considered this to be identical to the previously described P. mexicanum [9]. This statement makes little sense, and Loeblich et al in fact do not mention P. mexicanum in their article. Faust [8] illustrated material which resembled P. rhathymum using the radical arrangement of some of the trichocyst pores on the two large amphiesma plates, while no such arrangement was described in P. mexicanum by Osorio-Tafall [9]. The amphiesma surface in Fausts [8] beautiful SEMs is rugose, in contrast to both P. mexicanum and P. rhathymum, and Fausts material was subsequently given the name Prorocentrum steidingerae by Gómez et al. [4]. However, Faust [8] mentions that her material was sometimes smooth (as P. mexicanum), sometimes rugose, thus removing a main distinguishing character of P. steidingerae. Fausts rugose cells resemble P. rhathymum in the radial arrangement of some of the trichocyst pores (as in another benthic species, P. lima). If we accept Fausts statement that cells are sometimes rugose, sometimes smooth, then P. steidingerae is a synonym of P. rhathymum. Osorio-Tafalls Prorocentrum mexicanum is a separate species, which lacks the radiating arrangement of trichocyst pores. Present evidence indicates that P. rhathymum is a benthic species which occurs in sediments or attached to macroalgae and floating detritus ([8] and references herein) while P. mexicanum appears to be planktonic. Cells of Prorocentrum rhathymum from Malaysia produce okadaic acid (cells documented by an excellent micrograph in Caillaud et al. [10]) as does material from Florida (not illustrated but genetically identical to the Malaysian cells: [11]). There appears to be no reliable information on the toxic potential of P. mexicanum. Problem 4. The Ceratium question: Ceratium, Neoceratium or Tripos? One of the editors asked me some time ago about which of the names Ceratium, Neoceratium and Tripos, should be used in monitoring programmes? Ceratium species are only harmful in large numbers when they may cause low levels of oxygen in the water. However since many HAB people are involved in monitoring of marine phytoplankton in general, I will address this question, which is relatively straightforward and which HARMFUL ALGAE NEWS NO. 64 / 2020 may serve as an example of the splitting concept. It has been known for a long time that freshwater and marine species of Ceratium fall into two different groups which differ in the number of cingular plates: 4 cingular plates in the marine species [2], 5 plates in the freshwater species [12]. It was therefore no great surprise when molecular sequencing found the species to be distributed into the same two groups. Gómez et al [13] accordingly suggested splitting the genus into two, one comprising the freshwater species and the other the marine species. As the type species is from freshwater the name Ceratium was retained for the freshwater species while the marine species were given the name Neoceratium gen. nov. [13]. However this last name was against the rules of the international code of nomenclature and therefore illegitimate [14]. New generic names must not be created if a name for the same group of species exists already, and this is the case for Ceratium. Thus the many new combinations of names based on Neoceratium created by Gómez et al [13] are not to be used. Among the generic names applied to species of the Ceratium group, the oldest available name for the marine species is the soon 200-year-old Tripos Bory 1823. When this had been established, the marine species, varieties and forms of Ceratium were transferred to Tripos [15]. Then to the question: should the name Tripos from now on be applied to all marine species of Ceratium? The answer is that it depends on whether one prefers to split the genus Ceratium into two genera, or to keep the species in one genus. Both solutions are acceptable. Ceratium sensu lato containing both the freshwater and the marine species is monophyletic. Ceratium sensu stricto, containing only the freshwater species, and Tripos