Harmful Algae最新文献_第7页

Mesozooplankton grazing patterns and preferences during a cyanobacterial harmful algal bloom (cHAB) in a large eutrophic lake 大型富营养化湖泊蓝藻有害藻华（cHAB）期间中浮游动物的放牧模式和偏好

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-29 DOI: 10.1016/j.hal.2025.102963

Daniel I. Peters , Lyndsie M. Collis , Morgan D. Shaw , Zak J. Slagle , Henry A. Vanderploeg , James M. Hood

Mesozooplankton (200–2,000 µm) are an important link between primary producers and higher-level consumers and can influence phytoplankton biomass and community structure via grazing. Yet, during cyanobacteria harmful algal blooms (cHABs) we have a poor understanding of which food resources mesozooplankton use and their grazing pressure on phytoplankton. To investigate this, we conducted two gradient-grazer assays to measure mesozooplankton community grazing rates in western Lake Erie during the 2021 cHAB season. We measured mesozooplankton grazing on various food sources, including: total phytoplankton, phytoplankton major taxa (Cyanobacteria, Cryptophyta/Bacillariophyta, Chlorophyta), and autotrophic and heterotrophic picoplankton and nanoplankton. We used these data to estimate mesozooplankton feeding selectivity, the importance of each food source toward mesozooplankton carbon intake, as well as the percent standing stock and growth consumed by mesozooplankton. Mesozooplankton selected for autotrophic and heterotrophic nanoplankton, were neutrally selective for Cryptophyta/Bacillariophyta, and avoided Cyanobacteria and the total phytoplankton community. Mesozooplankton carbon intake was dominated by autotrophic nanoplankton and Cyanobacteria, indicating these food sources may be important in supporting zooplankton production during these cHAB events, although our understanding of the incorporation of Cyanobacteria carbon into mesozooplankton production is limited. While mesozooplankton grazed a small portion of total phytoplankton (1–12 % d^-1) and Cyanobacteria (5–13 % d^-1) standing stock biomass (<200 µm), they exerted a relatively stronger control on the growth of total phytoplankton (4–38 % d^-1) and Cyanobacteria (64–106 % d^-1), primarily due to the low measured growth rates of these food items during the study. Our results demonstrate that mesozooplankton graze on Cyanobacteria during cHAB events, and under the right conditions influence cHAB dynamics through direct consumption of Cyanobacteria and indirect effects on Cyanobacteria grazers and competitors.

中浮游动物（200 - 2000µm）是初级生产者和高级消费者之间的重要纽带，可以通过放牧影响浮游植物的生物量和群落结构。然而，在蓝藻有害藻华（cHABs）期间，我们对浮游动物利用的食物资源及其对浮游植物的放牧压力知之甚少。为了研究这一点，我们在2021年cHAB季节对伊利湖西部的浮游动物群落进行了两次梯度放牧试验，测量了它们的放牧率。我们测量了以不同食物来源为食的中浮游动物，包括：总浮游植物、浮游植物主要分类群（蓝藻、隐藻/硅藻、绿藻）、自养和异养微浮游生物和纳米浮游生物。我们利用这些数据估计了浮游动物的取食选择性、每种食物来源对浮游动物碳摄入量的重要性，以及浮游动物的存量和生长消耗的百分比。中浮游动物对自养和异养纳米浮游生物有选择性，对隐藻/硅藻有中性选择性，对蓝藻和总浮游植物群落有选择性。中游浮游动物的碳摄入量主要由自养型纳米浮游生物和蓝藻控制，这表明这些食物来源可能在这些cHAB事件中支持浮游动物的生产中发挥重要作用，尽管我们对蓝藻碳在中游浮游动物生产中的作用的了解有限。虽然中浮游动物只占总浮游植物（1 - 12% d-1）和蓝藻（5 - 13% d-1）总生物量（200µm）的一小部分，但它们对总浮游植物（4 - 38% d-1）和蓝藻（64 - 106% d-1）的生长具有相对较强的控制作用，这主要是由于研究期间这些食物的测量生长率较低。研究结果表明，在cHAB事件中，中浮游动物以蓝藻为食，并在适当的条件下通过直接消耗蓝藻和间接影响蓝藻捕食者和竞争对手来影响cHAB动态。

{"title":"Mesozooplankton grazing patterns and preferences during a cyanobacterial harmful algal bloom (cHAB) in a large eutrophic lake","authors":"Daniel I. Peters , Lyndsie M. Collis , Morgan D. Shaw , Zak J. Slagle , Henry A. Vanderploeg , James M. Hood","doi":"10.1016/j.hal.2025.102963","DOIUrl":"10.1016/j.hal.2025.102963","url":null,"abstract":"<div><div>Mesozooplankton (200–2,000 µm) are an important link between primary producers and higher-level consumers and can influence phytoplankton biomass and community structure via grazing. Yet, during cyanobacteria harmful algal blooms (cHABs) we have a poor understanding of which food resources mesozooplankton use and their grazing pressure on phytoplankton. To investigate this, we conducted two gradient-grazer assays to measure mesozooplankton community grazing rates in western Lake Erie during the 2021 cHAB season. We measured mesozooplankton grazing on various food sources, including: total phytoplankton, phytoplankton major taxa (Cyanobacteria, Cryptophyta/Bacillariophyta, Chlorophyta), and autotrophic and heterotrophic picoplankton and nanoplankton. We used these data to estimate mesozooplankton feeding selectivity, the importance of each food source toward mesozooplankton carbon intake, as well as the percent standing stock and growth consumed by mesozooplankton. Mesozooplankton selected for autotrophic and heterotrophic nanoplankton, were neutrally selective for Cryptophyta/Bacillariophyta, and avoided Cyanobacteria and the total phytoplankton community. Mesozooplankton carbon intake was dominated by autotrophic nanoplankton and Cyanobacteria, indicating these food sources may be important in supporting zooplankton production during these cHAB events, although our understanding of the incorporation of Cyanobacteria carbon into mesozooplankton production is limited. While mesozooplankton grazed a small portion of total phytoplankton (1–12 % d<sup>-1</sup>) and Cyanobacteria (5–13 % d<sup>-1</sup>) standing stock biomass (<200 µm), they exerted a relatively stronger control on the growth of total phytoplankton (4–38 % d<sup>-1</sup>) and Cyanobacteria (64–106 % d<sup>-1</sup>), primarily due to the low measured growth rates of these food items during the study. Our results demonstrate that mesozooplankton graze on Cyanobacteria during cHAB events, and under the right conditions influence cHAB dynamics through direct consumption of Cyanobacteria and indirect effects on Cyanobacteria grazers and competitors.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102963"},"PeriodicalIF":4.5,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Critical flow velocity thresholds for preventing persistent thermal stratification and cyanobacterial blooms in rivers 防止河流中持续热分层和蓝藻华的临界流速阈值

