Harmful Algae最新文献

{"title":"Combined effects of CO2 and nitrogen on the stoichiometry of toxin synthesis in a harmful cyanobacterium","authors":"Savannah Sarkis ,&nbsp;Jing Liu ,&nbsp;Jef Huisman ,&nbsp;Uwe John ,&nbsp;Jolanda M.H. Verspagen ,&nbsp;Dedmer B. Van de Waal","doi":"10.1016/j.hal.2025.102964","DOIUrl":"10.1016/j.hal.2025.102964","url":null,"abstract":"<div><div>The increase in frequency and intensity of harmful cyanobacterial blooms in freshwater ecosystems over past decades has been attributed to anthropogenic influence, notably eutrophication and climate change. <em>Microcystis</em> is among the most widespread cyanobacterial bloom-forming genera, some strains of which can produce a range of microcystin variants having different toxicities. The synthesis of microcystins (MCs) is closely linked to carbon and nitrogen metabolism as microcystin variants differ in their nitrogen:carbon ratio. Thus, changes in availability of both CO₂ and nitrogen may impact microcystin production and composition. While the separate effects of CO₂ and nitrogen have been documented, their combined effect is less understood. We therefore assessed the effects of a CO₂ gradient at both nitrogen-replete and -deplete conditions on cellular nitrogen and carbon contents, N:C stoichiometry and microcystin synthesis in three <em>Microcystis aeruginosa</em> strains. We observed an interactive effect of increasing CO₂ concentrations with nitrogen availability across strains. Specifically, with increasing CO₂ availability, cellular N:C stoichiometry decreased under nitrogen-deplete conditions from 0.14 to 0.07 but increased under nitrogen-replete conditions from 0.11 to 0.17. Although total cellular microcystin content remained largely unaffected by both CO₂ and nitrogen despite shifts in N:C stoichiometry, changes in variant composition were consistent across strains and followed a stoichiometrically predictable pattern. N-rich but less toxic microcystin variants were favored at high cellular N:C ratios (e.g. MC-RR reached up to 44 % of total MC at highest N:C ratios), whereas relatively less N-containing but more toxic variants became more prevalent at low N:C ratios (e.g. MC-LW shifted from 9 % to 36 % of total MC for one of the strains). This study shows that shifts in CO₂ and nitrogen availability affect cellular N:C stoichiometry and alter microcystin composition, which may cause changes in the toxicity of cyanobacterial blooms.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102964"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145059939","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":"Ship-based eDNA tracking unveils early dispersal patterns and microecological dynamics of Ulva prolifera micropropagules in yellow sea green tide outbreaks","authors":"Runze Chen ,&nbsp;Yinqing Zeng ,&nbsp;Caihua Yao ,&nbsp;Faqing He ,&nbsp;Shulin Tan ,&nbsp;Yutao Qin ,&nbsp;Huanhong Ji ,&nbsp;Lihua Xia ,&nbsp;Lining Xia ,&nbsp;Yuru Yan ,&nbsp;Peimin He ,&nbsp;Jianheng Zhang","doi":"10.1016/j.hal.2025.102966","DOIUrl":"10.1016/j.hal.2025.102966","url":null,"abstract":"<div><div>Green tides caused by <em>Ulva prolifera</em> in the South Yellow Sea (SYS) pose significant ecological and economic threats. <em>Neopyropia</em> aquaculture rafts in the Subei Shoal are considered to be the main source of green tides in the SYS, where micropropagules are the ‘Seed Bank’ for green tides. But the early dynamics of the <em>U. prolifera</em> remain unclear due to the limitations of conventional monitoring methods. This study systematically investigated the spatiotemporal distribution characteristics and key environmental driving mechanisms of environmental DNA (eDNA) from <em>U. prolifera</em> in development areas of Yellow Sea green tide, using eDNA technology combined with environmental parameters. Surveys in April and June 2024 across <em>Neopyropia</em> raft-farming (RD transect) and non-raft (SY transect) areas revealed ecological differences during early green tide development. Key findings include:(1) In April, <em>U. prolifera</em> eDNA abundance in RD exhibited a \"high near rafts, low farther away\" distribution, regulated by temperature and total nitrogen, while SY followed similar trends driven primarily by temperature. No environmental factors were found to be significantly correlated with the distribution of <em>U. prolifera</em> eDNA in June. (2) High <em>U. prolifera</em> eDNA abundance at SY4 in April was driven by hydrodynamics (tidal asymmetry), temperature, and