Harmful AlgaePub Date : 2025-05-05DOI: 10.1016/j.hal.2025.102883
Tatiana E. Gámez , Schonna R. Manning
{"title":"Blooming in the Anthropocene: Perspectives on the development of freshwater blooms, changing phytoplankton communities, and mitigation strategies","authors":"Tatiana E. Gámez , Schonna R. Manning","doi":"10.1016/j.hal.2025.102883","DOIUrl":"10.1016/j.hal.2025.102883","url":null,"abstract":"<div><div>Freshwater is a declining natural resource sensitive to anthropogenic impacts on the environment, now exacerbated by climate change and elevated global temperatures. Among modern predicaments associated with the Anthropocene are nuisance and harmful algal blooms (HABs), which typically correlate with eutrophication resulting in the rapid growth and overabundance of planktonic microalgae, including cyanobacteria. Regions of hypoxia are common following bloom collapse, and some species of microalgae produce potent toxins, intensifying environmental impacts. While there has been some success implementing mitigation strategies against common bloom-forming microalgae, their responses to treatments are inconsistent. Routine mitigation can be incredibly costly while not being entirely effective, warranting innovation in mitigation strategies. Ultimately, a significant reduction in nutrient loading has the greatest potential for successful mitigation yet is not feasible due to societal requirements. At present, eutrophication and water pollution associated with bloom events are treated on a case-by-case basis, which can be unique depending on the microalgae present. This review provides a comprehensive summary of nuisance and harmful bloom-forming taxa, driving environmental factors, and existing mitigation strategies unique to freshwater microalgae. The major groups of bloom-forming microalgae are discussed, integrating factors responsible for increasing blooms in a rapidly changing climate, including potential treatment strategies.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"147 ","pages":"Article 102883"},"PeriodicalIF":5.5,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928915","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}
Harmful AlgaePub Date : 2025-04-30DOI: 10.1016/j.hal.2025.102872
Buhari Lawan Muhammad , Han-Sol Kim , Quynh Thi Nhu Bui , Jang-Seu Ki
{"title":"Transcriptomic comparison unveils saxitoxin biosynthesis genes in the marine dinoflagellate Gymnodinium catenatum","authors":"Buhari Lawan Muhammad , Han-Sol Kim , Quynh Thi Nhu Bui , Jang-Seu Ki","doi":"10.1016/j.hal.2025.102872","DOIUrl":"10.1016/j.hal.2025.102872","url":null,"abstract":"<div><div>The marine dinoflagellate <em>Gymnodinium catenatum</em> is known to produce saxitoxins (STXs) that are responsible for paralytic shellfish poisoning (PSP); however, the genes involved in STX synthesis are insufficiently understood. In the present study, we determined transcriptome sequences of toxic <em>G. catenatum</em> isolated from Korea (Gc-KR) and compared them with <em>G. catenatum</em> strains reported in other regions such as Spain (Gc-SP) and the United States (Gc-US). Toxin analysis showed that the Korean strain produced the toxins at 6.0 ± 1.9 STXs eq fmol/cell. Comparative transcriptomics of the three strains identified more than 1000 homologs of nearly all STXs biosynthesis genes in dinoflagellates, except <em>sxtB, sxtN</em>, and <em>sxtY</em>. Gene expression analysis revealed similar <em>sxt</em> expression patterns across all strains, with the highest expression levels observed for <em>sxtA</em> and <em>sxtG</em>. Phylogenetic analysis of <em>sxtA, sxtG, sxtI, sxtU</em>, and <em>sxtS</em> revealed distinct evolutionary patterns, with <em>sxtA</em> being more conserved across <em>G. catenatum, Alexandrium</em> spp., and toxic cyanobacteria, particularly at the <em>sxtA4</em> domain, suggesting its significance in STXs synthesis. Other <em>sxt</em> genes in <em>G. catenatum</em> showed distinct patterns and significant divergence from <em>Alexandrium</em> spp., suggesting independent acquisition in <em>G. catenatum</em>. Moreover, the absence of core genes, such as <em>sxtB</em>, indicates it may not be essential for STXs production in <em>G. catenatum</em>. These findings provide insight into the <em>sxt</em> candidate genes in <em>G. catenatum</em>, enhancing our understanding of STXs biosynthesis in dinoflagellates.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"147 ","pages":"Article 102872"},"PeriodicalIF":5.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906502","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}