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-26 DOI: 10.1016/j.hal.2025.102962

D.C. Davis , J.A. Facey , A.J. Brooks , D.P. Westhorpe , M. Balzer , N. Williamson , S.M. Mitrovic

Toxic cyanobacterial harmful algal blooms (cHABs) are a major worldwide issue in freshwater environments, exacerbated by climate change with rising water temperatures and prolonged and intensified periods of thermal stratification. The Barwon-Darling River in Australia, a dryland river with a highly variable flow regime, often experiences persistent thermal stratification (PTS), i.e., continuous stratification for days or weeks, during periods of low discharge, commonly resulting in cHABs. This study evaluated whether a critical flow velocity threshold can prevent or disrupt the formation of PTS and subsequent cHABs. The relationships between gauged discharge and flow velocity were determined within six weir pools along the river using acoustic Doppler current profiling. These relationships were used to interpret 20 years of historic daily river discharge data as mean cross-sectional flow velocities which were then compared to cyanobacterial biovolumes over the same period, focusing predominantly on the potentially toxic genera Dolichospermum. An upper limiting relationship between flow velocity and Dolichospermum biovolume was found and almost all blooms > 4 mm³/L (exceeding the Australian recreational safety guidelines for toxic cyanobacteria) occurred when maximum antecedent 7-day flow velocities were less than 0.05 m/s. Quantile regression estimates suggested maintaining flow velocities of 0.05 m/s can limit blooms to 3.96 mm³/L while increasing flow velocities will reduce this limit. These findings support the premise of using river flow velocity thresholds for cHAB management when blooms are related to PTS. These flow velocities should be applicable to other rivers in similar climates while the approach could be utilised more widely.

有毒蓝藻有害藻华（cHABs）是淡水环境中的一个主要全球性问题，随着水温上升和热分层期的延长和加剧，气候变化加剧了这一问题。澳大利亚的巴温-达令河是一条流量变化很大的旱地河流，在低流量期间，经常经历持续的热分层（PTS），即连续分层数天或数周，通常导致chab。本研究评估了临界流速阈值是否可以阻止或破坏PTS和随后的chab的形成。利用声学多普勒电流谱法测定了沿江6个堰池的流量与流速之间的关系。这些关系被用来解释20年的历史每日河流流量数据作为平均横断面流速，然后将其与同期的蓝藻生物量进行比较，主要关注潜在有毒的Dolichospermum属。水流速度与Dolichospermum生物体积之间存在上限关系，几乎所有的水华>； 4 mm3/L（超过澳大利亚有毒蓝藻娱乐安全指南）都发生在之前最大7天水流速度小于0.05 m/s时。分位数回归估计表明，保持0.05 m/s的流速可以将华花限制在3.96 mm3/L，而增加流速会降低这一限制。这些发现支持了在华花与PTS相关时使用河流流速阈值进行cHAB管理的前提。这些流速应该适用于类似气候条件下的其他河流，而这种方法可以得到更广泛的应用。

{"title":"Critical flow velocity thresholds for preventing persistent thermal stratification and cyanobacterial blooms in rivers","authors":"D.C. Davis , J.A. Facey , A.J. Brooks , D.P. Westhorpe , M. Balzer , N. Williamson , S.M. Mitrovic","doi":"10.1016/j.hal.2025.102962","DOIUrl":"10.1016/j.hal.2025.102962","url":null,"abstract":"<div><div>Toxic cyanobacterial harmful algal blooms (cHABs) are a major worldwide issue in freshwater environments, exacerbated by climate change with rising water temperatures and prolonged and intensified periods of thermal stratification. The Barwon-Darling River in Australia, a dryland river with a highly variable flow regime, often experiences persistent thermal stratification (PTS), i.e., continuous stratification for days or weeks, during periods of low discharge, commonly resulting in cHABs. This study evaluated whether a critical flow velocity threshold can prevent or disrupt the formation of PTS and subsequent cHABs. The relationships between gauged discharge and flow velocity were determined within six weir pools along the river using acoustic Doppler current profiling. These relationships were used to interpret 20 years of historic daily river discharge data as mean cross-sectional flow velocities which were then compared to cyanobacterial biovolumes over the same period, focusing predominantly on the potentially toxic genera <em>Dolichospermum</em>. An upper limiting relationship between flow velocity and <em>Dolichospermum</em> biovolume was found and almost all blooms > 4 mm<sup>3</sup>/L (exceeding the Australian recreational safety guidelines for toxic cyanobacteria) occurred when maximum antecedent 7-day flow velocities were less than 0.05 m/s. Quantile regression estimates suggested maintaining flow velocities of 0.05 m/s can limit blooms to 3.96 mm<sup>3</sup>/L while increasing flow velocities will reduce this limit. These findings support the premise of using river flow velocity thresholds for cHAB management when blooms are related to PTS. These flow velocities should be applicable to other rivers in similar climates while the approach could be utilised more widely.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102962"},"PeriodicalIF":4.5,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Faunal associations of holopelagic Sargassum spp. in the subtropical and tropical northern Atlantic: A review 亚热带和热带北大西洋全浮游马尾藻的区系关联研究进展

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-25 DOI: 10.1016/j.hal.2025.102961

L.Verónica Monroy-Velázquez , Hazel M. Canizales-Flores , Karla A. Camacho-Cruz , Makeda Corbin , Patricia Briones-Fourzán , Brigitta I. van Tussenbroek

Holopelagic Sargassum spp. (Sargassum from hereon) are the founding seaweeds of biodiverse high-sea rafts. The floating rafts provide substrate, shelter, feeding-, and breeding grounds for numerous marine species, making them unique communities in the high seas. Similar to other pelagic systems, the community associated with the rafts is dynamic, inherently variable, and defined by the dynamics of the rafts and interactions between the seaweed and associated fauna. The high biodiversity, including organisms from different trophic levels, results in multiple interactions and complex food webs, which are covered in this review. Additionally, we highlight how floating Sargassum acts as a vector of ecological connectivity, influencing distant ecosystems such as coastal and deep-sea habitats. These cross-ecosystem interactions occur through organism transport, organic matter export and trophic linkages. Understanding these connections is key to recognizing the broader ecological role of Sargassum rafts and the multiple ecosystem services they provide.

