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Aydin H, Uzar S, Cingöz EE, Küçüksezgin F, Pospelova V. Environmental factors influencing the abundance and spatial distribution of modern dinoflagellate cysts in Izmir Bay (Eastern Mediterranean). MARINE POLLUTION BULLETIN 2024; 205:116612. [PMID: 38991358 DOI: 10.1016/j.marpolbul.2024.116612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 06/12/2024] [Accepted: 06/16/2024] [Indexed: 07/13/2024]
Abstract
We analyzed surface sediments from 12 stations located in Izmir Bay to determine the impact of anthropogenic pollution on dinoflagellate cysts. Forty-three dinoflagellate cyst taxa and two cyst assemblage zones were identified. Zone 1 is characterized by the dominance of cysts of Gymnodinium nolleri, Selenopemphix nephroides, and Operculodinium centrocarpum from the oligotrophic part of Izmir Bay. Zone 2 is in the highly productive inner part of the bay and is characterized by the high abundances of Lingulodinium machaerophorum, Spiniferites ramosus, cysts of Scrippsiella spp., cysts of Polykrikos spp. and Quinquecuspis concreta. We used multivariate statistical analysis (DCA and CCA) on dinoflagellate cysts and environmental variables to support the identification of Zones 1 and 2. Our analyses also revealed that summer and winter chlorophyll-a as well as elevated nitrate and nitrite concentrations are significant parameters in controlling dinoflagellate cyst distribution in Izmir Bay.
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Affiliation(s)
- Hilal Aydin
- Manisa Celal Bayar University, Faculty of Science and Arts, Biology Department, 45140, Manisa, Turkiye.
| | - Serdar Uzar
- Manisa Celal Bayar University, Faculty of Science and Arts, Biology Department, 45140, Manisa, Turkiye
| | - Emine Erdem Cingöz
- Manisa Celal Bayar University, Faculty of Science and Arts, Biology Department, 45140, Manisa, Turkiye
| | - Filiz Küçüksezgin
- Institute of Marine Sciences and Technology Institute of Marine Sciences and Technology, Dokuz Eylul University, Inciralti, Izmir 35340, Turkiye
| | - Vera Pospelova
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN 55455-0149, USA
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2
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Shang J, Zhao M, Yan S. Comprehensive analysis of cyanobacterial secondary metabolites distribution and toxicity in urban water bodies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 932:173023. [PMID: 38719060 DOI: 10.1016/j.scitotenv.2024.173023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/23/2024] [Accepted: 05/04/2024] [Indexed: 05/12/2024]
Abstract
This study addresses the increasing concern regarding cyanotoxin contamination of water bodies, highlighting the diversity of these toxins and their potential health implications. Cyanobacteria, which are prevalent in aquatic environments, produce toxic metabolites, raising concerns regarding human exposure and associated health risks, including a potential increase in cancer risk. Although existing research has primarily focused on well-known cyanotoxins, recent technological advancements have revealed numerous unknown cyanotoxins, necessitating a comprehensive assessment of multiple toxin categories. To enhance the cyanotoxin databases, we optimized the CyanoMetDB cyanobacterial secondary metabolites database by incorporating secondary fragmentation patterns using the Mass Frontier fragmentation data prediction software. Water samples from diverse locations in Shanghai were analyzed using high-resolution mass spectrometry. Subsequently, the toxicity of cyanobacterial metabolites in the water samples was examined through acute toxicity assays using the crustacean Thamnocephalus platyurus. After 24 h of exposure, the semi-lethal concentrations (LC50) of the water samples ranged from 0.31 mg L-1 to 1.78 mg L-1 (MC-LR equivalent concentration). Our findings revealed a critical correlation between the overall concentration of cyanobacterial metabolites and toxicity. The robust framework and insights of this study underscore the need for an inclusive approach to water quality management, emphasizing continuous efforts to refine detection methods and comprehend the broader ecological impact of cyanobacterial blooms on aquatic ecosystems.
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Affiliation(s)
- Jiong Shang
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, PR China
| | - Mengzhe Zhao
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, PR China
| | - Shuwen Yan
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, PR China.
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3
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Wolf KKE, Hoppe CJM, Rehder L, Schaum E, John U, Rost B. Heatwave responses of Arctic phytoplankton communities are driven by combined impacts of warming and cooling. SCIENCE ADVANCES 2024; 10:eadl5904. [PMID: 38758795 PMCID: PMC11100554 DOI: 10.1126/sciadv.adl5904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 04/15/2024] [Indexed: 05/19/2024]
Abstract
Marine heatwaves are increasing in frequency and intensity as climate change progresses, especially in the highly productive Arctic regions. Although their effects on primary producers will largely determine the impacts on ecosystem services, mechanistic understanding on phytoplankton responses to these extreme events is still very limited. We experimentally exposed Arctic phytoplankton assemblages to stable warming, as well as to repeated heatwaves, and measured temporally resolved productivity, physiology, and composition. Our results show that even extreme stable warming increases productivity, while the response to heatwaves depends on the specific scenario applied and is not predictable from stable warming responses. This appears to be largely due to the underestimated impact of the cool phase following a heatwave, which can be at least as important as the warm phase for the overall response. We show that physiological and compositional adjustments to both warm and cool phases drive overall phytoplankton productivity and need to be considered mechanistically to predict overall ecosystem impacts.
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Affiliation(s)
- Klara K. E. Wolf
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Hamburg, Germany
- Environmental Genomics, University of Konstanz, Konstanz, Germany
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Clara J. M. Hoppe
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Linda Rehder
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Elisa Schaum
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Hamburg, Germany
| | - Uwe John
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Oldenburg, Germany
| | - Björn Rost
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- FB2, University of Bremen, Bremen, Germany
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4
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Chen Z, Zakrzewska S, Hajare HS, Du Bois J, Minor DL. Expression, purification, and characterization of anuran saxiphilins using thermofluor, fluorescence polarization, and isothermal titration calorimetry. STAR Protoc 2024; 5:102792. [PMID: 38133955 PMCID: PMC10776646 DOI: 10.1016/j.xpro.2023.102792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/10/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Anuran saxiphilins (Sxphs) are "toxin sponge" proteins thought to prevent the lethal effects of small-molecule neurotoxins through sequestration. Here, we present a protocol for the expression, purification, and characterization of Sxphs. We describe steps for using thermofluor, fluorescence polarization, and isothermal titration calorimetry assays that probe Sxph:saxitoxin interactions using a range of sample quantities. These assays are generalizable and can be used for other paralytic shellfish poisoning toxin-binding proteins. For complete details on the use and execution of this protocol, please refer to Chen et al. (2022).1.
