Harmful Algae最新文献

{"title":"Mechanistic insights into Ginkgo-nerolidol compound preparation against the bloom-forming dinoflagellate Prorocentrum donghaiense","authors":"Anglu Shen ,&nbsp;Aixue Qian ,&nbsp;Wuyou Shen ,&nbsp;Xinfeng Dai ,&nbsp;Liu Shao","doi":"10.1016/j.hal.2025.102994","DOIUrl":"10.1016/j.hal.2025.102994","url":null,"abstract":"<div><div><em>Prorocentrum donghaiense</em> is a major bloom-forming species in the East China Sea and has severe adverse effects on marine ecosystems. To address this issue, the development of efficient and eco-friendly algal inhibitors is essential. However, research in this area remains limited. In this study, <em>Ginkgo biloba</em> extract (GB), nerolidol (NE), and a compound preparation (GN = GB + NE) were selected as algae-inhibiting materials, and the mechanisms of action of GB, NE, and GN on <em>P. donghaiense</em> were analyzed via RNA-seq. In total, 59,151, 152, and 25,363 differentially expressed genes (DEGs) were identified in algae treated with GB, NE, and GN, respectively. The top three GO- and KEGG-annotated DEGs were shared between GB and GN treatments, indicating that GB was the primary active component of GN. KEGG enrichment further showed that photosynthesis-related pathways were among the top five pathways affected by GN. Key genes in photosystem II (<em>PsbA-E</em>), cytochrome <em>b₆/f</em> complex (<em>PetD</em>), and ATP synthase (<em>atpD</em>) were downregulated, and 10 photosynthesis-antenna protein genes (<em>Lhca1–4, Lhcb1–6</em>) were upregulated under GN treatment. However, most of these genes did not show significant expression under the GB treatment, except for <em>Lhca1</em> and <em>Lhcb1–2</em>. Furthermore, NE treatment upregulated <em>ushA</em> and downregulated <em>pncC</em>, disrupting algal nucleotide and NAD⁺ biosynthesis. This suggests that NE may accelerate GB-induced inhibition of photosynthesis-related pathways. These findings provide new insights into the molecular mechanisms underlying <em>P. donghaiense</em> exposure to GN and provide a theoretical basis for the prevention and control of harmful algal blooms.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102994"},"PeriodicalIF":4.5,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217317","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":"Comparative toxicity of Karlodinium veneficum from France and New Zealand on fish gill cells and oyster gametes","authors":"Anne Rolton ,&nbsp;Guillaume Barnouin ,&nbsp;Hannah Greenhough ,&nbsp;Audrey Duval ,&nbsp;Karthiga Kumanan ,&nbsp;Nelly Quéré Le Goïc ,&nbsp;Lucy Thompson ,&nbsp;Damien Réveillon ,&nbsp;Fabienne Hervé ,&nbsp;Andrew I. Selwood ,&nbsp;Hélène Hégaret ,&nbsp;Kirsty F. Smith ,&nbsp;Malwenn Lassudrie","doi":"10.1016/j.hal.2025.102991","DOIUrl":"10.1016/j.hal.2025.102991","url":null,"abstract":"<div><div>Harmful algal blooms (HABs) can cause mass mortalities of marine fauna, leading to major economic losses in aquaculture and fisheries worldwide. Toxicity varies widely among strains of the same HAB species, making broad assumptions of toxicity inaccurate. This study investigated the ichthyotoxic activity of <em>Karlodinium veneficum</em>, a HAB species of risk for aquaculture in France (FR) and New Zealand (NZ). Five <em>K. veneficum</em> strains (3 FR, 2 NZ) were cultured and extracted under standardized conditions. Following inter-laboratory assay comparison, crude (culture) and methanolic intra- and extracellular extracts were tested on <em>in vitro</em> models: rainbow trout gill cells (RTgill-W1) and Pacific oyster, <em>Crassostrea</em> (=<em>Magallana</em>) <em>gigas,</em> sperm.</div><div>Crude and methanolic extracts showed toxicity to both cell types, with variation between intra- (IN) and extracellular (EX) fractions. Of the crude extracts, only CAWD93 IN was toxic to gill and sperm cells, inducing 44 % and 81 % mortality, respectively, at 8.75 × 10⁴ equiv. cells mL^-1. Most methanolic extracts were toxic; MAR1F7 EX and CAWD93 IN induced the highest mortality rates, with EC₅₀’s reaching cell concentrations equivalent to high environmental bloom levels.