jérôme Bourjea , Quentin Schull , Sylvie Lapègue , Corinne Bouvier , Stéphane Ciccione , Claire Jean , Katia Ballorain , Phillipe Gaspar , Julien Temple Boyer , Christopher Jones , Annabelle Constance , Mayeul Dalleau , Michael Jensen

The increasing anthropogenic and climatic pressures on marine ecosystems raise concerns about the sustainability of their functions, uses and conservation. Marine megafauna such as marine turtles are particularly vulnerable to these pressures due to their life cycle and the variability of habitats they occupy during their life cycle. Understanding how juvenile population dynamics respond to environmental conditions is crucial for designing effective conservation strategies. The present study investigates whether the genetic composition of juvenile green turtles at recruitment sites changes over time. A total of 346 juveniles were sampled at four key recruitment sites in the South Western Indian Ocean - SWIO (Glorieuses, Mayotte, Reunion and Aldabra) during two sampling phases at an interval between 6 and 17 years depending on the site. Based on mtDNA control region sequences, genetic structures were compared between periods within each site. Even if subtle changes in genetic composition may not be detectable with current genetic resolution, our results suggest that the structure of the juvenile green turtle population has not significantly changed over the course of the study period. Such stability in population structure may be correlated with the stability of regional oceanic currents over the last decades in the SWIO, as well as the dynamics of nesting populations in the different regional genetic stocks contributing in regional juvenile green turtle production.

对海洋生态系统日益增加的人为和气候压力引起了人们对其功能、利用和保护的可持续性的关注。海龟等海洋巨型动物由于其生命周期和生命周期中栖息地的可变性，特别容易受到这些压力的影响。了解幼鱼种群动态对环境条件的响应对于设计有效的保护策略至关重要。本研究调查了绿海龟幼龟在招募地点的基因组成是否随时间而变化。在西南印度洋swo的四个主要招募地点（格洛里厄斯、马约特、留尼汪和阿尔达布拉），共有346只幼鱼在两个采样阶段取样，间隔时间为6至17年，具体取决于地点。基于mtDNA控制区序列，比较了每个位点内不同时期的遗传结构。即使遗传组成的细微变化可能无法用当前的遗传分辨率检测到，我们的结果表明，幼绿海龟种群的结构在研究期间没有显着变化。这种种群结构的稳定性可能与近几十年来西南大西洋区域洋流的稳定性有关，也可能与不同区域遗传种群的筑巢种群动态有关，这些种群对区域绿海龟幼崽的生产起着重要作用。

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引用次数: 0

Microbial food web dynamics in tropical waters of the bluefin tuna spawning region off northwestern Australia 澳大利亚西北部蓝鳍金枪鱼产卵区热带水域的微生物食物网动态

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-12-01 Epub Date: 2025-09-13 DOI: 10.1016/j.dsr2.2025.105547

Michael R. Landry , Michael R. Stukel , Natalia Yingling , Karen E. Selph , Sven A. Kranz , Christian K. Fender , Rasmus Swalethorp , Ria I. Bhabu

Whereas recruitment success for many fisheries depends on coincident timing of larvae with abundance peaks of their prey, less can be more in the tropical/subtropical spawning areas of bluefin tunas if lower but steady food resources are offset by reduced larval vulnerability to pelagic predators. To understand larval habitat characteristics for Southern Bluefin Tuna (SBT), we quantified microbial community carbon flows based on growth and grazing rates from depth profiles of dilution incubations and carbon biomass assessments from microscopy and flow cytometry (FCM) during their peak spawning off NW Australia (Indian Ocean) in February 2022. Two Chla-based estimates of phytoplankton production gave differing offsets due to cycling or mixotrophy, exceeding ¹⁴C net community production on average (677 ± 98 versus 447 ± 43 mg C m⁻² d⁻¹). Productivity was higher than in the Gulf of Mexico spawning area for Atlantic Bluefin Tuna but less than similar studies of oceanic upwelling regions. Microzooplankton grazing averaged 482 ± 63 mg C m⁻² d⁻¹ (71 ± 13 % of production). Two measurement variables for Prochlorococcus gave average production and grazing rates of 282 ± 36 and 248 ± 32 mg C m⁻² d⁻¹ (86 ± 6 % grazed). Prochlorococcus comprised almost half of production and grazing fluxes in the upper (0–25 m) euphotic zone where SBT larvae reside. Prochlorococcus declined and eukaryotic phytoplankton and heterotrophic bacteria increased in relative importance in the lower euphotic zone. These results describe relatively classic open-ocean oligotrophic conditions as the food web base for nutritional flows to SBT larvae.

