Harmful Algae最新文献_第3页

HAB species of the Bohai Sea detected through metabarcoding in three large-scale seasonal expeditions 利用元条形码技术对三次大规模季节性考察渤海有害藻的种类进行了检测

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-03-01 Epub Date: 2026-02-03 DOI: 10.1016/j.hal.2026.103071

Shuya Liu , Xiangxiang Ding , Hailong Huang , Wentao Wang , Nansheng Chen

The Bohai Sea (BS) is a semi-enclosed ocean region famous for fisheries and marine aquacultures. Harmful algal blooms (HABs) in the forms of red tides and brown tides have become increasingly frequent in BS, resulting in the death of marine animals and economic losses. Many HAB species have been identified in BS. However, the identification of HAB species in BS is still incomplete because earlier studies applied primarily morphology-based methods, while more recent studies often focused on small sampling regions. Here, we identified HAB species in the BS through metabarcoding analysis of water samples collected in three large-scale cruises of three different seasons in BS. This study identified 72 HAB species, including 20 reported for the first time in BS, demonstrating the strength of metabarcoding analysis. Specifically, 50, 67, and 65 HAB species were detected in spring, summer, and autumn, respectively. Many of these HAB species exhibited distinct seasonal preferences, even among congeneric taxa, demonstrating differential adaptation and the necessity of multi-seasonal sampling. Correlation analysis confirmed that temperature was the major factor mediating seasonal differences, alone explaining over 50% of the phytoplankton community variations. These findings demonstrated that BS harbors high HAB biodiversity, with many HAB species showing strong seasonal adaptation, substantially advancing our understanding of both HAB diversity and seasonal succession in the region.

渤海是一个以渔业和水产养殖闻名的半封闭海域。赤潮和褐潮形式的有害藻华（HABs）在BS中日益频繁，造成海洋动物死亡和经济损失。在BS中发现了许多HAB物种。然而，由于早期的研究主要采用基于形态学的方法，而最近的研究往往集中在小样本区域，因此对BS中HAB物种的鉴定仍然不完整。本文通过对三次大型邮轮在三个不同季节采集的水样进行元条形码分析，确定了BS中有害藻华的种类。本研究共鉴定出72种HAB，其中20种为BS首次报道，显示了元条形码分析的优势。其中，春、夏、秋共检出HAB 50种、67种、65种。许多HAB物种表现出明显的季节偏好，甚至在同类分类群中也表现出差异适应和多季节采样的必要性。相关分析证实，温度是影响季节差异的主要因素，仅温度就能解释50%以上的浮游植物群落变化。这些发现表明，BS具有较高的HAB多样性，许多HAB物种具有较强的季节适应性，这大大提高了我们对该地区HAB多样性和季节演替的认识。

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引用次数: 0

Microplastic-derived dissolved organic matter components determine Microcystis aeruginosa-bacteria interaction network and community assembly 微塑料衍生的溶解有机物组分决定了铜绿微囊藻与细菌的相互作用网络和群落组装

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-03-01 Epub Date: 2026-02-04 DOI: 10.1016/j.hal.2026.103074