biological interactions (e.g., Cercozoa), identifying a hotspot for monitoring. (3) Raft-farming areas exhibited stronger species interactions, with Chlorophyta and Cercozoa closely linked to <em>U. prolifera</em>. The identification of <em>Pirsonia</em> sp. and other species provides a new perspective for elucidating the competitive mechanisms underlying early-stage <em>U. prolifera</em> outbreaks and for developing early biological control strategies against green tides. This study provides molecular ecological evidence for analyzing the aggregation driving mechanism of the development areas of early green tide in the SYS, highlights the utility of eDNA in monitoring, and offers theoretical support for marine ecosystem management under climate change.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102966"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020298","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":"Simplifying marine biotoxin data analysis: Advancing the Neuro-2a cell-based assay using R","authors":"Synne T. Frøstrup ,&nbsp;Christian Ritz ,&nbsp;Oliver Kappenstein ,&nbsp;Astrid Spielmeyer ,&nbsp;Christopher R. Loeffler","doi":"10.1016/j.hal.2025.102968","DOIUrl":"10.1016/j.hal.2025.102968","url":null,"abstract":"<div><div>Marine biotoxins (MBs) pose a significant public health risk as seafood contaminants. Testing seafood for MBs before consumption can protect consumers and further provide quality assurances. The in vitro Neuro-2a (N2a) cell-based assay (CBA), is a sensitive, high-throughput, and cost-effective method for the semi-quantification of MBs such as ciguatoxins (CTXs) and brevetoxins (PbTxs), serving as an alternative to animal-based testing. However, the N2a CBA has not been validated, limiting its utility. High data variability based on several potential sources including inter-software inconsistencies, data transfer errors, and improper data processing (calculation errors), or handling (dealing with missing, corrupted, or inconsistent data), have been cited as major challenges to the method. Data errors or inaccuracies can disrupt data integrity and lead to false positive or negative results, with serious health implications. To address these issues, a customized R package, <em>n2a</em>, was developed as the first standardized and free data analysis operating procedure for the N2a CBA. It is designed for simultaneous dose-response analysis of assay derived data and displays parameter estimates, calculates effective concentration (EC₅₀), and generates high-quality graphical outputs. The <em>n2a</em> package ensures rapid dose-response model fitting for larger datasets (2 s per dataset) compared to traditional software (3 min per dataset), increasing data processing efficiency and reducing the potential for data handling errors.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102968"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026326","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":"Transcriptomic responses of toxic and non-toxic Microcystis aeruginosa to hydrogen peroxide and l-lysine treatments","authors":"Elizabeth K. Dahedl ,&nbsp;Taylor L. Hancock ,&nbsp;Hidetoshi Urakawa","doi":"10.1016/j.hal.2025.102992","DOIUrl":"10.1016/j.hal.2025.102992","url":null,"abstract":"<div><div><em>Microcystis aeruginosa</em> is a ubiquitous, toxic, bloom-forming cyanobacterium found in freshwater ecosystems worldwide. In this study, we assessed two algaecidal mitigation methods (hydrogen peroxide and <span>l</span>-lysine) for the treatment of two toxic and two non-toxic strains of <em>M. aeruginosa</em>. Whole-transcriptome analysis with total RNA sequencing was used to assess the modes of action of these algaecides. We found both treatments led to increased transcriptional activity for genes associated with sulfur and cysteine pathways, which both support antioxidant enzyme activity. These regulatory mechanisms along with methionine metabolism were more enhanced for <span>l</span>-lysine treated strains, and may demonstrate a lack of <span>l</span>-lysine regulatory mechanisms and potential impact to the biosynthesis of other amino acids as well as intracellular sulfur recycling processes seen in transcription results. Toxic and non-toxic strains displayed a differential regulatory response to reduce oxidative stress levels. Two toxic strains downregulated the expression of microcystin biosynthesis genes and increased the expression of genes encoding antioxidant enzymes. Our results