health hazards posed by the proliferation of this species in French Polynesian lagoons. Future studies should aim at developing a better understanding the biogeographic distribution of this species, as well as assessing the impacts of its associated toxins on coral reef ecosystems and/or putative accumulation in marine organisms. Acknowledgements These data were obtained in the framework of the research program TATOO funded by the Délégation à la Recherche de Polynésie française (Conv. n 02400/MTF/REC of April 9th, 2018). We are grateful to Kevin Henry, André Ung, Mayalen Zubia and Christophe Vieira for help in field samplings. Fig. 2. Scanning electron micrographs of two previously unreported Ostreopsis species in French Polynesia. (A) Apical view of O. rhodesiae. (B) Detail of the apical pore complex (APC) of O. rhodesiae. (C) Apical view of Ostreopsis sp. 6. (D) Left lateral view of Ostreopsis sp. 6 showing the undulated cingulum (c). (E) Detail of the APC of Ostreopsis sp. 6. Scale bars = 10 μm (A and C, D), 2 μm (B and E). cally, it was easily distinguished from other species by a typical undulation of the cingulum (Fig. 2D) and a rather large size (58-82 μm) [7]. Interestingly, this species is closely related morphologically to O. siamensis, as described by Schmidt [10] and interpreted by Fukuyo [4]. However, our detailed study revealed that it also has a long plate 2 (Fig. 2E), and this feature now appears to be common to several Ostreopsis species and probably not a relevant taxonomic character [9]. In this species, thecal pores were surrounded with a small collar rim, which was typical and absent in O. rhodesiae (Fig. 2). Genetic analysis revealed that this species corresponds to Ostreopsis sp. 6, which is also found in several tropical areas such as Gulf of Thailand, Malaysia, Viet Nam, Japan and more recently Korea [9]. Following this outbreak in Tahiti, this species was also observed in Moorea Island in November 2019, indicating that it is widespread in the Society archipelago. Both HARMFUL ALGAE NEWS NO. 65 / 2020 the genetic proximity of Ostreopsis sp. 6 sequences from Tahiti from those of the Gulf of Thailand, and the type locality of O. siamensis [10] suggest that it can be the same species. Fukuyo [4] emphasized the absence of O. siamensis in the samples from French Polynesia in the early 1980s, and it was not observed before 2019. Hence our observations constitute a new record of this species in the Pacific Ocean. Preliminary toxicity analyses revealed that none of the O. lenticularis ( 47), O. cf. ovata (13) and O. rhodesiae ( 1) clonal strains screened by CBA-N2a showed toxic activity, whereas strains of Ostreopsis sp. 6 ( 8) proved toxic, with a toxin profile dominated by ostreocinD as confirmed by LC-MS/MS [9]. Due to the lack of analytical standards, its toxin profile is not completely resolved as yet, however, as Ostreopsis sp. 6 is capable of forming large blooms, these findings warrant further investigation on the potential environmental and/or References 1. Chinain M et al 2020. Harmful Algae, in press 2. Yasumoto T et al 1977. Bull Japan Soc Fish 43: 1021-1026 3. Adachi R and Fukuyo Y 1979. Bull Japan Soc Sci Fish 45: 67-71. 4. Fukuyo Y 1981. Bull Jap Soc Sci Fish 47: 967-978 5. Bagnis R et al 1985. In: Anderson DM et al (eds), Toxic Dinoflagellates, Elsevier, New York, pp 177-182 6. Tester PA et al 2020. Harmful Algae 91; 101655; doi:10.1016/j.hal.2019.101655 7. Chomérat N et al 2019. Harmful Algae 84: 95-111 8. Verma A et al 2016. Harmful Algae 60: 116-130 9. Chomérat N et al 2020 Harmful Algae 98; 101888; doi:10.1016/j. hal.2020.101888 10. Schmidt J 1901. Bot. Tidsskr. 