Deep-sea Research Part Ii-topical Studies in Oceanography最新文献_第4页

Offshore demersal fish community structure and habitat associations in Amundsen Gulf, Canadian Arctic 加拿大北极阿蒙森湾近海底栖鱼类群落结构与生境关联

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-09-16 DOI: 10.1016/j.dsr2.2025.105548

Andrew R. Majewski , Krystal Woodard , Andrea Niemi , Sheila Atchison , Jane Eert , Shannon MacPhee , James D. Reist

Marine fishes occupy a range of trophic positions, all of which play integral roles in energy pathways within and amongst habitats. Understanding marine fish community structure and habitat associations is prerequisite to understanding ecosystem structure and function in the western Canadian Arctic, and the lack of regional-scale information impedes effective regulation of emerging industrial activities and climate adaptation strategies. Our study documented 46 demersal fish species from 29 genera, recording eight new species occurrences for Amundsen Gulf. The demersal fish community of Amundsen Gulf is largely structured by the depth-mediated water masses of the region where they interface with seafloor habitats. The fish assemblages appeared stable over the seven-year span of the study, while interannual fluctuations in abundance reflected species-level variability. Species richness was higher in Amundsen Gulf relative to the adjacent Canadian Beaufort Shelf and slope, but indexes for evenness and species dominance in Amundsen Gulf were skewed by the pervasiveness of Boreogadus saida. The average abundance of B. saida was 4.7 times higher at stations where fishing occurred within Atlantic waters relative to Pacific waters, with peak average abundance documented in Minto Inlet. The deep Atlantic water and large embayments of Amundsen Gulf support high abundances of B. saida across life-history stages and warrant special consideration for industrial planning and conservation initiatives. Our results provide contemporary baselines on marine fish community structure and diversity for the Amundsen Gulf region and provide a basis for evaluating future change and comparisons with neighboring regions.

海洋鱼类占据着一系列的营养位置，所有这些都在栖息地内部和之间的能量途径中发挥着不可或缺的作用。了解海洋鱼类群落结构和栖息地关联是了解加拿大北极西部生态系统结构和功能的先决条件，缺乏区域尺度的信息阻碍了对新兴工业活动和气候适应战略的有效调控。我们的研究记录了来自29属的46种底栖鱼类，记录了阿蒙森湾出现的8个新物种。阿蒙森湾的底栖鱼类群落在很大程度上是由该地区的深水水体构成的，在那里它们与海底栖息地相连接。在研究的7年时间里，鱼类组合似乎很稳定，而丰度的年际波动反映了物种水平的可变性。阿蒙森湾的物种丰富度相对于邻近的加拿大波弗特陆架和斜坡较高，但均匀度和物种优势度指数受北海北岸的普遍影响而有所偏斜。在大西洋水域捕鱼的站点，相对于太平洋水域，B. saida的平均丰度高出4.7倍，记录的平均丰度峰值出现在Minto Inlet。大西洋深水和阿蒙森湾的大型海湾在整个生命史阶段都支持着丰富的白鲟，因此需要特别考虑工业规划和保护措施。我们的研究结果为阿蒙森湾地区的海洋鱼类群落结构和多样性提供了当代基线，并为评估未来变化和与邻近地区的比较提供了基础。

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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 : 2025-09-13 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

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 : 2025-09-11 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

A comparison of deep-sea coral and sponge species distribution models and the impact of ocean currents in the Southern California Bight 南加州湾深海珊瑚和海绵物种分布模型的比较及洋流的影响

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-09-11 DOI: 10.1016/j.dsr2.2025.105546

Nissa Kreidler , Andre Buchheister , David D. Huff , Jerome Fiechter , Mary Yoklavich , Mark J. Henderson

Deep-sea corals and sponges (DSCS) are signature taxa of deep-water habitats, but ecological mechanisms that drive their geographic distributions can be difficult to uncover due to the challenges of surveying deep-water ecosystems and limited oceanographic data. A comparison of species distribution models was made for three DSCS (Antipathes dendochristos, Plumarella longispina, and an unidentified sponge morphotype known as Porifera #2), two of which are associated with young-of-the-year and adult rockfish taxa (Sebastes spp.). Models were built using generalized additive models (GAMs) that accounted for spatial autocorrelation. These models were compared to Maxent models, a commonly used method. All models utilized bathymetrically derived variables (including depth, slope, and Bathymetric Position Index) and output from a coupled physical-biogeochemical ocean model (including current direction and magnitude, food abundance, and dissolved oxygen). Direction of benthic ocean currents played an important role in predictions, pointing to large-scale ecological processes that may determine presence of DSCS. GAMs outperformed Maxent models and predicted more ecologically interpretable patterns. Additionally we quantified the predicted amount of suitable habitat that is currently located within some protected areas of the Southern California Bight and show that many hot spots occur outside protected areas. Given the importance of DSCS for multiple demersal fish species of commercial or conservation concerns, this research provides valuable information that natural resource managers can use as a tool in the Southern California Bight.