provide further support for the view that microcystins do not offer protection against high levels of oxidative stress. Production of microcystin may interfere with antioxidant enzyme functionality, and additionally, sulfur and cysteine demands for antioxidant enzymes likely outcompete their use for microcystin production under oxidative stress conditions. These findings can aid in the mitigation of toxin-producing <em>M. aeruginosa</em> blooms, suggesting high-dose hydrogen peroxide application has the potential to lower bloom toxicity through fast-acting impairment to microcystin gene synthetase expression as well as other metabolic functioning, likely lowering intracellular microcystin content, which may be released upon cell lysis after treatments. To our knowledge, the expression of microcystin synthetase genes after exposure to <span>l</span>-lysine has never been examined before. Seeing as this is a safe algaecide specifically targeting <em>M. aeruginosa,</em> this was another beneficial finding.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102992"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321125","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":"Application of a hydrodynamic model to long-term monitoring data: exploring transport pathways to identify the source of high toxicity populations of Dinophysis fortii in aquaculture sites in northern Japan","authors":"Akira Miyazono ,&nbsp;Takanori Kuribayashi ,&nbsp;Yasufumi Hada ,&nbsp;Ken Asakura ,&nbsp;Kazuma Kobayashi ,&nbsp;Katsuhiko Mizuno ,&nbsp;Wai Mun Lum ,&nbsp;Sirje Sildever ,&nbsp;Hiroshi Kuroda ,&nbsp;Satoshi Nagai","doi":"10.1016/j.hal.2025.102976","DOIUrl":"10.1016/j.hal.2025.102976","url":null,"abstract":"<div><div>Diarrhetic Shellfish Toxicity (DST) occurs in northern Japan, Hokkaido and Tohoku, and is rarely observed in the southwest. A recent study using cultured strains of <em>Dinophysis fortii</em> revealed that high toxicity (HT) strains exist in northern Japan, while low-toxicity (LT) strains are found in the southwest. In this study, we analyzed 40 years of DST and plankton monitoring data from Hokkaido, eight years from Akita Prefecture, 33 years of oceanographic data from the Sea of Japan off northern Hokkaido, and the results of an ocean model experiment. The relationship between the annual DST maximum value and the cell density of <em>D. fortii</em> maxima in Hokkaido suggests the presence of both HT and LT strains. Results from the particle tracking experiment showed that transport of offshore populations of <em>D. fortii</em> to the coast is a key factor in HT DST events. Oceanographic data support that high DST along the Sea of Japan coasts in northern Hokkaido occurs in years of strong influence of the subarctic water of the Sea of Japan (SWSOJ). In northwestern Japan (Akita Prefecture), HT DST events were detected in years with strong influence of the second and third components of the Tsushima Warm Current (TWC2, 3) transporting particles from the SWSOJ. These results led to the conclusion that i) HT strains of <em>D. fortii</em> are transported by the SWSOJ reaching Hokkaido via its extension and Akita via the TWC2, 3, and ii) LT strains are transported to northern Japan via the first component of the Tsushima Warm Current (TWC1).</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102976"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145059938","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":"Non-target effects of a harmful algal bloom biocontrol technology (DinoSHIELD) in an in-situ mesocosm experiment","authors":"Yanfei Wang ,&nbsp;William C. Holland ,&nbsp;Alexandria G. Hounshell ,&nbsp;Alan Kennedy ,&nbsp;Kaytee Pokrzywinski ,&nbsp;Kathryn J. Coyne","doi":"10.1016/j.hal.2025.102984","DOIUrl":"10.1016/j.hal.2025.102984","url":null,"abstract":"<div><div>Harmful algal blooms (HABs) of toxic dinoflagellates, including <em>Karenia brevis</em>, pose significant threats to marine organisms and human health worldwide. Previous research identified a naturally occurring algicidal bacterium, <em>Shewanella</em> sp. IRI-160, which secretes algicidal compounds that limit the growth of dinoflagellates. More recent research focused on the development of a HAB bio-control technology, now called DinoSHIELD, using alginate hydrogel to immobilize <em>Shewanella</em> sp. IRI-160. DinoSHIELD continuously releases bacteria-derived algicides that target dinoflagellate growth while limiting bacterial dispersion. In this study, an <em>in-situ</em> mesocosm experiment using natural microbial communities was conducted to assess the environmental impacts of DinoSHIELD. This study aimed to evaluate the effects of DinoSHIELD on water quality and on non-target microbial communities under non-HAB conditions. At an application rate effective at controlling the growth of <em>K. brevis</em> in laboratory cultures, DinoSHIELD had minimal effects on water quality within the mesocosms. There was no significant effect on overall photosynthetic biomass or the abundance of non-target microbial organisms during the 6-day mesocosm experiment. Although there was no significant change in microbial eukaryotic community structure, 18S rRNA gene sequencing analysis showed that DinoSHIELD significantly increased species richness in the treatment compared to controls. Importantly, analysis of total bacterial and <em>Shewanella</em> sp. IRI-160-specific cell densities showed limited release of bacteria from DinoSHIELD and no change in total bacterial densities. Overall, these results support the eventual use of DinoSHIELD as a biocontrol strategy for managing dinoflagellate HABs without negatively affecting natural microbial communities or the surrounding environment.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102984"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217316","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":"Ranking the cytotoxic potency of Ostreopsis cf. ovata, Ostreopsis cf. siamensis (O. sp. 9), and purified ovatoxins in human keratinocytes","authors":"Loïc Plessis ,&nbsp;Korian Lhaute ,&nbsp;Fabienne Hervé ,&nbsp;Madeleine Thimann ,&nbsp;Véronique Séchet ,&nbsp;Liliane Carpentier ,&nbsp;Ariana B. Moutinho ,&nbsp;Tiago Simões ,&nbsp;Ana Amorim ,&nbsp;Kevin Henry ,&nbsp;Jorge L.B. Neves ,&nbsp;Léana Gorse ,&nbsp;Margaux Paradis ,&nbsp;Stéphanie Brédif ,&nbsp;Philipp Hess ,&nbsp;Damien Réveillon","doi":"10.1016/j.hal.2025.103000","DOIUrl":"10.1016/j.hal.2025.103000","url":null,"abstract":"<div><div>Ovatoxins (OVTXs), a family of marine polyketides structurally similar to palytoxin (PLTX), are suspected to cause respiratory symptoms and skin irritation among coastal users during blooms of the dinoflagellate <em>Ostreopsis</em> cf. <em>ovata</em>. To investigate their role in cutaneous toxicity, crude extracts from six <em>O.</em> cf. <em>ovata</em> strains (OVTX(+) and OVTX(−)) and three <em>O.</em> cf. <em>siamensis</em> (<em>O</em>. sp. 9) strains (OVTX(−)), along with six purified OVTX analogs, were tested for cytotoxicity (MTT assay) and cell death phenotypes (microscopy) in human keratinocyte models. Interestingly, cytotoxicity was driven by OVTX content, while OVTX(−) extracts were, on average, 150-fold and &gt;1000-fold less potent for <em>O.</em> cf. <em>siamensis</em> and <em>O.</em> cf. <em>ovata</em>, respectively. Nevertheless, the latter two induced PLTX-like cell death, suggesting the presence of unidentified PLTX-like toxins. Purified OVTXs exhibited sub-nanomolar cytotoxicity, 3.5- to 12.5-fold lower than PLTX (IC₅₀ = 0.036–0.642 nM vs. 0.011–0.049 nM), ranking in potency: PLTX &gt; OVTX-d &gt; OVTX-b &gt; OVTX-a &gt; OVTX-c &gt; OVTX-e &gt;&gt;&gt; OVTX-h (non-toxic, likely due to ring-opening). This study demonstrates the high toxic potency of OVTXs, close to that of PLTX, while providing a comprehensive cytotoxicity assessment of OVTX analogs, which could be useful for assessing the risks of human exposure.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 103000"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358092","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":"A modeling investigation into the ecological role of mixotrophy in Karenia brevis blooms on the West Florida Shelf","authors":"Yuren Chen ,&nbsp;Ming Li ,&nbsp;Patricia M. Glibert ,&nbsp;Cynthia Heil ,&nbsp;So Hyun Ahn","doi":"10.1016/j.hal.2025.102979","DOIUrl":"10.1016/j.hal.2025.102979","url":null,"abstract":"<div><div>While laboratory experiments show <em>Karenia brevis</em> graze on <em>Synechococcus</em> to supplement nutrition, the ecological role of mixotrophy in <em>K. brevis</em> blooms on the West Florida Shelf remains unquantified. This study employs a three-dimensional coupled hydrodynamic-biogeochemical model to investigate the contribution of mixotrophic feeding to the <em>K. brevis</em> growth as well as the role of mixotrophic grazing in suppressing prey population and delivering a competitive advantage to the mixotroph. It is shown that mixotrophy moderately