Fig. 2. Long-term history of HABs off Eastern Tasmania, Australia, using sedimentary DNA (courtesy of Linda Armbrecht) French Mediterranean and a French Atlantic K. veneficum strain induced over 50% loss of cell viability. A high level of intra-specific variability of ichthyotoxic activity was observed among strains, and cytotoxicity of the intracellular and extracellular fractions were strain dependent. In general, the methanolic extracts were more cytotoxic than their corresponding extracts in the culture media (Rima Beesso). The emergent toxin pinnatoxin is shown to interact with nicotinic receptors (nAChRs), especially the muscle and neuronal (α7) subtypes, through binding and electrophysiological experiments. High-resolution 3D-imaging and in vitro competition studies on rat embryo sections revealed the specificity of [3H]-PnTx-G binding and its selectivity for muscle and neuronal nAChR subtypes (such as the α7 subtype). Results from the use of 6 a human perfused cotyledon model and mass spectrometry analyses furthermore showed that PnTx-G crosses the human placental barrier, which indicates the potential adverse impact that exposure to pinnatoxins may have for human health (Denis Servent). 4. Species and interactions What are they doing? There were a number of presentations about Alexandrium life cycles including how cyst dormancy cycling controls Alexandrium catenella bloom termination in the Nauset Marsh estuary (Michael Brosnahan) and the degree day-based cyst germination rates and in situ germling production of this species (Alexis Fischer). These studies confirm with experimental data the usefulness of the approach (combining the effect of temperature and time) in life cycle ex- periments involving cyst germination, latitudinal differences, and the effect of global warming in phenological changes. The role of sexual reproduction, cyst dormancy cycling and germination rate in HAB development was also proved in the dinoflagellate Alexandrium monilatum in lower Chesapeake Bay (Savana Mapes). In the case of Microcystis blooms, the species was able to be successfully revived from the natural sediments in laboratory mesocosm studies (Caitlin Romanis), highlighting the success and pervasiveness of the genus stems from a meroplanktonic life cycle that features dense pelagic blooms in the summer and the benthic sedimentation of vegetative cells in the winter and the contrary. A cryopreservation method was developed that allows vegetative cells of thecate dinoflagellates (Vulcanodinium rugosum, Alexandrium HARMFUL ALGAE NEWS NO. 69 / 20221 Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 69 - February 2022 https://hab.ioc-unesco.org/ The 19th (1st Virtual) International Conference on Harmful Algae hosted from Mexico The 19th International Conference on Harmful Algae (19 ICHA), was held in a virtual format for Lobby of the virtual ICHA 2021 costs to attend the meeting. The Conference started with two pre-conference sessions of the Young Investigator Networking Session coordinated by Lorena Durán, Carlos Rodríguez, Philipp Hess, and Harry Nelson. Previously, Lorena Durán and Carlos Rodríguez interviewed o The Mexican scientists comprising the Local Organizing Committee special sessions held live on Zoom that covered breakthrough topics on harmful algae from marine and freshwater environments: HAB Early Warning Systems Session, Impacts of HABs on fish farms: Addressing industry and global insurance n Scientific Highlights of the 19th International Conference on Harmful Algae Summarizing all of the science from a conference is a huge and perhaps impossible task, but once done, it can serve as a reference for the future. We had five exciting and intensive virtual conference days where all the late predatorial protists, viruses, and bacteria (Alexandra Worden). Several plenary talks highlighted insights on HAB management, including emergent management strategies for monitoring, biotoxin detection, and human health risks associated with Ciguatera Poisoning (Marie-Yasmine Dechraoui Bottein); com Fig. 2. Long-term history of HABs off Eastern Tasmania, Australia, using sedimentary DNA (courtesy of Linda Armbrecht) French Mediterranean and a French Atlantic K. veneficum strain induced over 50% loss of cell