深海珊瑚和海绵（DSCS）是深海栖息地的标志性分类群，但由于调查深水生态系统的挑战和有限的海洋学数据，驱动其地理分布的生态机制很难揭示。对三种DSCS （Antipathes dendochristos， Plumarella longispina和一种未识别的海绵形态称为Porifera #2）的物种分布模型进行了比较，其中两种与幼年和成年岩鱼分类群（sebases spp.）有关。利用广义加性模型（GAMs）建立模型，考虑空间自相关。将这些模型与常用的Maxent模型进行比较。所有的模型都利用了水深衍生变量（包括深度、坡度和水深位置指数）和物理-生物地球化学耦合海洋模型的输出（包括洋流方向和震级、食物丰度和溶解氧）。底栖洋流的方向在预测中发挥了重要作用，指出了可能决定DSCS存在的大规模生态过程。GAMs优于Maxent模型，并预测了更多的生态可解释性模式。此外，我们量化了目前位于南加州湾一些保护区内的适宜栖息地的预测数量，并表明许多热点发生在保护区外。鉴于DSCS对多种商业或保护的底栖鱼类物种的重要性，本研究提供了有价值的信息，自然资源管理者可以将其作为南加州湾的工具。

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引用次数: 0

Enhanced eddy kinetic energy in the southeastern Arabian Sea during winter: the influence of surface currents and wind force 冬季阿拉伯海东南部涡旋动能增强：海面洋流和风力的影响

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-09-03 DOI: 10.1016/j.dsr2.2025.105537

Ullas M. Pillai , Ajith Joseph K , Roshin P. Raj , Ola M. Johannessen

Eddy kinetic energy (EKE) in the southeastern Arabian Sea (SEAS) during the relatively least explored winter season spanning 28 years (1993–2020) was studied using satellite observational and reanalysis data from the Copernicus Marine Service Data Center. The generation and enhancement of EKE resulting from current instabilities are discussed, and the significant role of barotropic energy conversion in the SEAS, is further examined, considering the roles of surface currents and wind forcing obtained from ERA5 reanalysis dataset. The strong EKE observed during winter within the Laccadive Sea in the SEAS is partly attributed to dominant barotropic instability arising from horizontal shear in surface currents driven by strong negative wind stress curl. Furthermore, EKE shows a significant positive correlation with chlorophyll-a (Chl-a) concentration during winter in the SEAS, highlighting the influence of physical-biological coupling associated with eddies and the zonal advection of Bay of Bengal waters by the northeast monsoon current.

利用哥白尼海洋服务数据中心的卫星观测和再分析数据，研究了阿拉伯海东南部（SEAS）相对较少探测的28年冬季（1993-2020年）的涡旋动能（EKE）。本文讨论了洋流不稳定导致的EKE的产生和增强，并结合ERA5再分析数据获得的地表流和风强迫的作用，进一步探讨了正压能量转换在海洋中的重要作用。冬季在南海拉卡迪夫海观测到的强EKE部分归因于强负风应力旋度驱动的地表流水平切变引起的主要正压不稳定。此外，EKE与冬季海洋叶绿素-a （Chl-a）浓度呈显著正相关，突出了东北季风流对孟加拉湾水域涡旋和纬向平流的物理-生物耦合的影响。

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引用次数: 0

Diatom assemblages in coral patches of the Northwestern Persian Gulf: Community structure across substrates and proximity to oil sites 波斯湾西北部珊瑚斑块中的硅藻组合：跨底物和靠近石油点的群落结构

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-09-01 DOI: 10.1016/j.dsr2.2025.105535

