Eva ÁlvarezInstituto Español de Oceanografia | IEO · Centro Oceanográfico de Gijón
Eva Álvarez
PhD
Modelling the ecology and biochemistry of phytoplankton in the ocean
About
36
Publications
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513
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Introduction
Skills and Expertise
Additional affiliations
October 2019 - February 2024
May 2016 - August 2019
August 2013 - October 2013
National Marine Information and Research Centre (NATMIRC)
Position
- Consultant
Publications
Publications (36)
In unicellular phytoplankton, the size scaling exponent of chlorophyll content per cell decreases with increasing light limitation. Empirical studies have explored this allometry combining data from several species using average values of pigment content and cell size for each species. The resulting allometry, includes thus phylogenetic and size sc...
Shelf waters of the Cantabrian Sea (southern Bay of Biscay) are productive ecosystems with a marked seasonality. We present here the results from one year of monthly monitoring of the phytoplankton community together with an intensive sampling carried out in two contrasting scenarios during the summer and autumn in a mid-shelf area. Stratification...
Plenary Session 2: Light field in the ocean: Primary production and ocean dynamics.
Inversion models, in the context of oceanography, relate the observed ocean color to the concentrations of the different biogeochemical components present in the water of the ocean. However, building accurate inversion models can be quite complex due to the many factors that can influence the observed ocean color, such as variations in the composit...
Chromophoric dissolved organic matter (CDOM) significantly contributes to the non-water absorption budget in the Mediterranean Sea. The absorption coefficient of CDOM, aCDOM(λ), is measurable in situ and can be retrieved remotely, although ocean-colour algorithms do not distinguish it from the absorption of detritus. These observations can be used...
The Mediterranean Forecasting System produces operational analyses and reanalyses and 10 d forecasts for many essential ocean variables (EOVs), from currents, temperature, salinity, and sea level to wind waves and pelagic biogeochemistry. The products are available at a horizontal resolution of 1/24∘ (approximately 4 km) and with 141 unevenly space...
The functions of phytoplankton groups determine both how they are affected by climate change and how their responses alter global biogeochemistry. Incorporating the functional diversity of phytoplankton into biogeochemical models is therefore a growing area of research. With the aim of increasing the realism of biodiversity representation, some bio...
Chromophoric dissolved organic matter (CDOM) significantly contributes to the non-water absorption budget in the Mediterranean Sea. The absorption coefficient of CDOM, αCDOM(λ), is measurable in situ and remotely from different platforms and can be used as an indicator of the concentration of other relevant biogeochemical variables, e.g., dissolved...
The Mediterranean Forecasting Systems produces operational analyses, reanalyses and 10-day forecasts for many Essential Ocean Variables (EOVs), from currents, temperature to wind waves and pelagic biogeochemistry. The products are available at a horizontal resolution of 1/24 degrees (approximately 4 km) and 141 unevenly spaced vertical levels. The...
The chlorophyll‐specific absorption spectrum of phytoplankton multiplied with phytoplankton chlorophyll provides the total absorption coefficient of phytoplankton [ ], a fundamental quantity with significance in many marine biogeochemical (BGC) and environmental processes. Representing accurately the sources of variability of in BGC ocean models is...
The phytoplankton absorption cross-section is a fundamental quantity in biogeochemical ocean models that alters the underwater spectral light field and the photosynthetic response of phytoplankton. Phytoplankton taxa are characterized by absorption spectra with defined absorption bands in the visible region of the light spectrum that govern the cap...
Spectrally-resolved biogeochemical models of the ocean describe the penetration of different wavelengths of light along the water column as they are attenuated by optically active constituents. Phytoplankton is one of such optically active elements but the optical properties of the community are variable depending on the pigment composition and the...
Phytoplankton absorption cross-section is a key quantity in biogeochemical ocean models that alters the underwater spectral light field and the photosynthetic response of phytoplankton. Phytoplankton taxa are characterized by absorption spectra with defined absorption bands in the visible region of the light spectrum that govern the capability of d...
