Coccolithophore biodiversity controls carbonate export in the Southern Ocean

Southern Ocean waters are projected to undergo profound changes in their physical and chemical properties in the coming decades. Coccolithophore blooms in the Southern Ocean are thought to account for a major fraction of the global marine calcium carbonate (CaCO3) production and export to the deep sea. Therefore, changes in the composition and abundance of Southern Ocean coccolithophore populations are likely to alter the marine carbon cycle, with feedbacks to the rate of global climate change. However, the contribution of coccolithophores to CaCO3 export in the Southern Ocean is uncertain, particularly in the circumpolar subantarctic zone that represents about half of the areal extent of the Southern Ocean and where coccolithophores are most abundant. Here, we present measurements of annual CaCO3 flux and quantitatively partition them amongst coccolithophore species and heterotrophic calcifiers at two sites representative of a large portion of the subantarctic zone. We find that coccolithophores account for a major fraction of the annual CaCO3 export, with the highest contributions in waters with low algal biomass accumulations. Notably, our analysis reveals that although Emiliania huxleyi is an important vector for CaCO3 export to the deep sea, less abundant but larger species account for most of the annual coccolithophore CaCO3 flux. This observation contrasts with the generally accepted notion that high particulate inorganic carbon accumulations during the austral summer in the subantarctic Southern Ocean are mainly caused by E. huxleyi blooms. It appears likely that the climate-induced migration of oceanic fronts will initially result in the poleward expansion of large coccolithophore species increasing CaCO3 production. However, subantarctic coccolithophore populations will eventually diminish as acidification overwhelms those changes. Overall, our analysis emphasizes the need for species-centred studies to improve our ability to project future changes in phytoplankton communities and their influence on marine biogeochemical cycles.info:eu-repo/semantics/publishedVersio

Mejora de la competencia científica y la resolución de problemas en la formación inicial on-line de futuros maestros a través de la creación de materiales digitales y píldoras audiovisuales

Memoria ID-018 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2020-2021

Percepción del profesorado latinoamericano y español sobre el cambio climático: aproximaciones desde un MOOC de formación docente

This study focuses on analyzing the beliefs that Spanish and Latin American teachers have about climate change, paying special attention to their general perception of the phenomenon, awareness, concerns and knowledge about certain scientific concepts. To collect information, a questionnaire of 38 closed-response items (questions and statements) was used, which was answered by a total of 85 pre-university teachers during an online teacher education course on climate change. Regardless of their place of origin, Spain or Latin America, the teachers presented very similar results in the aspects considered in the study, with very few of them showing significant differences. Teachers believe that the phenomenon is real and caused by human activity, but despite recognizing the threat to health it poses, they perceive it as something that will affect more to future generations. Both groups share the idea that society is not prepared to adopt adaptation and mitigation measures. In addition, several misconceptions about the scientific knowledge have been detected , which are in agreement with similar studies carried out in other contexts with general population. Finally, some implications for teacher education are discussed. Keywords: Climate change; Education; Teachers; Spain; Latin America. Percepción del profesorado latinoamericano y español sobre el cambio climático: aproximaciones desde un MOOC de formación docente Resumen: Este estudio se centra en analizar las creencias que tienen profesores de España y Latinoamérica sobre el cambio climático, prestando especial atención a la percepción general que tienen del fenómeno, la concienciación, las preocupaciones y al conocimiento de determinados fundamentos científicos. Para recoger la información, se utilizó un cuestionario de 38 ítems (preguntas y afirmaciones) de respuesta cerrada que respondieron un total de 85 profesores de niveles preuniversitarios durante un curso online de formación docente sobre el cambio climático. Independientemente del lugar de procedencia, España o América Latina, los profesores presentan entre ellos resultados muy similares en los aspectos considerados en el estudio, registrándose diferencias significativas en muy pocos de ellos. Creen que el fenómeno es algo real y provocado por la actividad humana, pero a pesar de reconocer la amenaza para la salud que supone, sostienen que afectará más gravemente a futuras generaciones. Ambos grupos comparten la idea de que la sociedad no está preparada para adoptar medidas de adaptación y mitigación. Además, se ha detectado entre el profesorado varias concepciones alternativas sobre los fundamentos científicos y los conocimientos conceptuales que tienen sobre el problema, que están en concordancia con estudios similares realizados en otros contextos con la población en general. Por último, se discuten algunas implicaciones en la formación docente. Palabras clave: Cambio climático; Educación; profesores; España; Latinoamérica.Este estudio se centra en analizar las creencias que tienen profesores de España y Latinoamérica sobre el cambio climático, prestando especial atención a la percepción general que tienen del fenómeno, la concienciación, las preocupaciones y al conocimiento de determinados fundamentos científicos. Para recoger la información, se utilizó un cuestionario de 38 ítems (preguntas y afirmaciones) de respuesta cerrada que respondieron un total de 85 profesores de niveles preuniversitarios durante un curso online de formación docente sobre el cambio climático. Independientemente del lugar de procedencia, España o América Latina, los profesores presentan entre ellos resultados muy similares en los aspectos considerados en el estudio, registrándose diferencias significativas en muy pocos de ellos. Creen que el fenómeno es algo real y provocado por la actividad humana, pero a pesar de reconocer la amenaza para la salud que supone, sostienen que afectará más gravemente a futuras generaciones. Ambos grupos comparten la idea de que la sociedad no está preparada para adoptar medidas de adaptación y mitigación. Además, se ha detectado entre el profesorado varias concepciones alternativas sobre los fundamentos científicos y los conocimientos conceptuales que tienen sobre el problema, que están en concordancia con estudios similares realizados en otros contextos con la población en general. Por último, se discuten algunas implicaciones en la formación docente. Palabras clave: Cambio climático; Educación; profesores; España; Latinoamérica. Latin American and Spanish teachers' perception of climate change: approaches from a teacher education MOOC Abstract: This study focuses on analyzing the beliefs that Spanish and Latin American teachers have about climate change, paying special attention to their general perception of the phenomenon, awareness, concerns and knowledge about certain scientific concepts. To collect information, a questionnaire of 38 closed-response items (questions and statements) was used, which was answered by a total of 85 pre-university teachers during an online teacher education course on climate change. Regardless of their place of origin, Spain or Latin America, the teachers presented very similar results in the aspects considered in the study, with very few of them showing significant differences. Teachers believe that the phenomenon is real and caused by human activity, but despite recognizing the threat to health it poses, they perceive it as something that will affect more to future generations. Both groups share the idea that society is not prepared to adopt adaptation and mitigation measures. In addition, several misconceptions about the scientific knowledge have been detected , which are in agreement with similar studies carried out in other contexts with general population. Finally, some implications for teacher education are discussed. Keywords: Climate change; Education; Teachers; Spain; Latin America