Mahtab Azari , Ali Nasrolahi , Mohammad Reza Shokri , Roksana Majewska

Diatoms, essential primary producers in coral reef ecosystems, are highly sensitive to environmental changes, making them effective bioindicators of ecosystem health. This study investigates diatom assemblages in northwestern Persian Gulf coral reefs, comparing communities in oil-polluted sites around Kharg Island with those in less-impacted conditions near Khargoo Island. A total of 86 diatom taxa from 37 genera were identified across live and dead coral tissues and coral rubble. The most abundant species across all samples (average ± SD) were Halamphora coffeiformis (8.43 ± 1.4 %), Nitzschia dissipata (5.94 ± 2.11 %), and H. borealis (5.75 ± 1.39 %). Statistical analyses revealed that substrate type significantly influenced species richness, with dead corals hosting more diatom species than live corals and coral rubble. While no significant difference in species richness was observed between the oil-polluted and control sites, the assemblages differed compositionally. Diatom communities growing on living corals from the polluted site showed the highest level of within-group dissimilarity, which may indicate habitat instability and a state of dysbiosis. These findings suggest that community differences may be associated with chronic oil exposure, and that substrate type plays an important role in shaping diatom communities. The results also signal the potential of certain diatom species as indirect bioindicators responding not only to the pollutants present at the sampling location but also to the condition of a possibly more sensitive host. Further research is needed to assess the long-term effects of oil pollution on coral reef health and diatom-coral interactions.

硅藻是珊瑚礁生态系统重要的初级生产者，对环境变化高度敏感，是生态系统健康的有效生物指标。本研究调查了波斯湾西北部珊瑚礁的硅藻群落，比较了哈尔格岛周围受石油污染的地区和哈尔格岛附近受影响较小的地区的群落。在活珊瑚、死珊瑚组织和珊瑚碎石中共鉴定出37属86个硅藻类群。在所有样本中丰度最高的物种（平均±SD）分别为：黑腹虫（8.43±1.4%）、耗散Nitzschia（5.94±2.11%）和北方黑腹虫（5.75±1.39%）。统计分析显示，基质类型显著影响物种丰富度，死珊瑚比活珊瑚和珊瑚碎石承载更多的硅藻物种。油污染样地与对照样地物种丰富度差异不显著，但群落组成存在差异。生长在受污染地点的活珊瑚上的硅藻群落表现出最高的群内差异，这可能表明生境不稳定和生态失调状态。这些发现表明，群落差异可能与长期油暴露有关，并且底物类型在硅藻群落的形成中起重要作用。研究结果还表明，某些硅藻物种具有作为间接生物指标的潜力，不仅对采样地点存在的污染物作出反应，而且对可能更敏感的宿主的状况作出反应。需要进一步的研究来评估石油污染对珊瑚礁健康和硅藻-珊瑚相互作用的长期影响。

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引用次数: 0

Impacts of barite and bentonite sedimentation on the behaviour, mucus production and cnidocytes of the deep-sea coral Flabellum (Ulocyathus) alabastrum 重晶石和膨润土沉积对深海珊瑚Flabellum (Ulocyathus) alabastrum行为、粘液生成和刺丝细胞的影响

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-08-23 DOI: 10.1016/j.dsr2.2025.105536

Kathryn Murray , Bárbara de Moura Neves , Jean-François Hamel , Johanne Vad , Vonda Hayes , Annie Mercier

As oil and gas exploration expands in deep-sea environments, understanding the impacts of wastes produced by this industry is urgent. One of the main wastes of offshore drilling is the discharge of drill muds, commonly including barite and bentonite clay. Here, we investigated the effects of these two byproducts on the expansion behaviour, mucus secretion and cnidocyte density of the solitary cup coral Flabellum (Ulocyathus) alabastrum. A total of 96 live corals were exposed over 10 days to one of three treatments (barite, bentonite, or barite and bentonite combined) or assigned as an untreated control. Daily waste additions aimed to reach a total sedimentation depth of 6.3 mm (common ‘probable no-effects threshold’). Photography was used to monitor behavioural changes and mucus production, and histology was used to assess changes in tentacle cnidocytes. Overall, responses of F. alabastrum in the form of excessive polyp expansion (swelling) and mucus production were more severe under the barite and bentonite combined treatment, followed by barite alone, bentonite alone and lowest/absent in the control. Moreover, elevated nematocyte densities were measured under exposure to the mix of barite and bentonite. However, F. alabastrum returned to baseline metrics during a 10-day recovery period. The results suggest that sedimentation of common drill mud ingredients to <6.3 mm depth can cause observable and non-lethal responses in F. alabastrum, but remain conservative relative to what may be experienced in situ. As the most adverse effects were observed under the barite and bentonite combination treatment (tested together for the first time here), potential synergistic effects of the two should be considered in future research. Understanding long-term consequences, as well as impacts of more abrasive drilling waste (drill cuttings) on F. alabastrum requires further study.