</div><div>Karlotoxin analysis of methanolic extracts revealed distinct profiles by country. Karlotoxins were detected only in the three most toxic strains (MAR1F7, IFR-CC-20-44, CAWD93) and cytotoxicity was only weakly correlated with karlotoxin concentration, suggesting involvement of additional toxic compounds.</div><div>This study highlights strain-specific toxicity in <em>K. veneficum</em>, underscoring the importance of testing local HAB strains. The bioassays used offer a rapid, cost-effective, high-throughput, and ethical approach to evaluating HAB toxicity—crucial as ichthyotoxic blooms become more frequent globally.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102991"},"PeriodicalIF":4.5,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217318","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":"Why do some dinoflagellates produce toxins, whereas ciliates rarely do?","authors":"Albert Calbet","doi":"10.1016/j.hal.2025.102988","DOIUrl":"10.1016/j.hal.2025.102988","url":null,"abstract":"<div><div>Dinoflagellates and ciliates dominate marine microzooplankton, yet widespread toxin production is largely restricted to dinoflagellates. This perspective synthesizes evolutionary, genomic, and ecological drivers of that asymmetry with direct relevance to harmful algal events. From a molecular and biochemical point of view, dinoflagellates possess vast, repeat-rich genomes that support modular PKS/NRPS pathways yielding chemically diverse metabolites, whereas ciliates generally lack complete PKS/NRPS clusters (apart from a few predatory lineages) and instead emphasize behavioral defenses and rapid reproduction. Most confirmed toxic dinoflagellates are photosynthetic or mixotrophic; robust cases in purely heterotrophic taxa are lacking. Despite environment-dependent costs, dinoflagellate metabolites confer grazer deterrence, allelopathy, prey lysis, and potential nutrient acquisition. Socio-economically, paralytic shellfish toxins (saxitoxins) produced by <em>Alexandrium</em> spp., <em>Gymnodinium catenatum</em>, and <em>Pyrodinium bahamense</em>—non-PKS alkaloids associated with sxt genes—are among the most consequential. An integrated approach coupling genomics, metabolomics, targeted bioassays, and in situ observations will clarify when chemical versus behavioral strategies prevail across ocean regimes, thereby improving HAB risk assessment, monitoring, and mitigation.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102988"},"PeriodicalIF":4.5,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217440","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":"Possible accumulation of harmful flagellates caused by interaction between vertical swimming and upper ocean turbulence","authors":"Goh Onitsuka ,&nbsp;Yutaka Yoshikawa","doi":"10.1016/j.hal.2025.102990","DOIUrl":"10.1016/j.hal.2025.102990","url":null,"abstract":"<div><div>In the natural oceanic environment, microalgae occasionally form blooms with rates of increase that exceed their growth rates observed under laboratory conditions. We hypothesized that these elevated rates result from the accumulation caused by the combined effects of vertical swimming behavior and physical processes in the upper ocean. To test this hypothesis, we conducted numerical experiments using a Lagrangian particle-tracking model coupled with a hydrodynamic model. In a stratified ocean forced by sea surface winds and waves, we released particles simulating three fish- and shellfish-killing flagellates with different swimming speeds, namely <em>Chattonella marina</em> complex, <em>Karenia mikimotoi</em>, and <em>Margalefidinium polykrikoides</em>. Due to the interplay of diel vertical migration (DVM) and upper ocean turbulence, the particles accumulated vertically, exhibiting peak concentrations in the surface layer in the afternoon. These concentrations were several times higher than those observed at night or in the morning. Strong turbulence resulting from high wind speeds reduced surface accumulation and altered the depth of the maximum particle concentration compared to the still-water case (i.e., DVM only), especially for the slow-swimming <em>Chattonella</em>. Under low wind speeds (<em>U</em>₁₀ = 1.5–2.0 m s⁻¹), particles simulating the fast-swimming <em>M. polykrikoides</em> horizontally accumulated in streaks where surface flow converged, increasing particle concentration by up to one order of magnitude. This horizontal accumulation was caused by the balance between the upward swimming speed of <em>M. polykrikoides</em> and the downwelling associated with horizontal convergence driven by Langmuir circulations. Compared to algal growth, these vertical and horizontal accumulation processes occurred over shorter timescales, highlighting the importance of considering accumulation in monitoring harmful algal blooms.