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Affiliation(s)
- Zhou Chen
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158-2330, USA
| | - Sandra Zakrzewska
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158-2330, USA
| | - Holly S Hajare
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - J Du Bois
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158-2330, USA; Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158-2330, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158-2330, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158-2330, USA; Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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5
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Hörstmann C, Hattermann T, Thomé PC, Buttigieg PL, Morel I, Waite AM, John U. Biogeographic gradients of picoplankton diversity indicate increasing dominance of prokaryotes in warmer Arctic fjords. Commun Biol 2024; 7:256. [PMID: 38431695 PMCID: PMC10908816 DOI: 10.1038/s42003-024-05946-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 02/21/2024] [Indexed: 03/05/2024] Open
Abstract
Climate change is opening the Arctic Ocean to increasing human impact and ecosystem changes. Arctic fjords, the region's most productive ecosystems, are sustained by a diverse microbial community at the base of the food web. Here we show that Arctic fjords become more prokaryotic in the picoplankton (0.2-3 µm) with increasing water temperatures. Across 21 fjords, we found that Arctic fjords had proportionally more trophically diverse (autotrophic, mixotrophic, and heterotrophic) picoeukaryotes, while subarctic and temperate fjords had relatively more diverse prokaryotic trophic groups. Modeled oceanographic connectivity between fjords suggested that transport alone would create a smooth gradient in beta diversity largely following the North Atlantic Current and East Greenland Current. Deviations from this suggested that picoeukaryotes had some strong regional patterns in beta diversity that reduced the effect of oceanographic connectivity, while prokaryotes were mainly stopped in their dispersal if strong temperature differences between sites were present. Fjords located in high Arctic regions also generally had very low prokaryotic alpha diversity. Ultimately, warming of Arctic fjords could induce a fundamental shift from more trophic diverse eukaryotic- to prokaryotic-dominated communities, with profound implications for Arctic ecosystem dynamics including their productivity patterns.
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Affiliation(s)
- Cora Hörstmann
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
- Aix Marseille Univ, Universite de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France.
- Turing Center for Living Systems, Aix-Marseille University, 13009, Marseille, France.
| | - Tore Hattermann
- Norwegian Polar Institute, iC3: Centre for Ice, Cryosphere, Carbon and Climate, Framsenteret, Hjalmar Johansens gate 14, 9296, Tromsø, Norway
- Complex Systems Group, Department of Mathematics and Statistics, The Arctic University - University of Tromsø, Hansine Hansens veg 18, 9019, Tromsø, Norway
| | - Pauline C Thomé
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587, Berlin, Germany
| | - Pier Luigi Buttigieg
- Helmholtz Metadata Collaboration, GEOMAR, Wischhofstraße 1-3, 24148, Kiel, Germany
| | - Isidora Morel
- Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359, Bremen, Germany
| | - Anya M Waite
- Ocean Frontier Institute, Dalhousie University, 1355 Oxford Street, Halifax, NS, Canada
| | - Uwe John
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, 26129, Oldenburg, Germany
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6
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Roland HB, Kohlhoff J, Lanphier K, Hoysala S, Kennedy EG, Harley J, Whitehead C, Gribble MO. Perceived Challenges to Tribally Led Shellfish Toxin Testing in Southeast Alaska: Findings From Key Informant Interviews. GEOHEALTH 2024; 8:e2023GH000988. [PMID: 38516504 PMCID: PMC10956280 DOI: 10.1029/2023gh000988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/12/2024] [Accepted: 01/12/2024] [Indexed: 03/23/2024]
Abstract
Shellfish harvesting is central to coastal Alaska Native ways of life, and tribes in Southeast Alaska are committed to preserving sustainable and safe access to subsistence foods. However, consumption of non-commercially harvested shellfish puts Alaska Native communities at elevated risk of exposure to shellfish toxins. To address a lack of state or federal toxin testing for subsistence and recreational harvesting, tribes across Southeast Alaska have formed their own toxin testing and ocean monitoring program. In this study, we interviewed environmental managers responsible for tribes' testing and others with shellfish toxin expertise to report on perceptions of barriers to tribally led testing in Southeast Alaska. Tribal staff identified 40 prospective key informants to interview, including all environmental managers responsible for shellfish toxin testing at subsistence sites in Southeast Alaska. All 40 individuals were invited to participate in an interview and 27 individuals were interviewed. The most frequently discussed barriers to shellfish toxin testing in Southeast Alaska relate to logistical and staffing difficulties associated with communities' remote locations, inconsistent and inadequate funding and funding structures that increase staff burdens, risk communication challenges related to conveying exposure risks while supporting subsistence harvesting, and implications of climate change-related shifts in toxin exposures for risk perception and risk communication. Participants stressed the social origins of perceived barriers. Disinvestment may create and sustain barriers and be most severely felt in Native communities and remote places. Climate change impacts may interact with social and cultural factors to further complicate risk management.
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Affiliation(s)
- Hugh B. Roland
- Department of Epidemiology, School of Public HealthUniversity of Alabama at BirminghamBirminghamALUSA
| | | | | | - Sneha Hoysala
- Rollins School of Public HealthEmory UniversityAtlantaGAUSA
| | - Esther G. Kennedy
- Bodega Marine Laboratory and Department of Earth and Planetary SciencesUniversity of California, DavisBodega BayCAUSA
| | - John Harley
- Alaska Coastal Rainforest CenterUniversity of Alaska SoutheastJuneauAKUSA
| | | | - Matthew O. Gribble
- Division of Occupational, Environmental and Climate MedicineDepartment of MedicineUniversity of California, San FranciscoSan FranciscoCAUSA
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Montuori E, De Luca D, Penna A, Stalberga D, Lauritano C. Alexandrium spp.: From Toxicity to Potential Biotechnological Benefits. Mar Drugs 2023; 22:31. [PMID: 38248656 PMCID: PMC10821459 DOI: 10.3390/md22010031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024] Open
Abstract
Many dinoflagellates of the genus Alexandrium are well known for being responsible for harmful algal blooms (HABs), producing potent toxins that cause damages to other marine organisms, aquaculture, fishery, tourism, as well as induce human intoxications and even death after consumption of contaminated shellfish or fish. In this review, we summarize potential bioprospecting associated to the genus Alexandrium, including which Alexandrium spp. produce metabolites with anticancer, antimicrobial, antiviral, as well as anti-Alzheimer applications. When available, we report their mechanisms of action and targets. We also discuss recent progress on the identification of secondary metabolites with biological properties favorable to human health and aquaculture. Altogether, this information highlights the importance of studying which culturing conditions induce the activation of enzymatic pathways responsible for the synthesis of bioactive metabolites. It also suggests considering and comparing clones collected in different locations for toxin monitoring and marine bioprospecting. This review can be of interest not only for the scientific community, but also for the entire population and industries.
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Affiliation(s)
- Eleonora Montuori
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d’Alcontres 31, 98166 Messina, Italy;
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Acton 55, 80133 Napoli, Italy
| | - Daniele De Luca
- Research Infrastructure for Marine Biological Resources Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy;
| | - Antonella Penna
- Department of Biomolecular Sciences, University of Urbino, Campus E. Mattei, 61029 Urbino, Italy;
| | - Darta Stalberga
- Department of Biomedical and Clinical Sciences, Division of Clinical Chemistry and Pharmacology, Linköping University, SE-58183 Linköping, Sweden;
| | - Chiara Lauritano
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Acton 55, 80133 Napoli, Italy
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Dees P, Dale A, Whyte C, Mouat B, Davidson K. Operational modelling to assess advective harmful algal bloom development and its potential to impact aquaculture. HARMFUL ALGAE 2023; 129:102517. [PMID: 37951611 DOI: 10.1016/j.hal.2023.102517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/05/2023] [Accepted: 09/22/2023] [Indexed: 11/14/2023]
Abstract
A particle tracking model is described and used to explore the role of advection as the source of harmful algal blooms that impact the Shetland Islands, where much of Scotland's aquaculture is located. The movement of particles, representing algal cells, was modelled using surface velocities obtained from the 1.5 km resolution Atlantic Margin Model AMM15. Following validation of model performance against drifter tracks, the model results recreate previously hypothesised onshore advection of harmful algal cells from west of the archipelago during 2006 and 2013, when exceptional Dinophysis spp. abundances were measured at Shetland aquaculture sites. Higher eastward advection of Dinophysis spp. cells was also suggested during 2018. Wind roses explain this higher eastward advection during 2006, 2013 and 2018. The study suggests that the European Slope Current is important for the transport of harmful algal blooms, particularly those composed of dinoflagellates.