Harmful AlgaePub Date : 2025-04-29DOI: 10.1016/j.hal.2025.102868
Andreas Seger , James Brady , Kellen S. Vandeveer , Timothy Jordan , Andrew J. Trotter , Grace Robinson , John J. Keane , Alison Turnbull
{"title":"Toxin uptake and slowed reflexes by the marine snail Lunella undulata following exposure to paralytic shellfish toxin producing Alexandrium catenella","authors":"Andreas Seger , James Brady , Kellen S. Vandeveer , Timothy Jordan , Andrew J. Trotter , Grace Robinson , John J. Keane , Alison Turnbull","doi":"10.1016/j.hal.2025.102868","DOIUrl":"10.1016/j.hal.2025.102868","url":null,"abstract":"<div><div>Comparatively little is known about paralytic shellfish toxin (PST) accumulation by marine grazers, yet recurrent blooms of <em>Alexandrium catenella</em> have caused repeated closures of wild fisheries and require ongoing monitoring. To determine if the commercially harvested periwinkle <em>Lunella undulata</em> is at risk of PST uptake, a laboratory experiment was conducted exposing the herbivorous/detritovorous marine snails to either live or senescent <em>Alexandrium catenella</em> microalgae. After 21 days of exposure, the highest PST concentrations were observed in the viscera of animals in the senescent and live algal treatments (0.55±0.08 and 0.82±0.12 mg STX.2HCl eq./kg, respectively). No quantifiable PST was observed in the foot of animals from either exposure treatment. The PST profile in the viscera closely matched that of the microalgal source, suggesting PST uptake through direct grazing of <em>L. undulata</em> on vegetative <em>A. catenella</em> cells. Grazing activity remained unchanged throughout the exposure period across all treatments. However, periwinkles exposed to <em>A. catenella</em> were significantly slower to retract their foot in response to touch than those animals in the control treatment (first observed on days 7 and 11 in the dead and live algae treatments, respectively). This effect became more pronounced over time and coincided with higher PST concentrations. While righting speed did not differ between animals exposed to live microalgae and the control, those exposed to senescent algae were generally slower to right (observed from day 4 onwards). The implications of these findings for biotoxin management in periwinkles and related marine grazers are discussed.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"147 ","pages":"Article 102868"},"PeriodicalIF":5.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906571","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}
Harmful AlgaePub Date : 2025-04-28DOI: 10.1016/j.hal.2025.102870
Giorgia Zoffoli , Laura Pezzolesi , Mara Simonazzi , Franca Guerrini , Silvana Vanucci , Anna Calfapietra , Sonia Dall’Ara , Irene Servadei , Rossella Pistocchi
{"title":"A decade-long study on harmful dinoflagellate blooms and biotoxin contamination in mussels from the north-western Adriatic Sea (Mediterranean Sea)","authors":"Giorgia Zoffoli , Laura Pezzolesi , Mara Simonazzi , Franca Guerrini , Silvana Vanucci , Anna Calfapietra , Sonia Dall’Ara , Irene Servadei , Rossella Pistocchi","doi":"10.1016/j.hal.2025.102870","DOIUrl":"10.1016/j.hal.2025.102870","url":null,"abstract":"<div><div>The north-western Adriatic Sea is one of the most eutrophic areas of the Mediterranean Sea and an important aquaculture region, accounting for about 90% of Italian shellfish production. Since the 1970s, this area has experienced frequent harmful algal blooms, posing risks to consumers and coastal ecosystems. Despite the regular monitoring required by European legislation, long-term studies integrating taxonomic analysis of phytoplankton species, associated biotoxins, and environmental data remain limited. This study examines an 11-year dataset (2012–2022) from the Emilia-Romagna region coast, focusing on timing and occurrence trends of toxic dinoflagellates related to the shellfish toxicity. Phytoplankton species distribution and biotoxins content in farmed mussels were analysed, with particular attention to the presence of analogues. From 2012 to 2015, the most prevalent toxins were yessotoxins (YTXs, up to 8.44 mg kg<sup>-1</sup>), primarily homo-YTX and 45OH homo-YTX, which were associated