Evolution of Marine Organisms under Climate Change at Different Levels of Biological Organisation

Research to date has suggested that both individual marine species and ecological processes are expected to exhibit diverse responses to the environmental effects of climate change. Evolutionary responses can occur on rapid (ecological) timescales, and yet studies typically do not consider the role that adaptive evolution will play in modulating biological responses to climate change. Investigations into such responses have typically been focused at particular biological levels (e.g., cellular, population, community), often lacking interactions among levels. Since all levels of biological organisation are sensitive to global climate change, there is a need to elucidate how different processes and hierarchical interactions will influence species fitness. Therefore, predicting the responses of communities and populations to global change will require multidisciplinary efforts across multiple levels of hierarchy, from the genetic and cellular to communities and ecosystems. Eventually, this may allow us to establish the role that acclimatisation and adaptation will play in determining marine community structures in future scenarios

INT reduction is a valid proxy for eukaryotic plankton respiration despite the inherent toxicity of INT and differences in cell wall structure

The reduction of 2-para (iodophenyl)-3(nitrophenyl)-5(phenyl) tetrazolium chloride (INT) is increasingly being used as an indirect method to measure plankton respiration. Its greater sensitivity and shorter incubation time compared to the standard method of measuring the decrease in dissolved oxygen concentration, allows the determination of total and size-fractionated plankton respiration with higher precision and temporal resolution. However, there are still concerns as to the method’s applicability due to the toxicity of INT and the potential differential effect of plankton cell wall composition on the diffusion of INT into the cell, and therefore on the rate of INT reduction. Working with cultures of 5 marine plankton (Thalassiosira pseudonana CCMP1080/5, Emiliania huxleyi RCC1217, Pleurochrysis carterae PLY-406, Scrippsiella sp. RCC1720 and Oxyrrhis marina CCMP1133/5) which have different cell wall compositions (silica frustule, presence/absence of calcite and cellulose plates), we demonstrate that INT does not have a toxic effect on oxygen consumption at short incubation times. There was no difference in the oxygen consumption of a culture to which INT had been added and that of a replicate culture without INT, for periods of time ranging from 1 to 7 hours. For four of the cultures (T. pseudonana CCMP1080/5, P. carterae PLY-406, E. huxleyi RCC1217, and O. marina CCMP1133/5) the log of the rates of dissolved oxygen consumption were linearly related to the log of the rates of INT reduction, and there was no significant difference between the regression lines for each culture (ANCOVA test, F = 1.696, df = 3, p = 0.18). Thus, INT reduction is not affected by the structure of the plankton cell wall and a single INT reduction to oxygen consumption conversion equation is appropriate for this range of eukaryotic plankton. These results further support the use of the INT technique as a valid proxy for marine plankton respiration

Effect of a simulated oil spill on natural assemblages of marine phytoplankton enclosed in microcosms

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Linkage between bacterial assemblage structure, environmental factors and microbial carbon processing in a highly dynamic coastal ecosystem

Symposium GLOBEC-IMBER España celebrado del 28-30 marzo de 2007 en Valencia.-- 2 pagesBacterioplankton communities play an important role in the flow of energy and nutrients through plankton food webs, as a consequence of their high abundance, efficient nutrient uptake and large growth potential. A number of studies have shown changes in bulk bacterial properties, as a response to biological or environmental factors. However, much less is known about how such factors may influence bacterial composition, and how potential shifts in bacterial assemblage structure may in turn influence microbial carbon processing. Even the distribution of the major phylogenetic groups of bacteria is still not well understood. We used mesocosm experiments to study the dynamics of the bacterioplankton assemblage in an extraordinarily hydrodynamic system during the four contrasting periods of the seasonal cycle: winter period, spring phytoplankton bloom, summer stratification and upwelling. We used a correlation approach in order to investigate the degree of coupling between bacterial diversity, carbon cycling and environmental factors. As a proxy for bacterial diversity we used the relative abundance of the most abundant phylogenetic groups of bacteria (Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes) as determined with CARD-FISH. Carbon flux-related variables included, primary production, extracellular release, bacterial production and microbial community respiration. The environmental set of factors and variables included temperature, concentrations of inorganic and organic nutrients, and chlorophyll-a concentration. Contrary to previous studies, we found out that even at this broad phylogenetic level, rapid shifts in bacterial assemblage structure occur associated to biotic and abiotic changes, and a significant correlation exists between bacterial diversity and both carbon flux and environmental factors. Microbial carbon processing also significantly correlated to environmental factorsPeer reviewe

Linkage between bacterial assemblage structure, environmental factors and microbial carbon processing in a highly dynamic coastal ecosystem

