Ceratium balechii sp. nov. (Dinophyceae: Gonyaulacales) from the Mexican Pacific

We propose a new species Ceratium balechii sp. nov., a bloom-producing dinoflagellate in the Mexican tropical Pacific, and often by mistake referred to as C. dens. In order to know its morphological variability, a morphometric study was perfomed, on the basis of 584 cells from 48 populations collected in 11 coastal localities of the Mexican tropical Pacific. Sixteen morphological characters (14 quantitative and 2 qualitative) were studied in each cell, and another 6 characters, relevant for establishing allometric relationships, were taken into account. To perform the statistical analysis, four different cell shapes were distinguished based on their appearance. A discriminant analysis distinguished two forms that were also correlated with water temperature and salinity. Two forms are proposed, C. balechii f. balechii and C. balechii f. longum. The latter occurred in water with temperature higher than 26ºC and salinity less than 32. The species is subjected to cyclomorphosis and intense synchronized autotomy in both antapical horns.The new species is compared with other morphologically similar species and intraspecific taxa (C. dens, C. dens var. reflexa, C. tripos "var. benguela", C. tripos var. dalmaticum, C. tripos var. ponticum, C. californiense, C. ehrenbergii and C. porrectum). The presence of C. dens in the Mexican Pacific is heavily questioned

Planktonic algal blooms from 2000 to 2015 in Acapulco Bay, Guerrero, Mexico

Background and Aims: Harmful algal blooms (HABs) affect the marine ecosystem in multiple ways. The objective was to document the species that produced blooms in Acapulco Bay over a 15-year period (20002015) and analyze the presence of these events with El Niño-Southern Oscillation (ENSO). Methods: Thirty-five collections, made during the years 2000, 2002-2004, 2006-2011, 2013-2015, were undertaken with phytoplankton nets and Van Dorn bottle, yielding 526 samples, of which 423 were quantified using the Utermöhl method. The relationship of HAB with ENSO was made with standardized values of Multivariate ENSO Index (MEI) and the significance was evaluated with the method quadrant sums of Olmstead-Tukey. Key results: Using data of cell density and high relative abundance (>60%), 53 blooms were recorded, most of them occurring during the rainy season (June-October) and dry-cold season (November-March), plus 37 blooms reported by other authors. These 90 blooms were composed of 40 taxa: 21 diatoms and 19 dinoflagellates, the former mostly innocuous. Sixty-seven blooms had species reported as noxious, of which 11 species commonly produce toxic HAB. Toxic taxa are Pseudo-nitzschia spp. (four taxa), and seven dinoflagellates. Conclusions: Abundance analyses of Pyrodinium bahamense var. compressum and Gymnodinium catenatum against values of MEI showed a clear tendency to produce HAB in La Niña conditions. Both taxa, producers of saxitoxins, cause paralytic shellfish poisoning (PSP) and coexist in Acapulco; therefore, they present a risk to human health. Another noxious 52 taxa found in Acapulco were currently considered potential HABs, because they have been recorded at low densities. Given the sharp differences in density values of bloom-forming species found in this work compared to those reported by other authors on similar dates, it is important to perform calibration tests to rule out possible errors in cell counts.Antecedentes y Objetivos: Los florecimientos algales nocivos (FAN) afectan al ecosistema marino de varias maneras. El objetivo fue reconocer las especies productoras de dichos florecimientos en la Bahía de Acapulco, durante un periodo de 15 años (2000-2015) y relacionar su presencia con el fenómeno El NiñoOscilación del Sur (ENSO). Métodos: Analizamos 526 muestras de 35 colectas efectuadas durante los años 2000, 2002-2004, 2006-2011 y 2013-2015, realizadas con red y botella Van Dorn; éstas últimas (423) cuantificadas con el método de Utermöhl. La relación de FAN con ENSO se hizo con valores estandarizados del Índice Multivariado ENSO (MEI), y las significancia evaluada con el método de Asociación de Cuadrantes de Olmstead-Tukey. Resultados clave: Con base en la densidad celular y abundancia relativa alta (>60%) se reconocieron 53 florecimientos, la mayoría durante la época de lluvias (junio-octubre) y secas-fría (noviembre-marzo), más otros 37 eventos reportados por distintos autores. Estos 90 eventos estuvieron conformados por 40 taxa (21 diatomeas y 19 dinoflagelados); los de diatomeas, en su mayoría, inocuos. Sesenta y siete florecimientos estuvieron conformados por especies reportadas como dañinas, de las cuales 11 comúnmente producen FAN tóxicos. Los taxa tóxicos fueron Pseudo-nitzschia spp. (cuatro taxa) y siete dinoflagelados. Conclusiones: Los análisis de abundancia de Pyrodinium bahamense var. compressum y Gymnodinium catenatum, en relación con los valores MEI, mostraron una clara tendencia a producir FAN en condiciones La Niña. Ambos taxa, productores de saxitoxinas y causantes de envenenamiento paralítico por moluscos, incluso llegan a coexistir en Acapulco, representando un riesgo para la salud humana. Otros 52 taxa dañinos por encontrarse en bajas densidades, se consideraron por el momento potenciales formadores de FAN. Dadas las agudas diferencias encontradas en valores de densidad de especies formadoras de florecimientos respecto a las reportadas por otros autores en fechas similares, es importante realizar pruebas de calibración para descartar posibles errores en conteos celulares