viability. A high level of intra-specific variability of ichthyotoxic activity was obse pacificum and Durusdinium trenchii) to be successfully frozen and revived with high viability (Joseph Kihika). This highlights the potential to have a microalgae diversity bank in the future. Several presentations were focused on the intimate association between hosts and their microbiomes (Chri Fig. 4. Example from a weekly HAB bulletin reporting HAB events along the Irish coast (courtesy of Dave Clarke) harvested along the coast. Analysis of seawater and oyster samples confirmed high levels of PSP toxins (Margarita Fernández-Tejedor). The design, implementation, and contents of HAB bulle for lake ecosystem services and selection of environmental measures together with local farmers, which may reduce overall costs (Claudia Wiegand). A special session on the new WHO book Toxic cyanobacteria in water provided advice and guidelines for the management of freshwater cyanobacterial blooms, ISSHA's Corner The International Society for the Study of Harmful Algae (ISSHA) convened the 19th (1st Digital) International Conference on Harmful Algae (19 ICHA), held in La Paz, México, from 10th to 15th October 2021. The ISSHA Council had monthly meetings on-line between May and October to plan molecular probes targeting HAB species (including their different life cycle stages), difficult to identify with conventional microscopy methods. More information about Lindas biography and publications can be found here. Nomination letter of Linda Medlin to the ISSHA Council There are many, many re waters of the South China Sea, a marginal sea of the Western Pacific (Teng et al. 2013, 2014). Sing Tung Teng has demonstrated his training and dissemination skills by introducing a taxonomic grouping of Pseudo-nitzschia based on frustule morphology, which eventually developed into an interactive ke from some species of Rhodophyta to the cultures significantly enhanced the growth of the two Gambierdiscus species that occur in Japan. He is now starting an investigation to clarify the effect of bacteria on Gambierdiscus growth in an attempt to elucidate the growth characteristics of Gambierdiscus ISSHA President goodbye Dear ISSHA members: As many of you know, at the general glection held prior to the International Conference on Harmful Algae (ICHA2021) from 11-15 October 2021 (La Paz, Mexico), I stepped down as the president of the International Society for the Study of Harmful Algae (ISSHA UNESCO Taxonomic Reference List of Harmful Micro Algae Editors Workshop 2021 On November 18-19th 2021, the nine thematic editors responsible for the UNESCO Taxonomic Reference List of Harmful Micro Algae and Henrik Enevoldsen from IOC-UNESCO gathered together in a hybrid format workshop, to discuss Book Review: A Catalogue of Phytoplankton from the Mexican CentralPacific (in Spanish) Authors: Hernández-Becerril, D.U., Barón-Campis, S.A., Ceballos-Corona, J.G.A., Alonso-Rodríguez, R., RinconesReyes, K.M., Becerra-Reynoso, R.T. & Arce-Rocha, G. 2021. Catálogo de fitoplancton del Pacífico central Forthcoming Events 2022 UN Ocean Conference GLOBAL ONLINE STAKEHOLDER CONSULTATION Inputs to concept papers of interactive dialogues Contribute your inputs to the concept papers of the interactive dialogues for the 2022 UN Ocean Conference! (see back page) Deadline: 21 February 2022 Contribute your GlobalHAB symposium on automated in situ observations of plankton Aims and background Harmful Algal Blooms (HABs) are affecting aquatic ecosystems and human societies. Biotoxin-producing HABs species and species causing fish mortalities are problems for aquaculture, fisheries and also for tourism. H www.neiwpcc.org/events/ushab11 #USHAB2022 For logo contest rules, please visit our conference website. We are pleased to announce that the 11th U.S. Symposium on Harmful Algae will be held on October 23-28, 2022 in Albany, New York, at the Hilton Albany. Local coordination is being led by NEIWPCC, Eds-in-chief Beatriz Reguera, IEO (CSIC), Vigo, Spain Eileen Bresnan, Marine Scotland, UK Regional Editors Caribbean: Ernesto Mancera jemancerap@unal.edu.co Atlantic Europe: Maud Lemoine Maud.Lemoine@ifremer.fr Mediterranean Sea: Adriana Zingone zingone@szn.it India: K.B. Padmakumar kbpadmakumar