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The dinoflagellate Alexandrium minutum is responsible for paralytic shellfish poisoning (PSP) episodes in Western Europe, commonly in areas directly affected by significant freshwater inputs, as the Ría de Vigo (NW Spain), a coastal embayment with estuarine influence characterized by seasonal upwelling. Because pronounced environmental short-term changes characterized these ecosystems, tolerance windows for A. minutum against temperature (T) and salinity (S) stress were studied using a factorial approach

Three strains of the toxic benthic dinoflagellate Prorocentrum hoffmannianum were isolated in the Canary Islands (north-east Atlantic Ocean, Spain). The identity of the strains was determined by phylogenetic analyses of partial LSU rDNA (D1-D2 regions) but their morphology based on SEM images corresponded to P. maculosum. Their toxin profiles were analyzed by liquid chromatography and high resolution mass spectrometry analysis (LC–HRMS) on cell extracts and culture media. Okadaic acid and three analogs were detected in all strains. Rather, in culture media the detected compounds were variable among strains, two of them being okadaic acid analogs not found on cell extracts. As a result, the taxonomy of the species was revised and P. maculosum is proposed as a junior synonym of P. hoffmannianum whose description is emended.

Harmful algal blooms (HABs) are a natural global phenomena emerging in severity and extent. Incidents have many economic, ecological and human health impacts. Monitoring and providing early warning of toxic HABs are critical for protecting public health. Current monitoring programmes include measuring the number of toxic phytoplankton cells in the water and biotoxin levels in shellfish tissue. As these efforts are demanding and labour intensive, methods which improve the efficiency are essential. This study compares the utilisation of a multitoxin surface plasmon resonance (multitoxin SPR) biosensor with enzyme-linked immunosorbent assay (ELISA) and analytical methods such as high performance liquid chromatography with fluorescence detection (HPLC-FLD) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) for toxic HAB monitoring efforts in Europe. Seawater samples (n = 256) from European waters, collected 2009–2011, were analysed for biotoxins: saxitoxin and analogues, okadaic acid and dinophysistoxins 1/2 (DTX1/DTX2) and domoic acid responsible for paralytic shellfish poisoning (PSP), diarrheic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP), respectively. Biotoxins were detected mainly in samples from Spain and Ireland. France and Norway appeared to have the lowest number of toxic samples. Both the multitoxin SPR biosensor and the RNA microarray were more sensitive at detecting toxic HABs than standard light microscopy phytoplankton monitoring. Correlations between each of the detection methods were performed with the overall agreement, based on statistical 2 × 2 comparison tables, between each testing platform ranging between 32% and 74% for all three toxin families illustrating that one individual testing method may not be an ideal solution. An efficient early warning monitoring system for the detection of toxic HABs could therefore be achieved by combining both the multitoxin SPR biosensor and RNA microarray., SI

Aquatic Sciences Meeting, Aquatic Sciences: Global And Regional Perspectives - North Meets South, 22-27 February 2015, Granada, Spain, The relationships between environmental forcing (hydrographic characteristics of the water column, in situ PAR and major nutrient profiles) and the vertical distribution patterns of in vivo fluorescence and chlorophyll a (Chl a) concentration have been studied along transects of the Malaspina 2010 expedition covering several biogeographic regions in the Indian and Pacific Oceans. Except in the zone of the Equatorial upwelling, a subsurface Chl a maximum (SCM) was generally found at depths between 60 and 150 m. It was typically located at about the 1% light level, in association with the nutriclines and the nitrite maximum. The SCM occurred well below the depth of maximum Brunt-Väisälä frequency in the open Indian Ocean and South Equatorial Pacific, and near or above it in zones strongly influenced by advection (Agulhas, Great Australian Bight). The average proportion of Chl a in the size fraction < 2 micrometers ranged from 60% at surface to 66% at the DCM. The relationship between surface Chl a concentration and integrated Chl a was significant for some geographical regions, but not for the whole data set

The epibenthic dinoflagellate Ostreopsis is a potentially toxic bloom-forming organism. Ostreopsis spp. have the ability to produce palytoxin-like compounds which have demonstrated to be harmful for both human health and 4benthic invertebrates (sea urchins). This genus often co-occurs with other dinoflagellates (i.e. Coolia, Prorocentrum) but little is known about the potential interactions between these dinoflagellates in the benthic environment. The aim of the present study was to explore the potential inhibitory effects on growth and/or cell behavior by toxic strains of Ostreopsis cf. ovata (VGO 1001) and Ostreopsis sp. (Lanzarote type VGO 1000), on two non-toxin producer dinoflagellates (Coolia monotis and Prorocentrum elegans) isolated from the same geographical area (Canary Islands, NE Atlantic).