Harmful Algae最新文献

{"title":"Accumulation and depuration of 4,5-dihydro-KmTx2 from Karlodinium veneficum in the bivalves, Mercenaria mercenaria and Sinonovacula constricta","authors":"Yanrong Li ,&nbsp;Rong Chen ,&nbsp;Zhujun Zhu ,&nbsp;Tong Mu ,&nbsp;Zhaoshou Ran ,&nbsp;Jilin Xu ,&nbsp;Chengxu Zhou ,&nbsp;Xiaojun Yan","doi":"10.1016/j.hal.2024.102736","DOIUrl":"10.1016/j.hal.2024.102736","url":null,"abstract":"<div><div>Bivalves (e.g., clams, oysters, mussels, scallops) are a significant part of the global diet and are harvested for their nutritional value, but as filter feeders they are susceptible to the accumulation of toxins produced by certain species of phytoplankton. Karlotoxins (KmTxs) are a class of amphidinol-like compounds with hemolytic, ichthyotoxic, and cytotoxic properties that have been associated with harmful algal blooms, and the dinoflagellate <em>Karlodinium veneficum</em> uses KmTxs to facilitate prey capture and deter grazing by other organisms. In this work, we examined the accumulation and depuration of 4,5-dihydro-KmTx2, a karlotoxin previously isolated from <em>K. veneficum</em>, in two bivalves with different life habits, i.e., <em>Sinonovacula constricta</em> Lamarck and <em>Mercenaria mercenaria</em> Linnaeus. After both bivalves received <em>K. veneficum</em> GM5 in their feed for a long period of 10 days, 4,5-dihydro-KmTx2 was accumulated considerably in the visceral mass, but there was almost no toxin accumulation in the muscle. The accumulation was more severe for <em>M. mercenaria</em> than <em>S. constricta</em>. The toxin was cleared almost completely from the bivalves 5 days after <em>K. veneficum</em> GM5 was removed from the feed. For both bivalves, the bait microalgae <em>I. galbana</em> slowed both the accumulation and the depuration of the toxin.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102736"},"PeriodicalIF":5.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533010","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}

{"title":"Ciguatera poisoning: A review of the ecology and detection methods for Gambierdiscus and Fukuyoa species","authors":"Joseph C. Perkins ,&nbsp;Kyall R. Zenger ,&nbsp;Yang Liu ,&nbsp;Jan M. Strugnell","doi":"10.1016/j.hal.2024.102735","DOIUrl":"10.1016/j.hal.2024.102735","url":null,"abstract":"<div><div>Ciguatera poisoning is the most prevalent non-bacterial seafood illness globally, with an estimated 10,000 to 50,000 human cases reported annually. While most symptoms are generally mild, some cases can result in severe and long-lasting neurological and psychological damage, and in some instances, even death. The known causative agents of ciguatera poisoning are benthic toxic dinoflagellate species belonging to the genera <em>Gambierdiscus</em> and <em>Fukuyoa</em>. These species produce highly potent ciguatoxins that bioaccumulate through the marine food chain, eventually reaching humans through seafood consumption. Although <em>Gambierdiscus</em> and <em>Fukuyoa</em> species are widespread in tropical waters worldwide, the full extent of their distribution remains uncertain. This review provides a detailed examination of the ecological dynamics of these dinoflagellates and explores the diverse range of detection methods used to monitor them. These include a focus on molecular techniques for detection, alongside morphological methods, emerging technologies, and a toxin detection overview. Additionally, we offer recommendations on how the field can advance, highlighting novel solutions and next steps for improving detection and monitoring practices. By assessing the strengths and limitations of current approaches and proposing directions for future research, this review aims to support efforts in better understanding and mitigating the risk of ciguatera poisoning.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102735"},"PeriodicalIF":5.5,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Defining algal bloom phenology in Lake Erie","authors":"Timothy J. Maguire ,&nbsp;Alain Isabwe ,&nbsp;Craig A. Stow ,&nbsp;Casey M. Godwin","doi":"10.1016/j.hal.2024.102731","DOIUrl":"10.1016/j.hal.2024.102731","url":null,"abstract":"<div><div>Elucidating the impact of global climate change on aquatic ecosystems, particularly through phenological shifts in primary producers, is critical for understanding ecological resilience. Here, we focus on the phenological shifts in chlorophyll as a proxy for algae biomass and primary production in aquatic ecosystems, specifically in Lake Erie as well as concentrations of the toxin microcystin. By tracking temporal changes in each, we identified key phenological phases important to estimate duration, magnitude, and intensity of harmful algal blooms (HABs). Determining which influential biotic and abiotic factors such as temperature, wind speed, nutrient availability, and climate change is most important, is a long-term management need for Lake Erie, which can be explored using our methodology. Our novel statistical framework employing Bayesian generalized additive mixed models described seasonal chlorophyll and particulate microcystin concentration from Lake Erie and our simple geometric method identified the start, peak, and end of algal blooms. This research enhances our understanding of the ecological effects of nutrient pollution on aquatic ecosystems and provides a repeatable method for determining phenological events without the need for user defined cutoffs which aids in the management and mitigation of HABs, safeguarding water quality in regions dependent on lakes for drinking water.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102731"},"PeriodicalIF":5.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533605","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}