全海马尾藻属（此处为马尾藻）是生物多样性高海筏的基础海藻。浮筏为许多海洋物种提供了基质、庇护所、觅食和繁殖地，使它们成为公海上独特的群落。与其他远洋系统类似，与木筏相关的群落是动态的，内在可变的，并由木筏的动态以及海藻和相关动物群之间的相互作用来定义。生物多样性高，包括来自不同营养水平的生物，导致多种相互作用和复杂的食物网，这是本文的综述。此外，我们强调了漂浮马尾藻如何作为生态连通性的载体，影响遥远的生态系统，如沿海和深海栖息地。这些跨生态系统的相互作用通过生物运输、有机物输出和营养联系发生。了解这些联系是认识马尾藻筏更广泛的生态作用及其提供的多种生态系统服务的关键。

{"title":"Faunal associations of holopelagic Sargassum spp. in the subtropical and tropical northern Atlantic: A review","authors":"L.Verónica Monroy-Velázquez , Hazel M. Canizales-Flores , Karla A. Camacho-Cruz , Makeda Corbin , Patricia Briones-Fourzán , Brigitta I. van Tussenbroek","doi":"10.1016/j.hal.2025.102961","DOIUrl":"10.1016/j.hal.2025.102961","url":null,"abstract":"<div><div>Holopelagic <em>Sargassum</em> spp. (<em>Sargassum</em> from hereon) are the founding seaweeds of biodiverse high-sea rafts. The floating rafts provide substrate, shelter, feeding-, and breeding grounds for numerous marine species, making them unique communities in the high seas. Similar to other pelagic systems, the community associated with the rafts is dynamic, inherently variable, and defined by the dynamics of the rafts and interactions between the seaweed and associated fauna. The high biodiversity, including organisms from different trophic levels, results in multiple interactions and complex food webs, which are covered in this review. Additionally, we highlight how floating <em>Sargassum</em> acts as a vector of ecological connectivity, influencing distant ecosystems such as coastal and deep-sea habitats. These cross-ecosystem interactions occur through organism transport, organic matter export and trophic linkages. Understanding these connections is key to recognizing the broader ecological role of <em>Sargassum</em> rafts and the multiple ecosystem services they provide.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102961"},"PeriodicalIF":4.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Salinity adaption and toxicity of harmful algal blooms in three bays of Great Salt Lake (USA) 美国大盐湖三个海湾有害藻华的盐度适应及毒性研究

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-25 DOI: 10.1016/j.hal.2025.102959

W.A. Wurtsbaugh , Malin Olofsson , Gregory L. Boyer , Amy M. Marcarelli

Cyanobacterial blooms can be harmful to animals and humans exposed to their toxins; however, their environmental drivers and boundaries still need to be elucidated. Salinity has been demonstrated to be an important driver of community composition that sets boundaries of species migration and survival. The filamentous cyanobacteria Nodularia spumigena forms dense blooms in estuaries around the world, produces the hepatotoxin nodularin, and has been thought to not survive or fix nitrogen (N) in high salinities. From 2005–2009 we studied three bays of Great Salt Lake (USA), two of which are estuaries with salinities ranging from 0 to >90 g l^-1 while the third, Gilbert Bay, had a salinity near 160 g l^-1. Bear River Bay and the larger Gilbert Bay were meso‑eutrophic, while Farmington Bay, which receives direct inputs of secondary-treated sewage, was hypereutrophic with mean chlorophyll concentrations of 149 µg l^-1 and dense blooms of N. spumigena. Cell densities were >500 times those of Nodularia studied in the Baltic Sea. In Farmington Bay blooms occur at salinities ranging from 8–50 g l^-1, which are much higher than usually reported for this taxon. Concentrations of the cyanotoxin nodularin reached 660 µg l^-1 (mean = 41 µg l^-1), far above critical thresholds for contact recreation and above those causing bird mortalities elsewhere. The mean N₂ fixation rate of Nodularia measured over a salinity range of 14 to 52 g l^-1 was 47 mg N m^-2 d^-1, which is among the highest reported values for freshwater and marine ecosystems. The local adaptation of Nodularia to the extreme salinity conditions in Great Salt Lake furthers our understanding of salinity adaptation and the potential spread of this species to new regions.

蓝藻的大量繁殖可能对接触其毒素的动物和人类有害；然而，它们的环境驱动因素和边界仍然需要阐明。盐度已被证明是群落组成的重要驱动因素，它设定了物种迁移和生存的界限。丝状藻蓝藻结核菌在世界各地的河口形成密集的水华，产生肝毒素结核素，并且被认为不能在高盐度中生存或固定氮(N)。2005-2009年，我们研究了美国大盐湖的三个海湾，其中两个是盐度在0到90 g -1之间的河口，而第三个吉尔伯特湾的盐度接近160 g -1。熊河湾和较大的吉尔伯特湾为中富营养化，而法明顿湾则为富营养化，平均叶绿素浓度为149µg l-1，藻华密集。细胞密度是波罗的海结核菌的500倍。在法明顿湾，水华发生在8 - 50g -1的盐度范围内，这比通常报道的这个分类单元要高得多。蓝藻毒素结核素的浓度达到660µg -1（平均值为41µg -1），远远高于接触娱乐的临界阈值，也高于其他地方导致鸟类死亡的阈值。在14 ~ 52 g -1的盐度范围内，结核菌的平均固氮率为47 mg N - m-2 - d-1，是淡水和海洋生态系统中报告的最高值之一。大盐湖极端盐度条件下结节藻的局部适应进一步加深了我们对盐度适应和该物种向新地区传播的潜在认识。

{"title":"Salinity adaption and toxicity of harmful algal blooms in three bays of Great Salt Lake (USA)","authors":"W.A. Wurtsbaugh , Malin Olofsson , Gregory L. Boyer , Amy M. Marcarelli","doi":"10.1016/j.hal.2025.102959","DOIUrl":"10.1016/j.hal.2025.102959","url":null,"abstract":"<div><div>Cyanobacterial blooms can be harmful to animals and humans exposed to their toxins; however, their environmental drivers and boundaries still need to be elucidated. Salinity has been demonstrated to be an important driver of community composition that sets boundaries of species migration and survival. The filamentous cyanobacteria <em>Nodularia spumigena</em> forms dense blooms in estuaries around the world, produces the hepatotoxin nodularin, and has been thought to not survive or fix nitrogen (N) in high salinities. From 2005–2009 we studied three bays of Great Salt Lake (USA), two of which are estuaries with salinities ranging from 0 to >90 g <span>l</span><sup>-1</sup> while the third, Gilbert Bay, had a salinity near 160 g <span>l</span><sup>-1</sup>. Bear River Bay and the larger Gilbert Bay were meso‑eutrophic, while Farmington Bay, which receives direct inputs of secondary-treated sewage, was hypereutrophic with mean chlorophyll concentrations of 149 µg <span>l</span><sup>-1</sup> and dense blooms of <em>N. spumigena.</em> Cell densities were >500 times those of <em>Nodularia</em> studied in the Baltic Sea. In Farmington Bay blooms occur at salinities ranging from 8–50 g <span>l</span><sup>-1</sup>, which are much higher than usually reported for this taxon. Concentrations of the cyanotoxin nodularin reached 660 µg <span>l</span><sup>-1</sup> (mean = 41 µg <span>l</span><sup>-1</sup>), far above critical thresholds for contact recreation and above those causing bird mortalities elsewhere. The mean N<sub>2</sub> fixation rate of <em>Nodularia</em> measured over a salinity range of 14 to 52 g <span>l</span><sup>-1</sup> was 47 mg N m<sup>-2</sup> <span>d</span><sup>-1</sup>, which is among the highest reported values for freshwater and marine ecosystems. The local adaptation of <em>Nodularia</em> to the extreme salinity conditions in Great Salt Lake furthers our understanding of salinity adaptation and the potential spread of this species to new regions.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102959"},"PeriodicalIF":4.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Responses of a harmful algal bloom-causing dinoflagellate Prorocentrum obtusidens to elevated temperature and urea 引起藻华的鞭毛原藻对高温和尿素的反应