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Affiliation(s)
- Paul Dees
- Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, United Kingdom; Geophysical Institute, University of Bergen, 5020 Bergen, Norway.
| | - Andrew Dale
- Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, United Kingdom
| | - Callum Whyte
- Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, United Kingdom
| | - Beth Mouat
- UHI Shetland, Port Arthur, Scalloway ZE1 0UN, United Kingdom
| | - Keith Davidson
- Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, United Kingdom
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9
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Kim JH, Park BS, Kim JH. Comprehensive understanding of the life history of harmful raphidophyte Heterosigma akashiwo: Integrating in situ and in vitro observations. HARMFUL ALGAE 2023; 129:102521. [PMID: 37951620 DOI: 10.1016/j.hal.2023.102521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/31/2023] [Accepted: 09/29/2023] [Indexed: 11/14/2023]
Abstract
Heterosigma akashiwo (Raphidophyceae) is widely recognized as a species responsible for harmful algal blooms worldwide. The species has long been speculated to possess a more complex life history, attributed to the diverse morphological variations observed during cell cultivation. However, the understanding of its life history has remained insufficient due to limitations in observing transitions between life cycle stages in vitro and challenges associated with in situ investigations. In this study, a combination of in vitro (laboratory-based) and in situ (field-based) observations was employed to define the life cycle stages of H. akashiwo and elucidate the pathways of transition between these stages. Notably, novel homothallic sexual reproduction processes involving the fusion of hologametes and the subsequent formation of zygotes were observed for the first time in vitro. These zygotes were found to either divide into vegetative cells (Pathway I) or undergo enlargement, resulting in the formation of multiple cells with multiple nuclei (Pathway II). Furthermore, this study provides the first documentation of large cells and cell clusters in situ, including intermediate stages referred to as large cells with ongoing cytoplasmic division that serve as a bridge between these two cell types. The observed zygotes in vitro exhibited a large size (21.9-51.8 µm) and multinucleated characteristics, similar to the large cells (38.2-45.8 μm) and cell clusters observed in situ. This finding suggests that the large cells observed in situ were zygotes undergoing cell division to form cell clusters (Pathway III). Moreover, based on the striking similarities in cell morphology and nuclear size between the cells comprising the cell cluster (2.7-4.4 μm) and the cyst clusters of this species, along with the synchronized germination characteristics of cyst clusters, it is proposed that the cell cluster serves as a precursor to cysts. By integrating the in situ and in vitro observations, this study provides a comprehensive understanding of the previously poorly understood life history of H. akashiwo.
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Affiliation(s)
- Joo-Hwan Kim
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea; Ministry of Environment, Government Complex-Sejong, Sejong 30103, Republic of Korea
| | - Bum Soo Park
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea; Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul 04763, Republic of Korea; Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea; Hanyang Institute of Advanced BioConvergence, Hanyang University, Seoul 04763, Republic of Korea.
| | - Jin Ho Kim
- Department of Earth and Marine Science, College of Ocean Sciences, Jeju National University, Jeju 63243, Republic of Korea.
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10
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Frey KE, Comiso JC, Stock LV, Young LNC, Cooper LW, Grebmeier JM. A comprehensive satellite-based assessment across the Pacific Arctic Distributed Biological Observatory shows widespread late-season sea surface warming and sea ice declines with significant influences on primary productivity. PLoS One 2023; 18:e0287960. [PMID: 37432919 DOI: 10.1371/journal.pone.0287960] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 06/14/2023] [Indexed: 07/13/2023] Open
Abstract
Massive declines in sea ice cover and widespread warming seawaters across the Pacific Arctic region over the past several decades have resulted in profound shifts in marine ecosystems that have cascaded throughout all trophic levels. The Distributed Biological Observatory (DBO) provides sampling infrastructure for a latitudinal gradient of biological "hotspot" regions across the Pacific Arctic region, with eight sites spanning the northern Bering, Chukchi, and Beaufort Seas. The purpose of this study is two-fold: (a) to provide an assessment of satellite-based environmental variables for the eight DBO sites (including sea surface temperature (SST), sea ice concentration, annual sea ice persistence and the timing of sea ice breakup/formation, chlorophyll-a concentrations, primary productivity, and photosynthetically available radiation (PAR)) as well as their trends across the 2003-2020 time period; and (b) to assess the importance of sea ice presence/open water for influencing primary productivity across the region and for the eight DBO sites in particular. While we observe significant trends in SST, sea ice, and chlorophyll-a/primary productivity throughout the year, the most significant and synoptic trends for the DBO sites have been those during late summer and autumn (warming SST during October/November, later shifts in the timing of sea ice formation, and increases in chlorophyll-a/primary productivity during August/September). Those DBO sites where significant increases in annual primary productivity over the 2003-2020 time period have been observed include DBO1 in the Bering Sea (37.7 g C/m2/year/decade), DBO3 in the Chukchi Sea (48.0 g C/m2/year/decade), and DBO8 in the Beaufort Sea (38.8 g C/m2/year/decade). The length of the open water season explains the variance of annual primary productivity most strongly for sites DBO3 (74%), DBO4 in the Chukchi Sea (79%), and DBO6 in the Beaufort Sea (78%), with DBO3 influenced most strongly with each day of additional increased open water (3.8 g C/m2/year per day). These synoptic satellite-based observations across the suite of DBO sites will provide the legacy groundwork necessary to track additional and inevitable future physical and biological change across the region in response to ongoing climate warming.
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Affiliation(s)
- Karen E Frey
- Graduate School of Geography, Clark University, Worcester, Massachusetts, United States of America
| | - Josefino C Comiso
- Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, United States of America
| | - Larry V Stock
- Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, United States of America
| | - Luisa N C Young
- Graduate School of Geography, Clark University, Worcester, Massachusetts, United States of America
| | - Lee W Cooper
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, Maryland, United States of America
| | - Jacqueline M Grebmeier
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, Maryland, United States of America
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11
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Grémillet D, Descamps S. Ecological impacts of climate change on Arctic marine megafauna. Trends Ecol Evol 2023:S0169-5347(23)00082-4. [PMID: 37202284 DOI: 10.1016/j.tree.2023.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/28/2023] [Accepted: 04/04/2023] [Indexed: 05/20/2023]
Abstract
Global warming affects the Arctic more than any other region. Mass media constantly relay apocalyptic visions of climate change threatening Arctic wildlife, especially emblematic megafauna such as polar bears, whales, and seabirds. Yet, we are just beginning to understand such ecological impacts on marine megafauna at the scale of the Arctic. This knowledge is geographically and taxonomically biased, with striking deficiencies in the Russian Arctic and strong focus on exploited species such as cod. Beyond a synthesis of scientific advances in the past 5 years, we provide ten key questions to be addressed by future work and outline the requested methodology. This framework builds upon long-term Arctic monitoring inclusive of local communities whilst capitalising on high-tech and big data approaches.