随着石油和天然气勘探在深海环境中的扩展，了解该行业产生的废物的影响迫在眉睫。海上钻井的主要废物之一是钻井泥浆的排放，通常包括重晶石和膨润土粘土。本文研究了这两种副产物对单杯珊瑚Flabellum (Ulocyathus) alabastrum的膨胀行为、粘液分泌和刺胞细胞密度的影响。共有96个活珊瑚在10天内暴露于三种处理（重晶石、膨润土或重晶石和膨润土混合）中的一种，或被指定为未经处理的对照组。每日添加废物的目标是达到总沉降深度6.3毫米（常见的“可能无影响阈值”）。摄影用于监测行为变化和粘液产生，组织学用于评估触须毛囊细胞的变化。总体而言，重晶石和膨润土联合处理下，alabastrum的反应以息肉过度膨胀（肿胀）和粘液产生的形式更为严重，其次是单独的重晶石，单独的膨润土，而对照组最低或没有。此外，在暴露于重晶石和膨润土混合物下，测量了线虫细胞密度的升高。然而，在10天的恢复期内，鹅角菇恢复到基线指标。结果表明，普通钻井泥浆成分沉积至6.3 mm深度可引起F. alabastrum的可观察和非致命反应，但相对于原位可能经历的反应仍然保守。由于重晶石和膨润土组合处理（本文首次同时进行试验）的不良反应最多，因此在今后的研究中应考虑两者的潜在协同效应。了解长期后果，以及更多的研磨性钻井废物（钻屑）对alabastrum的影响，需要进一步研究。

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引用次数: 0

Distribution of free–Living marine nematodes along environmental gradients in the strait of hormuz 霍尔木兹海峡自由海洋线虫沿环境梯度的分布

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-08-20 DOI: 10.1016/j.dsr2.2025.105532

Mehrshad Taheri , Mohammad Ali Hamzeh , Abolfazl Saleh , Maryam Yazdani Foshtomi , Ahmad Radmanesh

Understanding the drivers of nematode community structure in subtidal ecosystems is critical for assessing marine biodiversity and ecosystem health. As sensitive bioindicators of environmental change, marine nematodes provide crucial insights into ecosystem dynamics; however, their spatial distribution patterns in the Persian Gulf's subtidal zones remain poorly understood. This study investigates the spatial variability of free–living nematode communities across five distinct transects in this understudied region. A total of 2189 specimens, representing 60 different genera, were identified. Nematode density showed significant variation, ranging from 16.7 to 92.6 individuals in 10 cm², with the highest densities typically found at the shallowest stations. The average number of genera per sample ranged from 1 to 18.67. The Shannon diversity indices varied significantly, with a maximum of 2.58 and a minimum of 0, while evenness scores ranged from 0.76 to 1. Notable differences in nematode community structure were observed across the various transects and stations. The overall nematode community was dominated by genera such as Actinonema, Axonolaimus, Dorylaimopsis, Gnomoxyala, Halalaimus, Hopperia, Marylynnia, Pierrickia, Sabatieria, Subsphaerolaimus, and Terschellingia across different transects. According to DistLM analysis, depth, salinity, mean grain size, pH, and temperature together explained 22.9 % of the total variance in the nematode community, with depth accounting for 9.3 % and the other significant variables contributing an additional 13.6 %. Further research is essential to clarify the relationship between nematode communities and environmental conditions in underexplored ecosystems like this region.

了解潮下生态系统中线虫群落结构的驱动因素对于评估海洋生物多样性和生态系统健康至关重要。作为环境变化的敏感生物指标，海洋线虫为生态系统动力学提供了重要的见解；然而，它们在波斯湾潮下带的空间分布模式仍然知之甚少。本研究调查了该地区5个不同样带中自由生活线虫群落的空间变异。共鉴定了60个不同属的2189个标本。线虫密度变化显著，在16.7 ~ 92.6只/ 10 cm2之间，最浅的站点密度最高。每个样本的平均属数为1 ~ 18.67。Shannon多样性指数变化显著，最大值为2.58，最小值为0，均匀度评分范围为0.76 ~ 1。线虫群落结构在不同样带和站点间存在显著差异。线虫群落总体上以放线线虫属、轴索线虫属、Dorylaimopsis属、Gnomoxyala属、Halalaimus属、Hopperia属、Marylynnia属、Pierrickia属、Sabatieria属、Subsphaerolaimus属和Terschellingia属为主。根据DistLM分析，深度、盐度、平均粒度、pH和温度共同解释了线虫群落总方差的22.9%，深度占9.3%，其他显著变量贡献了13.6%。进一步的研究是必要的，以澄清线虫群落和环境条件之间的关系，在未开发的生态系统，如该地区。