Zongjie Xie, Huimin Li, Jia Feng, Shulian Xie, Yang Liu

Freshwater ecosystems face mounting threats from microplastic pollution, and the dissolved organic matter (DOM) released by these particles represents an emerging ecological risk factor. In this study, a 28-day co-culture experiment was conducted to investigate the comparative effects of photo-aged (UVA-340) MPs-DOM derived from biodegradable poly(butylene adipate-co-terephthalate) (PBAT) versus conventional polyethylene (PE) and polyethylene terephthalate (PET) microplastics on the bacterial community associated with the harmful cyanobacterium Microcystis aeruginosa PCC 7806. Excitation-emission matrix with parallel factor analysis revealed that PBAT-DOM was rich in recalcitrant humic-like components and depleted in labile, protein-like components, whereas PE-DOM and PET-DOM were dominated by protein-like fluorescence. These chemical signatures had strong biological consequences: PBAT-DOM dramatically reduced bacterial diversity and promoted late-stage dominance by Burkholderia–Caballeronia–Paraburkholderia, coupled with a higher inferred contribution of stochastic processes based on null-model and βNTI analyses. In contrast, PE-DOM and PET-DOM maintained higher community evenness and supported temporally variable succession among multiple co-dominant genera (e.g., transient enrichment of Bdellovibrio, Sphingomonas, and Bacteroidota-related genera such as Chryseobacterium/Flavobacterium). Sparse InversE Covariance Estimation for Ecological Association Inference (SPIEC-EASI)–inferred association networks indicated that PBAT-DOM yielded the most modular network with a comparatively lower fraction of positive conditional associations, whereas PE-DOM and PET-DOM maintained well-connected networks with distinct organization patterns. These findings demonstrate that the chemical signature of microplastic-derived DOM critically influences microbial assembly mechanisms. In particular, persistent humic substances from biodegradable plastics may modulate ecological processes by restructuring bacterial communities and carbon cycling, potentially elevating environmental risks in nutrient-sensitive freshwater ecosystems. In summary, microplastic risk assessments should incorporate DOM-mediated effects to better predict long-term impacts on aquatic ecosystems.

淡水生态系统面临着日益严重的微塑料污染威胁，这些颗粒释放的溶解有机物（DOM）是一个新兴的生态风险因素。本研究进行了为期28天的共培养实验，研究了由可生物降解的聚己二酸丁二酯（PBAT）与常规聚乙烯（PE）和聚对苯二甲酸乙二醇酯（PET）微塑料制成的光老化（UVA-340） MPs-DOM对有害蓝藻铜绿微囊藻PCC 7806相关细菌群落的影响。激发-发射矩阵并行因子分析显示，PBAT-DOM富含顽固性腐殖质样成分，缺乏不稳定的蛋白样成分，而PE-DOM和PET-DOM则以蛋白样荧光为主。这些化学特征具有强烈的生物学后果：PBAT-DOM显著降低了细菌多样性，促进了伯克霍尔德菌-卡瓦洛尼亚菌-副伯克霍尔德菌的后期优势，同时基于零模型和βNTI分析推断了随机过程的更高贡献。相比之下，PE-DOM和PET-DOM保持了较高的群落均匀性，并支持多个共同优势属之间的暂时可变演代（例如，Bdellovibrio， Sphingomonas和bacterodota相关属（如Chryseobacterium/Flavobacterium）的短暂富集）。生态关联推理（SPIEC-EASI）推断关联网络的稀疏反协方差估计表明，PBAT-DOM产生的网络模块化程度最高，正条件关联比例相对较低，而PE-DOM和PET-DOM则保持了良好的网络连接，组织模式不同。这些发现表明，微塑料衍生的DOM的化学特征对微生物组装机制有重要影响。特别是，来自可生物降解塑料的持久性腐殖质可能通过重组细菌群落和碳循环来调节生态过程，潜在地增加对营养敏感的淡水生态系统的环境风险。总之，微塑料风险评估应纳入dom介导的影响，以更好地预测对水生生态系统的长期影响。

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引用次数: 0

The Adriatic Sea mucilage: The history of a hidden harmful dinoflagellate bloom 亚得里亚海粘液：一个隐藏的有害鞭毛藻华的历史

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-03-01 Epub Date: 2026-01-24 DOI: 10.1016/j.hal.2026.103065

Rossella Pistocchi , Franca Guerrini , Mara Simonazzi , Silvana Vanucci , Monica Cangini , Stefania Milandri , Cristina Mazziotti , Laura Pezzolesi