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Affiliation(s)
- David Grémillet
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France; Percy FitzPatrick Institute, DST/NRF Excellence Center at the University of Cape Town, Cape Town, South Africa.
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12
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Chatterjee S, More M. Cyanobacterial Harmful Algal Bloom Toxin Microcystin and Increased Vibrio Occurrence as Climate-Change-Induced Biological Co-Stressors: Exposure and Disease Outcomes via Their Interaction with Gut-Liver-Brain Axis. Toxins (Basel) 2023; 15:289. [PMID: 37104227 PMCID: PMC10144574 DOI: 10.3390/toxins15040289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/12/2023] [Accepted: 04/12/2023] [Indexed: 04/28/2023] Open
Abstract
The effects of global warming are not limited to rising global temperatures and have set in motion a complex chain of events contributing to climate change. A consequence of global warming and the resultant climate change is the rise in cyanobacterial harmful algal blooms (cyano-HABs) across the world, which pose a threat to public health, aquatic biodiversity, and the livelihood of communities that depend on these water systems, such as farmers and fishers. An increase in cyano-HABs and their intensity is associated with an increase in the leakage of cyanotoxins. Microcystins (MCs) are hepatotoxins produced by some cyanobacterial species, and their organ toxicology has been extensively studied. Recent mouse studies suggest that MCs can induce gut resistome changes. Opportunistic pathogens such as Vibrios are abundantly found in the same habitat as phytoplankton, such as cyanobacteria. Further, MCs can complicate human disorders such as heat stress, cardiovascular diseases, type II diabetes, and non-alcoholic fatty liver disease. Firstly, this review describes how climate change mediates the rise in cyanobacterial harmful algal blooms in freshwater, causing increased levels of MCs. In the later sections, we aim to untangle the ways in which MCs can impact various public health concerns, either solely or in combination with other factors resulting from climate change. In conclusion, this review helps researchers understand the multiple challenges brought forth by a changing climate and the complex relationships between microcystin, Vibrios, and various environmental factors and their effect on human health and disease.
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Affiliation(s)
- Saurabh Chatterjee
- Environmental Health and Disease Laboratory, Department of Environmental and Occupational Health, Program in Public Health, University of California–Irvine, Irvine, CA 92697, USA
- Toxicology Core, NIEHS Center for Oceans and Human Health on Climate Change Interactions, Department of Environmental and Occupational Health, Program in Public Health, University of California–Irvine, Irvine, CA 92697, USA
- Division of Infectious Disease, Department of Medicine, UCI School of Medicine, University of California–Irvine, Irvine, CA 92697, USA
| | - Madhura More
- Environmental Health and Disease Laboratory, Department of Environmental and Occupational Health, Program in Public Health, University of California–Irvine, Irvine, CA 92697, USA
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13
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Hubbard KA, Villac MC, Chadwick C, DeSmidt AA, Flewelling L, Granholm A, Joseph M, Wood T, Fachon E, Brosnahan ML, Richlen M, Pathare M, Stockwell D, Lin P, Bouchard JN, Pickart R, Anderson DM. Spatiotemporal transitions in Pseudo-nitzschia species assemblages and domoic acid along the Alaska coast. PLoS One 2023; 18:e0282794. [PMID: 36947524 PMCID: PMC10032537 DOI: 10.1371/journal.pone.0282794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 03/23/2023] Open
Abstract
The toxic diatom genus Pseudo-nitzschia is distributed from equatorial to polar regions and is comprised of >57 species, some capable of producing the neurotoxin domoic acid (DA). In the Pacific Arctic Region spanning the Bering, Chukchi, and Beaufort seas, DA is recognized as an emerging human and ecosystem health threat, yet little is known about the composition and distribution of Pseudo-nitzschia species in these waters. This investigation characterized Pseudo-nitzschia assemblages in samples collected in 2018 during summer (August) and fall (October-November) surveys as part of the Distributed Biological Observatory and Arctic Observing Network, encompassing a broad geographic range (57.8° to 73.0°N, -138.9° to -169.9°W) and spanning temperature (-1.79 to 11.7°C) and salinity (22.9 to 32.9) gradients associated with distinct water masses. Species were identified using a genus-specific Automated Ribosomal Intergenic Spacer Analysis (ARISA). Seventeen amplicons were observed; seven corresponded to temperate, sub-polar, or polar Pseudo-nitzschia species based on parallel sequencing efforts (P. arctica, P. delicatissima, P. granii, P. obtusa, P. pungens, and two genotypes of P. seriata), and one represented Fragilariopsis oceanica. During summer, particulate DA (pDA; 4.0 to 130.0 ng L-1) was observed in the Bering Strait and Chukchi Sea where P. obtusa was prevalent. In fall, pDA (3.3 to 111.8 ng L-1) occurred along the Beaufort Sea shelf coincident with one P. seriata genotype, and south of the Bering Strait in association with the other P. seriata genotype. Taxa were correlated with latitude, longitude, temperature, salinity, pDA, and/or chlorophyll a, and each had a distinct distribution pattern. The observation of DA in association with different species, seasons, geographic regions, and water masses underscores the significant risk of Amnesic Shellfish Poisoning (ASP) and DA-poisoning in Alaska waters.
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Affiliation(s)
- Katherine A. Hubbard
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Maria Célia Villac
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
| | - Christina Chadwick
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
| | - Alexandra A. DeSmidt
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
| | - Leanne Flewelling
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
| | - April Granholm
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
| | - Molly Joseph
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
| | - Taylor Wood
- Florida Fish and Wildlife Conservation Commission-Fish and Wildlife Research Institute, Saint Petersburg, Florida, United States of America
| | - Evangeline Fachon
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
- Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Michael L. Brosnahan
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Mindy Richlen
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Mrunmayee Pathare
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Dean Stockwell
- College of Fisheries and Ocean Sciences, Institute of Marine Science, Fairbanks, Alaska, United States of America
| | - Peigen Lin
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Josée N. Bouchard
- Centre de recherche sur les biotechnologies marines, Rimouski, Québec, Canada
| | - Robert Pickart
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Donald M. Anderson
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
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14
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Dai Y, Yang S, Zhao D, Hu C, Xu W, Anderson DM, Li Y, Song XP, Boyce DG, Gibson L, Zheng C, Feng L. Coastal phytoplankton blooms expand and intensify in the 21st century. Nature 2023; 615:280-284. [PMID: 36859547 PMCID: PMC9995273 DOI: 10.1038/s41586-023-05760-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 01/25/2023] [Indexed: 03/03/2023]
Abstract
Phytoplankton blooms in coastal oceans can be beneficial to coastal fisheries production and ecosystem function, but can also cause major environmental problems1,2-yet detailed characterizations of bloom incidence and distribution are not available worldwide. Here we map daily marine coastal algal blooms between 2003 and 2020 using global satellite observations at 1-km spatial resolution. We found that algal blooms occurred in 126 out of the 153 coastal countries examined. Globally, the spatial extent (+13.2%) and frequency (+59.2%) of blooms increased significantly (P < 0.05) over the study period, whereas blooms weakened in tropical and subtropical areas of the Northern Hemisphere. We documented the relationship between the bloom trends and ocean circulation, and identified the stimulatory effects of recent increases in sea surface temperature. Our compilation of daily mapped coastal phytoplankton blooms provides the basis for global assessments of bloom risks and benefits, and for the formulation or evaluation of management or policy actions.