24: 212221 Authors Nicolas Chomérat & Gwenael Bilien, IFREMER, LER Bretagne Occidentale, Place de la Croix, F-29900 Concarneau, France Damien Réveillon & Fabienne Hervé, IFREMER, Phycotoxins Laboratory, PO Box 21105, F-44311 Nantes, France Jérôme Viallon, H. Taiana Darius & Mireille Chinain, Institut Louis Malardé, Laboratory of Marine Biotoxins, UMR 241-EIO, PO Box 30, 98713 Papeete, French Polynesia Email corresponding author: nicolas.chomerat@ifremer.fr 9 Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 65 - September 2020 www.ioc-unesco.org/hab Genomic resources for the domoic acid-producing diatom Pseudo-nitzschia multistriata Species responsible for Harmful Algal Blooms (HABs) are among the best studied unicellular microa Fig. 2. Schematic drawing of the life cycle of the pennate diatom Pseudo-nitzschia multistriata. The vegetative phase is characterized by progressive cell size reduction of the population. When cells reach the sexual size threshold (SST), they can either keep decreasing in size until they die, or un Fig. 3. The genome browser available on the SZN BioInforma platform. The genome could be sequenced exploiting inbred strains, obtained from the cross of a first generation of sibling strains [7]. Because of the lower polymorphism of inbreds, it was possible to reconstruct long fragments of DNA from When tides collide: Harmful cyanobacterial and microalgal blooms in Florida and implications for risk assessment Cyanobacterial blooms are a regular occurrence in southern Florida. Water releases from Lake Okeechobee to maintain the water level in this large lake regularly occur along the St. Lucie Pim and Calusa Waterkeepers for assistance in sampling. References 1. Metcalf JS et al (in press). Neurotox Res 2. Matthiensen et al 2000. In: de Koe WJ et al (eds), Mycotoxins and Phycotoxins in Perspective at the Turn of the Millenium. Proc Xth Int IUPAC symposium on Mycotoxins and Phycotoxins, Gu Record levels of Dinophysistoxin-2 in clams from Douarnenez Bay, France, after an unusual bloom of Dinophysis acuta Fig. 1. Location of Douarnenez Bay (48 5 29 North; 4 19 51 West), Western French Atlantic coast. The official monitoring network for phytoplankton and algal toxins in French shellfis Fig. 4. Weekly lipophilic toxin concentrations in Donax spp. in 2019 and 2020. Fig. 3. (A) Percentage of Dinophysis species in Douarnenez Bay water samples between 2010 and August 2020. (B) Mean percentage of DSP toxins in Douarnenez Bay in Donax spp. between 2010 and August 2020. recorded in Dona New insights on the diversity of the dinoflagellate genus Ostreopsis in lagoons of French Polynesia, South Pacific Ocean French Polynesia is a vast territory in the South Pacific Ocean, stretching over an expanse of more than 1,200 miles with a surface area as large as Europe. It is composed of 118 health hazards posed by the proliferation of this species in French Polynesian lagoons. Future studies should aim at developing a better understanding the biogeographic distribution of this species, as well as assessing the impacts of its associated toxins on coral reef ecosystems and/or putative ac Toxin profiles of Gambierdiscus lapillus from the Cook Islands Species of the dinoflagellate genus Gambierdiscus produce the toxins responsible for ciguatera fish poisoning (CFP), an illness that has been prevalent throughout the Pacific and particularly in the Cook Islands [1]. The illness is cause Fig. 3. Phylogenetic analysis of partial large subunit ribosomal DNA sequences (D8D10 region) from the Gambierdiscus strains isolated in this study (in bold font) using Bayesian analyses. Values at nodes represent Bayesian posterior probability support. Scale bar is substitutions per site. lus was Unusual bloom of the red alga Ceramium sp. (Ceramiales, Rhodophyta) in Cartagena, Colombia, SW Caribbean Sea Fig. 1. Map of the study site. Macroalgal blooms are frequently associated with eutrophication of coastal waters [1]. These blooms are mainly composed of ephemeral and opportunistic green a ported as bloom forming species, and this finding adds another genus to the group of harmful bloom-forming macroalgae. Furthermore, this report highlights the potential introduction of a new species which has passed undetected until now. This would not be the first case of a potentially introduced b Distribution of the fish-killing dinoflagellate Karlodinium (Dinophyceae) in the Johor