Mucilage events, characterized by the accumulation of gelatinous, polysaccharide-rich organic aggregates in seawater, are irregularly occurring phenomena in the northern Adriatic Sea. While mucilage in other seas is typically linked to blooms of a single phytoplankton or phytobenthic species, Adriatic events have been mostly attributed to complex biogeochemical processes, rapidly leading to the formation of extensive gelatinous masses. Long-term studies on Northern Adriatic phytoplankton communities have revealed a consistent association, since the 1990s, between mucilage events and blooms of a non-toxic dinoflagellate. Originally identified as Gonyaulax fragilis, the ongoing debate regarding its definitive classification leads us to refer to the species as Gonyaulax cf. hyalina. Generally, this species acts as the primary biological trigger for these phenomena, which subsequently develop into a distinct, recurrent mucilage-associated microbial ecosystem. This review provides a comprehensive synthesis of the taxonomic debate, the main hypotheses proposed over the years, historical and recent evidence leading to G. cf. hyalina as the mucilage causative organism, and the ecological and economic impacts of these outbreaks. Regarding the interannual variability of the events, a link with specific environmental conditions could not be assessed; however, based on G. cf. hyalina growth and nutrient dynamics, we speculate about the importance of specific nutritional requirements (i.e., phosphate inputs or still unknown organic compounds) and of competitive interactions. This review would contribute to increasing knowledge on the most recurrent mucilage phenomenon in the Mediterranean Sea, opening the question on the inclusion of the investigated species in the list of harmful algal species.

黏液事件是亚得里亚海北部不规则发生的现象，其特征是凝胶状、富含多糖的有机聚集体在海水中积累。虽然其他海域的粘液通常与单一浮游植物或底栖植物物种的大量繁殖有关，但亚得里亚海事件主要归因于复杂的生物地球化学过程，迅速导致广泛胶质团块的形成。自20世纪90年代以来，对北亚得里亚海浮游植物群落的长期研究表明，粘液事件与无毒鞭毛藻的大量繁殖之间存在一致的联系。最初被确定为脆弱Gonyaulax fragilis，关于其最终分类的持续争论使我们将该物种称为Gonyaulax cf. hyalina。一般来说，这个物种作为这些现象的主要生物触发器，随后发展成一个独特的，反复出现的粘液相关微生物生态系统。这篇综述提供了一个全面的综合分类辩论，多年来提出的主要假设，历史和最近的证据，导致G. cf. hyalina作为粘液致病生物，以及这些暴发的生态和经济影响。关于这些事件的年际变率，无法评估其与特定环境条件的联系；然而，基于g.c.f.透明藻的生长和营养动态，我们推测了特定营养需求（即磷酸盐输入或仍未知的有机化合物）和竞争相互作用的重要性。这项审查将有助于增加对地中海最常见的粘液现象的认识，并开启将所调查物种列入有害藻类物种清单的问题。

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引用次数: 0

Passive sampling and molecular networking for surveillance of lipophilic marine biotoxins along the south coast of Korea 被动采样和分子网络监测亲脂性海洋生物毒素沿韩国南部海岸

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-03-01 Epub Date: 2026-01-27 DOI: 10.1016/j.hal.2026.103067

Mungi Kim , Young Kyun Lim , Youngnam Kim , Jihyun Cha , Xiaowan Liu , Leo Lai Chan , Kenneth M.Y. Leung , Seung-Ho Baek , Seongjin Hong

Lipophilic marine biotoxins (LMTs) are increasingly reported in coastal ecosystems, posing risks to seafood safety and public health. This study investigated the spatial and seasonal distributions of LMTs along the south coast of Korea in 2022 by integrating phytoplankton and mussel sampling with passive solid-phase adsorption toxin tracking (SPATT) and molecular networking-based high-resolution mass spectrometry. Diatoms dominated the phytoplankton community, but toxin-producing dinoflagellates such as Dinophysis acuminata and Gonyaulax spinifera appeared during seasonal peaks in spring and summer. Four LMTs, including pectenotoxin-2 (PTX2), PTX1, yessotoxin (YTX), and homo-YTX (hYTX), were detected in phytoplankton, whereas mussels accumulated only hYTX, peaking later, consistent with prolonged retention in bivalves. SPATT captured a broader toxin spectrum, including okadaic acid (OA), dinophysistoxin-1 (DTX1), azaspiracid-2 (AZA2), and domoic acid (DA), and often detected toxins earlier than biological samples. The combined application of SPATT and molecular networking further revealed putative PTX-related features based on MS/MS spectral similarity that were not observed in phytoplankton or mussels. Dietary exposure assessment of commercially distributed shellfish based on detected free toxin forms indicated hazard quotients and indices well below regulatory thresholds, suggesting low acute health risk. Repeated detection of LMTs in domestic seafood raises concerns about chronic exposure. Integrating SPATT with molecular networking proved highly effective for early biotoxin surveillance, underscoring the necessity of sustained, multi-matrix monitoring to ensure seafood safety.