{"title":"Predator-induced defense decreases growth rate and photoprotective capacity in a nitrogen-limited dinoflagellate, Alexandrium minutum","authors":"Jingjing Zhang ,&nbsp;Fredrik Ryderheim ,&nbsp;Erik Selander ,&nbsp;Urban Wünsch ,&nbsp;Thomas Kiørboe","doi":"10.1016/j.hal.2024.102734","DOIUrl":"10.1016/j.hal.2024.102734","url":null,"abstract":"<div><div>Some dinoflagellates produce toxic secondary metabolites that correlate with increased resistance to grazers. The allocation costs of toxin production have been repeatedly addressed, but with conflicting results. Few studies have considered the potential costs of this defense to the photosystem, even though defense toxins (e.g., karlotoxins and brevetoxins) are closely linked to the photoprotective process. Here, we used chemical cues from copepods to induce paralytic shellfish toxin (PST) production in resource-limited <em>Alexandrium minutum</em> and quantitatively determined the growth rate and potential trade-offs with the photosystem process. The results show that grazer-induced, more toxic <em>A. minutum</em> had larger cell volume, lower cell division rate, and lower pigment content under nitrogen-limited conditions than control cells. In addition, predator cues led to a lower relative abundance of photoprotective xanthophylls and a reduced de-epoxidation efficiency of the xanthophyll cycle under high light conditions, reducing the ability of the cells to resist photodamage. Decreased photoprotective capacity may reflect an overlooked defense cost of toxin production.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102734"},"PeriodicalIF":5.5,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417518","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}

{"title":"The occurrence patterns and alternative host use of the generalist parasitoid Parvilucifera infectans (Alveolata, Perkinsozoa) of marine dinoflagellates revealed by a high-frequency time series microscopic data at a temperate coastal site","authors":"Boo Seong Jeon,&nbsp;Myung Gil Park","doi":"10.1016/j.hal.2024.102732","DOIUrl":"10.1016/j.hal.2024.102732","url":null,"abstract":"<div><div>Species belonging to the genus <em>Parvilucifera</em> (Alveolata, Perkinsozoa) are known as generalist parasitoids that can infect a variety of marine dinoflagellates and ultimately kill the host cell. Despite the accumulation of knowledge on <em>Parvilucifera</em> parasitoids over the last twenty years, the occurrence pattern and use of alternative hosts for persistent transmission within fluctuating natural dinoflagellate host communities have received relatively little attention. To address this, high-frequency (i.e., daily) time series protist monitoring was conducted for 411 days, from April 2020 to May 2021, at a temperate coastal site in Jinhae Bay, Republic of Korea. This site was characterized by frequent blooms of mixed dinoflagellates throughout most of the year. Nonetheless, <em>Parvilucifera</em> infections were detected only in the spring seasons, and its occurrence pattern was primarily governed by the presence and cell density of its primary dinoflagellate host, <em>Akashiwo sanguinea</em>. As long as the primary host was present at high densities (greater than 10⁴ cells L^-1), this primary host alone could support the transmission and persistence of the parasitoid. However, if the cell density of the primary host started to decline, then <em>Parvilucifera</em> searched for and exploited alternative hosts for its continued survival. Taken together, this study suggests that the presence and cell density of its preferred primary host species and the duration for which the density remains above the threshold level are key factors that regulate the timing of <em>Parvilucifera</em> occurrence and alternative host use.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102732"},"PeriodicalIF":5.5,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417519","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}

