Quantifying dinoflagellate cysts in bottom sediments: a response to Anderson 2018 Problems associated with quantifying dinoflagellate cysts in bottom sediments featured prominently in Don Anderson s personal retrospective view of his contribution to the early days of HAB cyst research published recently in this newsletter [1]. He correctly recognizes that cysts/g dry weight is the appropriate method for quantifying cysts in core samples as well as in surface sediment samples to be compared with cores for geologically based studies. However, the impression given that his work has been criticized for not using this method for biological studies is in my experience incorrect, and I wish to address this here. The reference cited by Anderson to my criticism of the wet method utilizing cysts/volume wet sediment is incorrect the correct reference is: Dale B, 2001. Marine dinoflagellate cysts as indicators of eutrophication and industrial pollution: a discussion [2]. Readers will see that this criticizes the wet method as inappropriate for a study of cores for eutrophication signals, and my recommendation to standardize methods based on the dry method for such work (on recommendation by one of the referees for this 2001 paper) has been adopted by others in the field ever since. This was not a criticism of biological studies by Anderson or others, nor do I know of such criticism from elsewhere. However, criticism of some of the biological work investigating cysts in sediments has been expressed at meetings when these studies ignored basic elements of the science of sedimentology, and I believe sedimentation processes should be the main focus of this discussion on quantitative methods. Cysts in sediments have the potential to act as seedbeds for some HAB species, as first pointed out by Karen Steidinger, but the cysts also have to be recognized as just one (often very minor) component of finer-grained particles in a dynamic process of transport and deposition in the broader sedimentary regime. Modelling the role of cysts as seedbeds not 4 to model a HAB from cysts in sediments is that bottom sediments are a dynamic feature of, rather than a benign end product of a complex sedimentary system. Dynamics of the sedimentary regime that affect cyst concentrations in bottom sediments Professor Barrie Dale only requires an understanding of phytoplankton ecology from the biological sciences (e.g. Dale & Murphy, 2014, [3]), but it also necessitates an understanding of the basic elements of sedimentology developed as an important field in geology. This is not the place to summarize Sedimentology 101, but it should suffice to point out that geologists have studied modern sediments extensively, using sophisticated methods to investigate the full range of processes of transport and sedimentation down to the micro-fabric of bottom sediments. The extent to which knowledge of sedimentology is critical for studies of cysts in sediments depends very much on the objectives of the study. For example, our research provides quantitative data of cysts/volume of sediment (i.e. the wet method) to help the Environment Agency, Abu Dhabi, with environmental impact assessments for sediment dredging projects. The objective, in this case, is simply to estimate the numbers of HAB cysts potentially released from sediment dredged by the project, a factor which is not dependent on sediment characteristics. In contrast, attempts to quantitatively model cysts in sediment after the occurrence of a HAB to forecast blooms for the following year (e.g. Anderson and co-workers in the Gulf of Maine) necessitate much more consideration of sedimentology. The main aspect of sedimentology that has to be considered in attempts There are areas of quiescent sedimentation where bottom sediments accumulate layer upon layer without disturbance for long periods of time (varved sediments), almost always in deeper marine basins with extremely low oxygen levels that prevents disturbance by benthic organisms (bioturbation). Since low oxygen levels are known to inhibit excystment, these low-oxygen sediments are not likely to be of interest for modelling seed beds. For better oxygenated sediments that may be of interest, two main sedimentological parameters affect cyst concentrations: transport and disturbance, often constantly working together. Bodies of water do not usually remain still for long periods of time; turbulence from wind, waves and currents affect the water column, and sediment traps suspended at different levels confirm that fine-grained particles including cysts may be transported for long distances from where they enter the system, before reaching bottom sediment. Once on the bottom, fine particles are often subjected to further turbulence and bioturbation that tends to transport and concentrate finer-grained sediment including cysts into deeper parts of the system (seen on sea charts where mud often characterizes the bottom in deeper water while more sandy sediments are found on higher ground). When particles reach their point of accumulation they are subject to bioturbation by benthic organisms which, particularly in productive waters, are constantly mixing the sediments burying new particles and re-suspending older material from deeper sediment. In addition to these natural processes coastal waters are increasingly affected by intensive bottom trawling, and dramatic pictures are emerging from robot cameras that show large areas of seabed crisscrossed with scour-marks from fishing gear that caused massive resuspension and resedimentation of bottom sediment. ObHARMFUL ALGAE NEWS NO. 60 / 2018 Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 60 - July 2018 www.ioc-unesco.org/hab Marine eukaryote and HAB monitoring in Japan with next generation technology Sequencing technologies such as Illumina MiSeq have made it possible to obtain billions of sequence reads in a Frequency distribution (%) the surface data was used in this study. Surface seawater (0.5 L) was collected weekly with a plastic bucket during the same period. For MPS-based monitoring