亲脂性海洋生物毒素（lmt）在沿海生态系统中被越来越多地报道，对海产品安全和公众健康构成威胁。本研究利用浮游植物和贻贝采样、被动固相吸附毒素追踪（SPATT）和基于分子网络的高分辨率质谱技术，研究了2022年韩国南海岸lmt的空间和季节分布。浮游植物群落以硅藻为主，但产毒鞭毛藻如尖藻和尖刺藻在春季和夏季出现。浮游植物中检测到果皮毒素-2 （PTX2）、PTX1、叶索毒素（YTX）和同型YTX (hYTX) 4种LMTs，而贻贝只积累hYTX，峰值较晚，与双壳类动物中滞留时间较长一致。SPATT捕获了更广泛的毒素谱，包括冈田酸（OA）、甲藻毒素-1 （DTX1）、氮氮藻酸-2 （AZA2）和软骨藻酸（DA），并且通常比生物样品更早检测到毒素。SPATT和分子网络的联合应用进一步揭示了在浮游植物和贻贝中未观察到的基于MS/MS光谱相似性的推测的ptx相关特征。基于检测到的游离毒素形式对商业分销贝类的饮食暴露评估表明，危害商数和指数远低于监管阈值，表明急性健康风险较低。在国内海产品中反复检测到LMTs引起了人们对慢性暴露的担忧。将SPATT与分子网络相结合被证明对早期生物毒素监测非常有效，强调了持续、多基质监测以确保海产品安全的必要性。

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引用次数: 0

Evaluating the ten-year health impact of hydrogen sulfide (H2S) and ammonia (NH3) exposure from sargassum seaweed invasions in the Caribbean: Public health implications 评估加勒比马尾藻入侵造成的硫化氢（H2S）和氨（NH3）暴露对健康的十年影响：公共卫生影响

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-02-01 Epub Date: 2025-11-13 DOI: 10.1016/j.hal.2025.103027

Dabor Resiere , Jonathan Florentin , Rémi Névière

Since 2011, the Caribbean region—including Martinique, Guadeloupe, and French Guiana—has experienced increasing invasions of Sargassum seaweed, leading to significant environmental, economic, and public health challenges. This study evaluates the health impacts of hydrogen sulfide (H₂S) and ammonia (NH₃) emissions from decomposing Sargassum on affected populations. Data were collected from 850 patients admitted to the University Hospital of Martinique between January 2018 and September 2024, all of whom had been exposed to Sargassum emissions for an average of 2–3 months annually. Reported symptoms included neurological (80%), respiratory (80%), and digestive (70%) disorders, as well as central sleep apnea (60%). Pulmonary inflammation was assessed through spirometry and fractional exhaled nitric oxide (FeNO) levels. Psychological and social impacts were also documented. Findings indicate a toxicological syndrome associated with chronic Sargassum exposure, resembling acute H₂S inhalation at low concentrations. This study underscores the urgent need for multidisciplinary research to mitigate these health impacts, calling for immediate attention from governments, international stakeholders, and environmental experts.