with autumn blooms of <em>Gonyaulax spinifera</em> and <em>Lingulaulax polyedra</em>. From 2015, okadaic acids and derivatives (OAs, up to 941 µg kg<sup>-1</sup>) became the most prevalent phycotoxin group, associated to <em>Dinophysis fortii</em> and <em>Dinophysis acuminata</em> presence during autumn. This temporal shift was likely driven by increasing surface water temperature and salinity, which contributed to reduced water column mixing favouring oligotrophic species. Notably, low levels of YTXs persisted in mussels despite decreased abundances of producing species. Additionally, <em>Alexandrium</em> spp. cells were consistently detected, even in the absence of saxitoxins (STXs) in bivalves. These findings highlighted the need for integrated studies on strain-specific toxicity, phycotoxins accumulation in bivalves, and field monitoring.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"146 ","pages":"Article 102870"},"PeriodicalIF":5.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143913124","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":"Analysis of ciguatoxins in fish with a single-step sandwich immunoassay","authors":"Jaume Reverté , Shivangi Shukla , Takeshi Tsumuraya , Masahiro Hirama , Jean Turquet , Jorge Diogène , Mònica Campàs","doi":"10.1016/j.hal.2025.102869","DOIUrl":"10.1016/j.hal.2025.102869","url":null,"abstract":"<div><div>Ciguatoxins (CTXs) are the primary cause of ciguatera poisoning (CP), one of the most prevalent non-bacterial seafood-borne illnesses worldwide. With no cure available beyond palliative treatments to alleviate symptoms, effective CP management relies on prevention. However, the detection of CTXs in seafood poses significant analytical challenges due to their typically low concentrations in specimens and the high variability among CTX congeners, many of which remain poorly characterized. These challenges have led to a growing demand for the development of rapid, sensitive, and user-friendly bioanalytical tools for CP surveillance. In this study, several simplified sandwich immunoassay strategies were evaluated for the detection of Pacific CTXs in fish. Among them, the single-step strategy was identified as the most promising, as it enables the detection of Pacific CTXs in complex fish matrixes within only 40 min at levels as low as 0.01 µg CTX1B equivalents/kg of fish, aligned with the safety guidance level proposed by the United States Food and Drug Administration (FDA). Unlike traditional sandwich immunoassays, which require several sequential incubation steps, the single-step strategy involves a simultaneous incubation of all components with the sample, uniquely followed by a washing and substrate incubation step prior to signal measurement. This approach significantly reduces both the complexity and time required for analysis, positioning this immunoassay as a highly promising tool for CP risk assessment and management.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"146 ","pages":"Article 102869"},"PeriodicalIF":5.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899590","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}
Harmful AlgaePub Date : 2025-04-28DOI: 10.1016/j.hal.2025.102871
Wenxin Liu, Ilias Semmouri, Suzanne Bulckaert, Colin R. Janssen, Jana Asselman
{"title":"Temperature and salinity affect growth and toxin content of cyanobacterium Microcystis aeruginosa (PCC 7806) in estuarine environments","authors":"Wenxin Liu, Ilias Semmouri, Suzanne Bulckaert, Colin R. Janssen, Jana Asselman","doi":"10.1016/j.hal.2025.102871","DOIUrl":"10.1016/j.hal.2025.102871","url":null,"abstract":"<div><div><em>Microcystis aeruginosa</em> is considered a harmful cyanobacterial species due to its ability to produce microcystins (MCs) and its increasing prevalence in estuarine environments. While previous studies have demonstrated the effects of individual environmental factors on either growth or toxin content of <em>M. aeruginosa</em>, potential interactive effects and resulting changes in its toxicity remain unclear. In this study, we first conducted an orthogonally designed growth experiment to assess potential effects of changes in temperature, salinity, pH, and nutrient conditions. Subsequently, we performed a full-factorial growth experiment focusing on temperature and salinity as key variables. Intracellular and extracellular MCs content, as well as phycocyanin levels, were