containing the marine species only, are also (both) monophyletic. A simple solution is therefore to retain the name Ceratium for all the species, freshwater and marine, but to group them into subgenera, one comprising the freshwater species, the other the marine species. This solution has been applied to other large groups of algae (e.g. Chaetoceros) and to many vascular plants. All species then retain the old generic name Ceratium Schrank 1793. Acknowledgements I thank António Calado for his always valuable comments. References 1. Li Z et al 2019. Protist 170: 168-185 2. Kofoid CA 1907. Zoologischer Anzeiger 32: 177-183 3. Gómez F & LF Artigas 2019. J Mar Biol: 2019 https://doi. org/10.1155/2019/1284104 4. Gómez F et al 2017. J Euk Microbiol 64: 668-677 5. Okamura K 1916. Sikenjo Kenkyu Hokoku 12: 26-41 6. Steidinger K A 1983. Progr Phycol Res: 147-188 7. Loeblich AR III et al 1979. J Plankton Res 1: 113-120 8. Faust MA 1990. J Phycol 26, 548-558 9. Osorio-Tafall BF 1942. Anales de la E.N. de Ciencias Biologicas II (4): 435-447 10. Caillaud A et al 2010. Toxicon 55: 633637 11. An T 2010. Toxicon 55: 653-657 12. Bourrelly P 1968. Protistologica 4: 5-14, pls I-II 13. Gómez F et al 2010. Protist 161: 35-54 14. Calado AJ & JM Huisman 2010. Protist 161: 35-54 15. Gómez F 2013. CICIMAR Oceánides 28: 1-22 Author Øjvind Moestrup, Chairman of the IOC UNESCO Intergovernmental Panel on Harmful Algal Blooms Task Team on Algal Taxonomy, University of Copenhagen, Denmark E-mail corresponding author: moestrup@bio.ku.dk 3 Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 64 - June 2020 www.ioc-unesco.org/hab The IOC Taxonomic Reference List of Harmful Microalgae The creation of the IOC Taxonomic Reference List of Harmful Microalgae was first discussed 23 years ago at the Fourth Session of the ever the information presented in publications is not always easy to interpret. Toxic blooms often contain several species and studies on individual species are therefore required to determine the species responsible for the toxin production. In addition, species are sometimes difficult to identify considered this to be identical to the previously described P. mexicanum [9]. This statement makes little sense, and Loeblich et al in fact do not mention P. mexicanum in their article. Faust [8] illustrated material which resembled P. rhathymum using the radical arrangement of some of the trichocys Massive salmon mortalities during a Chrysochromulina leadbeateri bloom in Northern Norway From mid May to mid June 2019, fish farmers along the coast of Nordland and Troms, northern Norway, experienced sudden mortalities of caged salmon [1] (Fig. 1). These mortalities were assumed to be due to a blo Fish kill in numbers [2] 13 000 ton fish 7.5 mill salmon 80 mill EUR 14 companies Fig. 2. Map of Norway showing the area where the Chrysochromulina leadbeateri bloom occurred causing massive fish kills in May-June 2019 References 1. Fiskeridirektoratet 2019. https:// www.fiskeridir.no/Akvakult Mass mortality of marine invertebrates associated with the presence of yessotoxins in northern Chile Fig. 1. Map of the study area showing A) Chilean coast; B) Pabellón de Pica, Tarapacá Region C) Bahía Inglesa, Atacama Region; D) Puerto Aldea, Coquimbo Region During the austral summer of 2019, ma research is needed to determine the mechanism of action and the toxin effects on tissues and cells of the main affected species. Finally, there is a need to establish an educational plan to protect the public and avoid the consumption and commercialization of potentially toxic marine invertebrates. First Report of Heterocapsa minima (Dinophyceae) from Aotearoa/ New Zealand Small planktonic armoured dinoflagellates within the genus Heterocapsa are currently represented by 20 species with some having a world-wide distribution [1-2]. Blooms of some Heterocapsa species have been associated with fi Fig. 2. Maximum likelihood (ML) molecular phylogenetic tree of Heterocapsa minima and H. steinii strains isolated from coastal areas of New Zealand