自2011年以来，加勒比地区——包括马提尼克岛、瓜德罗普岛和法属圭亚那——经历了越来越多的马尾藻入侵，导致了重大的环境、经济和公共卫生挑战。这项研究评估了马尾藻分解产生的硫化氢（H₂S）和氨（NH₃）排放对受影响人群的健康影响。研究人员收集了2018年1月至2024年9月期间马提尼克大学医院收治的850名患者的数据，这些患者每年平均暴露于马尾藻排放的时间为2-3个月。报告的症状包括神经系统（80%）、呼吸系统（80%）和消化系统（70%）障碍，以及中枢性睡眠呼吸暂停（60%）。通过肺活量测定法和呼气一氧化氮分数（FeNO）水平评估肺部炎症。心理和社会影响也有记录。研究结果表明，慢性马尾藻暴露相关的毒理学综合征，类似于低浓度的急性h2s吸入。这项研究强调迫切需要开展多学科研究，以减轻这些健康影响，呼吁各国政府、国际利益攸关方和环境专家立即予以关注。

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引用次数: 0

Morphological and physiological adaptations of Dolichospermum flos-aquae to turbulence 水莲对湍流的形态和生理适应

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-02-01 Epub Date: 2025-12-16 DOI: 10.1016/j.hal.2025.103046

Yulin Wang, Wenting Zhong, Ruiwen Chen, Qin Tang, Gongzheng Li, Zhou Yang, Yuan Huang

Heterocystous cyanobacteria are increasingly forming surface blooms in freshwater ecosystems, with massive proliferation events influenced by multiple environmental factors—among which turbulence has emerged as a pivotal driver. This study investigated the effects of different turbulence intensities (ranging from 10⁻⁵ to 10⁻² m² s⁻³, within the natural environmental range) on the morphology and physiology of the bloom-forming diazotroph Dolichospermum flos-aquae. Results showed that high-intensity turbulence promoted population growth, dissolved nitrogen uptake, and photosynthetic performance of D. flos-aquae. Under high turbulence conditions, filament length exhibited greater uniformity alongside an increase in average length. Furthermore, heterocyst production was markedly enhanced, with no alteration in the spatial localization of heterocysts along filaments. These phenotypic responses were associated with upregulated carbon and nitrogen metabolisms—particularly nitrogen assimilation and carbon fixation—supported by the increased expression of key functional genes. Collectively, these findings reveal the morphological and physiological adaptive strategies of heterocystous cyanobacteria to turbulent environments, thereby advancing our understanding of diazotrophic cyanobacterial bloom dynamics in hydrologically dynamic freshwater ecosystems.

在淡水生态系统中，异囊蓝藻越来越多地形成地表水华，其大规模增殖事件受到多种环境因素的影响，其中湍流已成为关键驱动因素。本研究研究了不同湍流强度（10−5 ~ 10−2 m2 s−3，在自然环境范围内）对重氮营养菌水藻（Dolichospermum flos-aquae）形态和生理的影响。结果表明，高强度湍流对水藻种群生长、溶氮吸收和光合性能有促进作用。在高湍流条件下，灯丝长度表现出更大的均匀性，同时平均长度增加。此外，杂种囊的产生明显增强，但杂种囊沿丝的空间定位没有改变。这些表型反应与碳氮代谢的上调有关，特别是氮同化和碳固定，并得到关键功能基因表达增加的支持。总的来说，这些发现揭示了异囊蓝藻对湍流环境的形态和生理适应策略，从而促进了我们对水文动态淡水生态系统中重氮营养蓝藻华动态的理解。

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引用次数: 0

Spatiotemporal dynamics of Phaeocystis globosa genotypes in a P. globosa bloom in the Beibu Gulf, China revealed differential contributions to bloom development 北部湾全球褐囊藻（Phaeocystis globbosa）基因型的时空动态揭示了其对华花发育的差异贡献

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-02-01 Epub Date: 2025-11-27 DOI: 10.1016/j.hal.2025.103032

