First evidence of high saxitoxin concentration in Crassostrea iridiscens associated with Gymnodinium catenatum blooms at Banderas Bay, Jalisco México Fig. 1. Location of sampling stations in Banderas Bay Jalisco México during Gymnodinium catenatum bloom from March to June of 2017. Banderas Bay has a long-standing history of toxic HABs. The presence of saxitoxins (STXs) had been associated with dinoflagellates belonging to the genus Alexandrium and with Gymnodinium catenatum [1, 2]. Blooms of both of these microalgae can pose a high risk for marine food resources to become contaminated with STXs, some of the most potent neurotoxins (PSP syndrome) which can prove fatally toxic to humans [3]. During 2017 the highest density of toxic G. catenatum and the first evidence of high STX concentrations in rock oysters (Crassostrea iridiscens), one of the most iconic species for the shellfish industry in the region, were recorded. A review of this event was carried out by the CIC-CUCOSTA-U de G in collaboration with the local health authorities of the Epidemiology Section (Department of Health Jalisco) for health protection and shellfish toxins regulatory purposes. Banderas Bay is located on the western Mexican coast (20 15 to 20 47 N, 105 15 to 105 4 W) [4]. It has a total area of ~ 975 km2, and is limited by Punta de Mita (north) and Cabo Corrientes (south), with a range of ~40 km between the two points (Fig. 1). The mean sea surface temperature is 26.4oC with a seasonal range from 23.3 oC dur8 ing winter-spring, to 30.0 oC during summer-autumn. The area has a complex hydrodynamic regime due to its location in a transitional area seasonally influenced by three important current systems: (1) the California Current that flows southward, bringing cold and low salinity water to the region, (2) the Costa Rican Costal Current that flows northward, transporting warm waters of intermediate salinity, and (3) the warm and dense water of the Gulf of California, which is transported southward into the Banderas Bay region [4]. Samples of native C. iridiscens were obtained from three commercial oyster harvesting areas and the shellfish extracts prepared for toxin analysis at the CCAYAC-COFEPRIS (Comisión del Control Analítico y Ampliación de Cobertura) laboratories, according to the Mexican Official NOM-242-SSA1-2009 standards and procedures [5]. Samples from G. catenatum bloom areas were collected from March to June at eight stations (E1-E8), stored in 500-ml plastic bottle and preserved with Lugol-acetate solution for identification and cell counts at a Leica light microscope. Phytoplankton quantitative analyses were carried out with 20x and 40x magnification, using a 1 ml Sedgewick-Rafter settling chamber. Temperature and salinity were measured in situ using a YSI 85 multiparameter probe, and micrographs of G. catenatum obtained with a digital camera. Based on mouse bioassay analysis (MBA), the maximum toxin concentration in C. iridiscens samples, 389.82 μg STX eq 100 g-1 shellfish flesh , was observed at Station E-7 (Sheraton), the same location where the highest density of G. catenatum (2.42 x 106 cells L-1) was found (Fig. 2). Regulations from the health authorities stipulate that bivalve molluscs for the market must not contain more than 80 μg STX eq 100 g-1 tissue [5]. Given the magnitude of this PSP event, a temporary ban was immediately implemented by COFEPRIS authority, and a suspension of the extraction, commercialization and consumption of rock oysters was enforced through notification advice SST-CRS/599/2017, until STXs and G. catenatum densities in sea water dropped to safe levels. There were differences of three orders of magnitude (range, 3 x 103 - 3 x 106) in G. catenatum cell densities between the 8 sample sites (Fig. 3a). These densities were the the highest recorded since 2001 to date [1, 2]. During the toxic event, the mean surface temperature Table 1. Toxin content (μg STX eq 100 g-1) in soft tissue of Crassostrea iridiscens (rock oyster) from Banderas Bay, Jalisco, México at stations. E-8 (Velas), E-7 (Sheraton) and E-6 (Malecón). Date μg STX eq 100g-1 Station March 14th March 24th April 6th April 7th May 8th June 6th June 23th 32.52 389.82 48.86 not detected 38.61 not detected 59.52 E-8 E-7 E-7 E-7 E-7 E-7 E-6 Mean Temperature o C 22.85 24.52 22.5 22.5 25.1 23.12 Mean Salinity ups 33.48 33.43 33.26 33.26 33.16 33.25 Mean pH 8.28 8.34 8.18 8.18 8.14 16.23 HARMFUL ALGAE NEWS NO. 58 / 2017 Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 58 - November 2017 www.ioc-unesco.org/hab Call to Contribute to Global Harmful Algal