Symposium GLOBEC-IMBER España celebrado del 28-30 marzo de 2007 en Valencia.-- 2 pagesBacterioplankton communities play an important role in the flow of energy and nutrients through plankton food webs, as a consequence of their high abundance, efficient nutrient uptake and large growth potential. A number of studies have shown changes in bulk bacterial properties, as a response to biological or environmental factors. However, much less is known about how such factors may influence bacterial composition, and how potential shifts in bacterial assemblage structure may in turn influence microbial carbon processing. Even the distribution of the major phylogenetic groups of bacteria is still not well understood. We used mesocosm experiments to study the dynamics of the bacterioplankton assemblage in an extraordinarily hydrodynamic system during the four contrasting periods of the seasonal cycle: winter period, spring phytoplankton bloom, summer stratification and upwelling. We used a correlation approach in order to investigate the degree of coupling between bacterial diversity, carbon cycling and environmental factors. As a proxy for bacterial diversity we used the relative abundance of the most abundant phylogenetic groups of bacteria (Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes) as determined with CARD-FISH. Carbon flux-related variables included, primary production, extracellular release, bacterial production and microbial community respiration. The environmental set of factors and variables included temperature, concentrations of inorganic and organic nutrients, and chlorophyll-a concentration. Contrary to previous studies, we found out that even at this broad phylogenetic level, rapid shifts in bacterial assemblage structure occur associated to biotic and abiotic changes, and a significant correlation exists between bacterial diversity and both carbon flux and environmental factors. Microbial carbon processing also significantly correlated to environmental factorsPeer reviewe

Zotracos surveys: basic hydrographic and chemical data

Este dataset está compuesto por 2 archivos, de los cuales el primero es el conjunto de datos con 371 análisis de muestras de agua de temperatura, salinidad, oxígeno, nutrientes, pH, alcalinidad, clorofila y materia orgánica, y el otro (Readme.txt) incluye una pequeña descripción de las variables calculadasLa zona costera de transición del noroeste de la Península Ibérica fue objeto de muestreo en tres cruceros realizados del 4 al 2 de diciembre de 2004, del 7 al 14 de febrero y del 23 al 30 de octubre de 2005 a bordo del buque oceanográfico "Cornide de Saavedra". Se muestreo a lo largo de un transecto latitudinal centrado a 41.92°N, cerca de la desembocadura del río Miño y otro frente a la Ría de Vigo. Un total de 5 a 7 estaciones fueron ocupadas durante cada crucero. La salinidad y la temperatura se registraron con una sonda de profundidad de conductividad-temperatura SBE 9/11 conectada al muestreador de roseta con doce botellas de PVC Niskin de 10 L con muelles internos de acero inoxidable. Las mediciones de la conductividad se convirtieron en valores prácticos de la escala de salinidad con la ecuación de la UNESCO (1986). La precisión de las mediciones de CTD para temperatura y salinidad fueron de 0,004 DEG-C y 0,005, respectivamente. Las muestras para los análisis de oxígeno disuelto, pH, alcalinidad total, sales de nutrientes, carbono orgánico disuelto y particulado y nitrógeno fueron recogidas semanalmente con la roseta de 12 botellas Niskin. Para la determinación de nutrientes, las muestras de agua se recogieron en botellas de polietileno de 50 ml y se mantuvieron frías (4ºC) hasta su análisis en el laboratorio utilizando procedimientos estándar de análisis de flujo segmentado. Las precisiones fueron 0,02 micromol/kg para nitrito, 0,1 micromol/kg para nitrato, 0,05 microM para amonio, 0,02 micromol/kg para fosfato y 0,05 micromol/kg para silicato. El oxígeno se determinó por titulación potenciométrica de Winkler utilizando un analizador Titrino 720 con una precisión de ±0,5 micromol/kg. Las muestras de alcalinidad total (TA) y pH (escala de concentración total de hidrógeno, 25°C) se recogieron en frascos de vidrio de 500 ml y se analizaron en pocas horas en el laboratorio base. El pH del agua de mar se midió espectrofotométricamente siguiendo a Clayton y Byrne (1993) aplicándose una adición de 0,0047 (DelValls & Dickson, 1998). La precisión fue 0,003 unidades de pH. El TA se determinó por titulación a pH 4,4 con HCl, según el método potenciométrico de Pérez y Fraga (1987) con una precisión de ±2 micromol/kg. La materia orgánica suspendida se recolectó bajo vacío en filtros precombustionados (450ºC, 4 horas) Whatman GF/F de 25 mm de diámetro y 0,7 micrómetros de tamaño nominal de poro (POC/PON, 0,5-1,5 L de agua de mar). Todos los filtros se secaron durante la noche y se congelaron (-20ºC) antes del análisis. Las mediciones de POC y PON se realizaron con un analizador Perkin Elmer 2400 CHN. Se utilizó un estándar de acetanilida diariamente. La precisión del método es de 0,3 micromol C/L y 0,1 micromol N/LCSIC y Plan Nacional de I+D del Gobierno de España1 data csv ‘29CS20041004_hy1.csv’ file and 1 readme.txt filePeer reviewe