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-24 DOI: 10.1016/j.hal.2025.102958

Wei-Ping Zhang , Yang Zhou , Wen-Jing Sun , Shuo-Yu Zhang , Shu-Feng Zhang , Jae-Seong Lee , Minghua Wang , Da-Zhi Wang

Elevated temperature and nitrogen (N) availability affect dinoflagellates differently; however, their interactive effects remain largely unexplored. This study investigated the physiological and transcriptomic responses of a harmful algal bloom-causing dinoflagellate, Prorocentrum obtusidens, to elevated temperature (22 °C vs. 26 °C) under three N conditions (16 μM nitrate, 8 and 16 μM urea) after 32 days of exposure. Elevated temperature enhanced cell growth across all N conditions, with a more pronounced increase in urea-grown cells, regardless of the insignificant interaction between temperature and N. Physiological responses to elevated temperature varied under N conditions. The nitrate-grown cells had higher particulate organic carbon (POC) content, C:N ratio, and activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), phosphoenolpyruvate carboxykinase, and urease, but lower particulate organic N (PON) content. The low urea-grown cells showed higher C:N ratio, total carbohydrate content, and activities of carbonic anhydrase (CA), glutamine synthetase (GS), and urease, but lower phosphoenolpyruvate carboxylase activity, total protein, and total antioxidant capacity. The high urea-grown cells exhibited higher maximum photosynthetic efficiency, POC content, C:N ratio, and activities of CA, RubisCO, GS, and urease. Transcriptomic analysis revealed that elevated temperature increased the expression of genes associated with photosynthesis under all N conditions. The nitrate-grown cells produced more energy to mitigate thermal stress, whereas the urea-grown cells decreased energy production. These findings suggest that P. obtusidens is more resilient to future ocean warming when grown with urea, and predictions of dinoflagellate responses to warming oceans should consider N conditions in the environment.

升高的温度和氮(N)有效性对鞭毛藻的影响不同；然而，它们的相互作用在很大程度上仍未被探索。本研究研究了在3种N浓度（16 μM硝酸盐、8和16 μM尿素）条件下，对22°C和26°C的高温（22°C和26°C）暴露32天后的生理和转录组反应。在所有的N条件下，升高的温度都促进了细胞的生长，尽管温度和N之间的相互作用不明显，但尿素生长的细胞的增长更为明显。硝酸盐培养的细胞颗粒有机碳（POC）含量、碳氮比、核酮糖-1,5-二磷酸羧化酶/加氧酶（RubisCO）、磷酸烯醇丙酮酸羧激酶和脲酶活性较高，颗粒有机氮（PON）含量较低。低尿素培养的细胞C:N比、总碳水化合物含量、碳酸酐酶（CA）、谷氨酰胺合成酶（GS）和脲酶活性较高，但磷酸烯醇丙酮酸羧化酶活性、总蛋白和总抗氧化能力较低。高尿素培养的细胞表现出更高的最大光合效率、POC含量、C:N比以及CA、RubisCO、GS和脲酶活性。转录组学分析显示，在所有氮条件下，温度升高均增加了光合作用相关基因的表达。硝酸盐生长的细胞产生更多的能量来缓解热应激，而尿素生长的细胞则减少能量产生。这些发现表明，当与尿素一起生长时，P. obtusidens对未来海洋变暖的适应能力更强，并且预测鞭毛藻对变暖海洋的反应应考虑环境中的N条件。

{"title":"Responses of a harmful algal bloom-causing dinoflagellate Prorocentrum obtusidens to elevated temperature and urea","authors":"Wei-Ping Zhang , Yang Zhou , Wen-Jing Sun , Shuo-Yu Zhang , Shu-Feng Zhang , Jae-Seong Lee , Minghua Wang , Da-Zhi Wang","doi":"10.1016/j.hal.2025.102958","DOIUrl":"10.1016/j.hal.2025.102958","url":null,"abstract":"<div><div>Elevated temperature and nitrogen (N) availability affect dinoflagellates differently; however, their interactive effects remain largely unexplored. This study investigated the physiological and transcriptomic responses of a harmful algal bloom-causing dinoflagellate, <em>Prorocentrum obtusidens</em>, to elevated temperature (22 °C vs. 26 °C) under three N conditions (16 μM nitrate, 8 and 16 μM urea) after 32 days of exposure. Elevated temperature enhanced cell growth across all N conditions, with a more pronounced increase in urea-grown cells, regardless of the insignificant interaction between temperature and N. Physiological responses to elevated temperature varied under N conditions. The nitrate-grown cells had higher particulate organic carbon (POC) content, C:N ratio, and activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), phosphoenolpyruvate carboxykinase, and urease, but lower particulate organic N (PON) content. The low urea-grown cells showed higher C:N ratio, total carbohydrate content, and activities of carbonic anhydrase (CA), glutamine synthetase (GS), and urease, but lower phosphoenolpyruvate carboxylase activity, total protein, and total antioxidant capacity. The high urea-grown cells exhibited higher maximum photosynthetic efficiency, POC content, C:N ratio, and activities of CA, RubisCO, GS, and urease. Transcriptomic analysis revealed that elevated temperature increased the expression of genes associated with photosynthesis under all N conditions. The nitrate-grown cells produced more energy to mitigate thermal stress, whereas the urea-grown cells decreased energy production. These findings suggest that <em>P. obtusidens</em> is more resilient to future ocean warming when grown with urea, and predictions of dinoflagellate responses to warming oceans should consider N conditions in the environment.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102958"},"PeriodicalIF":4.5,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144912873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sargassum transport to the Amazon Coast: Explaining the stranding through meteorological and oceanographic conditions 马尾藻运输到亚马逊海岸：通过气象和海洋学条件解释搁浅

