Harmful Algae最新文献

{"title":"Influence of nitrate and salinity on growth and toxin production of Prymnesium parvum","authors":"Wenhui Yan ,&nbsp;Guixiang Wang ,&nbsp;Ying Ji ,&nbsp;Jiangbing Qiu ,&nbsp;Chengxu Zhou ,&nbsp;Aifeng Li","doi":"10.1016/j.hal.2024.102760","DOIUrl":"10.1016/j.hal.2024.102760","url":null,"abstract":"<div><div>Fish-killing events caused by haptophyte <em>Prymnesium parvum</em> have been reported in aquatic environments worldwide. This haptophyte could produce diverse prymnesins (PRMs) that harm to aquatic organisms like fishes. In this study, the components of prymnesins in the strain of <em>P. parvum</em> (NMBjih029) isolated from the coast of Ningbo city, China, were elucidated by a high-resolution mass spectrometer (HRMS), and the influence of nitrate levels and salinity on growth and toxin production of <em>P. parvum</em> were also explored. Results showed that the <em>P. parvum</em> produced C-type prymnesins with structure variations in saturation, chlorination, and sugar modifications. The growth and toxin production were significantly affected by nitrate levels in the batch cultures. At the lowest level of nitrate (N:P = 4:1), growth of <em>P. parvum</em> was inhibited but toxin quotas per cell increased up to approximately 4 times of that in control group (N:P = 16:1) during the exponential growth stage. Growth of <em>P. parvum</em> was not obviously affected by different salinities, but the biosynthesis of prymnesins increased with decreasing salinity from 32 to 14 in the culture media. The proportion of high chlorination of prymnesins (tetrachloride) increased in <em>P. parvum</em> under nitrogen limitation stress and low salinity. And the toxin quotas per cell also markedly increased with the extension of culture period in <em>P. parvum</em> under nitrogen limitation and different salinity conditions. This study provides some important cues for toxin profile and environmental impacts on the biosynthesis of prymnesins in the strain of <em>P. parvum</em> isolated from Chinese aquatic environments.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"140 ","pages":"Article 102760"},"PeriodicalIF":5.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700429","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":"Species and genetic diversity of notorious dinoflagellates Pfiesteria piscicida, Luciella masanensis, and relatives in marine sediments of China","authors":"Zhe Tao ,&nbsp;Xiaohan Liu ,&nbsp;Xiaoying Song ,&nbsp;Yunyan Deng ,&nbsp;Lixia Shang ,&nbsp;Zhaoyang Chai ,&nbsp;Zhangxi Hu ,&nbsp;Yuyang Liu ,&nbsp;Ying Zhong Tang","doi":"10.1016/j.hal.2024.102746","DOIUrl":"10.1016/j.hal.2024.102746","url":null,"abstract":"<div><div>The dinoflagellate genus <em>Pfiesteria</em>, encompassing <em>Pfiesteria piscicida</em> and <em>P. shumwayae</em>, became a hot topic in HABs research in the early 2000s due to numerous but controversial reports regarding life cycle and toxicity. While <em>Pfiesteria</em> presence has been reported from all continents, surprisingly, there has been no documented presence in China to date. Here, we report our findings on the presence, species, and genetic diversity of <em>Pfiesteria</em> and its phylogenetic relatives (particularly <em>Luciella masanensis</em>) using a combined approach. First, we demonstrated the presence of <em>P. piscicida</em> and <em>L. masanensis</em> using metabarcoding analysis of &gt;320 sediment samples. <em>Pfiesteria piscicida</em> was identified in 32 sampling sites across all four seas of China, with rDNA sequences exhibiting considerable differences from the type strain (up to 3.83 %), while <em>Luciella masanensis</em> presented in 212 sites from all four seas and included only ribotypes 1 and 3 among the four known ribotypes. Second, based on the metabarcoding detections, our application of FISH with species-specific probes and subsequent single-cyst PCR sequencing to the “positive” sediments confirmed, both morphologically and molecularly, the existence of <em>P. piscicida</em> and <em>L. masanensis</em> cysts in the sediments. Finally, individual cysts were isolated using the sodium polytungstate protocol and sequenced targeting 28S rDNA D1–D6 domains. Phylogenetic analysis revealed that 35 resting cysts were relatives of <em>Pfiesteria</em>, likely belonging to either new species or novel genera and family because they formed at least two distinct clades in the phylogenetic tree. <em>Pfiesteria shumwayae</em> was not detected from any sample, suggesting its absence in Chinese waters. We believe this work provides important factual basis for the global biogeography of these species and future HABs monitoring of in China.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"140 ","pages":"Article 102746"},"PeriodicalIF":5.