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Affiliation(s)
- Yanhui Dai
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Shangbo Yang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Dan Zhao
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Chuanmin Hu
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - Wang Xu
- Shenzhen Ecological and Environmental Monitoring Center of Guangdong Province, Shenzhen, China
| | | | - Yun Li
- School of Marine Science and Policy, College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, USA
| | - Xiao-Peng Song
- Department of Geographical Sciences, University of Maryland, College Park, MD, USA
| | - Daniel G Boyce
- Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, Nova Scotia, Canada
| | - Luke Gibson
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Chunmiao Zheng
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
- EIT Institute for Advanced Study, Ningbo, China
| | - Lian Feng
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China.
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15
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Cho Y, Tsuchiya S, Omura T, Koike K, Konoki K, Oshima Y, Yotsu-Yamashita M. Metabolic inhibitor induces dynamic changes in saxitoxin biosynthesis and metabolism in the dinoflagellate Alexandrium pacificum (Group IV) under in vivo labeling condition. HARMFUL ALGAE 2023; 122:102372. [PMID: 36754461 DOI: 10.1016/j.hal.2022.102372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
In paralytic shellfish toxin-producing dinoflagellates, intracellular levels of saxitoxin and its analogues (STXs) are controlled by a balance between degradation and biosynthesis in response to marine environmental fluctuations and stresses. The purpose of this study was to demonstrate the utility of statistical analysis of in vivo labeling data for the dynamic analysis of variations in toxin production under stress. A toxic strain of the dinoflagellate Alexandrium pacificum (Group IV) was cultured in colchicine-containing 15N-labeled sodium nitrate-medium and metabolite levels were analyzed over time by liquid chromatography-mass spectrometry. Quantitative values of all isotopomers of precursor amino acids, biosynthetic intermediates, and major STXs were subjected to statistical analysis. The decrease of the nitrogen incorporation rates for all compounds suggested that colchicine decreased nitrate assimilation upstream of glutamate biosynthesis. In colchicine-treated cultures, the per-cell content of total STX analogues did not change significantly over time; however, the production rate of each pathway varied greatly. De novo STX biosynthesis was decreased by colchicine until Day 3, while the salvage pathway was not. Subsequently, biosynthesis by both pathways was enhanced. This analysis of dynamic metabolism provides new insights into the complex mechanisms regulating STX metabolism in dinoflagellates.
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Affiliation(s)
- Yuko Cho
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8572, Japan.
| | - Shigeki Tsuchiya
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Takuo Omura
- Laboratory of Aquatic Science Consultant Co., LTD. 2-30-17, Higashikamata, Ota-ku, Tokyo 144-0031, Japan
| | - Kazuhiko Koike
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan
| | - Keiichi Konoki
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Yasukatsu Oshima
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8572, Japan
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16
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Einarsson SV, Lowry KE, Lin P, Pickart RS, Ashjian CJ, Chappell PD. Alexandrium on the Alaskan Beaufort Sea shelf: Impact of upwelling in a warming Arctic. HARMFUL ALGAE 2022; 120:102346. [PMID: 36470603 DOI: 10.1016/j.hal.2022.102346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
The harmful algal genus Alexandrium has characteristically been found in temperate and subtropical regions; however recent evidence suggests global warming may be expanding its range into high latitude waters. Alexandrium cysts have previously been documented in the Chukchi Sea and we hypothesize that Alexandrium may be expanding further into the Arctic due to distribution by the Beaufort shelfbreak jet. Here we document the presence of Alexandrium catenella along the Alaskan Beaufort Sea shelf, marking an expansion of its known range. The observations of A. catenella were made using three different methods: FlowCAM imaging, 18S eukaryotic sequencing, and real-time quantitative PCR. Four occupations of a shelf/slope transect spanned the evolution of a strong wind-driven upwelling event over a 5-day period. A nearby mooring provided the physical context for the event, revealing that enhanced easterly winds reversed the Beaufort shelfbreak jet to the west and induced upwelling of colder, denser water onto the outer shelf. A. catenella sequences dominated the surface phytoplankton community at the onset of the upwelling event. This signal vanished during and after the event, likely due to a combination of alongstream advection, cross-stream advection, and wind mixing. These results suggest contrasting physical processes that are both subject to global warming amplification, delivery of warm waters via the Beaufort shelfbreak jet and upwelling, may control the proliferation of this potential harmful alga into the Arctic.
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Affiliation(s)
- Sveinn V Einarsson
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA
| | - Kate E Lowry
- Science Philanthropy Alliance, Palo Alto, CA, USA; Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Peigen Lin
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | | | | | - P Dreux Chappell
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA.
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17
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Definition of a saxitoxin (STX) binding code enables discovery and characterization of the anuran saxiphilin family. Proc Natl Acad Sci U S A 2022; 119:e2210114119. [PMID: 36279441 PMCID: PMC9636910 DOI: 10.1073/pnas.2210114119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
American bullfrog (Rana castesbeiana) saxiphilin (RcSxph) is a high-affinity "toxin sponge" protein thought to prevent intoxication by saxitoxin (STX), a lethal bis-guanidinium neurotoxin that causes paralytic shellfish poisoning (PSP) by blocking voltage-gated sodium channels (NaVs). How specific RcSxph interactions contribute to STX binding has not been defined and whether other organisms have similar proteins is unclear. Here, we use mutagenesis, ligand binding, and structural studies to define the energetic basis of Sxph:STX recognition. The resultant STX "recognition code" enabled engineering of RcSxph to improve its ability to rescue NaVs from STX and facilitated discovery of 10 new frog and toad Sxphs. Definition of the STX binding code and Sxph family expansion among diverse anurans separated by ∼140 My of evolution provides a molecular basis for understanding the roles of toxin sponge proteins in toxin resistance and for developing novel proteins to sense or neutralize STX and related PSP toxins.
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18
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Klemm K, Cembella A, Clarke D, Cusack C, Arneborg L, Karlson B, Liu Y, Naustvoll L, Siano R, Gran-Stadniczeñko S, John U. Apparent biogeographical trends in Alexandrium blooms for northern Europe: identifying links to climate change and effective adaptive actions. HARMFUL ALGAE 2022; 119:102335. [PMID: 36344194 DOI: 10.1016/j.hal.2022.102335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 09/15/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
The marine dinoflagellate Alexandrium Halim represents perhaps the most significant and intensively studied genus with respect to species diversity, life history strategies, toxigenicity, biogeographical distribution, and global magnitude and consequences harmful algal blooms (HABs). The socioeconomic impacts, environmental and human health risks, and mitigation strategies for toxigenic Alexandrium blooms have also been explored in recent years. Human adaptive actions based on future scenarios of bloom dynamics and shifts in biogeographical distribution under climate-change parameters remain under development and not yet implemented on a regional scale. In the CoCliME (Co-development of climate services for adaptation to changing marine ecosystems) project these issues were addressed with respect to past, current and anticipated future status of key HAB genera and expected benefits of enhanced monitoring. Data on the distribution and frequency of Alexandrium blooms related to paralytic shellfish toxin (PST) events from key CoCliME Case Study areas, comprising the North Sea and adjacent Kattegat-Skagerrak, Norwegian Sea, and Baltic Sea, and eastern North Atlantic marginal seas, were evaluated in a contemporary and historical context over the past several decades. The first evidence of possible biogeographical expansion of Alexandrium taxa into eastern Arctic gateways was provided from DNA barcoding signatures. Various key climate change indicators, such as salinity, temperature, and water-column stratification, relevant to Alexandrium bloom initiation and development were identified. The possible influence of changing variables on bloom dynamics, magnitude, frequency and spatial and temporal distribution were interpreted in the context of regional ocean climate models. These climate change impact indicators may play key roles in selecting for the occurrence and diversity of Alexandrium species within the broader microeukaryote communities. For example, shifts to higher temperature and lower salinity regimes predicted for the southern North Sea indicate the potential for increased Alexandrium blooms, currently absent from this area. Ecological and socioeconomic impacts of Alexandrium blooms and effects on fisheries and aquaculture resources and coastal ecosystem function are evaluated, and, where feasible, effective adaptation strategies are proposed herein as emerging climate services.
