Toxic microalgae and global change : why have proliferations increased along the Mediterranean coast?

The ocean and the continent converge in a very narrow line that is, nonetheless, truly relevant to the health, leisure, and economy of our society. The Mediterranean coastline has undergone major changes over the last fifty years, which is evident in the alteration of its microalgae species. The proliferation of dinoflagellates is now common in microscopic organism communities in this ecosystem as a result of the modifications caused by humans and climate change. The increased frequency with which toxic microalgae blooms are detected has been key to raising awareness of this change

LLINÀS, Mireia: Petites Paraules. ¿D'on surt la gramàtica?, Barcelona, Editorial Empúries, 2001 («Biblioteca Universal», 149)

Obra ressenyada: Mireia LLINÀS, Petites Paraules. ¿D'on surt la gramàtica? Barcelona: Editorial Empúries, 2001

La terminologia lingüística

Obra ressenyada: Jaume MACIÀ i Joan SOLÀ (eds.), La terminologia lingüística en l'ensenyament secundari. Propostes pràctiques. Barcelona: Editorial GRAÓ, 2000

Trends in Ostreopsis proliferation along the Northern Mediterranean coasts

14 pages, 6 figures, 2 tableHarmful benthic microalgae blooms represent an emergent phenomenon in temperate zones, causing health, ecological and economic concern. The main goal of this work was to compile records of Ostreopsis at large temporal and spatial scales, in order to study the relationship between cell abundances, the periodicity and intensity of the blooms and the role of sea water temperature in 14 Spanish, French, Monegasque and Italian sites located along the northern limits of the Mediterranean Sea. General trends were observed in the two considered basins: the north-western Mediterranean Sea, in which higher cell abundances were mostly recorded in mid-summer (end of July), and the northern Adriatic Sea where they occur in early fall (end of September). The sea-water temperature does not seem to be a primary driver, and the maximal abundance periods were site and year specific. Such results represent an important step in the understanding of harmful benthic microalgae blooms in temperate areas, and provide a good base for policy makers and managers in the attempt to monitor and forecast benthic harmful microalgae bloomsThe research of the Barcelona group was financed by the national project CTQ 2008-06754-C04-04 EBITOX (Study of the biological and toxinologic aspects of benthic dinoflagellates associated with risks to the human health). We also acknowledge the support given by the CatalanWater Agency (Generalitat de Catalunya), and the facilities kindly offered by the family Aceña from the Restaurant Pins Mar (Sant Andreu de Llavaneres). The research of the French groups was supported by the national program MediOs 2 (LITEAU-Ministère de l’Ecologie, Conseil Général des Alpes-Maritimes, Agence de l’Eau Rhône Méditerrannée et Corse), by a researchers exchange program Galilée (Université franco-italienne, Egide, Ministère des Affaires Etrangères) and by the Monaco Environmental Agency. The research of the Italian groups was supported by the national project “Marine biotoxins in Italian coastal waters: characteristics, origin, actions”, (PRIN 2007), MURST, by the project “Ostreopsis ovata e Ostreopsis spp.: nuovi rischi di tossicità microalgale nei mari italiani”, ISPRA-Italian Ministry of Environment, by the project “Qualità ecologica e fioriture di Ostreopsis in Liguria” of the Genova University and by a researchers exchange program Galileo (Università franco-italiana, CRUI)Peer reviewe

Aproximación ecológica y epidemiológica para establecer la relación entre las proliferaciones de Ostreopsis cf. ovata y sus impactos sobre la salud humana

Blooms of the benthic dinoflagellate Ostreopsis have been related to sporadic acute respiratory symptoms and general malaise in people exposed to marine aerosols on some Mediterranean beaches. However, the direct link between recurrent Ostreopsis blooms and health problems has not been clearly established. In order to establish and elucidate the connection, we conducted a joint ecology and epidemiology study in an Ostreopsis hot spot. Throughout the bloom, which extended from the end of June until the end of October 2013, 81% of the human cohort that we studied experienced at least one Ostreopsis-related symptom. Paradoxically, the time when the effects were greatest was during a short time window in early August. This corresponded to the transition from the exponential growth to the stationary phase of the bloom. Negligible symptoms were reported from August to mid-October, during the stationary period of the proliferation, when O. cf. ovata maintained high concentrations of epiphytic cells. No clear patterns in the landward wind component were noted during the time when health effects were greatest. Our main hypothesis is that the irritants present in the aerosol are produced during a particular physiological phase of the Ostreopsis cells during the bloom.Las proliferaciones del dinoflagelado bentónico Ostreopsis en algunas playas del Mediterráneo se han relacionado con síntomas respiratorios agudos esporádicos y malestar general en las personas expuestas a los aerosoles marinos. Sin embargo, la relación directa entre las proliferaciones recurrentes de Ostreopsis y los problemas en la salud no ha sido claramente establecida. Con el fin de establecer esta conexión se realizó un estudio ecológico y epidemiológico conjunto en una playa afectada por dichos eventos. A lo largo de la proliferación, que se extendió desde finales de junio hasta finales de octubre de 2013, el 81% de la cohorte humana estudiada presentó al menos un síntoma relacionado con los potencialmente producidos por Ostreopsis. Paradójicamente, la mayoría de los efectos se produjeron durante un breve período de tiempo, a principios de agosto, coincidiendo con la transición de la fase de crecimiento exponencial de la proliferación a la fase estacionaria. A partir de agosto y hasta mediados de octubre, durante dicha fase estacionaria en que se mantuvieron concentraciones elevadas de O. cf. ovata, los síntomas fueron negligibles. Durante el período de tiempo con mayor afectación en la salud, no se observó un patrón claro en la componente de viento de mar hacia tierra. Nuestra hipótesis principal es que los compuestos irritantes presentes en el aerosol se producen durante una fase fisiológica particular de las células de Ostreopsis en un momento concreto de la proliferación