虽然许多渔业的成功招募取决于幼虫与猎物丰度高峰的时间一致，但在热带/亚热带蓝鳍金枪鱼产卵区，如果较低但稳定的食物资源被较低的幼虫对远洋捕食者的脆弱性降低所抵消，则可能会减少。为了了解南蓝鳍金枪鱼（SBT）的幼虫栖息地特征，我们基于稀释孵育深度剖面的生长和放牧率，以及显微镜和流式细胞术（FCM）的碳生物量评估，对南蓝鳍金枪鱼（SBT）在西北澳大利亚（印度洋）产卵高峰期间的微生物群落碳流量进行了量化。两种基于chla的浮游植物产量估计值由于循环或混合营养作用而产生了不同的抵消，平均超过14C净群落产量（677±98和447±43 mg C m - 2 d - 1）。生产力高于墨西哥湾大西洋蓝鳍金枪鱼的产卵区，但低于海洋上升流地区的类似研究。小型浮游动物的平均放牧量为482±63 mg C m−2 d−1（占产量的71±13%）。原绿球藻的两个测量变量给出的平均产量和放牧率分别为282±36和248±32 mg C m - 2 d - 1（放牧率为86±6%）。原绿球藻几乎占SBT幼虫居住的上（0-25米）高光区生产和放牧通量的一半。原绿球藻数量减少，真核浮游植物和异养细菌在较低光带的相对重要性增加。这些结果描述了相对经典的开放海洋寡营养条件作为SBT幼虫营养流动的食物网基础。

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引用次数: 0

Implications of gear selection for monitoring benthic fish communities in the Beaufort Sea 波弗特海底栖鱼类群落监测的渔具选择意义

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-12-01 Epub Date: 2025-11-06 DOI: 10.1016/j.dsr2.2025.105561

Duane E. Stevenson , Stan Kotwicki , Brenda Norcross , Andrew Majewski

A series of bottom-trawl surveys were conducted in the Beaufort Sea in the years 2012–2014 to compare catch characteristics among gear types using paired research trawls. In the western Beaufort Sea, an American team compared two types of benthic beam trawls, while in the eastern Beaufort Sea, a Canadian team compared a benthic beam trawl with a larger Otter trawl. These surveys documented a relatively low-diversity community of primarily benthic and demersal fishes, which consisted of primarily small (<20 cm TL) individuals. Catch biomass in the eastern Beaufort Sea was dominated by Arctic cod, while in the western Beaufort Sea the biomass was more evenly distributed among Arctic cod, skates, eelpouts, and other species. Large gadids (>20 cm TL) were notably absent from all catches. Size selectivity among the two benthic beam trawls in the western Beaufort Sea was similar. However, the plumb-staff beam trawl captured a higher proportion of the smallest specimens and had a higher probability of detection than the high-rise benthic beam trawl throughout the size range of fish specimens encountered. Selectivity differences between the beam trawl and Otter trawl in the eastern Beaufort Sea were more pronounced, as the benthic beam trawl captured a greater proportion of smaller fishes, but the Otter trawl captured a much higher proportion of larger fishes. Probability of detection was notably higher for the Otter trawl throughout the size range. These results confirm that estimates of diversity, biomass, and size distribution produced from trawl surveys are highly dependent on gear type.

2012-2014年，在波弗特海进行了一系列底拖网调查，使用配对研究拖网来比较不同渔具类型的捕获特性。在波弗特海西部，一个美国团队比较了两种底生物束拖网，而在波弗特海东部，一个加拿大团队比较了底生物束拖网和更大的水獭拖网。这些调查记录了一个相对低多样性的主要底栖和底栖鱼类群落，主要由小型（< 20cm TL）个体组成。东波弗特海的渔获生物量以北极鳕鱼为主，西波弗特海的渔获生物量以北极鳕鱼、冰鱼、鳗鱼等物种分布较为均匀。在所有捕获物中明显没有大的小穗状花序（> 20cm TL）。波弗特海西部两种底栖梁拖网的尺寸选择性相似。然而，在遇到的所有鱼类标本的大小范围内，铅杆梁拖网捕获的最小标本比例高于高层底栖梁拖网，并且具有更高的检测概率。在东波弗特海，梁拖网和水獭拖网的选择性差异更为明显，底底生物拖网捕获的小鱼比例更高，而水獭拖网捕获的大鱼比例更高。在整个大小范围内，水獭拖网的探测概率明显更高。这些结果证实，从拖网调查中得出的多样性、生物量和大小分布的估计高度依赖于渔具类型。