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661258","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":"Molecular investigation of harmful cyanobacteria reveals hidden risks and niche partitioning in Kenyan Lakes","authors":"Brittany N. Zepernick ,&nbsp;Lauren N. Hart ,&nbsp;Emily E. Chase ,&nbsp;Kaela E. Natwora ,&nbsp;Julia A. Obuya ,&nbsp;Mark Olokotum ,&nbsp;Katelyn A. Houghton ,&nbsp;E. Anders Kiledal","doi":"10.1016/j.hal.2024.102757","DOIUrl":"10.1016/j.hal.2024.102757","url":null,"abstract":"<div><div>Despite the global expansion of cyanobacterial harmful algal blooms (cHABs), research is biased to temperate systems within the global north, such as the Laurentian Great Lakes. This lack of diversity represents a significant gap in the field and jeopardizes the health of those who reside along at-risk watersheds in the global south. The African Great Lake, Lake Victoria, is understudied despite serving as the second largest lake by surface area and demonstrating year-round cHABs. Here, we address this knowledge gap by performing a molecular survey of cHAB communities in three anthropogenically and ecologically important freshwater systems of Victoria's Kenyan watershed: Winam Gulf (Lake Victoria), Lake Simbi and Lake Naivasha. We identified a bloom of non-toxic <em>Dolichospermum</em> and toxic <em>Microcystis</em> in the Winam Gulf, with data suggesting sulfur limitation shapes competition dynamics between these two bloom-formers. Though we did not detect a bloom in Naivasha, it contained the largest diversity of cHAB genera amongst the three lakes. In turn, our results indicated methane metabolism may allow non-toxic picoplankton to outcompete cHAB genera, while suggesting <em>Synechococcus</em> spp. serves as a methane source and sink in this system. Lake Simbi exhibited a non-toxic <em>Limnospira</em> bloom at the time of sampling with very low abundances of cHAB genera present. Subsequently, these results were employed to design a cHAB screening and risk assessment framework for local stakeholders. Cumulatively, this work serves to increase cHAB research efforts on the international scale while serving as an impetus for cHAB monitoring on the local scale.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"140 ","pages":"Article 102757"},"PeriodicalIF":5.5,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661259","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":"Effects of temperature, salinity and CO2 concentration on growth and toxin production of the harmful algal bloom species Alexandrium pseudogonyaulax (Dinophyceae) from the Danish Limfjord","authors":"Simon Tulatz ,&nbsp;Bernd Krock ,&nbsp;Urban Tillmann ,&nbsp;Cédric Leo Meunier","doi":"10.1016/j.hal.2024.102756","DOIUrl":"10.1016/j.hal.2024.102756","url":null,"abstract":"<div><div>The marine dinoflagellate <em>Alexandrium pseudogonyaulax</em> is a widely distributed Harmful Algal Bloom (HAB) species that produces the macrocyclic polyketide goniodomin A (GDA). Occurrences in northern European waters are increasing and a spreading of the species along a salinity gradient into the Baltic Sea has been observed. As GDA is suspected to lead to invertebrate mortality, the spreading is of concern for the environment and possibly human health. In order to assess the potential of <em>A. pseudogonyaulax</em> to adapt to the environmental conditions in the Baltic Sea and the risk of future harmful blooms of that species, we quantified the influence of bottom-up factors on the growth and toxin content of three strains of <em>A. pseudogonyaulax</em> from the Danish Limfjord. Specifically, we exposed these strains to salinities ranging from 5 to 50, temperatures in the range of 10 – 30 °C and to three different CO₂ concentrations of 250, 400 and 1000 µatm. All strains tolerated a broad range of salinities and temperatures, resulting in positive growth rates ranging from 0.06 to 0.33 d^-1 between temperatures of 12 and 27 °C and between salinities of 10 and 40. The highest cell quotas of GDA were measured at low temperatures. For two strains, GDA amounts were almost unaffected by salinity, while the cell quota of the third strain decreased about 20-fold when salinity increased above 30. Different CO₂ concentrations had no effect on growth or GDA production. In summary, these findings show a high ecological tolerance towards a wide range of temperatures and salinities of the Limfjord population of <em>A. pseudogonyaulax</em>, together with distinct intraspecific physiological differences within the population. Our results also suggest that a further spreading into the Baltic Sea might be possible.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"140 ","pages":"Article 102756"},"PeriodicalIF":5.