Concienciación de los futuros maestros sobre las supersticiones, las pseudociencias y sus consecuencias

Memoria ID-193. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020

Full annual monitoring of Subantarctic Emiliania huxleyi populations reveals highly calcified morphotypes in high-CO2 winter conditions [Dataset]

[EN]Supplement Table S1. a. Sampling dates and morphotype relative abundance of E. huxleyi coccolith assemblages collected in the surface layer at the SOTS site. b. Sampling intervals, fluxes and morphotype relative abundance and morphometric measurements of E. huxleyi coccolith assemblages intercepted by the sediment traps at the SOTS and SAM sites. Table S2. Environmental parameters measured at the surface layer of the SOTS site from August 2011 to July 2012.European Union's Horizon 2020, Marie Skłodowska-Curie Individual fellowshipThe dataset includes Supplementary Information, Table S1. : abundance, composition and morphometric data of E. huxleyi coccolith assemblages generated during the current study Table S2: environmental data Environmental parameters measured at the surface layer of the SOTS site from August 2011 to July 2012

Full annual monitoring of Subantarctic Emiliania huxleyi populations reveals highly calcified morphotypes in high-CO2 winter conditions

Datos de investigación en: http://hdl.handle.net/10366/143074[EN]Ocean acidifcation is expected to have detrimental consequences for the most abundant calcifying phytoplankton species Emiliania huxleyi. However, this assumption is mainly based on laboratory manipulations that are unable to reproduce the complexity of natural ecosystems. Here, E. huxleyi coccolith assemblages collected over a year by an autonomous water sampler and sediment traps in the Subantarctic Zone were analysed. The combination of taxonomic and morphometric analyses together with in situ measurements of surface-water properties allowed us to monitor, with unprecedented detail, the seasonal cycle of E. huxleyi at two Subantarctic stations. E. huxleyi subantarctic assemblages were composed of a mixture of, at least, four diferent morphotypes. Heavier morphotypes exhibited their maximum relative abundances during winter, coinciding with peak annual TCO2 and nutrient concentrations, while lighter morphotypes dominated during summer, coinciding with lowest TCO2 and nutrients levels. The similar seasonality observed in both time-series suggests that it may be a circumpolar feature of the Subantarctic zone. Our results challenge the view that ocean acidifcation will necessarily lead to a replacement of heavily-calcifed coccolithophores by lightly-calcifed ones in subpolar ecosystems, and emphasize the need to consider the cumulative efect of multiple stressors on the probable succession of morphotypes.European Union's Horizon 2020, Marie Skłodowska-Curie Individual fellowshi