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-23 DOI: 10.1016/j.hal.2025.102955

João Pedro Mancio de Amorim , Alexandre Melo Casseb do Carmo , José Eduardo Martinelli Filho

Over the recent years, different areas around the tropical Atlantic Ocean experienced an increase in pelagic Sargassum stranding events. Such incidents pose ecological and socioeconomic challenges, since they are difficult to predict and can impact coastal communities. In this study, we investigate the physical mechanisms behind Sargassum stranding events on the Brazilian Amazon Coast, focusing on the northeastern Pará region (northern Brazil), especially during the sporadic massive events registered in May 2014, April 2015, March 2019 and March 2025. We used a combination of observational data, reanalysis, forecast products, and Lagrangian experiments to explore the role of meteorological and oceanographic conditions during the occurrence of the strandings. Our results suggest that the events are related to the rainy season, when the Intertropical Convergence Zone (ITCZ) is positioned at its southernmost extent, bringing intense rainfall and northeasterly winds to the region. These winds can increase the landward transport of floating particles into the Amazon Continental Shelf (ACS). The results from the Lagrangian simulations highlighted the importance of wind drag and local processes (i.e., tidal currents and Stokes drift) in promoting the intrusion of floating particles into the inner shelf, particularly in the northeastern sector of the ACS, which emerges as a preferential pathway for the entrance of offshore Sargassum patches. This pathway was also highlighted by the sighting of Sargassum close to this area prior to the massive event of 2025, reinforcing the role of winds and tidal currents in connecting the northeastern offshore sector of ACS to the coast. While global reanalysis products and forecast systems provided valuable insights, future research should focus on the implementation of regional models to provide more accurate predictions near the coast, improving predictive capabilities to mitigate the impacts of these phenomena.

近年来，热带大西洋周围的不同地区经历了上层马尾藻搁浅事件的增加。此类事件带来了生态和社会经济挑战，因为它们难以预测，并可能影响沿海社区。在这项研究中，我们研究了巴西亚马逊海岸马尾藻搁浅事件背后的物理机制，重点研究了par东北部地区（巴西北部），特别是在2014年5月、2015年4月、2019年3月和2025年3月记录的零星大规模事件期间。我们采用观测资料、再分析、预报产品和拉格朗日实验相结合的方法，探讨了气象和海洋条件在搁浅发生过程中的作用。结果表明，这些事件与雨季有关，此时热带辐合带（ITCZ）位于其最南端，为该地区带来强降雨和东北风。这些风可以增加漂浮粒子向陆地输送到亚马逊大陆架（ACS）。拉格朗日模拟的结果强调了风阻和局部过程（即潮汐流和斯托克斯漂移）在促进漂浮粒子侵入内大陆架方面的重要性，特别是在ACS的东北部分，这是近海马尾藻斑块进入的优先途径。在2025年的大规模事件发生之前，在该地区附近发现了马尾藻，这也突出了这条路径，加强了风和潮流在连接ACS东北近海地区和海岸方面的作用。虽然全球再分析产品和预测系统提供了有价值的见解，但未来的研究应侧重于实施区域模型，以便在海岸附近提供更准确的预测，提高预测能力，以减轻这些现象的影响。

{"title":"Sargassum transport to the Amazon Coast: Explaining the stranding through meteorological and oceanographic conditions","authors":"João Pedro Mancio de Amorim , Alexandre Melo Casseb do Carmo , José Eduardo Martinelli Filho","doi":"10.1016/j.hal.2025.102955","DOIUrl":"10.1016/j.hal.2025.102955","url":null,"abstract":"<div><div>Over the recent years, different areas around the tropical Atlantic Ocean experienced an increase in pelagic <em>Sargassum</em> stranding events. Such incidents pose ecological and socioeconomic challenges, since they are difficult to predict and can impact coastal communities. In this study, we investigate the physical mechanisms behind <em>Sargassum</em> stranding events on the Brazilian Amazon Coast, focusing on the northeastern Pará region (northern Brazil), especially during the sporadic massive events registered in May 2014, April 2015, March 2019 and March 2025. We used a combination of observational data, reanalysis, forecast products, and Lagrangian experiments to explore the role of meteorological and oceanographic conditions during the occurrence of the strandings. Our results suggest that the events are related to the rainy season, when the Intertropical Convergence Zone (ITCZ) is positioned at its southernmost extent, bringing intense rainfall and northeasterly winds to the region. These winds can increase the landward transport of floating particles into the Amazon Continental Shelf (ACS). The results from the Lagrangian simulations highlighted the importance of wind drag and local processes (<em>i.e.</em>, tidal currents and Stokes drift) in promoting the intrusion of floating particles into the inner shelf, particularly in the northeastern sector of the ACS, which emerges as a preferential pathway for the entrance of offshore <em>Sargassum</em> patches. This pathway was also highlighted by the sighting of <em>Sargassum</em> close to this area prior to the massive event of 2025, reinforcing the role of winds and tidal currents in connecting the northeastern offshore sector of ACS to the coast. While global reanalysis products and forecast systems provided valuable insights, future research should focus on the implementation of regional models to provide more accurate predictions near the coast, improving predictive capabilities to mitigate the impacts of these phenomena.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102955"},"PeriodicalIF":4.5,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Walruses are potentially exposed to paralytic shellfish toxin concentrations that impact their health during Alexandrium blooms in the Alaskan Arctic 在阿拉斯加北极的亚历山大藻繁盛期间，海象可能暴露于麻痹性贝类毒素浓度，影响它们的健康

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-23 DOI: 10.1016/j.hal.2025.102960

Patrick Charapata , Evangeline Fachon , Donald M. Anderson , Gay Sheffield , Emily K. Bowers , Robert S. Pickart , Peigen Lin , Kathi A. Lefebvre

Harmful algal bloom (HAB) activity of Alexandrium catenella, a dinoflagellate that produces paralytic shellfish toxins (PSTs), has increased in the Alaskan Arctic due to warming ocean conditions. Arctic wildlife exposure to PSTs due to these blooms remains unknown. The Pacific walrus (Odobenus rosmarus divergens) is a marine mammal that preys primarily on efficient vectors of PSTs (benthic invertebrates), making walruses an important model for assessing PST exposure risks. Here, we used paired Alexandrium data (Alexandrium cell and cyst densities and PST content), and PSTs measured in benthic invertebrates (clams, worms, and gastropods) to construct and validate trophic transfer models of PSTs in a critical Arctic food chain. Further, we used observed PSTs in walrus prey to estimate daily walrus oral PST doses (µg STX eq. kg^-1) during summers (2019 and 2022) with well-characterized and widespread Alexandrium blooms. Models were validated using various model metrics, however, predictions underestimated toxicity (STX eq.) of invertebrates. Observed PSTs in walrus prey resulted in 89 % (n = 47 of 53 total; 2019) and 67 % (n = 41 of 61; 2022) of PST doses exceeding thresholds posing a moderate health risk to walruses (> 11.6 μg STX eq. kg^-1). Ledyard Bay in the northeastern Chukchi Sea was identified as a PST exposure risk hotspot because it contained the highest estimated doses, while walruses simultaneously occupied the neighboring Point Lay haulout. Additional studies are required to assess how HAB activity will impact walrus health as well as food-security and food-safety for Indigenous communities that rely on walruses for subsistence.