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102990"},"PeriodicalIF":4.5,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217319","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":"Unique distribution pattern of Aureococcus anophagefferens in the Yellow Sea during late summer influenced by complex hydrodynamics and green tide decomposition","authors":"Lu Sun ,&nbsp;Huixia Geng ,&nbsp;Qingchun Zhang ,&nbsp;Zhenfan Chen ,&nbsp;Chao Liu ,&nbsp;Fanzhou Kong ,&nbsp;Rencheng Yu","doi":"10.1016/j.hal.2025.102987","DOIUrl":"10.1016/j.hal.2025.102987","url":null,"abstract":"<div><div>Since 2009, brown tide-causing pelagophyte <em>Aureococcus anophagefferens</em> has recurrently impacted northern Chinese coastal waters. Previous observations suggest elevated abundances of <em>A. anophagefferens</em> occur in specific regions of the Yellow Sea (YS) where the decomposition of <em>Ulva prolifera</em> green tides during late summer, implying supportive role on its growth for green algae decomposition. However, the complex hydrodynamic processes in these areas complicate the disentanglement of the effects of green tide decomposition and hydrodynamic influences. In this study, quantitative PCR and environmental analyses were employed to examine the spatial distribution, interannual variations, and environmental drivers of <em>A. anophagefferens</em> during late summers in 2016, characterized by a high-intensity green tide, and 2017, marked by a low-intensity green tide. <em>A. anophagefferens</em> exhibited a vertically spindle-shaped distribution with peak cell densities at the deep chlorophyll maximum layer, primarily along the Shandong Peninsula and in the eastern YS. Notably, cell abundances in 2016 were significantly higher than those in 2017, linking to increased ammonium, phosphate, and dissolved organic matter resulting from green tide decomposition. Hydrodynamic factors, especially temperature stratification and the Yellow Sea Bottom Cold Water, appeared to significantly affect the distribution of <em>A. anophagefferens</em>. The enhanced nutrient release during the large-scale green tide event in 2016 further promoted the growth of <em>A. anophagefferens</em>, highlighting the link between green tide events and the emergence of other harmful algal blooms in northern Chinese coastal waters.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102987"},"PeriodicalIF":4.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217334","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":"Dynamics of harmful algal bloom species are independent of the extent of the Changjiang Diluted Water Intrusion Off Western Jeju Island in the Northern East China Sea","authors":"Yeongji Oh ,&nbsp;Min-Sun Lee ,&nbsp;Eunbi Lee ,&nbsp;Chan-Woo Kwon ,&nbsp;Minji Lee ,&nbsp;Ho Young Soh ,&nbsp;Yoonja Kang","doi":"10.1016/j.hal.2025.102986","DOIUrl":"10.1016/j.hal.2025.102986","url":null,"abstract":"<div><div>The western Jeju Island region, located on the continental shelf of the northern East China Sea, is influenced by Changjiang Diluted Water (CDW), Yellow Sea Bottom Cold Water, and branches of Kuroshio Current. Due to its proximity to the South Sea of Korea, an area historically subject to annual harmful algal blooms (HABs) but experiencing a recent decline in bloom frequency, we investigated variations in the HAB species occurrence during the CDW intrusion in June 2022 and 2023, when the extent of CDW intrusion drastically differed. Additionally, current flows from the study region toward the South Sea were investigated using a data-assimilative ocean circulation model that integrated multiple satellite and in situ observations. Microscopy and 18S