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Affiliation(s)
- Kerstin Klemm
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, Oldenburg 26129, Germany
| | - Allan Cembella
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany
| | - Dave Clarke
- Marine Institute, Rinville, Oranmore, Co. Galway, Ireland
| | | | - Lars Arneborg
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Bengt Karlson
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Ye Liu
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Lars Naustvoll
- Institute of Marine Research, PO Box 1870 Nordnes, Bergen NO-5817, Norway
| | | | - Sandra Gran-Stadniczeñko
- Section for Aquatic Biology and Toxicology, Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, Oslo 0316, Norway
| | - Uwe John
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, Oldenburg 26129, Germany.
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19
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Lin S, Yu L, Wu X, Li M, Zhang Y, Luo H, Li H, Li T, Li L. Active meiosis during dinoflagellate blooms: A 'sex for proliferation' hypothesis. HARMFUL ALGAE 2022; 118:102307. [PMID: 36195414 DOI: 10.1016/j.hal.2022.102307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 06/16/2023]
Abstract
In dinoflagellates, sexual reproduction is best known to be induced by adverse environmental conditions and culminate in encystment for survival ('sex for encystment'). Although increasing laboratory observations indicate that sex can lead to production of vegetative cells bypassing encystment, the occurrence of this alternative pathway in natural populations and its ecological roles remain poorly understood. Here we report evidence that sex in dinoflagellates can potentially be an instrument for bloom proliferation or extension. By bloom metatranscriptome profiling, we documented elevated expression of meiosis genes in two evolutionarily distinct species (Prorocentrum shikokuense and Karenia mikimotoi) during bloom, a timing unexpected of the 'sex for encystment' scenario. To link these genes to meiosis, we induced encystment and cyst germination in the cyst-forming species Scrippsiella acuminata, and found that five of these genes were upregulated during cyst germination, when meiosis occurs. Integrating data from all three species revealed that SPO11, MND1, and DMC1 were likely common between cyst-forming and non-encysting sex in dinoflagellates. Furthermore, flow cytometric analyses revealed consecutive rounds of DNA halving during blooms of P. shikokuense and K. mikimotoi, evidencing meiosis. These data provided novel evidence that sexual reproduction in dinoflagellates might serve to promote cell proliferation, and along with the consequent enhancement of genetic diversity facilitating resistance against pathogens and environmental stress, to boost or extend a bloom ('sex for proliferation'). The putative meiosis-specific genes and insights reported here will prove to be helpful for rigorously testing the hypothesis and addressing whether the two modes of sex are genetically predisposed (i.e. species-specific) or environmentally induced (switchable within species), and if the latter what triggers the switch.
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Affiliation(s)
- Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
| | - Liying Yu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaomei Wu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Meizhen Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yaqun Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Hao Luo
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Hongfei Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Tangcheng Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Ling Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
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20
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Borges FO, Lopes VM, Amorim A, Santos CF, Costa PR, Rosa R. Projecting Future Climate Change-Mediated Impacts in Three Paralytic Shellfish Toxins-Producing Dinoflagellate Species. BIOLOGY 2022; 11:1424. [PMID: 36290328 PMCID: PMC9598431 DOI: 10.3390/biology11101424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/19/2022]
Abstract
Toxin-producing microalgae present a significant environmental risk for ecosystems and human societies when they reach concentrations that affect other aquatic organisms or human health. Harmful algal blooms (HAB) have been linked to mass wildlife die-offs and human food poisoning episodes, and climate change has the potential to alter the frequency, magnitude, and geographical extent of such events. Thus, a framework of species distribution models (SDMs), employing MaxEnt modeling, was used to project changes in habitat suitability and distribution of three key paralytic shellfish toxin (PST)-producing dinoflagellate species (i.e., Alexandrium catenella, A. minutum, and Gymnodinium catenatum), up to 2050 and 2100, across four representative concentration pathway scenarios (RCP-2.6, 4.5, 6.0, and 8.5; CMIP5). Despite slightly different responses at the regional level, the global habitat suitability has decreased for all the species, leading to an overall contraction in their tropical and sub-tropical ranges, while considerable expansions are projected in higher latitudes, particularly in the Northern Hemisphere, suggesting poleward distributional shifts. Such trends were exacerbated with increasing RCP severity. Yet, further research is required, with a greater assemblage of environmental predictors and improved occurrence datasets, to gain a more holistic understanding of the potential impacts of climate change on PST-producing species.
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Affiliation(s)
- Francisco O. Borges
- MARE—Marine and Environmental Sciences Centre & ARNET—Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Vanessa M. Lopes
- MARE—Marine and Environmental Sciences Centre & ARNET—Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Ana Amorim
- MARE—Marine and Environmental Sciences Centre & ARNET—Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Catarina F. Santos
- MARE—Marine and Environmental Sciences Centre & ARNET—Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Pedro Reis Costa
- Portuguese Institute for the Sea and Atmosphere (IPMA, I.P.), 1749-077 Lisboa, Portugal
- S2AQUA—Collaborative Laboratory, Association for a Sustainable and Smart Aquaculture, Av. Parque Natural da Ria Formosa s/n, 8700-194 Olhão, Portugal
- CCMAR—Centre of Marine Sciences, Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal
| | - Rui Rosa
- MARE—Marine and Environmental Sciences Centre & ARNET—Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
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21
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Agathokleous E, Peñuelas J, Azevedo RA, Rillig MC, Sun H, Calabrese EJ. Low Levels of Contaminants Stimulate Harmful Algal Organisms and Enrich Their Toxins. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11991-12002. [PMID: 35968681 DOI: 10.1021/acs.est.2c02763] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A widespread increase in intense phytoplankton blooms has been noted in lakes worldwide since the 1980s, with the summertime peak intensity amplifying in most lakes. Such blooms cause annual economic losses of multibillion USD and present a major challenge, affecting 11 out of the 17 United Nations Sustainable Development Goals. Here, we evaluate recent scientific evidence for hormetic effects of emerging contaminants and regulated pollutants on Microcystis sp., the most notorious cyanobacteria forming harmful algal blooms and releasing phycotoxins in eutrophic freshwater systems. This new evidence leads to the conclusion that pollution is linked to algal bloom intensification. Concentrations of contaminants that are considerably smaller than the threshold for toxicity enhance the formation of harmful colonies, increase the production of phycotoxins and their release into the environment, and lower the efficacy of algaecides to control algal blooms. The low-dose enhancement of microcystins is attributed to the up-regulation of a protein controlling microcystin release (McyH) and various microcystin synthetases in tandem with the global nitrogen regulator Ycf28, nonribosomal peptide synthetases, and several ATP-binding cassette transport proteins. Given that colony formation and phycotoxin production and release are enhanced by contaminant concentrations smaller than the toxicological threshold and are widely occurring in the environment, the effect of contaminants on harmful algal blooms is more prevalent than previously thought. Climate change and nutrient enrichment, known mechanisms underpinning algal blooms, are thus joined by low-level pollutants as another causal mechanism.