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661267","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":"Unprecedented toxic blooms of Microcystis spp. in 2019 in the Chowan River, North Carolina","authors":"Emily Pierce ,&nbsp;Marco Valera ,&nbsp;Mark Vander Borgh ,&nbsp;Daniel Wiltsie ,&nbsp;Elizabeth Fensin ,&nbsp;Charlton Godwin ,&nbsp;Jill Paxson ,&nbsp;Gloria Putnam ,&nbsp;Colleen Karl ,&nbsp;Blake Schaeffer ,&nbsp;Astrid Schnetzer","doi":"10.1016/j.hal.2024.102747","DOIUrl":"10.1016/j.hal.2024.102747","url":null,"abstract":"<div><div>The Chowan River flows from southern Virginia through northeastern North Carolina and into the Albemarle Sound, a part of the second largest U.S. estuary. The Chowan, which serves as an important recreational area and provides critical nursery habitat for multiple vulnerable species, has garnered much attention in recent years due to recurrent cyanobacterial harmful algal blooms (cHABs) associated with microcystins (MCs). Here we document unprecedented toxic blooms of <em>Microcystis</em> spp. during summer and fall of 2019 with MC concentrations two to three orders above the recreational guidelines of the Environmental Protection Agency (EPA, 2019). Based on 16S sequencing results in this study and previously published reports, the genus <em>Microcystis</em> emerged as a primary concern within the region. Shifts in assemblage composition, including relative abundance of <em>Microcystis</em> spp. and contributions from potential MC-degraders, linked to overall toxin concentrations and bloom stage. Congeners of varying toxicity, mainly MC-RR and MC-LR, were the most prevalent, corroborating that congeners other than MC-LR should be considered as health risk guidelines are developed. Downstream toxin transport was indicated based on changes in accumulated dissolved MC within the western Albemarle Sound which matched toxin dynamics in the Chowan River. This study provides important novel data on bacterial community composition, MC dynamics, and spatial connectivity for the Chowan River region that can aid monitoring approaches and management strategies for the protection of public health along the Chowan River and within the western Albemarle Sound.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"140 ","pages":"Article 102747"},"PeriodicalIF":5.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700354","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":"Perturbations in a pelagic food web during the NE pacific large marine heatwave and persistent harmful diatom blooms","authors":"Rocio I. Ruiz-Cooley ,&nbsp;Clarissa Anderson ,&nbsp;Raphael Kudela ,&nbsp;Robin Dunkin ,&nbsp;John Field","doi":"10.1016/j.hal.2024.102743","DOIUrl":"10.1016/j.hal.2024.102743","url":null,"abstract":"<div><div>Unprecedented warm ocean conditions, driven by the Large Marine Heatwave (LMH) and the 2015–16 El Niño in the Northeast Pacific favored pervasive toxigenic <em>Pseudo-nitzschia</em> spp. blooms that caused widespread ecological impacts, but little is known about the magnitude to which marine food webs were altered. Here, we assessed the trophic transfer of domoic acid (DA; a neurotoxin) and changes in trophic position from multiple key species during the peak of the LMH and El Niño in 2015 in comparison with 2018, a reference non-anomalous warm year. DA and amino acid nitrogen isotopes (δ¹⁵N _AAs) were quantified using liquid and gas chromatography mass spectrometry, respectively. Our integrative approach revealed extremely high levels of DA in anchovy viscera (&gt;3000 μg/g) with contrasting baseline values (δ¹⁵N _Phe) for southern California fish. These results together with data from northern CA revealed an unforeseen latitudinal isotopic variation in key DA vectors along California, possibly driven by anomalous restructuring of water masses. At the regional level, the observed cross-shore differences in baseline isotope values and DA toxicity suggest distinct pathways for DA trophic transfer for nearshore vs. offshore sites. Given the high levels of environmental disturbance during the LMH and persistence of toxigenic <em>P. australis</em> blooms, our resultant higher trophic position proxies in 2015 compared to 2018 were particularly unexpected. Such results highlight complex trophic interactions, where the trophic status of some species increased while others decreased in response to changes in net primary productivity, and biodiversity, and abundance of forage species. Our study demonstrates the use of δ¹⁵N AAs to identify pathways of N and DA trophic transfer and to quantify shifts in animal trophic position, a critical facet of understanding the response of food webs to climate change and DA production.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"140 ","pages":"Article 102743"},"PeriodicalIF":5.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700353","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":"Corrigendum to “Defense against Paramecium predation via long filament morphology favors the survival of Raphidiopsis raciborskii populations” [Harmful Algae 137 (2024) 102678]","authors":"Zeshuang Wang ,&nbsp;Xiaoli Huang ,&nbsp;Yangyang Wu ,&nbsp;Xiang Hu ,&nbsp;Qihang Zhao ,&nbsp;Jun Zuo ,&nbsp;Peng Xiao ,&nbsp;Yao Cheng ,&nbsp;He Zhang ,&nbsp;Renhui Li","doi":"10.1016/j.hal.2024.102733","DOIUrl":"10.1016/j.hal.2024.102733","url":null,"abstract":"","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102733"},"PeriodicalIF":5.