Reduction in size of the calcifying phytoplankton Calcidiscus leptoporus to environmental changes between the Holocene and modern Subantarctic Southern Ocean

Unidad de excelencia María de Maeztu CEX2019-000940-MThe Subantarctic Zone of the Southern Ocean plays a disproportionally large role on the Earth system. Model projections predict rapid environmental change in the coming decades, including ocean acidification, warming, and changes in nutrient supply which pose a serious risk for marine ecosystems. Yet despite the importance of the Subantarctic Zone, annual and inter-annual time series are extremely rare, leading to important uncertainties about the current state of its ecosystems and hindering predictions of future response to climate change. Moreover, as the longest observational time series available are only a few decades long, it remains unknown whether marine pelagic ecosystems have already responded to ongoing environmental change during the industrial era. Here, we take advantage of multiple sampling efforts - monitoring of surface layer water properties together with sediment trap, seafloor sediment and sediment core sampling - to reconstruct the modern and pre-industrial state of the keystone calcifying phytoplankton Calcidiscus leptoporus, central to the global marine carbonate cycle. Morphometric measurements reveal that modern C. leptoporus coccoliths are 15% lighter and 25% smaller than those preserved in the underlying Holocene-aged sediments. The cumulative effect of multiple environmental factors appears responsible for the coccolith size variations since the Last Deglaciation, with warming and ocean acidification most likely playing a predominant role during the industrial era. Notably, extrapolation of our results suggests a future reduction in cell and coccolith size which will have a negative impact on the efficiency of the biological pump in the Southern Ocean through a reduction of carbonate ballasting. Lastly, our results tentatively suggest that C. leptoporus coccolith size could be used as a palaeo-proxy for growth rate. Future culture experiments will be needed to test this hypothesis

Improvement on social representation of climate change through a knowledge-based MOOC in spanish

Climate Change is the most important threat to our society and all species on Earth. Large alterations in the climate are affecting every aspect of our society and in order to limit this impact we must decarbonize the economy before 2050. Although science presents solid evidence on the magnitude of the problem and outlines precisely the consequences, people do not act accordingly and do not consider this issue a priority for their survival. The reason behind this paradox might be a non-appropriate Social Representation of Climate Change in society as the Social Representation conditions and forms the response of the society. In this paper, we extend previous investigations of how this Social Representation is formed in order to find ways to improve it through a Massive Online Open Course on the Science of Climate Change. Using a validated questionnaire, we investigated the knowledge dimension of the Social Representation of Climate Change in a group of students of a MOOC on Climate Change. A pre- and posttest revealed general improvements in all the categories that were considered in this study. A detailed analysis showed different degrees of improvement for different groups, providing new insights in the efficiency of knowledge-based online courses. Well designed Massive Online Open Courses, based on scientific evidence, targeted to the general public might improve the Social Representation of Climate Change, which may in turn trigger awareness and an effective mobilization to address this important and urgent topicThis research was funded by the project 2017/00287/001 of the Fundación Biodiversidad del Ministerio de Agricultura, Pesca, Alimentación y Medio Ambiente (España)S

Evolución paleoceanográfica del Oceáno Austral (sectores subantárticos del Atlántico y Pacífico) durante el Plioceno tardio-Pleistoceno

[ES] Esta tesis examina el registro de nanofósiles calcáreos de los testigos 1090 (Atlántico Sur) y 1172 (Pacífico Sur) del Ocean Drilling Program (ODP) durante el Plio-Pleistoceno (3.5-1.8 Ma). Los nanofósiles calcáreos (cocolitofóridos) son una excelente herramienta para monitorizar las condiciones de las aguas superficiales del Océano Sur dado que son sensibles a diferentes factores ambientales como la luz, temperatura y concentración de nutrientes. Los registros de nanofósiles han sido comparados con los isótopos bentónicos para reconstruir los cambios paleoceanográfi cos del Océano Sur durante el intervalo de estudio.[EN] This thesis examines the record of calcareous nannofossils witnesses 1090 (South Atlantic) and 1172 (South Pacific) from Ocean Drilling Program (ODP) during the Plio-Pleistocene (3.5-1.8 Ma). The calcareous nannofossils (coccolithophores) are an excellent tool to monitor the conditions of the Southern Ocean surface waters because they are sensitive to different environmental factors such as light, temperature and nutrient concentration. Nannofossils records have been compared with the benthic isotope paleoceanography to reconstruct changes cos Southern Ocean during the study interval