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Affiliation(s)
- Evgenios Agathokleous
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing 210044, Jiangsu, People's Republic of China
- Research Center for Global Changes and Ecosystem Carbon Sequestration & Mitigation, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, People's Republic of China
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia 08193, Spain
- CREAF, Cerdanyola del Vallès, Catalonia 08193, Spain
| | - Ricardo A Azevedo
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz"/Universidade de São Paulo (ESALQ/USP), Avenida Pádua Dias, 11, Piracicaba, São Paulo, São Paulo 13418-900, Brazil
| | - Matthias C Rillig
- Institut für Biologie, Freie Universität Berlin, Altensteinstr. 6, D-14195 Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), D-14195 Berlin, Germany
| | - Haoyu Sun
- Key Laboratory of Organic Compound Pollution Control Engineering (MOE), School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Edward J Calabrese
- Department of Environmental Health Sciences, University of Massachusetts, Morrill I, N344, Amherst, Massachusetts 01003, United States
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22
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Bowers EK, Stimmelmayr R, Hendrix A, Lefebvre KA. Stability of Saxitoxin in 50% Methanol Fecal Extracts and Raw Feces from Bowhead Whales (Balaena mysticetus). Mar Drugs 2022; 20:md20090547. [PMID: 36135736 PMCID: PMC9505082 DOI: 10.3390/md20090547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/24/2022] Open
Abstract
In recent decades, harmful algal blooms (HABs) producing paralytic shellfish toxins (including saxitoxin, STX) have become increasingly frequent in the marine waters of Alaska, USA, subjecting Pacific Arctic and subarctic communities and wildlife to increased toxin exposure risks. Research on the risks of HAB toxin exposures to marine mammal health commonly relies on the sampling of marine mammal gastrointestinal (GI) contents to quantify HAB toxins, yet no studies have been published testing the stability of STX in marine mammal GI matrices. An understanding of STX stability in test matrices under storage and handling conditions is imperative to the integrity of toxin quantifications and conclusions drawn thereby. Here, STX stability is characterized in field-collected bowhead whale feces (stored raw in several treatments) and in fecal extracts (50% methanol, MeOH) over multiple time points. Toxin stability, as the percent of initial concentration (T0), was reported for each storage treatment and time point. STX was stable (mean 99% T0) in 50% MeOH extracts over the 8-week study period, and there was no significant difference in STX concentrations quantified in split fecal samples extracted in 80% ethanol (EtOH) and 50% MeOH. STX was also relatively stable in raw fecal material stored in the freezer (mean 94% T0) and the refrigerator (mean 93% T0) up to 8 weeks. STX degraded over time in the room-temperature dark, room-temperature light, and warm treatments to means of 48 ± 1.9, 38 ± 2.8, and 20 ± 0.7% T0, respectively, after 8 weeks (mean ± standard error; SE). Additional opportunistically analyzed samples frozen for ≤4.5 years also showed STX to be relatively stable (mean 97% T0). Mean percent of T0 was measured slightly above 100% in some extracts following some treatments, and (most notably) at some long-term frozen time points, likely due to evaporation from samples causing STX to concentrate, or variability between ELISA plates. Overall, these results suggest that long-term frozen storage of raw fecal samples and the analysis of extracts within 8 weeks of extraction in 50% MeOH is sufficient for obtaining accurate STX quantifications in marine mammal fecal material without concerns about significant degradation.
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Affiliation(s)
- Emily K. Bowers
- Northwest Fisheries Science Center, Environmental and Fisheries Sciences Division, National Marine Fisheries Service, NOAA, 2725 Montlake Blvd E, Seattle, WA 98112, USA
| | - Raphaela Stimmelmayr
- The North Slope Borough Department of Wildlife Management, P.O. Box 69, Utqiagvik, AK 99723, USA
| | - Alicia Hendrix
- Department of Environmental and Occupational Health Sciences, University of Washington, Box 351618, Seattle, WA 98195, USA
| | - Kathi A. Lefebvre
- Northwest Fisheries Science Center, Environmental and Fisheries Sciences Division, National Marine Fisheries Service, NOAA, 2725 Montlake Blvd E, Seattle, WA 98112, USA
- Correspondence:
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23
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Van Hemert C, Harley JR, Baluss G, Smith MM, Dusek RJ, Lankton JS, Hardison DR, Schoen SK, Kaler RSA. Paralytic shellfish toxins associated with Arctic Tern mortalities in Alaska. HARMFUL ALGAE 2022; 117:102270. [PMID: 35944958 PMCID: PMC10237520 DOI: 10.1016/j.hal.2022.102270] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/25/2022] [Accepted: 06/08/2022] [Indexed: 06/04/2023]
Abstract
Harmful algal blooms produce biotoxins that can injure or kill fish, wildlife, and humans. These blooms occur naturally but have intensified in many locations globally due to recent climatic changes, including ocean warming. Such changes are especially pronounced in northern regions, where the effects of paralytic shellfish toxins (PSTs) on marine wildlife are of growing concern. In Alaska, seabird mortality events have increased in frequency, magnitude, and duration since 2015 alongside anomalously high ocean temperatures. Although starvation has been implicated as the apparent cause of death in many of these die-offs, saxitoxin (STX) and other PSTs have been identified as possible contributing factors. Here, we describe a mortality event at a nesting colony of Arctic Terns (Sterna paradisaea) near Juneau, Alaska in 2019 and report elevated concentrations of PSTs in bird, forage fish, and mussel samples. Concentrations of STX and other PSTs in tern tissues (2.5-51.2 µg 100g-1 STX-equivalents [STX-eq]) were of similar magnitude to those reported from other PST-induced bird die-offs. We documented high PST concentrations in blue mussels (>11,000 µg 100g-1 STX-eq; Mytilus edulis spp.) collected from nearby beaches, as well as in forage fish (up to 494 µg 100g-1 STX-eq) retrieved from Arctic Tern nests, thereby providing direct evidence of PST exposure via the terns' prey. At maximum concentrations measured in this study, a single 5 g Pacific Sand Lance (Ammodytes personatus) could exceed the median lethal STX dose (LD50) currently estimated for birds, offering strong support for PSTs as a likely source of tern mortality. In addition to describing this localized bird mortality event, we used existing energetics data from adult and nestling Arctic Terns to calculate estimated cumulative daily PST exposure based on ecologically relevant concentrations in forage fish. Our estimates revealed potentially lethal levels of PST exposure even at relatively low (≤30 ug 100g-1 STX-eq) toxin concentrations in prey. These findings suggest that PSTs present a significant hazard to Arctic Terns and other northern seabirds and should be included in future investigations of avian mortality events as well as assessments of population health.