increased the growth rate of <em>K. brevis</em> in the bloom center but was important along the offshore margin of the bloom region, where the prey-to-predator ratio was high. With the digestion rate reaching over 200 prey cells <em>K. brevis</em>^-1 day^-1, mixotrophy could support a heterotrophic growth rate of up to 0.16 day^-1 in the offshore region and may facilitate the offshore expansion of <em>K. brevis</em> blooms. Mixotrophic feeding also played a significant role in sustaining the <em>K. brevis</em> bloom during the late spring and summer periods when the inorganic nutrient concentrations were low. The grazing pressure exerted on <em>Synechococcus</em> was found to be vital for the slow-growing <em>K. brevis</em> to outcompete the oligotrophic-adapted prey. These model results demonstrate that mixotrophy not only functions as an additional nutrient source but also as an ecological mechanism that can reshape interspecific competition and harmful algal bloom dynamics.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102979"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106563","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":"Controlling harmful algal blooms (HABs) in marine waters: Review of current status and future prospects","authors":"Donald M. Anderson ,&nbsp;Mark L. Wells ,&nbsp;Vera L. Trainer ,&nbsp;Marc Suddleson ,&nbsp;Kevin Claridge ,&nbsp;Kathryn J. Coyne ,&nbsp;Quay Dortch ,&nbsp;Christopher J. Gobler ,&nbsp;Cynthia A. Heil ,&nbsp;Nobuharu Inaba ,&nbsp;H. Dail Laughinghouse IV ,&nbsp;Jorge I. Mardones ,&nbsp;Natsuko Nakayama ,&nbsp;Taegyu Park ,&nbsp;Melissa B. Peacock ,&nbsp;Kaytee Pokrzywinski ,&nbsp;Heather Raymond ,&nbsp;Jennifer H. Toyoda ,&nbsp;Dean Trethewey ,&nbsp;Petra M. Visser ,&nbsp;Yongquan Yuan","doi":"10.1016/j.hal.2025.102989","DOIUrl":"10.1016/j.hal.2025.102989","url":null,"abstract":"<div><div>The societal, economic, geographic, and environmental impacts from marine harmful algal blooms (HABs) have increased in many regions around the world. The growing array of impacts is large and varied, threatening human health, marine and freshwater wildlife, and ecosystems upon which many nations rely on for food, recreation, tourism, and a plethora of other goods and services. Although the HAB burden has grown substantially over the past few decades, marine and estuarine HAB control remains one of the least developed areas of HAB science. The disconnect between HAB control needs and solutions stems in part from public, stakeholder, and scientific uncertainties about the balance between benefits and potentially undesirable environmental consequences. Other more practical challenges can include substantial regulation of in situ testing, scaling up laboratory-proven technologies to attack widespread blooms that can move in three dimensions in open marine waters, and an immature commercial market. Here we describe the status of control strategies targeting marine coastal and estuarine HABs, in particular those few approaches that have been tested in mesocosm or field applications. We identify the regulatory support, targeted science, investments, and public outreach that will be needed to accelerate the availability of applications for controlling HABs in marine waters worldwide.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102989"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525833","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":"Salinity adaption and toxicity of harmful algal blooms in three bays of Great Salt Lake (USA)","authors":"W.A. Wurtsbaugh ,&nbsp;Malin Olofsson ,&nbsp;Gregory L. Boyer ,&nbsp;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 &gt;90 g <span>l</span>^-1 while the third, Gilbert Bay, had a salinity near 160 g <span>l</span>^-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 <span>l</span>^-1 and dense blooms of <em>N. spumigena.</em> Cell densities were &gt;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>^-1, which are much higher than usually reported for this taxon. Concentrations of the cyanotoxin nodularin reached 660 µg <span>l</span>^-1 (mean = 41 µg <span>l</span>^-1), far above critical thresholds for contact recreation and above those causing bird mortalities elsewhere. The mean N₂ fixation rate of <em>Nodularia</em> measured over a salinity range of 14 to 52 g <span>l</span>^-1 was 47 mg N m^-2 <span>d</span>^-1, 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":"2025-12-01","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}