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684068","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":"Response of heterocyst differentiation of Dolichospermum to different forms of nitrogen deficiency","authors":"Zichen Liu ,&nbsp;Fazhi Xie ,&nbsp;Liya Wang ,&nbsp;Li Yu ,&nbsp;Xiaoli Shi ,&nbsp;Zhen Yang ,&nbsp;Min Zhang","doi":"10.1016/j.hal.2024.102742","DOIUrl":"10.1016/j.hal.2024.102742","url":null,"abstract":"<div><div>In recent years, initiatives aimed at mitigating eutrophication have successfully reduced nitrogen and phosphorus concentrations in numerous lakes across China. Notably, the management of total nitrogen levels has prompted a shift in the dominant genera responsible for harmful algal blooms. Among these, <em>Dolichospermum</em>, a typical diazotrophic cyanobacterium, exhibits the ability to differentiate heterocysts for atmospheric N₂ fixation under nitrogen-limited conditions. However, the underlying mechanisms driving heterocyst differentiation in response to the absence of specific nitrogen compounds remain poorly understood. This study analyzed the driving factors influencing heterocyst frequency using field data from Lake Chaohu collected between January and June 2022. Furthermore, an experiment was conducted utilizing NH₄Cl, NaNO₃ and urea as nitrogen sources, with specific nitrogen deficiencies created to investigate the response mechanisms of <em>Dolichospermum</em> under these conditions. The results indicated significant monthly variations in heterocyst frequency in Lake Chaohu, which were associated with the interaction of multiple driving factors. Nutrient changes emerged as the most intuitive driving factor, with heterocyst frequency showing a significant negative correlation with total nitrogen and dissolved total nitrogen levels. Experimental results demonstrated that the absence of NO₃<img>N promoted both the biomass and heterocyst frequency of <em>Dolichospermum</em>. When NH_4<img>N was limited, the proliferation of <em>Dolichospermum</em> was inhibited, leading to an extended period of heterocyst development. Although a lack of urea eventually increased heterocyst frequency in <em>Dolichospermum</em>, there was no significant increase in biomass. The concentrations of the three nitrogen sources exhibited a negative correlation with heterocyst differentiation, with the effects of NO₃<img>N and urea deficiency on heterocyst differentiation being significantly stronger than those of NH₄<img>N. Moreover, heterocyst differentiation frequency was positively correlated with photosynthetic efficiency, which indicated that the acquisition and distribution of photosynthetic energy between heterocysts and vegetative cells also influence the differentiation process of heterocysts to some extent. The findings highlight the differing responses of heterocyst differentiation to various forms of nitrogen, emphasizing the importance of prioritizing NH₄<img>N removal in nutrient control. However, further research is needed to determine the key threshold concentrations of different nitrogen sources that trigger heterocyst differentiation.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102742"},"PeriodicalIF":5.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571861","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":"Identification of novel microcystins in algal extracts by a liquid chromatography–high-resolution mass spectrometry data analysis pipeline","authors":"Kirsten A. Cottrill ,&nbsp;Christopher O. Miles ,&nbsp;Logan C. Krajewski ,&nbsp;Brady R. Cunningham ,&nbsp;William Bragg ,&nbsp;Noelani R. Boise ,&nbsp;Kristin D. Victry ,&nbsp;David S. Wunschel ,&nbsp;Karen L. Wahl ,&nbsp;Elizabeth I. Hamelin","doi":"10.1016/j.hal.2024.102739","DOIUrl":"10.1016/j.hal.2024.102739","url":null,"abstract":"<div><h3>Background</h3><div>Microcystins are an emergent public health problem. These toxins are secondary metabolites of harmful cyanobacterial blooms, with blooms becoming more prevalent with eutrophication of water. Exposure to microcystins can result in sickness, liver damage, and even death. Over 300 microcystins have been identified to date, with differences in toxicity based on the specific amino acid composition. Because of this diversity in microcystins, as well as the likelihood of detecting as yet undiscovered microcystins, it is vital to establish a methodological workflow to identify any microcystin in a complex sample, regardless of the availability of a reference standard. Additionally, ascribing varying levels of confidence to these identifications is critical to effectively communicate discoveries.