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引用次数: 0

Mesozooplankton community responses to environmental stressors in Kuwait's first marine protected area 科威特首个海洋保护区中浮游动物群落对环境压力的响应

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-08-19 DOI: 10.1016/j.dsr2.2025.105533

Rakhesh Madhusoodhanan, Turki Al-Said, Faiza Al-Yamani, Gopikrishna Mantha, Takahiro Yamamoto, Loreta Fernandes, Ayaz Ahmed, Nithyanandan Manickam, Amit Sarkar, Sabeena Habeebullah Koduvayur Habeebullah, Fathima Thuslim, Waleed Al-Zekri, Jessy Sebastian, Maryam Al-Enezi

Understanding mesozooplankton (MSP) dynamics in nursery habitats is crucial for assessing ecosystem health and trophic interactions, particularly in anthropogenically stressed yet ecologically significant areas, such as Sulaibikhat Bay – home to Kuwait's first Marine Protected Area (MPA) in the northwestern Arabian/Persian Gulf (NWG). This study examines MSP community dynamics and environmental interactions over 26 months (October 2018–March 2021) across five fixed stations, including sites influenced by desalination and sewage outfalls. Seasonal fluctuations in water temperature, salinity, and nutrients significantly influenced MSP community structure. Copepods dominated, with cyclopoids (Oithona spp.) peaking in summer and fall, while calanoids (Parvocalanus crassirostris, Acartia spp.) were more prevalent in winter and spring. The cyclopoid-to-calanoid ratio, a potential indicator of trophic shifts, varied significantly across seasons, with cyclopoids prevailing in warmer months. Diversity and dispersion patterns, assessed through Venn diagrams and PERMDISP analysis, revealed higher species turnover near polluted sites and greater stability within the MPA. Taxonomic relatedness indices (AvTD, VarTD) indicated reduced diversity in chronically stressed areas. BIOENV and RELATE analyses identified temperature, dissolved oxygen, turbidity, and nanophytoplankton chlorophyll a as key drivers of the MSP community. Significant negative correlations between fish larvae and cyclopoids near the Al-Ghazali sewer outlet suggested potential prey-predator interactions, reinforcing the ecological implications of MSP composition shifts in this nursery habitat. While the MPA supports high MSP diversity, ongoing stressors, such as brine discharge and sewage, continue to shape the MSP community and trophic interactions. This study provides critical insights for ecosystem-based management of marine resources in and around Kuwait's first MPA in the NWG.

了解苗圃栖息地中浮游动物（MSP）的动态对于评估生态系统健康和营养相互作用至关重要，特别是在人为压力较大但具有重要生态意义的地区，如Sulaibikhat湾——科威特西北阿拉伯/波斯湾（NWG）首个海洋保护区（MPA）所在地。本研究考察了五个固定站点26个月（2018年10月至2021年3月）的MSP社区动态和环境相互作用，包括受海水淡化和污水排放影响的站点。水温、盐度和养分的季节波动对MSP群落结构有显著影响。以桡足类为主，夏秋两季以圆足类（Oithona）居多，冬春两季以卡拉类（Parvocalanus crassirostris, Acartia）居多。作为营养转移的潜在指标，环样体与类callanoid比值在不同季节变化显著，在温暖的月份环样体普遍存在。通过维恩图和PERMDISP分析评估的多样性和分散模式显示，污染地点附近的物种流动率更高，MPA内的稳定性更高。分类相关性指数（AvTD, VarTD）表明，慢性应激区物种多样性降低。BIOENV和RELATE分析发现温度、溶解氧、浊度和纳米浮游植物叶绿素a是MSP群落的关键驱动因素。Al-Ghazali下水道出口附近的鱼类幼虫和cyclopoids之间存在显著的负相关，表明潜在的捕食者-捕食者相互作用，加强了该苗期栖息地MSP组成变化的生态意义。虽然海洋保护区支持MSP的高度多样性，但持续的压力因素，如盐水排放和污水，继续塑造MSP群落和营养相互作用。这项研究为基于生态系统的海洋资源管理提供了重要的见解，这些海洋资源管理是科威特在NWG的第一个海洋保护区。