rRNA sequencing analyses and photosynthetic efficiency measurements using Phyto-PAM II revealed that more CDW intrusion increased nutrient stress for diatoms and dinoflagellates, mainly due to extreme phosphorus limitation. However, HAB species such as <em>Pseudo-nitzschia</em> spp. rapidly responded to increased nitrogen availability. In contrast, reduced CDW intrusion mitigated nutrient stress caused by imbalanced stoichiometry, and small-sized HAB species, including <em>Aureococcus anophagefferens, Karlodinium veneficum, Prorocentrum obtusidens</em> dominated under conditions of the DOP availability and light-limitation. Furthermore, ocean current simulations showed strong flows toward the southern coastal waters of Korea during summer. Collectively, our findings suggest that, regardless of the extent of CDW inflow, different types of HAB species can be developed in western Jeju, and ocean currents potentially transport them to the South Sea of Korea.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102986"},"PeriodicalIF":4.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155627","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":"Genetic diversity of Aureococcus anophagefferens in the coastal waters of China and implications for intraspecific differentiation of environmental adaptability","authors":"Chao Liu ,&nbsp;Qingchun Zhang ,&nbsp;Zhenfan Chen ,&nbsp;Lu Sun ,&nbsp;Fanzhou Kong ,&nbsp;Rencheng Yu","doi":"10.1016/j.hal.2025.102985","DOIUrl":"10.1016/j.hal.2025.102985","url":null,"abstract":"<div><div><em>Aureococcus anophagefferens</em>, a globally distributed picoplankton species, plays a critical role as a primary producer in marine ecosystems, and is responsible for brown tides in coastal waters, which significantly impact local environments and shellfisheries. Despite its pronounced adaptability across diverse marine habitats—from open oceans to estuaries—the genetic diversity underlying its niche differentiation remains poorly understood. This study investigated the intraspecific genetic diversity of <em>A. anophagefferens</em> in China’s coastal waters and the western Pacific, employing a novel mitochondrial marker (<em>trn</em>D-<em>dam</em>1) to resolve fine-scale population structure. Three distinct genotypes were identified, each exhibiting distinct environmental preferences: Type I dominated brown tide blooms in eutrophic, warm, low-salinity estuaries in the Bohai and Yellow Seas, correlating strongly with elevated dissolved organic nitrogen. In contrast, Types II (prevalent in U.S. strains) and III prevailed in high-salinity habitats, and associated with coastal zones influenced by transoceanic currents. Spatial-temporal analyses revealed genotype succession during bloom dynamics, with Type I constituting over 80 % of the population during peak bloom phases and coexisting with Type II during non-bloom periods. Samples from the Kuroshio Current exclusively harbored Types II and III, suggesting that oceanographic transport facilitates their dispersal. These findings indicate that <em>A. anophagefferens</em> populations have undergone adaptive divergence to exploit local environmental gradients, with genotype-specific preferences for temperature, salinity, and nutrient regimes shaping their biogeographic distribution.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102985"},"PeriodicalIF":4.5,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155628","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":"2025-09-20","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":"Transcriptomic analysis of dinoflagellate Prorocentrum cordatum exposed to microplastics under different nitrogen sources","authors":"Heng Chen ,&nbsp;Qianlou Liu ,&nbsp;Sihao Yang ,&nbsp;Yiyi Cai ,&nbsp;Ziyu Song ,&nbsp;Yao Yang ,&nbsp;Rodrigo J. Gonçalves ,&nbsp;Wanchun Guan","doi":"10.1016/j.hal.2025.102983","DOIUrl":"10.1016/j.hal.2025.102983","url":null,"abstract":"<div><div>Anthropogenic activities have significantly altered marine nitrogen (N) regimes by releasing different forms of N (e.g. nitrate and urea, the latter from wastewater/agricultural runoff). Some species can grow equally well under different N sources, while others show maximum