Yifei Wang , Jinxiu Wang , Rencheng Yu , Nansheng Chen

Recent studies suggest that the cosmopolitan harmful algal bloom (HAB) species Phaeocystis globosa has high genetic diversity, with two major genotypes (sASV_1 and sASV_2) characterized through comparative analysis of P. globosa strains. However, how they differ from each other phenotypically, and how they contribute differentially to bloom development remain unclear. In this study, phenotypic analysis of strains belonging to these two P. globosa genotypes revealed that the average cell size of sASV_2 strains was significantly larger than that of sASV_1 strains. Furthermore, sASV_1 strains contained two characteristic pigments 19′-butanoyloxyfucoxanthin (But-fuco) and 19′-hexanoyloxyfucoxanthin (Hex-fuco), while sASV_2 strains contained only But-fuco. Metabarcoding analysis of environmental samples collected during a P. globosa bloom in the Beibu Gulf in 2019 revealed that these genotypes showed different spatiotemporal distribution patterns, suggesting their differential contribution to the P. globosa bloom. And correlation analysis of environmental factors indicated that the responses of P. globosa genotypes to environmental factors showed significant differences. This study confirmed the existence of two P. globosa genotypes with substantial differences in cell sizes and pigment compositions for the first time, and showed that different genotypes may contribute differently during P. globosa bloom development. Results from this study set up a platform for exploring molecular mechanisms underlying genotype-specific P. globosa bloom development, and for monitoring causative strains leading to P. globosa bloom development.

近年来的研究表明，世界性有害藻华（HAB）物种globosa Phaeocystis具有较高的遗传多样性，通过对globosa菌株的比较分析，确定了两种主要基因型（sASV_1和sASV_2）。然而，它们在表型上如何不同，以及它们如何对开花发育做出不同的贡献仍不清楚。本研究对这两个基因型的菌株进行表型分析发现，sASV_2菌株的平均细胞大小明显大于sASV_1菌株。sASV_1菌株含有19′-丁烷氧基岩藻黄素（But-fuco）和19′-己烷氧基岩藻黄素（hexx -fuco）两种特征色素，而sASV_2菌株仅含有But-fuco。对2019年北部湾一次球藻华期间采集的环境样本进行元条形码分析发现，这些基因型呈现出不同的时空分布模式，表明它们对球藻华的贡献存在差异。环境因子的相关分析表明，不同基因型对环境因子的响应存在显著差异。本研究首次证实了两种基因型的存在，它们在细胞大小和色素组成上存在显著差异，并表明不同基因型在开花发育过程中可能起着不同的作用。本研究结果为探索基因型特异性球形假单胞菌开花发生的分子机制和监测导致球形假单胞菌开花发生的致病菌株提供了平台。

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引用次数: 0

Pixel-scale satellite forecasting of cyanobacteria in Florida lakes 佛罗里达湖泊蓝藻的像素级卫星预报

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-02-01 Epub Date: 2025-12-09 DOI: 10.1016/j.hal.2025.103041

Maxwell R.W. Beal , Blake Schaeffer

Rapid proliferation of potentially toxin-producing cyanobacteria (cyanobacterial harmful algal blooms, cHABs) is a significant challenge for water resource managers. The U.S. Harmful Algal Bloom and Hypoxia Research Control Act calls for robust approaches to forecasting cHABs in lakes and reservoirs. A previous national study developed a lake scale Bayesian spatiotemporal model to forecast weekly chlorophyll-a exceedance probability in 2192 satellite resolved lakes using Sentinel-3 Ocean Land Colour Instrument data. Building on this foundation, this study developed a machine learning based, spatially explicit forecasting model at the 300-m pixel scale for Sentinel-3 resolvable lakes, conditioned on environmental variables from 2017 – 2024. Three machine learning models were constructed for Sentinel-3 resolvable lakes across Florida to generate ensemble forecasts of chlorophyll-a concentration and World Health Organization Alert Level categories with multi-week leads. The pixel scale metric significantly increased the number of resolvable bloom events, recording 4682 (33%) more exceedance events than the lake scale metric. The best performing model (random forest) achieved 88.2% accuracy at Alert Level 1 and 92.2% accuracy at Alert Level 2. Overall R² was 0.56 and mean absolute error was 5.4

μ g L^{- 1}

The best performing model had notable skill at 1–2 week leads but diminished at a 4-week horizon. Probabilistic forecast performance shows that the model predicted observed chlorophyll concentrations and WHO Alert Levels with skill. Direct comparison showed similar skill between the lake and pixel scale forecast.