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引用次数: 0

Plastic pollution: A potential vector of both pathogens and probiotics for corals on the Mascarene Ridge, Indian Ocean 塑料污染：印度洋马斯克林海岭珊瑚病原体和益生菌的潜在载体

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-12-01 Epub Date: 2025-10-23 DOI: 10.1016/j.dsr2.2025.105556

Vyctoria Marillac , Philippe Jourand , Pierre-Louis Stenger , Gwennais Fustemberg , Julie Gindrey , Margot Thibault

In marine environments, plastic debris serves as a vector for pathogenic bacteria that can negatively impact marine fauna, including corals. The Saya de Malha and Nazareth Banks, located in the Indian Ocean, harbor an extensive area of coral reefs that may be susceptible to diseases associated with plastic pollution. In this context, we aimed to determine whether plastic debris in this region can act as a vector for coral-associated pathogenic bacteria. During the "Indian Ocean mission 2022," floating plastic debris (>500 μm) was collected from the Saya de Malha region using manta trawling. The collected debris were quantified, classified by type, size, and weighed. The associated microbiome, along with the viable bacterial communities attached to the plastic, were analyzed using 16S rDNA high-throughput sequencing and traditional molecular and microbiological techniques. A high concentration of plastic debris was recorded both on Saya de Malha and Nazareth Bank, with 10⁵ items.km⁻². The mean viable bacterial count was 15,519 ± 9340 CFU/g of plastic debris. Nine bacterial phyla were identified, with Firmicutes (58 % of the total) and Proteobacteria (42 %) being the dominant groups. The bacterial diversity on the plastic was measured at 0.92, including coral pathogens, such as Acinetobacter (27 %), Psychrobacter (2 %), and Pseudomonas (2 %). In addition, probiotic bacteria such as Exiguobacterium (58 %), Rheinheimera (1 %), and Idiomarina (1 %) were also detected. This preliminary study states the presence of both pathogenic and probiotic coral-associated fixed to plastic. Further research is needed to confirm their direct effect on coral reef disease. Nevertheless, these findings add to the growing evidence of the widespread presence of plastic debris floating in the region.

在海洋环境中，塑料碎片是致病菌的载体，会对包括珊瑚在内的海洋动物产生负面影响。位于印度洋的Saya de Malha和拿撒勒浅滩拥有大面积的珊瑚礁，可能容易受到与塑料污染有关的疾病的影响。在这种情况下，我们的目的是确定该地区的塑料碎片是否可以作为珊瑚相关致病菌的载体。在“印度洋任务2022”期间，使用蝠鲼拖网在Saya de Malha地区收集了漂浮的塑料碎片（>500 μm）。收集到的碎片按类型、大小和重量进行了量化、分类。使用16S rDNA高通量测序和传统的分子和微生物学技术分析了相关的微生物组，以及附着在塑料上的活菌群落。在Saya de Malha和拿撒勒银行都记录到了高浓度的塑料碎片，有105件。平均活菌数为15519±9340 CFU/g。共鉴定出9个细菌门，其中厚壁菌门（占总数的58%）和变形菌门（42%）是优势类群。塑料上的细菌多样性测量为0.92，包括珊瑚病原体，如不动杆菌（27%），冻干杆菌（2%）和假单胞菌（2%）。此外，还检出了Exiguobacterium（58%）、Rheinheimera（1%）和Idiomarina（1%）等益生菌。本初步研究表明，与珊瑚相关的致病性和益生菌均固定在塑料上。需要进一步的研究来证实它们对珊瑚礁疾病的直接影响。然而，这些发现进一步证明，该地区漂浮着广泛存在的塑料碎片。

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引用次数: 0