Phytoplanktonic richness of the Bahía de Acapulco, Guerrero, Mexico

We present the inventory of the planktonic algal flora of the Bahía de Acapulco and surrounding marine area, studied through a decade, including an intensive bimonthly sampling study using plankton net, bottle method and the observation of live samples, from February 2010 to February 2011. It recognized 641 taxa, corresponding to eight algal divisions. The most diverse groups were Dinophyta and Bacillariophyta with 347 and 274 taxa, respectively. Photographs of 131 taxa are presented, corresponding to 38 new records for the Mexican Pacific, 34 taxa were not identified at species level, and 59 taxa represent some taxonomic or ecological interest. Species accumulation curves allow to recognize that the species richness observed in the present study represents a good approximation of the planktonic algal flora from the Bahía de Acapulco. However, more detailed studies over phytoflagellates and picoplankton are necessary. A biological characterization of the phytoplankton community was made according to organization level, type of nutrition, life form, potential harmfulness or toxicity, origin (freshwater, brackish or marine), affinity (neritic or oceanic) and distribution (cosmopolitan, cold-temperate or subtropical-tropical). It recognized the common species of the bay and those that have produced blooms. The high species richness of planktonic algal flora observed in Acapulco may reflect a variable trophic status throughout the year, with nutrient limitation at certain times, condition which agrees with the symbiotic relationships found among phaeosomes (cyanophytes), dinoflagellates and diatoms. However, some species indicative of pollution such as Euglena pascheri, Phaeocystis sp. and the presence of the consortium Leptocilindrus mediterraneus (diatom)�Solenicola setigera (protozoan), show that some times the concentrations of nutrients and organic matter can be high. The typical form of �amphitheater� that characterizes the bay causes that, during the rainy season, the system receives an input of large amounts of waste and sewage from the surrounding densely populated hills. However, Acapulco Bay seems to have a high resilience, probably as a result of a conjugated role between ocean currents (which produce a washing effect of the anthropogen pollution) and the purification produced by the functional diversity of the phytoplankton community.Se presentan los resultados del inventario de la ficoflora planctónica de la bahía de Acapulco y zona marina aledaña, reconocida a través de una década de estudios, incluyendo uno intensivo con muestreos bimestrales usando red de fitoplancton, botella y observación de muestras vivas, de febrero/2010 a febrero/2011. Se reconocieron 641 taxa, pertenecientes a ocho divisiones algales. El grupo más diverso fue Dinophyta, con 347 taxa, seguido de Bacillariophyta con 274 taxa. Se incluyen fotografías de 131 taxa, 38 correspondientes a nuevos registros para el Pacífico Mexicano, 34 no identificadas al nivel de especie y 59 que tienen algún interés taxonómico-ecológico. El análisis de las curvas de acumulación de especies permite afirmar que la riqueza fitoplanctónica de la Bahía de Acapulco conocida hasta el momento es ya representativa de la ficoflora potencial del sitio; sin embargo, faltan aún estudios más detallados sobre fitoflagelados y picoplancton. Se hace la caracterización biológica de la comunidad fitoplanctónica en términos de: nivel de organización, tipo de nutrición, forma de vida, potencialidad de nocividad o toxicidad, origen (dulceacuícola, salobre o marina), afinidad (nerítica u oceánica) y distribución (cosmopolita, fría-templada, subtropical o tropical). Se reconocen las especies típicas de la bahía y aquellas que han producido florecimientos. La riqueza ficoflorística encontrada en Acapulco puede reflejar una condición trófica variable a lo largo del año, con limitación de nutrientes en ciertos momentos, hecho que se refuerza por las relaciones simbióticas encontradas entre feosomas de cianofitas con dinoflagelados y diatomeas; sin embargo, la presencia de otras especies indicadoras de contaminación, tales como Euglena pascheri, Phaeocystis sp. y el consorcio Leptocylindrus mediterraneus (diatomea)-Solenicola setigera (protozoario), muestran que en otros momentos las concentraciones de nutrientes y materia orgánica pueden ser altas. La forma típica de �anfiteatro� que presenta la bahía, propicia que en la época de lluvias reciba gran cantidad de desechos y aguas negras procedentes de los cerros circundantes sumamente poblados. Sin embargo, la bahía de Acapulco parece tener una alta resilencia, probablemente como resultado de un papel conjugado entre las corrientes marinas (que producen un efecto de lavado de la contaminación antropógena) y la depuración producida por la diversidad funcional de la comunidad fitoplanctónica