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Affiliation(s)
- Caroline Van Hemert
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA.
| | - John R Harley
- Alaska Coastal Rainforest Center, University of Alaska Southeast, 11066 Auke Lake Way, Juneau AK, 99801, USA
| | - Gwen Baluss
- U.S. Forest Service, Juneau Ranger District, 8510 Mendenhall Loop Road, Juneau, AK, 99801, USA
| | - Matthew M Smith
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA
| | - Robert J Dusek
- U.S. Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, WI, 53711, USA
| | - Julia S Lankton
- U.S. Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, WI, 53711, USA
| | - D Ransom Hardison
- National Oceanic and Atmospheric Administration, National Oceanic and Atmospheric Administration, Stressor Detection and Impacts Division, National Center for Coastal Ocean Sciences Beaufort Laboratory, 101 Pivers Road, Beaufort, NC, 28516, USA
| | - Sarah K Schoen
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA
| | - Robert S A Kaler
- U.S. Fish and Wildlife Service, Migratory Bird Management, 1011 East Tudor Road, Anchorage, AK, 99503, USA
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24
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Growing Degree-Day Measurement of Cyst Germination Rates in the Toxic Dinoflagellate Alexandrium catenella. Appl Environ Microbiol 2022; 88:e0251821. [PMID: 35604227 PMCID: PMC9238376 DOI: 10.1128/aem.02518-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Blooms of many dinoflagellates, including several harmful algal bloom (HAB) species, are seeded and revived through the germination of benthic resting cysts. Temperature is a key determinant of cysts’ germination rate, and temperature–germination rate relationships are therefore fundamental to understanding species’ germling cell production, cyst bed persistence, and resilience to climate warming. This study measured germination by cysts of the HAB dinoflagellate Alexandrium catenella using a growing degree-day (DD) approach that accounts for the time and intensity of warming above a critical temperature. Time courses of germination at different temperatures were fit to lognormal cumulative distribution functions for the estimation of the median days to germination. As temperature increased, germination times decreased hyperbolically. DD scaling collapsed variability in germination times between temperatures after cysts were oxygenated. A parallel experiment demonstrated stable temperature–rate relationships in cysts collected during different phases of seasonal temperature cycles in situ over three years. DD scaling of the results from prior A. catenella germination studies showed consistent differences between populations across a wide range of temperatures and suggests selective pressure for different germination rates. The DD model provides an elegant approach to quantify and compare the temperature dependency of germination among populations, between species, and in response to changing environmental conditions. IMPORTANCE Germination by benthic life history stages is the first step of bloom initiation in many, diverse phytoplankton species. This study outlines a growing degree-day (DD) approach for comparing the temperature dependence of germination rates measured in different populations. Germination by cysts of Alexandrium catenella, a harmful algal bloom dinoflagellate that causes paralytic shellfish poisoning, is shown to require a defined amount of warming, measured in DD after cysts are aerated. Scaling by DD, the time integral of temperature difference from a critical threshold, enabled direct comparison of rates measured at different temperatures and in different studies.
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25
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Lefebvre KA, Fachon E, Bowers EK, Kimmel DG, Snyder JA, Stimmelmayr R, Grebmeier JM, Kibler S, Ransom Hardison D, Anderson DM, Kulis D, Murphy J, Gann JC, Cooper D, Eisner LB, Duffy-Anderson JT, Sheffield G, Pickart RS, Mounsey A, Willis ML, Stabeno P, Siddon E. Paralytic shellfish toxins in Alaskan Arctic food webs during the anomalously warm ocean conditions of 2019 and estimated toxin doses to Pacific walruses and bowhead whales. HARMFUL ALGAE 2022; 114:102205. [PMID: 35550288 DOI: 10.1016/j.hal.2022.102205] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/09/2022] [Accepted: 02/15/2022] [Indexed: 06/15/2023]
Abstract
Climate change-related ocean warming and reduction in Arctic sea ice extent, duration and thickness increase the risk of toxic blooms of the dinoflagellate Alexandrium catenella in the Alaskan Arctic. This algal species produces neurotoxins that impact marine wildlife health and cause the human illness known as paralytic shellfish poisoning (PSP). This study reports Paralytic Shellfish Toxin (PST) concentrations quantified in Arctic food web samples that include phytoplankton, zooplankton, benthic clams, benthic worms, and pelagic fish collected throughout summer 2019 during anomalously warm ocean conditions. PSTs (saxitoxin equivalents, STX eq.) were detected in all trophic levels with concentrations above the seafood safety regulatory limit (80 μg STX eq. 100 g-1) in benthic clams collected offshore on the continental shelf in the Beaufort, Chukchi, and Bering Seas. Most notably, toxic benthic clams (Macoma calcarea) were found north of Saint Lawrence Island where Pacific walruses (Odobenus rosmarus) are known to forage for a variety of benthic species, including Macoma. Additionally, fecal samples collected from 13 walruses harvested for subsistence purposes near Saint Lawrence Island during March to May 2019, all contained detectable levels of STX, with fecal samples from two animals (78 and 72 μg STX eq. 100 g-1) near the seafood safety regulatory limit. In contrast, 64% of fecal samples from zooplankton-feeding bowhead whales (n = 9) harvested between March and September 2019 in coastal waters of the Beaufort Sea near Utqiaġvik (formerly Barrow) and Kaktovik were toxin-positive, and those levels were significantly lower than in walruses (max bowhead 8.5 μg STX eq. 100 g-1). This was consistent with the lower concentrations of PSTs found in regional zooplankton prey. Maximum ecologically-relevant daily toxin doses to walruses feeding on clams and bowhead whales feeding on zooplankton were estimated to be 21.5 and 0.7 μg STX eq. kg body weight-1 day-1, respectively, suggesting that walruses had higher PST exposures than bowhead whales. Average and maximum STX doses in walruses were in the range reported previously to cause illness and/or death in humans and humpback whales, while bowhead whale doses were well below those levels. These findings raise concerns regarding potential increases in PST/STX exposure risks and health impacts to Arctic marine mammals as ocean warming and sea ice reduction continue.
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Affiliation(s)
- Kathi A Lefebvre
- Environmental and Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98112, USA.
| | - Evangeline Fachon
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA; Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - Emily K Bowers
- Environmental and Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98112, USA.
| | - David G Kimmel
- Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, USA.
| | - Jonathan A Snyder
- US Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK 9950 USA.
| | - Raphaela Stimmelmayr
- North-Slope Borough Department of Wildlife management, Utqiaġvik, AK, USA; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.
| | - Jacqueline M Grebmeier
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, MD 20688, USA.
| | - Steve Kibler
- NOAA National Ocean Service, Beaufort Laboratory, Beaufort, NC 28516, USA.
| | - D Ransom Hardison
- NOAA National Ocean Service, Beaufort Laboratory, Beaufort, NC 28516, USA.
| | - Donald M Anderson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | - David Kulis
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | - Jim Murphy
- NOAA Alaska Fisheries Science Center, National Marine Fisheries Service, Juneau, AK 99801, USA.
| | - Jeanette C Gann
- NOAA Alaska Fisheries Science Center, National Marine Fisheries Service, Juneau, AK 99801, USA.
| | - Dan Cooper
- Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, USA.
| | - Lisa B Eisner
- Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, USA.
| | - Janet T Duffy-Anderson
- Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, USA.
| | - Gay Sheffield
- University of Alaska Fairbanks, Alaska Sea Grant / Marine Advisory Program, PO Box 400, Nome, AK 99762, USA.
| | - Robert S Pickart
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | - Anna Mounsey
- Environmental and Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98112, USA.
| | - Maryjean L Willis
- Environmental and Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98112, USA.
| | - Phyllis Stabeno
- Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, USA.
| | - Elizabeth Siddon
- NOAA Alaska Fisheries Science Center, National Marine Fisheries Service, Juneau, AK 99801, USA.
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