由于海洋环境变暖，阿拉斯加北极地区有害藻华（HAB）活动增加，这是一种产生麻痹性贝类毒素（PSTs）的双鞭毛藻。北极野生动物因这些水华而暴露于pst的情况尚不清楚。太平洋海象（Odobenus rosmarus divergens）是一种主要捕食PST（底栖无脊椎动物）有效载体的海洋哺乳动物，使海象成为评估PST暴露风险的重要模型。在这里，我们使用了配对的亚历山大菌数据（亚历山大菌细胞和囊密度以及PST含量），并在底栖无脊椎动物（蛤蜊、蠕虫和腹足类）中测量了PST，以构建和验证PST在北极关键食物链中的营养转移模型。此外，我们使用海象猎物中观察到的PST来估计海象在夏季（2019年和2022年）的每日口服PST剂量（µg STX = kg-1），其中亚历山大菌大量繁殖。使用各种模型指标验证了模型，然而，预测低估了无脊椎动物的毒性（STX eq.）。在海象猎物中观察到的PST导致89% （n = 47 / 53; 2019）和67% （n = 41 / 61; 2022）的PST剂量超过对海象构成中等健康风险的阈值（> 11.6 μg STX = kg-1）。楚科奇海东北部的Ledyard湾被确定为PST暴露风险热点，因为它含有最高的估计剂量，而海象同时占据了邻近的Point Lay港口。需要进一步的研究来评估有害藻华活动将如何影响海象的健康以及依赖海象为生的土著社区的粮食安全和食品安全。

{"title":"Walruses are potentially exposed to paralytic shellfish toxin concentrations that impact their health during Alexandrium blooms in the Alaskan Arctic","authors":"Patrick Charapata , Evangeline Fachon , Donald M. Anderson , Gay Sheffield , Emily K. Bowers , Robert S. Pickart , Peigen Lin , Kathi A. Lefebvre","doi":"10.1016/j.hal.2025.102960","DOIUrl":"10.1016/j.hal.2025.102960","url":null,"abstract":"<div><div>Harmful algal bloom (HAB) activity of <em>Alexandrium catenella</em>, a dinoflagellate that produces paralytic shellfish toxins (PSTs), has increased in the Alaskan Arctic due to warming ocean conditions. Arctic wildlife exposure to PSTs due to these blooms remains unknown. The Pacific walrus (<em>Odobenus rosmarus divergens</em>) is a marine mammal that preys primarily on efficient vectors of PSTs (benthic invertebrates), making walruses an important model for assessing PST exposure risks. Here, we used paired <em>Alexandrium</em> data (<em>Alexandrium</em> cell and cyst densities and PST content), and PSTs measured in benthic invertebrates (clams, worms, and gastropods) to construct and validate trophic transfer models of PSTs in a critical Arctic food chain. Further, we used observed PSTs in walrus prey to estimate daily walrus oral PST doses (µg STX eq. kg<sup>-1</sup>) during summers (2019 and 2022) with well-characterized and widespread <em>Alexandrium</em> blooms. Models were validated using various model metrics, however, predictions underestimated toxicity (STX eq.) of invertebrates. Observed PSTs in walrus prey resulted in 89 % (<em>n</em> <em>=</em> 47 of 53 total; 2019) and 67 % (<em>n</em> <em>=</em> 41 of 61; 2022) of PST doses exceeding thresholds posing a moderate health risk to walruses (> 11.6 μg STX eq. kg<sup>-1</sup>). Ledyard Bay in the northeastern Chukchi Sea was identified as a PST exposure risk hotspot because it contained the highest estimated doses, while walruses simultaneously occupied the neighboring Point Lay haulout. Additional studies are required to assess how HAB activity will impact walrus health as well as food-security and food-safety for Indigenous communities that rely on walruses for subsistence.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102960"},"PeriodicalIF":4.5,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144912872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Climate change will boost the invasion of the harmful cyanobacterium Raphidiopsis raciborskii in South America 气候变化将促进有害蓝藻Raphidiopsis raciborskii在南美洲的入侵

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-21 DOI: 10.1016/j.hal.2025.102957

Felipe Morais Zanon , Bruno Henrique Mioto Stabile , Beatriz Melissa Campos , Érica Oliveira de Lima , Matheus Juan Alarcon Sampaio , Yasmin Rodrigues de Souza , Leonardo Rodrigues Tolardo , Mayra Koma Gomes , Luddy Searom Carias de Moraes , Gabriela Sponchiado Hein , Jaqueline Dantas da Silva , Larissa da Silva Pinha , Loiani Oliveira Santana , Mariana Albuquerque , Vinicius da Silva , João Vitor Bredariol , Gabriel Arthur Lopes da Silva , Gabriel Delabio da Silva , Aline Aparecida Aguiar Ferreira , Luíz Fernando Esser , Luzia Cleide Rodrigues

The invasive cyanobacterium species Raphidiopsis raciborskii was first recorded in the Indo-Malaysian region in 1899, and studies currently report its presence in tropical, subtropical, and temperate environments around the world. In addition to its plasticity in colonizing new environments, R. raciborskii deserves attention for its ability to produce saxitoxin and cylindrospermopsin, which can cause the death of aquatic organisms and harm human health. In this work, we assessed the effect of global climate change towards the end of this century on the potential expansion of R. raciborskii using ecological niche models (ENMs). We applied a set of machine learning algorithms within the ensemble prediction approach to estimate the potential distribution of the species in South America under projected climate change, considering different carbon emission scenarios. In the moderate scenario, the northern Amazon basin, the southern Orinoco basin, and part of the North Atlantic basin showed increased environmental suitability for the species. In the pessimistic scenario, the basin with the greatest increase in suitability was the Paraná-Paraguay basin. Several basins remained highly suitable in both current and future scenarios, especially in Brazil. This study highlights the importance of understanding and addressing the impacts of climate change on the distribution of the invasive species R. raciborskii. South American countries must implement monitoring measures to assess the expansion of blooms of this species, as well as government actions to control water quality, given the strong impact of these organisms on biodiversity and ecosystem services.