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引用次数: 0

Functional group dynamics and environmental forcing of microphytoplankton in the Persian Gulf: Temporal patterns from Khark and Qeshm Islands 波斯湾微型浮游植物的功能群动力学和环境强迫：来自哈尔克和格什姆群岛的时间模式

IF 3 3区地球科学 Q2 OCEANOGRAPHY

Deep-sea Research Part Ii-topical Studies in Oceanography

Pub Date : 2025-08-18 DOI: 10.1016/j.dsr2.2025.105534

Emad Koochaknejad, Abolfazl Saleh

Phytoplankton communities play a crucial role in marine ecosystem resilience and biogeochemical cycling, yet their functional responses to environmental fluctuations in extreme environmental conditions like the Persian Gulf remain poorly understood. This study investigates the temporal and spatial structuring of microphytoplankton communities around Khark and Qeshm Islands in the Persian Gulf over an annual cycle (November 2021 to December 2022), integrating taxonomic diversity with a trait-based functional approach to assess adaptive strategies under varying physicochemical conditions. Monthly sampling was conducted at six stations (three per island), and phytoplankton functional diversity was quantified based on nine key traits: photosynthetic pigment composition, growth form, body size, motility, nitrogen-fixing ability, trophic strategy, cell wall composition, long projections, and vertical migration. The results reveal distinct ecological regimes between the two islands. The phytoplankton communities in Qeshm Island are taxonomically diverse but functionally stable, reflecting ecological stability under relatively constant environmental conditions. In contrast, the Khark phytoplankton communities exhibit pronounced seasonal shifts in functional diversity shaped by fluctuations in salinity, carbonate chemistry, and nutrient availability. Clustering analysis identified six functional groups with two dominant assemblages: Group 6 (Trichodesmium erythraeum, a diazotrophic cyanobacterium) and Group 4 (chain-forming diatoms such as Chaetoceros spp.). Carbonate saturation state, nitrate availability, and temperature were identified as key environmental factors shaping both taxonomic and functional community composition (as indicated by Canonical Correspondence Analysis (CCA) and Fourth-Corner Analysis). Furthermore, large-scale Trichodesmium erythraeum blooms in Khark during summer and early autumn significantly altered carbonate system equilibrium, a novel insight into phytoplankton trait-environment relationships in the Persian Gulf, highlighting the capacity of diazotrophic cyanobacteria to drive biogeochemical feedback loops through nitrogen fixation, pH modulation, and shifts in carbonate saturation state, with potential implications for regional carbon cycling.

浮游植物群落在海洋生态系统恢复力和生物地球化学循环中发挥着至关重要的作用，但在波斯湾等极端环境条件下，它们对环境波动的功能响应仍然知之甚少。本研究调查了波斯湾哈尔克岛和格什姆岛周围浮游植物群落在一个年度周期（2021年11月至2022年12月）的时空结构，将分类多样性与基于性状的功能方法结合起来，评估不同物理化学条件下的适应策略。每月在6个站点（每个岛屿3个）取样，并根据光合色素组成、生长形式、体型、能动性、固氮能力、营养策略、细胞壁组成、长投影和垂直迁移等9个关键性状对浮游植物的功能多样性进行量化。结果揭示了两个岛屿之间不同的生态制度。Qeshm岛浮游植物群落分类多样，功能稳定，反映了相对恒定环境条件下的生态稳定性。相比之下，哈尔克浮游植物群落在功能多样性上表现出明显的季节性变化，这种变化受盐度、碳酸盐化学和养分有效性的波动影响。聚类分析确定了6个功能基团，其中有两个优势组合：第6组（Trichodesmium erythraeum，一种重氮营养蓝藻）和第4组（Chaetoceros spp.等链状硅藻）。通过典型对应分析（Canonical Correspondence Analysis， CCA）和四角分析（Fourth-Corner Analysis）发现，碳酸盐饱和状态、硝酸盐有效性和温度是影响群落分类和功能组成的关键环境因素。此外，在夏季和初秋期间，Khark的大规模赤色菌繁殖显著改变了碳酸盐系统平衡，这是对波斯湾浮游植物性状-环境关系的新见解，突出了重氮营养蓝藻通过固氮、pH调节和碳酸盐饱和状态的变化驱动生物地球化学反馈回路的能力，并对区域碳循环具有潜在影响。

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引用次数: 0