</div></div><div><h3>Methods</h3><div>A liquid-chromatography–high-resolution mass spectrometry method was utilized to identify microcystins present in cyanobacterial extracts from a strain of <em>Microcystis aeruginosa</em> and an <em>Aphanizomenon</em> sp. First, microcystin congeners with available standards were identified in the cyanobacterial extract. These known-unknown microcystins were considered to have the highest confidence identifications due to availability of accurate masses, retention times, and library spectra for comparison. Utilizing the spectra of these microcystins, relatively high-abundance diagnostic product-ions were identified and employed to screen the data for additional candidate microcystins. Microcystins without a standard that had an exact mass matching a microcystin published in CyanoMetDB were considered semi-known-unknown microcystins. The remaining microcystins were considered unknown-unknown microcystins. The identities of the microcystins determined herein were additionally supported by product-ion analysis, thiol reactivity, esterification reactions, neutral loss analysis, and literature contextualization.</div></div><div><h3>Results</h3><div>In total, utilizing the systematic workflow presented herein, 23 microcystins were identified in the <em>M. aeruginosa</em> culture, including two not published previously: [<span>d</span>-Asp³]MC-LCit and the incompletely identified MC-L(C₇H₁₁NO₃).</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102739"},"PeriodicalIF":5.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586526","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":"Connectivity of toxigenic Pseudo-nitzschia species assemblages between the Northeast U.S. continental shelf and an adjacent estuary","authors":"Katherine M. Roche ,&nbsp;Isabella N. Church ,&nbsp;Alexa R. Sterling ,&nbsp;Tatiana A. Rynearson ,&nbsp;Matthew J. Bertin ,&nbsp;Andrew M. Kim ,&nbsp;Riley D. Kirk ,&nbsp;Bethany D. Jenkins","doi":"10.1016/j.hal.2024.102738","DOIUrl":"10.1016/j.hal.2024.102738","url":null,"abstract":"<div><div><em>Pseudo-nitzschia</em> harmful algal blooms have recently caused elevated domoic acid in coastal environments of the Northeast United States. In 2017, the toxigenic species <em>P. australis</em> was observed in Narragansett Bay, Rhode Island, a temperate estuarine ecosystem, for the first time since 2009 when DNA monitoring for <em>Pseudo-nitzschia</em> species began. This highly toxic species likely contributed to toxin-related shellfish harvest closures and is hypothesized to have been introduced by an offshore source. Little is known about offshore <em>Pseudo-nitzschia</em> spp. populations in the Northeast Continental Shelf marine ecosystem or how often toxigenic species enter Narragansett Bay through physical processes. Here, we collected filtered biomass samples from multiple time series sites within Narragansett Bay and along the Northeast U.S. Shelf Long-Term Ecological Research transect in winter and summer to investigate the frequency and seasonality of potential <em>Pseudo-nitzschia</em> spp. inflow from the continental shelf to the estuary. Species were taxonomically identified using DNA sequencing of the ITS1 region and domoic acid concentrations were quantified by liquid chromatography with tandem mass spectrometry and multiple reaction monitoring. During six years of sampling, <em>Pseudo-nitzschia</em> species assemblages were more similar between Narragansett Bay and the Northeast shelf in winter than summer, suggesting greater ecosystem connectivity in winter. These winter assemblages were often accompanied by higher domoic acid. Several <em>Pseudo-nitzschia</em> species co-occurred most often with domoic acid and were likely responsible for toxin production in this region, including <em>P. pungens</em> var<em>. pungens, P. multiseries, P. calliantha, P. plurisecta, P. australis</em>, and <em>P. fraudulenta</em>. Domoic acid was detected during periods of relatively low macronutrient concentrations in both seasons, warmer sea surface temperatures in winter, and colder temperatures in summer within this dataset. This study represents some of the first domoic acid measurements on the offshore Northeast U.S. Continental Shelf, a region that supplies water to other coastal environments and could seed future harmful algal blooms. The elevated domoic acid and frequency of hypothesized inflow of toxigenic <em>Pseudo-nitzschia</em> spp. from the Northeast continental shelf to Narragansett Bay in winter indicate the need to monitor coastal and offshore environments for toxins and harmful algal bloom taxa during colder months.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":"139 ","pages":"Article 102738"},"PeriodicalIF":5.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571860","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}