{"title":"An early-warning forecast model for red tide (Karenia brevis) blooms on the southwest coast of Florida","authors":"Miles Medina ,&nbsp;Paul Julian II ,&nbsp;Nicholas Chin ,&nbsp;Stephen E. Davis","doi":"10.1016/j.hal.2024.102729","DOIUrl":"10.1016/j.hal.2024.102729","url":null,"abstract":"<div><div><em>Karenia brevis</em> blooms occur nearly annually along the southwest coast of Florida, and effective mitigation of ecological, public health, and economic impacts requires reliable real-time forecasting. We present two boosted random forest models that predict the weekly maximum <em>K. brevis</em> abundance category across the Greater Charlotte Harbor estuaries over one-week and four-week forecast horizons. The feature set was restricted to data available in near-real time, consistent with adoption of the models as decision-support tools. Features include current and lagged <em>K. brevis</em> abundance statistics, Loop Current position, sea surface temperature, sea level, and riverine discharges and nitrogen concentrations. During cross-validation, the one-week and four-week forecasts exhibited 73 % and 84 % accuracy, respectively, during the 2010–2023 study period. In addition, we assessed the models’ reliability in forecasting the onset of 10 bloom events on time or in advance; the one-week and four-week models anticipated the onset eight times and five times, respectively.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102729"},"PeriodicalIF":5.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357965","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}

{"title":"Explainable machine learning for predicting diarrhetic shellfish poisoning events in the Adriatic Sea using long-term monitoring data","authors":"Martin Marzidovšek ,&nbsp;Janja Francé ,&nbsp;Vid Podpečan ,&nbsp;Stanka Vadnjal ,&nbsp;Jožica Dolenc ,&nbsp;Patricija Mozetič","doi":"10.1016/j.hal.2024.102728","DOIUrl":"10.1016/j.hal.2024.102728","url":null,"abstract":"<div><div>In this study, explainable machine learning techniques are applied to predict the toxicity of mussels in the Gulf of Trieste (Adriatic Sea) caused by harmful algal blooms. By analysing a newly created 28-year dataset containing records of toxic phytoplankton in mussel farming areas and diarrhetic shellfish toxins in mussels (<em>Mytilus galloprovincialis</em>), we train and evaluate the performance of machine learning (ML) models to accurately predict diarrhetic shellfish poisoning (DSP) events. Based on the F1 score, the random forest model provided the best prediction of toxicity results at which the harvesting of mussels is stopped according to EU regulations. Explainability methods such as permutation importance and Shapley Additive Explanations (SHAP) identified key species (<em>Dinophysis fortii</em> and <em>D. caudata</em>) and environmental factors (salinity, river discharge and precipitation) as the best predictors of DSP toxins above regulatory limits. These findings are important for improving early warning systems, which until now were based solely on empirically defined alert abundances of DSP species. They provide experts, aquaculture practitioners, and authorities with additional information to make informed risk management decisions.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102728"},"PeriodicalIF":5.5,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and distribution of dissolved paralytic shellfish toxins in seawater in the Yellow Sea and the Bohai Sea, China","authors":"Xiaoyun Wang ,&nbsp;Jiangbing Qiu ,&nbsp;Dongyue Li ,&nbsp;Aifeng Li","doi":"10.1016/j.hal.2024.102730","DOIUrl":"10.1016/j.hal.2024.102730","url":null,"abstract":"<div><div>Paralytic shellfish toxins (PSTs) could be secreted by PSTs-producing microalgae or released by ruptured cells in seawater. In this study, the distribution of dissolved PSTs in the Yellow Sea and the Bohai Sea, China, was investigated by two cruises in April and July 2023. Seawater samples were collected from the surface, middle and bottom layers, and the profiles of PSTs were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the spatial distribution characteristics of dissolved PSTs and their correlation with environmental factors were explored. Results showed that C1/2, GTX1/4, GTX2/3 and dcGTX2/3, were detected in seawater samples in both spring and summer, with the detection rates 100 % and 97.6 %, respectively. The total PST (ΣPSTs) concentrations ranged in 12 ∼ 590 pmol L⁻¹, 9.3 ∼ 546 pmol L⁻¹, 12 ∼ 2,452 pmol L⁻¹, and not detected (nd) ∼ 188 pmol L⁻¹ in seawater samples collected from the surface, middle and bottom layers in spring, and the surface layer in summer, respectively. Concentrations of PSTs markedly varied in the vertical water column in different sea regions. Generally, concentrations of ΣPSTs in the bottom seawater were higher than those in the surface and middle layers in the Bohai Sea and the North Yellow Sea, but no significant difference in the different water layers in the South Yellow Sea. In addition, concentrations of ΣPSTs in surface waters were much lower in summer than those in spring. In both spring and summer, dissolved PSTs in surface seawater were mainly distributed in the South Yellow Sea. These results indicate that PSTs were prevalent in the Yellow Sea and the Bohai Sea, of which the potential hazard to marine organisms should be highly concerned.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102730"},"PeriodicalIF":5.5,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316289","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}