This study investigates the spatial and temporal variability of chromophoric-dissolved organic matter (CDOM) in the Mediterranean Sea. The analysis is carried out using a state-of-the-art 3D biogeochemical model. The model describes the plankton dynamics, the cycles of the most important limiting nutrients, and the particulate and dissolved pools o...
We present the results of a series of simulations performed by a multi-spectral bio-optical model developed in the framework of the BIOPTIMOD Service Evolution project for the Copernicus Marine Environment Monitoring System (CMEMS-SE). In this research, we integrate the CMEMS Mediterranean Sea biogeochemical model MedBFM (multi-stoichiometric, phyt...
Microalgae are capable of acclimating to dynamic light environments, as they have developed mechanisms to optimize light harvesting and photosynthetic electron transport. When absorption of light exceeds photosynthetic capacity, various physiological protective mechanisms prevent damage of the photosynthetic apparatus. Xanthophyll pigments provide...
Microalgae are capable of acclimating to dynamic light environments as they have developed combined mechanisms to optimize light harvesting and photosynthetic electron transport. When absorption of light exceeds photosynthetic carbon fixation capacity, various physiological protective mechanisms prevent damage of the photosynthetic apparatus. The x...
Phytoplankton harvests light by integrating chlorophyll in protein‐pigment complexes (photosystems) that are variable in number and size. In ecosystem models, the capacity of light harvesting is described as the pool of chlorophyll. Since most of the variability in phytoplankton chlorophyll content is driven by acclimation to changing nutrient and...
Phytoplankton biomass is often inferred from chlorophyll (Chl), however, biogeochemistry in the ocean is coupled mostly to carbon. The Chl to carbon (Chl:C) ratio is variable and most of the variability is driven by acclimation to changing nutrient and light-conditions. Our current model, REcoM, is a global ecosystem model based on the phytoplankto...
In recent decades, the automatic study and analysis of plankton communities using imaging techniques has advanced significantly. The effectiveness of these automated systems appears to have improved, reaching acceptable levels of accuracy. However, plankton ecologists often find that classification systems do not work as well as expected when appli...
The structural attributes of the planktonic community, such as abundance, size-structure or taxonomic diversity, are emergent properties of processes taking place at the cellular, individual level. The analysis of individual cells could be applied to the study of the ecosystem dynamics, both in structural and physiological terms. Techniques for the...
In many applications, the mistakes made by an automatic classifier are not equal, they have different costs. These problems may be solved using a cost-sensitive learning approach. The main idea is not to minimize the number of errors, but the total cost produced by such mistakes. This brief presents a new multiclass cost-sensitive algorithm, in whi...
Samples from a monthly monitoring programme in the Cantabrian Sea were analysed with a FlowCAM-based automated technique.
The estimates of abundance, biomass size spectra and taxonomic diversity of nano- and microplankton communities were compared
with those obtained by traditional microscopical analysis of the same samples. The structure and abund...
The most commonly used biomass estimate for microalgae is obtained from cell biovolume, usually calculated from microscopically measured linear dimensions. Although reliable, this is a highly time-consuming and specialized technique. Automated sampling devices that acquire images of cells and use pattern recognition techniques to identify the image...
Any technique developed to enumerate plankton must take into account the size structure of the plankton community. Automatic sampling devices must be capable of analysing a minimum number of cells of the largest size to cover the whole size range intended to be sampled effectively. The Flow Cytometer And Microscope (FlowCAM ®) has been used in the...
Resumen A la hora de realizar un estudio biológico del plancton marino es muy importante analizar la distribución de los diferentes organismos pre-sentes en el mismo. Debido a la aparición en el mercado de nuevos instrumentos de moni-torización de organismos en el plancton, ca-paces de captar y segmentar sus imágenes de forma automática, es imposib...
The Spring Phytoplankton Bloom takes place in the Central Cantabrian Sea (Southern Bay of Biscay) from late-winter to spring as a series of blooms with variable biomass accumulation. In late-winter of 2004 and 2005, phytoplankton blooms occurred in this area following a change in the weather. In order to describe the dynamics of these late-winter b...