Relationship between vegetative cells and cyst production during Alexandrium minutum bloom in Arenys de Mar harbour (NW Mediterranean)

A recurrent Alexandrium minutum bloom in the Arenys de Mar harbour (Catalan coast, North Western Mediterranean) was monitored in order to establish the relationship between vegetative cells and cyst production. The bloom lasted from January 21 to February 24, 2002 and reached cell concentrations of up to 47 x106 cell L-1. Two aspects related to the resting cysts deposition were studied: (i) production of resting cysts during the bloom period (by means of sediment traps) and (ii) distribution of resting cysts in the sediment after the bloom (May 2002). Cyst formation in Arenys clearly started in a period with high vegetative cell densities in the water column. Once production was initiated encystment fluxes remained constant for two weeks, and covering the periods of maintenance and decline of the bloom. High cyst fluxes (up to 6000 cysts cm-2 day-1) were quantified as a result of the high vegetative cell concentration. Moreover, encystment occurring in less than 1% of the total population indicates that most of the cells are not involved in resting cysts formation. A comparison of the resting cyst flux values obtained from the sediment traps and the resting cyst concentrations in surface sediment (628–3270 cysts cm-3) three months later, revealed that the number of cysts in the sediment decreased during that time. The studies of excystment showed a high germination percentage (91%) and germling viability (100%). These data, together with the resting cyst distribution in the sediment, are important in assessing the role of resting cysts in the bloom dynamics of A. minutum in confined waters.Postprin

Presentació del trípic “L’alga Ostreopsis”

Presentació del trípic “L’alga Ostreopsis” para el Acord RAMOGE, Prevenció & Luita contra la Contaminació del Medi Marí, el 6 de agosto del 2015, Barcelona.-- 13 pagesPeer Reviewe

Variabilidad de vibrios planctónicos y epifíticos en un ambiente costero afectado por proliferaciones de Ostreopsis