入侵蓝藻物种Raphidiopsis raciborskii于1899年首次在印度-马来西亚地区被记录，目前研究报告它在世界各地的热带、亚热带和温带环境中都有存在。除了在新环境中具有可塑性外，raciborskii还具有产生蛤蚌毒素和柱精子素的能力，这些物质会导致水生生物死亡，危害人类健康，值得关注。本研究利用生态位模型（ENMs）评估了本世纪末全球气候变化对鼠耳鼠潜在扩张的影响。我们在集合预测方法中应用了一套机器学习算法来估计在预测的气候变化下南美洲物种的潜在分布，考虑不同的碳排放情景。在中等情景下，亚马逊盆地北部、奥里诺科河盆地南部和北大西洋盆地的部分地区对该物种的环境适应性增强。在悲观情景下，适宜性增加最大的盆地为Paraná-Paraguay盆地。在当前和未来的情况下，几个盆地仍然非常适合，尤其是巴西。本研究强调了认识和解决气候变化对入侵物种鼠唇蝗分布的影响的重要性。鉴于这些生物对生物多样性和生态系统服务的巨大影响，南美国家必须实施监测措施，以评估该物种繁殖的扩大，以及政府控制水质的行动。

{"title":"Climate change will boost the invasion of the harmful cyanobacterium Raphidiopsis raciborskii in South America","authors":"Felipe Morais Zanon , Bruno Henrique Mioto Stabile , Beatriz Melissa Campos , Érica Oliveira de Lima , Matheus Juan Alarcon Sampaio , Yasmin Rodrigues de Souza , Leonardo Rodrigues Tolardo , Mayra Koma Gomes , Luddy Searom Carias de Moraes , Gabriela Sponchiado Hein , Jaqueline Dantas da Silva , Larissa da Silva Pinha , Loiani Oliveira Santana , Mariana Albuquerque , Vinicius da Silva , João Vitor Bredariol , Gabriel Arthur Lopes da Silva , Gabriel Delabio da Silva , Aline Aparecida Aguiar Ferreira , Luíz Fernando Esser , Luzia Cleide Rodrigues","doi":"10.1016/j.hal.2025.102957","DOIUrl":"10.1016/j.hal.2025.102957","url":null,"abstract":"<div><div>The invasive cyanobacterium species <em>Raphidiopsis raciborskii</em> was first recorded in the Indo-Malaysian region in 1899, and studies currently report its presence in tropical, subtropical, and temperate environments around the world. In addition to its plasticity in colonizing new environments, <em>R. raciborskii</em> deserves attention for its ability to produce saxitoxin and cylindrospermopsin, which can cause the death of aquatic organisms and harm human health. In this work, we assessed the effect of global climate change towards the end of this century on the potential expansion of <em>R. raciborskii</em> using ecological niche models (ENMs). We applied a set of machine learning algorithms within the ensemble prediction approach to estimate the potential distribution of the species in South America under projected climate change, considering different carbon emission scenarios. In the moderate scenario, the northern Amazon basin, the southern Orinoco basin, and part of the North Atlantic basin showed increased environmental suitability for the species. In the pessimistic scenario, the basin with the greatest increase in suitability was the Paraná-Paraguay basin. Several basins remained highly suitable in both current and future scenarios, especially in Brazil. This study highlights the importance of understanding and addressing the impacts of climate change on the distribution of the invasive species <em>R. raciborskii</em>. South American countries must implement monitoring measures to assess the expansion of blooms of this species, as well as government actions to control water quality, given the strong impact of these organisms on biodiversity and ecosystem services.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102957"},"PeriodicalIF":4.5,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

First report of nodularin production by Nostochopsis sp. in a temperate eutrophic lake 温带富营养化湖泊Nostochopsis sp.产生结核素的首次报道

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-19 DOI: 10.1016/j.hal.2025.102956

Abby M. Webster , Zac Triumph , Bofan Wei , Robbie M. Martin , Laura E. Smith , Steven W. Wilhelm , Lisa B. Cleckner , N.Roxanna Razavi , Gregory L. Boyer

Benthic cyanobacteria are understudied in comparison to their planktonic counterparts. Consequently, our understanding of cyanotoxin production in benthic mats remains limited. We detected nodularin-R (NOD-R) in a population of Nostochopsis from Honeoye Lake (New York, United States). Identification as Nostochopsis was supported by morphological (see section 3.1 for a detailed description) and metagenomic analyses. The first metagenome assembled genome of Nostochopsis was drafted and estimated at 99.28 % complete. Cyanotoxin testing of Nostochopsis biomass showed production of NOD-R but not microcystins, anatoxins, or cylindrospermopsins. The complete nodularin synthetase cluster was confirmed in the Nostochopsis genome. To our knowledge, this is the first report of nodularin production, or any cyanotoxin production, by the benthic cyanobacteria Nostochopsis. This is the fourth genus of cyanobacteria reported to produce nodularins.

与浮游生物相比，底栖蓝藻的研究不足。因此，我们对底栖垫中蓝藻毒素产生的了解仍然有限。我们在来自美国纽约Honeoye Lake的Nostochopsis种群中检测到了结节素r （nodarin - r）。形态学（详细描述见3.1节）和宏基因组学分析支持了该菌株的Nostochopsis鉴定。绘制了首个Nostochopsis元基因组组装基因组，估计完成度为99.28%。蓝藻毒素测试表明，蓝藻生物量产生NOD-R，但不产生微囊藻毒素、anatoxins或圆筒精子蛋白酶。完整的结核素合成酶簇在结核杆菌基因组中得到证实。据我们所知，这是第一个报告结核素生产，或任何蓝藻毒素生产，由底栖蓝藻菌Nostochopsis。这是第四个据报道产生结核杆菌的蓝藻属。