可能产生毒素的蓝藻（蓝藻有害藻华，cHABs）的快速增殖是水资源管理者面临的重大挑战。美国有害藻华和缺氧研究控制法案要求采用强有力的方法来预测湖泊和水库中的有害藻华。先前的一项国家研究开发了一个湖泊尺度贝叶斯时空模型，利用Sentinel-3海洋陆地颜色仪器数据预测2192个卫星分辨率湖泊每周叶绿素A超标的概率。在此基础上，本研究基于2017 - 2024年的环境变量，开发了基于机器学习的哨兵3号可解析湖泊300米像素尺度的空间明确预测模型。为佛罗里达州的Sentinel-3可分解湖泊构建了三个机器学习模型，以生成叶绿素-a浓度和世界卫生组织警报级别类别的多周领先的整体预测。像素尺度显著增加了可解析的水华事件的数量，比湖泊尺度多记录了4682次（33%）的超标事件。表现最好的模型（随机森林）在警报级别1和警报级别2的准确率分别达到了88.2%和92.2%。总体R2为0.56，平均绝对误差为5.4 μgL−1，表现最好的模型在1 - 2周时具有显著的技能，但在4周时有所下降。概率预报性能表明，该模型能较好地预测观测到的叶绿素浓度和WHO警戒级别。湖尺度预报与像素尺度预报的直接对比表明，二者的预报技巧相近。

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引用次数: 0

Characterizing seasonal persistence of low levels of Pseudo-nitzschia australis in the Gulf of Maine with environmental DNA 用环境DNA表征缅因湾低水平的南方伪nitzschia季节性持久性

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-02-01 Epub Date: 2025-12-04 DOI: 10.1016/j.hal.2025.103039

Sydney M. Greenlee , Robin S. Sleith , Damian C. Brady , Peter D. Countway

The potent neurotoxin domoic acid is produced by some species of diatoms in the genus Pseudo-nitzschia, which can lead to amnesic shellfish poisoning (ASP) events in marine food webs. Of the toxin-producing Pseudo-nitzschia, P. australis has caused the most toxic and widespread events, making it a species of concern. Toxic and non-toxic Pseudo-nitzschia species cannot be distinguished easily by light microscopy, necessitating molecular testing. We designed a real-time quantitative PCR assay for rapid and accurate detection of P. australis in environmental DNA (eDNA) samples, targeting the intergenic region between rbcS and psaI in the chloroplast genome, providing species-level specificity and high sensitivity. Experimental determination of rbcS gene copies per cell revealed a limit of detection equivalent to 1 P. australis cell per liter of seawater, facilitating the early detection of this toxic species. This novel qPCR assay was applied to eDNA samples collected from Maine coastal waters between 2021 - 2024 to characterize the nearshore dynamics of P. australis within a regional hub for shellfish aquaculture. Though relatively rare, P. australis peaked in abundance in mid-October when conditions became favorable for this species following convective overturning. The eDNA assay was able to detect a low P. australis signal at a time when ‘large’ Pseudo-nitzschia spp. cell counts approached 8000 cells l^-1 (by microscopy) while qPCR-based estimates of P. australis remained below 10 cells l^-1. We demonstrate an eDNA approach for the early detection of HABs, calibration of qPCR assays to cell counts, and provide a new tool for coastal management.

软骨藻酸是一种强效神经毒素，可引起海洋食物网中失忆性贝类中毒（ASP）事件。在产生毒素的伪nitzschia中，australis引起了毒性最强和传播最广的事件，使其成为一个值得关注的物种。有毒和无毒的伪尼茨氏菌无法通过光学显微镜轻易区分，因此需要进行分子检测。我们设计了一种实时定量PCR方法，用于快速准确地检测环境DNA （eDNA）样品中的南方稻瘟菌，该方法针对叶绿体基因组中红细胞和psaI之间的基因间区域，具有种水平的特异性和高灵敏度。对每个细胞的红细胞基因拷贝数的实验测定显示，每升海水的检出限相当于1个南鳗细胞，有利于早期发现这种有毒物种。该新型qPCR检测方法应用于2021 - 2024年间从缅因州沿海水域收集的eDNA样本，以表征贝类养殖区域中心内南棘鲷的近岸动态。虽然相对稀少，但在对流翻转后的10月中旬条件变得有利时，南棘的丰度达到顶峰。当伪尼茨氏菌的“大”细胞计数接近8000细胞l-1（显微镜下）时，eDNA检测能够检测到低南方血吸虫信号，而基于qpcr的南方血吸虫估计仍低于10细胞l-1。我们展示了一种用于早期检测赤潮的eDNA方法，校准qPCR检测细胞计数，并为海岸管理提供了一种新的工具。