based on amplicon-seq of 18S-rRNA gene (V79 region), PCR amplification and 454 pyrosequencing were performed accor Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-045, Japan Hiroshi Shimada, Central Fisheries Research Institute of Hokkaido Research Organization, Hamanaka-cho 238, Yoichi, Hokkaido 0468555, Japan Seiji Katakura, City of Mombetsu, Kaiyo-koryukan, Kaiyo-koen, Mombetsu, Hokkaido 094-0031, Jap Quantifying dinoflagellate cysts in bottom sediments: a response to Anderson 2018 Problems associated with quantifying dinoflagellate cysts in bottom sediments featured prominently in Don Anderson s personal retrospective view of his contribution to the early days of HAB cyst research published rece viously, sample sites should be chosen to avoid such areas if possible. Clearly, there is room for questions or criticism when this dynamic system is modelled from the assumption that bottom sediments, for example in Anderson s work in The Gulf of Maine, are in a static stable condition whereby a sa Contribution of marine invertebrates to Ciguatera poisoning : the case study of French Polynesia Reported as early as the 15th century by explorers, ciguatera fish poisoning (CFP) is the most prominent non-bacterial seafood poisoning worldwide. Widespread in tropical and subtropical regions, CFP res au développement du phytoplancton ciguatérigène en Polynésie française: CARISTO-Pf n7937/MSR/REC of 4th of December 2015 and Arrêté nHC/491/ DIE/BPT of 30th March 2016). Figure 2. Comparison of Pacific ciguatoxins (P-CTXs) profiles in A) in vitro cultures of Gambierdiscus polynesiensis (TB-92 [14]) Solid Phase Adsorption Toxin Tracking (SPATT) technology for field monitoring of Gambierdiscus toxins with passive samplers Ciguatera poisoning is a seafood intoxication classically associated with the consumption of tropical coral reef fish contaminated with ciguatoxins (CTXs), although some marine Fig. 2. Summary of the results demonstrating that SPATT passive sampling could advantageously contribute to the reinforcement of ciguateric risk assessment and management programmes as a supplementary tool. or of very low densities of toxic Gambierdiscus cells. However, CTXs were detected in numero New limits of Ostreopsis distribution in the Bay of Biscay: a first report of Ostreopsis in Santander Bay, Cantabria (Northern Spain) Fig. 1. Location of sampling sites The genus Ostreopsis encompasses benthic dinoflagellates that represent one of the main microalgal threats for beach tourism in w Bloom of Ostreopsis cf. siamensis in Lisbon Bay Fig. 1. Sampling sites on Lisbon Bay Reports of benthic HAB events have increased during the last decade in temperate regions. These have been associated with proliferations of benthic toxic dinoflagellates, in particular species of Ostreopsis. The M Table1 1- List - List the macroalgaecommunity communityspecies species Table ofof the macroalgae ITSA and ITSB primers [6]. Phylogenetic analysis (not Asparagopsis armata Corallina sp. shown) revealed that all the Caulacanthus ustulatus Cystoseira sp. studied sequences grouped Ceramiacea Derbesia s A possible link between the breakdown of a fertilizer tank and a toxic Pseudonitzschia bloom fishery, leaving toxic blooms undetected in other areas. By the time of the bloom, the diatom community primarily consisted of P. seriata (Fig. 3). Identification of P. seriata as the potential culprit diat Fig. 3. Pseudo-nitzschia seriata TEM micrograph of the poroid structure arranged within the striae consisting of two outer rows of larger poroids and one or two inner rows of smaller poroids. induce DA production in P. australis [7], and the most potent DA-inducing N form has been shown to be urea. Golden alga Prymnesium parvum Carter bloom off Azhikode, southwest India In September 2009, during the southwest monsoon season, a quasi-monospecific bloom of Prymnesium parvum was collected off Azhikode (10o 11 02 N; 76o 09 22 E), on the southwest coast of India (Fig. 1). A conspicuous pale browni Regional Workshop on Monitoring and Management Strategies for Benthic HABs if possible, establish tools for standardized procedures. The exercise is open to the entire international community. The goal of achieving improved assessments of the risks associated with BHABs will help reduce the health, Workshop on morpho-molecular methods for the study of dinoflagellate cysts A workshop on techniques for the morphological and molecular identification of cysts from toxic HAB species, led by Drs Kenneth Neil Mertens, Kirsty Smith, Lesley Rhodes and Lincoln MacKenzie, was held recently at the Cawthro Cawthron Summer Scholar Explores Bloom-Forming Freshwater Cyano bacteria Globally, cyanobacteria blooms in freshwater environments are causing water quality problems and health risks with increasing frequency. New Zealand is no stranger to this, suffering from blooms of toxin-producing cyanobacteria Canadian HAB Scientists Hold Workshop to Establish National Priorities and Develop Research Network A National Harmful Algal Bloom (HAB) workshop was organized and chaired by Dr. Ian Perry at the Institute of Ocean Sciences (IOS), Fisheries and Oceans Canada (DFO), Sidney, British Columbia, July 11- Joint FAO, IAEA, IOC and WHO Technical Meeting for the development of an InterAgency Global Ciguatera Strategy Harmful Algae News has previously brought information on an initiative between the International Atomic Energy Agency (IAEA) Environment Laboratories in Monaco jointly with the Oceanographi 12th Advanced Phytoplankton Course - APC 12 Identification, Taxonomy, Systematics Roscoff Biological Station (France) - 19th May to 8th June 2019 APC12 is organized by the Station Biologique de Roscoff together with the Stazione Zoologica Anton Dohrn and the IOC Science and Communication Centre on H ICHA 2018 News: 669 abstracts evaluated ! 250 orals + 45 ignite talks selected and participants notified ICHA 2018 News: 669 abstracts evaluated ! 9 plenaries confirmed 250 orals + 45 ignite talks selected and participants notified 3 satellite sessions 9 plenaries confirmed 3 satellite sessions