Vibrios include several pathogenic bacteria that occur in aquatic environments. The presence of Vibrio has been assessed in many ecosystems by culture-based techniques. However, little is known on the contribution of Vibrios in the sea, especially in areas subject to harmful algal blooms. A preliminary study in Sant Andreu de Llavaneres beach (NW Mediterranean) showed the presence of some Vibrio species during a recurrent bloom of the harmful benthic dinoflagellate Ostreopsis cf. ovata. In order to establish the importance of Vibrios in a coastal area of the NW Mediterranean and to study the association with the dinoflagellate, we conducted a sampling monitoring for one year to quantify the concentration of Vibrios both in the water (free-living and attached to particles) and in the epiphytic community of macroalgae. The aims were 1) to evaluate the relative abundance of Vibrio in the epiphytic and in the planktonic bacterial community, 2) to assess the percentage of free-living and attached Vibrios in the planktonic community, and 3) to determine whether the presence of Vibrios is associated with the blooms of the toxic dinoflagellate Ostreopsis or with other environmental parameters. For this purpose, a CARD-FISH molecular probe was applied for the specific detection of bacteria belonging to the genus Vibrio. Cells were quantified and the abundance of both particles and bacteria attached to particles were assessed. The maximum Vibrio concentration (1.3x104 cells ml–1 and 1.4x106 cells g–1 FW, for planktonic and epiphytic samples, respectively) was detected in September. Free-living Vibrios contributed 0.38±0.24% to the total free-living planktonic community and 1.12±0.28% to the epiphytic bacterial community. However, their contribution was particularly high in the planktonic community attached to particles (17.37±20.49%). Although in the planktonic community Vibrio was found preferentially free-living (82.63±20.01%), particles are a niche for Vibrios, since in particles Vibrios may represent up to 72% of the total attached bacterial community. Abundance of planktonic Vibrio was correlated with Ostreopsis concentration and it is likely that they play a role in the wound infections suffered by beach users during the bloom.El género Vibrio incluye a varias bacterias patogénicas que se encuentran en ecosistemas acuáticos. La presencia de Vibrio se ha estimado en muchos ecosistemas mediante técnicas basadas en cultivos. Sin embargo, se conoce poco sobre la contribución de Vibrios en el mar, especialmente en áreas afectadas por proliferaciones algales nocivas. Un estudio preliminar en la playa de Sant Andreu de Llavaneres (Mediterráneo NO) mostró la presencia de algunas especies de Vibrio durante una proliferación recurrente del dinoflagelado béntico nocivo Ostreopsis cf. ovata. Para poder establecer la relevancia de los Vibrios en un área costera del Mediterráneo NO y estudiar su asociación con el dinoflagelado, realizamos un muestreo de monitoreo durante un año para cuantificar la concentración de Vibrios tanto en el agua (de vida libre y adheridos a partículas) y en la comunidad epifítica de macroalgas con los objetivos de 1) evaluar la abundancia relativa de Vibrio en la comunidad bacteriana tanto planctónica como epifítica, 2) estimar el porcentaje de Vibrios de vida libre y adheridos a partículas en la comunidad bacteriana planctónica y 3) determinar si la presencia de Vibrios está relacionada con las proliferaciones del dinoflagelado Ostreopsis o con otros parámetros ambientales. Para este propósito, se aplicó una sonda molecular de CARD-FISH para la detección específica de bacterias pertenecientes al género Vibrio. Se cuantificaron las células y también la abundancia de partículas y de las bacterias adheridas a estas partículas. La máxima concentración de Vibrio (1.3x104 cels ml–1 y 1.4x106 cels g–1 PF, para muestras planctónicas y epifíticas, respectivamente) fue detectada en Septiembre. Los Vibrios de vida libre contribuyeron un 0.38±0.24% al total de la comunidad bacteriana de vida libre y un 1.12±0.28% a la comunidad bacteriana epifítica. Sin embargo, su contribución fue especialmente elevada en la comunidad bacteriana adherida a partículas (17.37±20.49%). Aunque en la comunidad planctónica Vibrio se encontraba preferentemente no adheridos a partículas (82.63±20.01%), las partículas constituyen un nicho para Vibrios, ya que pueden llegar a representar hasta un 72% de la comunidad bacteriana adherida a partículas. La abundancia de Vibrio en el plancton se correlacionó con la concentración de Ostreopsis, y es posible que éstos jueguen un papel en las infecciones de heridas que sufren los bañistas durante las proliferaciones algales

Critical comparison of shake-flask, potentiometric and chromatographic methods for lipophilicity evaluation (log Po/w) of neutral, acidic, basic, amphoteric, and zwitterionic drugs

In the present study three different procedures have been compared for the determination of the lipophilicity of the unionized species (log Po/w) of neutral, acidic, basic, amphoteric, and zwitterionic drugs. Shake-flask, potentiometric and chromatographic approaches have been assayed in a set of 66 representative compounds in different phases of advanced development. An excellent equivalence has been found between log Po/w values obtained by shake-flask and potentiometry, while the chromatographic approach is less accurate but very convenient for screening purposes when a high-throughput is required. In the case of zwitterionic and amphoteric compounds, either for shake-flask and chromatographic methods, the pH has to be accurately selected in order to ensure the compound to be in its neutral form

Resultados del programa de seguimiento de fitoplancton tóxico y biotoxinas en las zonas de producción de bivalvos de Cataluña: años 2003-2006 y primer trimestre del 2007

[ESP] En el período que va desde Enero del 2003 hasta finales de Marzo del 2007 se han producido un total de 28 cierres administrativos de zonas de producción de bivalvos. De estos, 27 han sido por toxicidad diarreica (DSP) o presencia de ácido okadaico (OA) y sólo 1 por toxicidad paralizante (PSP). No ha habido ninguna detección de toxicidad amnésica (ASP) en bivalvos. La mayor parte de los cierres, 20, se han producido en las bahías del delta del Ebro. Las posibles especies de microalgas implicadas han sido Dinophysis sacculus, D. caudata, Protoceratium reticulatum y Alexandrium minutum. En relación a los casos de ictiotoxicidad, únicamente se registró un episodio en el año 2003 debido a una proliferación de Karlodinium spp que ocurrió a finales de la primavera.Agradecemos la colaboración al laboratorio de Anfaco y al Laboratorio del Departamento de Salud Pública de Tarragona por los análisis y bioensayos de toxinas. También agradecemos a todo el equipo técnico del IRTA por su apoyo