{"title":"Potential siderophore-dependent mutualism in the harmful dinoflagellate Alexandrium pacificum (Group IV) and bacterium Photobacterium sp. TY1-4 under iron-limited conditions","authors":"Yue Jiang ,&nbsp;Hyeon Ho Shin ,&nbsp;Bum Soo Park ,&nbsp;Zhun Li","doi":"10.1016/j.hal.2024.102726","DOIUrl":"10.1016/j.hal.2024.102726","url":null,"abstract":"<div><div>Specific bacterial species induce algal blooms by producing growth-promoting substances, such as siderophores, under iron-limited conditions. However, the molecular mechanisms underlying these effects remain poorly understood. This study investigates the interactions between the harmful dinoflagellate <em>Alexandrium pacificum</em> (Group IV) and siderophore-producing bacteria, with a focus on iron acquisition facilitated by bacterial siderophores. During algal bloom seasons in the South Sea of Korea, <em>Photobacterium</em> sp. TY1-4 was isolated, which enhances <em>A. pacificum</em> cell density under iron-deficient conditions, TY1-4 can use the sterile exudates from <em>A. pacificum</em> as the sole source of carbon<em>,</em> suggesting a mutualistic relationship. Transcriptomic and genomic analyses revealed siderophore-mediated redox-based signaling and non-reductive pathways enhancing iron bioavailability. <em>Photobacterium</em> sp. TY1-4 initiates siderophore production through quorum sensing, whereas <em>A. pacificum</em> utilizes specific receptors and transporters for hydroxamate-type siderophores (<em>ApFHUA</em> and <em>ApFHUC</em>) to uptake iron. Three redox key iron-uptake genes were also identified in <em>A. pacificum</em>: membrane-bound ferroxidase <em>ApFET3</em>, high-affinity iron permease <em>ApFTR1</em>, and ferric-chelate reductases/oxidoreductases <em>ApFRE1</em>, with transcription levels inversely related to bioavailable iron. Increased iron bioavailability mediated by siderophores alleviates iron stress in <em>A. pacificum</em>, supporting its growth in iron-scarce environments. Additionally, <em>A. pacificum</em> co-cultured with <em>Photobacterium</em> sp. TY1-4 synthesized high-toxicity STXs, including GTX4, GTX2, and STX. These findings highlight the critical role of bacterial siderophores in iron binding and their potential impact on harmful algal bloom dynamics.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102726"},"PeriodicalIF":5.5,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1568988324001598/pdfft?md5=193af3676fa67a46f3e3f7035ea047ab&pid=1-s2.0-S1568988324001598-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response to the CO2 concentrating mechanisms and transcriptional time series analysis of Ulva prolifera under inorganic carbon limitation","authors":"Jingyi Sun ,&nbsp;Wei Dai ,&nbsp;Shuang Zhao ,&nbsp;Jinlin Liu ,&nbsp;Jianheng Zhang ,&nbsp;Juntian Xu ,&nbsp;Peimin He","doi":"10.1016/j.hal.2024.102727","DOIUrl":"10.1016/j.hal.2024.102727","url":null,"abstract":"<div><div><em>Ulva prolifera</em> is a dominant species in green tides and has been affecting marine ecosystem for many years. Due to the low availability of CO₂ in the environment, <em>U. prolifera</em> utilizes the CO₂ concentrating mechanisms (CCMs) to increase intracellular inorganic carbon concentration. However, the transcriptional response mechanism and temporal changes of <em>U. prolifera</em> CCMs based on transcriptomics have not been thoroughly described. Therefore, we induced <em>U. prolifera</em> CCMs in a low CO₂ environment to explore the dynamic regulation of CCMs expression under inadequate inorganic carbon supply. The results showed that inorganic carbon limitation increased the inorganic carbon affinity of <em>U. prolifera</em>, upregulating CCMs. The first 24 h of inorganic carbon environmental changes were the most active period for <em>U. prolifera</em>'s expression regulation. <em>U. prolifera</em> gradually achieved a new steady state by regulating metabolic processes such as nucleic acids, energy, and ethylene-activated signaling pathways. In the carbon fixation system of <em>U. prolifera</em>, there are characteristics of both biophysical and biochemical CCMs. After 24 h of inorganic carbon limitation, the biophysical CCMs becomes more effective under conditions of inorganic carbon depletion. This study aids in exploring the CCMs of <em>U. prolifera</em> and their evolution in response to environmental changes<em>.</em></div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102727"},"PeriodicalIF":5.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316091","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}