{"title":"First report of nodularin production by Nostochopsis sp. in a temperate eutrophic lake","authors":"Abby M. Webster , Zac Triumph , Bofan Wei , Robbie M. Martin , Laura E. Smith , Steven W. Wilhelm , Lisa B. Cleckner , N.Roxanna Razavi , Gregory L. Boyer","doi":"10.1016/j.hal.2025.102956","DOIUrl":"10.1016/j.hal.2025.102956","url":null,"abstract":"<div><div>Benthic cyanobacteria are understudied in comparison to their planktonic counterparts. Consequently, our understanding of cyanotoxin production in benthic mats remains limited. We detected nodularin-R (NOD-R) in a population of <em>Nostochopsis</em> from Honeoye Lake (New York, United States). Identification as <em>Nostochopsis</em> was supported by morphological (see section 3.1 for a detailed description) and metagenomic analyses. The first metagenome assembled genome of <em>Nostochopsis</em> was drafted and estimated at 99.28 % complete. Cyanotoxin testing of <em>Nostochopsis</em> biomass showed production of NOD-R but not microcystins, anatoxins, or cylindrospermopsins. The complete nodularin synthetase cluster was confirmed in the <em>Nostochopsis</em> genome. To our knowledge, this is the first report of nodularin production, or any cyanotoxin production, by the benthic cyanobacteria <em>Nostochopsis</em>. This is the fourth genus of cyanobacteria reported to produce nodularins.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102956"},"PeriodicalIF":4.5,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seasonal and regional variability of lipophilic marine phycotoxins in eutrophic coastal waters of the South China Sea 南海富营养化沿海水域亲脂藻毒素的季节和区域变异

IF 4.5 1区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Harmful Algae

Pub Date : 2025-08-18 DOI: 10.1016/j.hal.2025.102954

Min Liu , Liyan Deng , Yan Wang , Xiaodong Wang , Sen Du , Zhicai She , Zhenjun Kang , Qingxia Liu , Peng Wu , Zexing Kuang , Lingxiang Zhu , Jiajun Wu , Lai Leo Chan , Yuanyue Cheng , Li Zhang , Yang Liu

Lipophilic marine phycotoxins (LMTs), primarily produced by toxigenic dinoflagellates, pose significant risks to marine ecosystems and human health due to their toxicity and widespread distribution. This study investigates the spatial and temporal distribution of LMTs in the surface seawater from representative estuarine and bay areas of the South China Sea (SCS) during period from 2022‒2023. Using active solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry (Active-SPE-LC-MS/MS), the study revealed that significantly higher LMTs concentrations in semi-enclosed bays (13.15 ± 8.61 ng L⁻¹) compared to estuarine regions (8.55 ± 8.59 ng L⁻¹), with Daya Bay (DB) and Jian River Estuary (JRE) exhibiting the highest toxin levels. The most prevalent toxins were diarrhetic shellfish toxins (OA, DTX1) and pectenotoxin-2 (PTX2), with PTX2 being dominant in most regions. Seasonal variations were evident, with higher LMTs concentrations observed during the wet season, particularly in spring and summer. Principal component analysis (PCA) revealed distinct toxin profiles, with PTX2, GYM, and OA being prevalent in the Pearl River Estuary (PRE), while AZA2 and DTX1 were more abundant in Qinzhou Bay (QB). The study highlights the influence of local environmental conditions, such as seasonal and region variations on LMTs distribution. These findings provide critical insights into the ecological dynamics of LMTs in eutrophic coastal waters, emphasizing the need for continuous monitoring to mitigate risks to marine ecosystems and human health. This research contributes to a deeper understanding of LMTs distribution patterns in the SCS, supporting future risk assessments and management strategies.

亲脂性海洋藻毒素（lmt）主要由产毒鞭毛藻产生，由于其毒性和广泛分布，对海洋生态系统和人类健康构成重大风险。研究了2022-2023年南海代表性河口湾区表层海水中lmt的时空分布特征。采用活性固相萃取-液相色谱-串联质谱联用技术（active - spe - lc -MS/MS）研究发现，半封闭海湾地区的毒素浓度（13.15±8.61 ng L−1）显著高于河口地区（8.55±8.59 ng L−1），其中大亚湾（DB）和剑江口（JRE）的毒素含量最高。最常见的毒素是腹泻性贝类毒素（OA、DTX1）和果皮毒素-2 (PTX2)，大部分地区以PTX2为主。季节变化明显，在雨季，特别是春季和夏季，观察到的LMTs浓度较高。主成分分析显示，珠江口（PRE）以PTX2、GYM和OA为主，而钦州湾（QB）以AZA2和DTX1为主。该研究强调了当地环境条件（如季节和区域变化）对LMTs分布的影响。这些发现为富营养化沿海水域中浮游生物的生态动态提供了重要见解，强调需要持续监测以减轻对海洋生态系统和人类健康的风险。这项研究有助于更深入地了解南中国海的LMTs分布模式，为未来的风险评估和管理策略提供支持。

{"title":"Seasonal and regional variability of lipophilic marine phycotoxins in eutrophic coastal waters of the South China Sea","authors":"Min Liu , Liyan Deng , Yan Wang , Xiaodong Wang , Sen Du , Zhicai She , Zhenjun Kang , Qingxia Liu , Peng Wu , Zexing Kuang , Lingxiang Zhu , Jiajun Wu , Lai Leo Chan , Yuanyue Cheng , Li Zhang , Yang Liu","doi":"10.1016/j.hal.2025.102954","DOIUrl":"10.1016/j.hal.2025.102954","url":null,"abstract":"<div><div>Lipophilic marine phycotoxins (LMTs), primarily produced by toxigenic dinoflagellates, pose significant risks to marine ecosystems and human health due to their toxicity and widespread distribution. This study investigates the spatial and temporal distribution of LMTs in the surface seawater from representative estuarine and bay areas of the South China Sea (SCS) during period from 2022‒2023. Using active solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry (Active-SPE-LC-MS/MS), the study revealed that significantly higher LMTs concentrations in semi-enclosed bays (13.15 ± 8.61 ng L<sup>−1</sup>) compared to estuarine regions (8.55 ± 8.59 ng L<sup>−1</sup>), with Daya Bay (DB) and Jian River Estuary (JRE) exhibiting the highest toxin levels. The most prevalent toxins were diarrhetic shellfish toxins (OA, DTX1) and pectenotoxin-2 (PTX2), with PTX2 being dominant in most regions. Seasonal variations were evident, with higher LMTs concentrations observed during the wet season, particularly in spring and summer. Principal component analysis (PCA) revealed distinct toxin profiles, with PTX2, GYM, and OA being prevalent in the Pearl River Estuary (PRE), while AZA2 and DTX1 were more abundant in Qinzhou Bay (QB). The study highlights the influence of local environmental conditions, such as seasonal and region variations on LMTs distribution. These findings provide critical insights into the ecological dynamics of LMTs in eutrophic coastal waters, emphasizing the need for continuous monitoring to mitigate risks to marine ecosystems and human health. This research contributes to a deeper understanding of LMTs distribution patterns in the SCS, supporting future risk assessments and management strategies.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"149 ","pages":"Article 102954"},"PeriodicalIF":4.5,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0