measured during both exponential and stationary growth phases. Toxicity was further evaluated based on mortality and swimming behavior of the epibenthic copepod <em>Nitokra spinipes</em> and the planktonic copepod <em>Acartia tonsa</em>. Results showed that both growth rate and MCs content significantly increased with temperature (from 15 to 28 °C) but decreased with higher salinity (from 8 to 16 ppt). Moreover, cell density was significantly correlated with both intracellular and extracellular MCs contents. A significant interaction between temperature and salinity was observed. No correlation was found between intracellular MCs and phycocyanin contents. Finally, exposure to <em>M. aeruginosa</em> resulted in decreased swimming speed, increased inactivity, and higher mortality in <em>A. tonsa,</em> compared to the non-toxic <em>Rhodomonas salina</em>. Our study highlights the consequences of temperature and salinity on <em>M. aeruginosa</em> growth and toxin production, offering increased insights into the potential ecotoxicological risks of future blooms.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"146 ","pages":"Article 102871"},"PeriodicalIF":5.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899589","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}
Harmful AlgaePub Date : 2025-04-25DOI: 10.1016/j.hal.2025.102866
Miles Medina , Paul Julian II , Nicholas Chin , Stephen E. Davis
{"title":"Corrigendum to “An early-warning forecast model for red tide (Karenia brevis) blooms on the southwest coast of Florida.” Harmful Algae 139 (2024) 102729","authors":"Miles Medina , Paul Julian II , Nicholas Chin , Stephen E. Davis","doi":"10.1016/j.hal.2025.102866","DOIUrl":"10.1016/j.hal.2025.102866","url":null,"abstract":"","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"145 ","pages":"Article 102866"},"PeriodicalIF":5.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869820","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}
Harmful AlgaePub Date : 2025-04-24DOI: 10.1016/j.hal.2025.102865
Kaisa Kraft , Lumi Haraguchi , Heidi Hällfors , Sanna Suikkanen , Pasi Ylöstalo , Sami Kielosto , Annaliina Skyttä , Lauri Laakso , Martti Honkanen , Mati Kahru , Jukka Seppälä
{"title":"Monitoring cyanobacteria blooms with complementary measurements – a similar story told using high-throughput imaging, optical sensors, light microscopy, and satellite-based methods","authors":"Kaisa Kraft , Lumi Haraguchi , Heidi Hällfors , Sanna Suikkanen , Pasi Ylöstalo , Sami Kielosto , Annaliina Skyttä , Lauri Laakso , Martti Honkanen , Mati Kahru , Jukka Seppälä","doi":"10.1016/j.hal.2025.102865","DOIUrl":"10.1016/j.hal.2025.102865","url":null,"abstract":"<div><div>Several methods to monitor cyanobacteria exist, based partly on characteristics that differentiate cyanobacteria from other phytoplankton, such as pigmentation and morphology. However, it is not certain whether all methods give similar insights into the development and properties of a cyanobacterial bloom. It is important to understand the level of consistency of measurements, especially in the case of novel methods. In situ imaging flow cytometry provides community composition information at high frequency but has been little used for filamentous bloom-forming cyanobacteria. To understand if different methods agree, we compared multi-year biomass data collected with Imaging FlowCytobot (IFCB), CytoSense (CS), phycocyanin (PC) and chlorophyll (Chl) <em>a</em> fluorescence, and turbidity sensors, light microscopy, and satellite-based Frequency of Cyanobacteria Accumulations (FCA). Continuous high-throughput data was recorded at Utö Atmospheric and Marine Research Station in the Baltic Sea during summers 2018–2022, along with samples for light microscopy and adjacent satellite observations. The IFCB cyanobacteria biomass pattern most closely resembled those of CS and PC fluorescence. IFCB also described the blooms similarly to FCA, and to some extent to turbidity, but differed from Chl <em>a</em> fluorescence. IFCB and light microscopy agreed on the bloom development and species composition but differed concerning exact biomass. Our study demonstrates that both IFCB and CS are suitable for studying filamentous cyanobacteria and that in situ imaging flow cytometry provides valuable support for cyanobacteria monitoring by yielding detailed high-frequency taxon-specific information. Still, the best overall coverage of rapid biological processes such as bloom development is achieved with the parallel use of multiple observation techniques.