based on the LSU rDNA D1/ D2 sequences (20 sequences, 700 positions). The alignment site corresponded to the 69768 bp site of a sequence from H. steinii Yellow-green tides could become a recurrent event along the Ligurian coast (Italy) Fig. 1. A) Sestri Levante and Baia del Silenzio bay, characterized by shallow water and mixed rocky-sandy seabed containing the macrophyte, Posidonia oceanica (dark grey) and carpet-like matte (light grey) habitat. B First report of a high biomass bloom of Peridinium quadridentatum (F. Stein) Gert Hansen from the tropical Cochin estuary SW coast of India Fig. 1. Map showing the area of P. quadridentatum bloom in Cochin estuary, southwest coast of India Peridinium quadridentatum (F. Stein) Gert Hansen is a cos Table 1. Physico-chemical parameters of P. quadridentatum bloom area in Cochin Estuary Parameters Water Temperature (oC) Salinity (psu) Dissolved Oxygen (ml L-1) Nitrate (μmol L-1) Silicate (μmol L-1) Phosphate (μmol L-1) Chlorophyll a (mg m-3) 28 20 2.01 10.6 23.3 1.3 27.5 higher turbidity, lowe Are mesophotic seamounts reservoirs for potentially toxic dinoflagellates associated with Ciguatera poisoning? A case study from the SW Indian ocean (expédition La Pérouse, 2019) Fig. 1. Location map of La Pérouse seamount off La Réunion. In the western Indian Ocean, a Ciguatera Fish Poisoning (CF Using Machine Learning to Observe Abundance Patterns of the Dino flagellate Noctiluca scintillans in the Western English Channel Noctiluca scintillans is a Harmful Algal Bloom (HAB) species with a wide geographic distribution. It frequently blooms and causes negative impacts on marine ecosystems [1] References 1. Sarma VVSS et al 2019. Mar Pollut Bull 138: 428-436 2. Faust MA & RA Gulledge 2002. Contributions for the US National Herbarium 42: 1-144 3. Graham MD et al 2018. Limnol Oceanogr-Meth 16: 669-679 Author Christian Bamber, The Marine Biological Association, Citadel Hill, Plymouth PL1 2PB International validation and recognition of method for paralytic shellfish toxins in bivalve molluscs Food safety scientists from Cefas (UK) and Cawthron Institute (New Zealand) have led an international study over the past four years to gain international recognition for a new method to quantify pa Aotearoa/New Zealands nationally significant Cawthron Institute Culture Collection of Microalgae (CICCM) The CICCM is critical to international research projects and the 500 isolates of microalgae and cyanobacteria in the collection have been sourced from oceans, lakes and rivers in New Zealand, the The 11th EASTHAB Symposium and 4th Philippine HAB Conference The 11th EASTHAB Symposium and 4th Philippine HAB Conference were held back-to-back from December 11 13, 2019 at the Microtel Hotel, Puerto Princesa, Palawan, the Philippines. The theme was Advances in Harmful Algal Bloom Research, Monito Fig. 1. Participants in the 11th EASTHAB Symposium/4th Philippine HAB Conference Fig. 2. Department of Science and Technology secretary Fortunato dela Peña with the keynote, plenary speakers and local organizing committee leads. Left to right: Dr. Ichiro Imai, representative of the Vice Mayor of Pu The ICES-IOC Working Group on Harmful Algal Bloom Dynamics 2020 Meeting The International Council for the Exploration of the Sea (ICES) and the Intergovernmental Oceanographic Commission of UNESCO (IOC) have collaborated closely for 26 years, stimulating research on HAB population dynamics and monit Fig. 2. Shared day between ICES-IOC WGHABD, ICES-IOC WGBOSV and ICES WGITMO ences using molecular methods as well as results from studies in Arctic areas. These studies presented data on HAB and invasive non-native species present in Arctic waters. A USA study focused on the distribution, community Typical benthic habitat with macroalgae and limestone rubble observed at ~ 60m depth on La Pérouse seamount, Indian Ocean (Photo courtesy of L. Ballesta). Eds-in-chief Beatriz Reguera, IEO, Vigo, Spain Eilen Bresnan, Marine Scotland, UK Regional Editors Caribbean: Ernesto Mancera jemancerap@unal.e