Bloom Status Reporting From 25 to 28 September 2017 sixteen HAB experts from 13 countries gathered at the headquarters of the IOC IODE (Inte the first of which will be launched in Nantes. Follow the development of the Global HAB Status Report at http://haedat. iode.org/ and see who is involved and how you may engage. Acknowledgements We thank Ward Appeltans and Pieter Provoost at the IOC/IODE Project Office for hospitality and technical PSP# # # # # # DSP# # # # # # AZP# ! ! ! Fig. 4. Maps showing the incidence of PSP, DSP and AZP during the period 2014 to 2016 in the North Atlantic as reported by the ICES-IOC WG HABD. Areas such as Northern Canada and Greenland are not routinely sampled and countries with pink borders have sti Pelagic Sargassum reaching Serranilla Bank, Caribbean Colombia, may pose a risk to baby turtles Fig. 1. Location of Serranilla Bank in the Caribbean Sea (Photo Wikipedia) Floating Sargassum has been known from centuries to occur in the Atlantic Ocean, in a region named the Sargasso Sea. Floating S NEW!! Harmful Algal Blooms (HABs) and Desalination: A Guide to Impacts, Monitoring, and Management Manuals and Guides 78 Harmful Algal Blooms (HABs) and Desalination: A Guide to Impacts, Monitoring, and Management Fig. 3. Sargassum accumulation as a thick mat on the nesting beach Edited by: Dona A red tide event associated with the dinoflagellate Karenia mikimotoi in the Firth of Clyde, Scotland Fig. 1. Maximum abundance of K. mikimotoi by month and year for monitoring sites in Scottish coastal waters. The densest bloom observed exceeded 4 million cells per litre in July 2016. The potenti Fig. 5. Theoretical effect of the K. mikimotoi bloom on background dissolved oxygen concentration (black horizontal dashed line: Firth of Clyde summer averaged SEPA data 2005-2015). Cell density was sufficient to cause hypoxia on 3 occasions at 4.59mg L-1[8] or once at 2mg L-1 (grey dashed lines). A First evidence of high saxitoxin concentration in Crassostrea iridiscens associated with Gymnodinium catenatum blooms at Banderas Bay, Jalisco México Fig. 1. Location of sampling stations in Banderas Bay Jalisco México during Gymnodinium catenatum bloom from March to June of 2017. Banderas Bay has Fig. 2. High saxitoxin concentration in Crassostrea iridiscens associated with Gymnodinium catenatum blooms in Banderas Bay, Jalisco México. Fig. 4. Micrographs of live cells of Gymnodinium catenatum from Banderas Bay at 400x (a) and 200x (b); Seawater discoloration due to a G. catenatum patch duri ICES-IOC Working Group on Harmful Algal Blooms Dynamics The report of the International Council for the Exploration of the Sea (ICES) and Intergovernmental Oceanographic Commission of UNESCO (IOC) Working Group on Harmful Algal Bloom Dy namics (ICES-IOC WGHABD) is now available on the ICES website ( SEAFDEC-MFRD Regional Training Course in Malaysia Harmful algal blooms (HAB) and their socio-economic impacts are recognized internationally due to the negative impacts from HABs on the the coastal ecosystem, safety and security of food and drinking water, and human health hazards. Some incidents an Forthcoming events Workshop on morpho-molecular methods for the study of dinoflagellate cysts ICES-IOC-IMO Working Group on Ballast and Other Ship Vectors 5-7 March 2018 Monday 12th and Tuesday 13th February 2018 Location: Cawthron Institute, 98 Halifax Street East, Nelson 7010, New Zealand Organi the 18th international conference on harmful algae from ecosystems to socio-ecosystems SAVE the date! FATMA GUELLATI/UPMC-UNIV BADJI MOKHTAR Minyvel Environnement/Phenomer Nicolas Chomérat/IFREmer Véronique Séchet/IFREmer Olivier BARBAROUX/IFREmer Stéphane LESBATS/IFREmer Olivier DUG Rex Munday in Memoriam Dr Rex Munday, an internationally renowned toxicologist, sadly passed away on the 20th July this year. His wife Christine, daughter Sarah (Finch) and son John were with him. Rex published with all his family at different times, an example being the paper Munday, Munday and Mun Rex Mundays HAB research highlights Discovery of Tetrodotoxin in grey side-gilled sea slugs: Rex had a sharp wit, best illustrated with an anecdote from 2013. We had collected hundreds of samples to explain why dogs were dying on Auckland beaches and sent twelve to Rex for toxicity screening using l ! Oostende OBIS/HAEDAT training workshop participants. Eds-in-chief Beatriz Reguera, IEO, Vigo, Spain Eilen Bresnan, MARLAB, Scotland, UK Regional Editors Caribbean: Ernesto Mancera jemancerap@unal.edu.co Europe: Philip Hess Philipp.Hess@ifremer.fr India: K.B. Padmakumar kbpadmakumar@gmail.c