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引用次数: 0

From laboratory to field: Temperature rise triggers increased release and toxicity of microcystins in Microcystis aeruginosa 从实验室到现场：温度升高引发铜绿微囊藻中微囊藻毒素的释放和毒性增加

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2026-02-01 Epub Date: 2025-12-09 DOI: 10.1016/j.hal.2025.103042

Shihao Wang , Yurong Gu , Weilu Li , Qingju Xue , Xinfeng Cheng , Chen Cheng , Liqiang Xie

Temperature rise increases the risk of microcystins (MCs) in aquatic ecosystems by affecting toxin-producing cyanobacteria, but strain-specific responses remain unclear. This study investigated the growth, MCs production and release, isomer composition, and mcyB and mcyH genes expression of two Microcystis aeruginosa strains (FACHB-1322 and FACHB-1203) during 20-day cultivation at temperatures of 15 °C, 20 °C, and 28 °C, with the ecological relevance of laboratory findings corroborated through field data conducted in Lake Taihu. The results revealed that by the endpoint of cultivation, M. aeruginosa FACHB-1322 exhibited a compensatory growth strategy at high-temperature (28 °C), while M. aeruginosa FACHB-1203 demonstrated eurythermal adaptation. Total MCs content and mcyB and mcyH expression decreased with rising temperature in M. aeruginosa FACHB-1322 but increased in M. aeruginosa FACHB-1203. Notably, both strains showed elevated extracellular MCs content and MCs release ratio with rising temperature. Regarding isomer profiles, M. aeruginosa FACHB-1322 primarily produced and released MC-LR, whereas M. aeruginosa FACHB-1203 predominantly produced MC-RR but exhibited temperature-enhanced MC-LR release. Critically, high-temperature specifically induced the production and release of the highly toxic MC-YR in both strains. Field data further confirmed that temperature rise promotes MCs release and increases the proportion of extracellular MC-LR. Thus, temperature rise amplifies the ecological risk of MCs through dual mechanisms: favoring the growth with high MCs release capacity strain and driving a compositional shift of MC isomers from less toxic isomers toward highly toxic isomers.

温度升高会影响产生毒素的蓝藻，从而增加水生生态系统中微囊藻毒素（MCs）的风险，但菌株特异性反应尚不清楚。本研究研究了两株铜绿微囊藻（FACHB-1322和FACHB-1203）菌株在15℃、20℃和28℃条件下的生长、MCs的产生和释放、异构体组成以及mcyB和mcyH基因的表达，并通过太湖现场数据验证了实验室研究结果的生态学相关性。结果表明，在培养结束时，M. aeruginosa FACHB-1322表现出高温（28°C）的代偿生长策略，而M. aeruginosa FACHB-1203表现出高温适应。随着温度升高，铜绿假单胞菌FACHB-1322的总MCs含量和mcyB、mcyH表达量降低，而FACHB-1203的MCs含量升高。值得注意的是，两种菌株的胞外MCs含量和MCs释放率均随温度升高而升高。就异构体谱而言，M. aeruginosa FACHB-1322主要产生和释放MC-LR，而M. aeruginosa FACHB-1203主要产生MC-RR，但表现出温度增强的MC-LR释放。关键的是，高温特异性地诱导了两种菌株中高毒性MC-YR的产生和释放。现场数据进一步证实，温度升高促进了MCs的释放，增加了胞外MC-LR的比例。因此，温度升高通过双重机制放大了MCs的生态风险：有利于MCs高释放能力菌株的生长，推动MCs同分异构体的组成从毒性较小的同分异构体向毒性较大的同分异构体转变。

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引用次数: 0