Strait, Malaysia Fig. 1. Sampling sites in the Johor Strait Species of Karlodinium are naked dinoflagellates. More than one third of the named species have been known to cause fish mortality. Toxigenic Karlod- Bloom of a red tide species Akashiwo sanguinea in Semerak Lagoon, Kelantan, Malaysia March 2016: i.e. Pseudo-nitzschia spp. (potentially toxic species), Chaetoceros, Skeletonema, and Blixaea quinquecornis (red tides, fish kills) [3]. In this survey, we confirmed the blooming species as the dinoflag Fig. 3 Bayesian trees of Akashiwo sanguinea inferred from (A) LSU rDNA and (B) ITS datasets. Values on nodes represent bootstrap supports of MP, ML, and posterior probabilities of BI Continued from page 14 sulcus extension invading the epicone is visible (Fig. 3B). Cells are slightly pigmented, wi CLEFSA project identifies Harmful Algal Blooms as a threat to food safety resulting from climate change Fig. 1. Organizations involved in the CLEFSA project Climate change is one of the key drivers of emerging risks for food and feed safety, plant and animal health (including terrestrial and aquat Fig. 3. CLEFSA Multi-Criteria strategy which several directly related to toxins produced by harmful algal blooms (HABs). These include: ciguatoxin, domoic acid, okadaic acid, saxitoxin, pinnatoxin, tetrodotoxin, beta-methylamino-L-alanine (BMAA) and palytoxin analogues. The analysis indicates that Blooming Buddies: MSc Research Projects Extend our Knowledge on Bloom-Forming Freshwater Cyanobacteria Freshwater cyanobacteria blooms are an increasing problem globally and much work is focussing on understanding bloom dynamics and toxin production in order to better manage the inherent health risk Fig. 2. Confocal microscopy images of Planktothrix sp. CAWBG59 (A), Microcystis aeruginosa CAWBG617 (B) and Nodularia spumigena CAWBG21 (C) stained with SYTOXTM green so that lysed cells fluoresce green, whilst intact cells are detected by red chlorophyll autofluorescence. bacterium interfering wit 25 years of service enhancing the capacity to monitor and manage HABs Fig. 1. Participants from the first course held at the IOC Centre in Copenhagen in 1995 The IOC Science and Communication Centre on Harmful Algae opened in May 1995 at the University of Copenhagen, Denmark. It was a new concept International Phytoplankton Intercomparison (IPI) exercise in abundance and composition of marine microalgae Dear participants of the annual IPI (International Phytoplankton Intercomparison) exercise in abundance and composition of marine microalgae: This note is to confirm that due to the ongoing p Canadian review: Marine harmful algal blooms and phycotoxins of concern to Canada As has been reinforced all too well in recent months with the COVID-19 pandemic, the world is indeed interconnected. The international harmful algal bloom community recognized this early on, with a series of internatio Fig. 2. Maps showing the location of selected phycotoxins on the Canadian east (left) and west (right) coast. Symbols represent domoic acid and okadaic acid group toxins above (closed symbols) and below (open symbols) the regulatory action level. The green shaded areas show the distribution of saxit Terri Wells (DFO-NAFC, St. Johns, NL); Michel Poulin (Canadian Museum of Nature, Ottawa, ON); Wade A. Rourke (CFIA, Dartmouth, NS). Fig. 4. Heterosigma akashiwo bloom in Kyuquot, British Columbia, 1996 (Photo courtesy of Nicky Haigh, Microthalassia Consultants Inc., Nanaimo, BC) References 1. LoCi ISSHAs Corner CHA 2021 Hybrid Conference, NEW DATE!! Dear ISSHA members and colleagues: Due to the COVID-19 pandemic and following recommendations of the World Health Organization and National Health Authorities, the 19th International Conference on Harmful Algae has been postponed to October 10-15 HAN Subscription To subscribe to Harmful Algae News anyone can send a mail to sympa@sympa. iode.org with the subject subscribe han do not write any text at all in the mail message itself. 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