growth rates under one source (e.g. urea). Another pollutant, plastic microparticles (MP), has been found in every ecosystem/habitat on Earth. A crucial deleterious effect of MP is the disruption of the cellular membrane integrity—a key mechanism affecting the N uptake and assimilation in single-cell organisms such as dinoflagellates and microalgae. The combined effects of MP and different N sources remain an open question. This study exposed the dinoflagellate <em>Prorocentrum cordatum</em> to microplastics (MP, concentrations of 0 or 10 mg <em>L</em>⁻¹) with urea (U) or nitrate as nitrogen sources, both at 440 µmol <em>L</em>⁻¹ during 16 d to investigate the response of <em>P. cordatum</em> in terms of physiology and nitrogen metabolism. <em>P. cordatum</em> showed a similar growth rate, pigment contents (chlorophyll a and carotenoids), lipid peroxidation (MDA), nitrate reductase, and nitrogen consumption rate (<em>C</em>_N) in both N sources. The addition of MP under both nitrogen sources decreased growth but increased pigments, SOD and Urease activity, and MDA level, significanlty. The <em>C</em>_N was reduced by ∼50 % in the Microplastics + nitrate treatment (MPN), whereas it remained unchanged in the Microplastics + Urea treatment (MPU). At the transcriptomic level, the MP addition resulted in an approximate 2.5-fold increase in the number of differentially expressed genes (1811) under MPU compared to MPN (731). The MPU significantly upregulated pathways involving nitrogen assimilation and metabolism, endocytosis and phagosome, and further electron transport in photosynthesis and energy metabolism, but MPN downregulated those pathways. This suggests higher cellular metabolism under MPU compared to MPN. Additionally, cells in MPU upregulated pathways of antioxidation, heat shock protein, ubiquitin-mediated proteolysis, and proteasome in response to MP-induced stress, whereas the variations of these pathways in MPN were limited. These results shed light on the combined effects of urea as a source of nitrogen and MP exposure, providing insight into the metabolic flexibility of <em>P. cordatum</em> under future environmental stress.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102983"},"PeriodicalIF":4.5,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155626","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 Guiana current: a fast-lane to the Caribbean for holopelagic Sargassum contaminated in arsenic and cadmium","authors":"Tristan Gobert ,&nbsp;Solène Connan ,&nbsp;Donald R. Johnson ,&nbsp;Matthieu Waeles","doi":"10.1016/j.hal.2025.102981","DOIUrl":"10.1016/j.hal.2025.102981","url":null,"abstract":"<div><div>To date, little key information about inorganic arsenic (iAs) and cadmium (Cd) has been promulgated to help manage the massive influxes of pelagic <em>Sargassum</em> that have inundated the Caribbean coasts since 2011 and are causing significant environmental, health and economic impacts. In particular, the levels of iAs and Cd, which often exceed regulatory levels and limit the seaweed valorization, have not been linked to an origin or route. By analyzing a large number of samples collected at different times in Guadeloupe and Martinique, we have highlighted for the first time a route that rapidly traces back through the Guiana, North-Brazil and equatorial currents, bringing <em>Sargassum</em> to the Lesser Antilles in &lt;3 months from the equator. All the <em>Sargassum</em> morphotypes from this problematic fast track displayed high levels of iAs and Cd, very often exceeding 40 ppm and 1 ppm, respectively. The other routes, which bring <em>Sargassum</em> more slowly, either from the Cape Verde basin or from the North Brazil Retroflection area, have low or intermediate levels of iAs and Cd. Following an in-depth examination of the cadmium-phosphorus relationship in the tropical Atlantic Ocean, we provide here for the first time an overview of the spatial disparities in the Cd and P composition of <em>Sargassum</em>.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"150 ","pages":"Article 102981"},"PeriodicalIF":4.5,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109784","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}