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"147 ","pages":"Article 102865"},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928917","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":"Morpho-phylogenetic and toxicological characterisation of Pseudo-nitzschia multiseries from the Sea of Marmara (Türkiye)","authors":"Rabia Sezgin , Turgay Durmus , Muharrem Balci , Fuat Dursun , Neslihan Balkis-Ozdelice , Bernd Krock , Seyfettin Tas","doi":"10.1016/j.hal.2025.102867","DOIUrl":"10.1016/j.hal.2025.102867","url":null,"abstract":"<div><div><em>Pseudo-nitzschia multiseries</em> is a diatom known for producing domoic acid (DA), a neurotoxin that can cause Amnesic Shellfish Poisoning (ASP), which poses risks to both marine life and human health. This study reports the first detailed investigation of <em>P. multiseries</em> in the Sea of Marmara, focusing on its morphology, phylogeny, and toxin production. Morphological analysis using light and electron microscopy confirmed key diagnostic features consistent with <em>P. multiseries</em>. Phylogenetic analysis, focusing on ITS and LSU gene sequences, showed a close genetic relationship between the Turkish strain and other strains of <em>P. multiseries</em>. Domoic acid levels, quantified using LC-MS/MS during exponential and stationary growth phases, ranged between 2.46 and 3.24 pg cell<sup>−1</sup>, with minor amounts of isoDA (A, D and E) also detected. These findings highlight the importance of monitoring <em>P. multiseries</em> in Turkish coastal waters due to its significant potential for DA production. This study provides valuable insights into the morphology, phylogeny, and toxin production of <em>P. multiseries</em>, as well as its potential implications for management of marine resources and public health protection. It offers a comprehensive examination of this potentially toxic diatom species in Turkish coastal waters.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"146 ","pages":"Article 102867"},"PeriodicalIF":5.5,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877440","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}
Harmful AlgaePub Date : 2025-04-19DOI: 10.1016/j.hal.2025.102864
Lu Wang , Yinsheng Wu , Siqi Pan , Feifei Pan , Jianming Chen
{"title":"Rapid and sensitive detection of Karlodinium veneficum using RAA and CRISPR-Cas12a technologies","authors":"Lu Wang , Yinsheng Wu , Siqi Pan , Feifei Pan , Jianming Chen","doi":"10.1016/j.hal.2025.102864","DOIUrl":"10.1016/j.hal.2025.102864","url":null,"abstract":"<div><div>The harmful algal species <em>Karlodinium veneficum</em> (<em>K. veneficum</em>) poses a significant threat to aquatic ecosystems, economic stability, and human health due to its toxin production and widespread occurrence. Rapid climatic changes and eutrophication have intensified harmful algal blooms (HABs), making the timely detection of <em>K. veneficum</em> critical. To address this need, we developed a rapid and accurate detection method of <em>K. veneficum</em> by combining Recombinase Aided Amplification (RAA) with CRISPR/LbCas12a. This method targets the internal transcribed spacer (ITS) sequence of <em>K. veneficum</em> and utilizes the \"collateral activity\" of CRISPR/LbCas12a for visualization. Our method can detect plasmid DNA as low as 5.9 × 10<sup>2</sup> copies/µL and genomic DNA as low as 3.6 × 10<sup>−2</sup> ng/µL, achieving a detection limit of 10 cells of <em>K. veneficum</em> through a simplified DNA extraction process. The entire detection process, from DNA crude extract to result visualization, can be completed in as fast as 90 min, making it suitable for field applications requiring a rapid response. In addition, our method was validated against a wide range of non-target microalgae species, confirming its specificity to <em>K. veneficum</em> and eliminating the risk of cross-reactivity. Overall, the RAA-CRISPR/LbCas12a system is simple, accurate, and sensitive, showing great potential for field applications in monitoring <em>K. veneficum</em>.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"146 ","pages":"Article 102864"},"PeriodicalIF":5.5,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892350","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}