Co-ocurrence of two toxic dinoflagellates in Acapulco Bay, Guerrero, Mexico: an opportunity to quantify their biology and ecology

Background and Aims: Harmful Algal Blooms (HAB) of diverse groups of phytoplankton occur commonly in the Mexican Pacific. Two of these are important, caused by saxitoxin-producing dinoflagellates that cause paralytic shellfish poisoning: Gymnodinium catenatum (Gc) and Pyrodinium bahamense var. compressum (Pbc). This study describes the behavior of both taxa throughout the annual cycle and analyzes their morphology, abundance, distribution, and their bloom dynamics in relation to environmental and climatological parameters. Methods: Phytoplankton collections were made in eight study locations within Acapulco Bay, and adjacent coastal zone together with measurements of physicochemical parameters. The climatic data were obtained from the meteorological station 76850 located in Acapulco. Abundance of phytoplankton was evaluated with the Utermöhl method. Statistical analyzes were made to investigate the relationship of Gc and Pbc abundances with environmental and climatic parameters.Key results: Gc was present throughout the year in low densities and in November 2010 it reached a maximum of 189×103 cells L-1, associated with several species of both diatoms and dinoflagellates, including Pbc.  Gc bloom coincides with decrease in ammonium, its preferred nitrogenous form and decrease in water temperature with respect to the average. Pbc formed an intense HAB in July 2010 (reaching a maximum abundance of 773×103 cells L-1), causing significant toxicity and had an upturn in November.Conclusions: Pbc HABs in Acapulco require the occurrence of a previous HAB in the central Pacific or Gulf of Tehuantepec, Mexico, the horizontal transportation of their cysts, as well as high water temperature conditions, abundant rainfall that increased the concentration of phosphates; that is propitiated in the periods of transition “El Niño”-“La Niña” events.Antecedentes y Objetivos: Los florecimientos algales nocivos (FAN) ocurren comúnmente en el Pacífico mexicano, siendo importantes los de Gymnodinium catenatum (Gc) y Pyrodinium bahamense var. compressum (Pbc), dinoflagelados productores de saxitoxina que causan envenenamiento paralítico por mariscos. Pbc se presenta esporádicamente en el Pacifico tropical mexicano. El estudio describe el comportamiento de ambos taxa en un ciclo anual y analiza su morfología, abundancia, distribución y dinámica del FAN en relación con parámetros ambientales y climatológicos. Métodos: Se realizaron diez recolectas de fitoplancton (octubre 2009-enero 2011) en la Bahía de Acapulco y zona costera adyacente, y mediciones de parámetros fisicoquímicos. Los datos climáticos se obtuvieron de la estación meteorológica de Acapulco. La abundancia del fitoplancton se evaluó con el método de Utermöhl. Se realizaron análisis estadísticos para investigar la relación de las abundancias de Gc y Pbc con parámetros ambientales y climáticos. Resultados clave: Gc estuvo presente durante todo el año 2010 con densidades bajas; en noviembre de 2010 alcanzó un máximo de 189×103 células l-1, asociado con especies de diatomeas y dinoflagelados, incluyendo Pbc. El florecimiento de Gc coincidió con disminución de amonio y disminución de temperatura del agua con respecto al promedio. La morfometría de Pb de Acapulco correspondió con la var. compressum. Pbc formó un intenso FAN en julio de 2010 (abundancia máxima de 773×103 células l-1), causando una toxicidad significativa y tuvo un repunte en noviembre. Conclusiones: Los FAN de Pbc en Acapulco requieren un FAN previo en el Pacífico central o en el Golfo de Tehuantepec, transporte horizontal de sus quistes, alta temperatura del agua y abundante precipitación que aumente la concentración de fosfatos; condiciones que se propician en los períodos de transición”El Niño”-La Niña”. Los FAN de Gc en Acapulco están relacionados con eventos “La Niña”, siendo importantes el cambio abrupto de temperatura del agua y el aumento de formas nitrogenadas

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)