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Position
- Managing Director
September 2010 - July 2011
January 1995 - present
Publications
Publications (202)
A high-resolution image sequence of sea surface temperature (SST) and Chlorophyll-a (Chl-a), together with numerical model solutions, is used to study the spatio-temporal variability of the two variables under intermittent upwelling-favourable winds. It is shown that the evolution of the cross-shore SST and Chl-a profiles over the shelf is linked t...
Essential Climate Variables (ECVs) like ocean colour provide crucial information on the Optically Active Constituents (OACs) of seawater, such as phytoplankton, non-algal particles, and coloured dissolved organic matter (CDOM). The challenge in estimating these constituents through remote sensing is in accurately distinguishing and quantifying opti...
In times when climate change and human pressures are threatening our ecosystems, cost-effective observation systems are crucial for a synoptic monitoring of the Earth's surface changes. At the Marine and Environmental Sciences Centre (MARE-ULisboa), the Phytoplankton Monitoring and Remote Sensing group focuses on monitoring aquatic environments usi...
The Antarctic Peninsula (West Antarctica) marine ecosystem has undergone substantial changes due to climate-induced shifts in atmospheric and oceanic temperatures since the 1950s. Using 25 years of satellite data (1998-2022), this study presents evidence that phytoplankton biomass and bloom phenology in the West Antarctic Peninsula are significantl...
Numerous policies have been proposed by international and supranational institutions, such as the European Union, to surveil Earth from space and furnish indicators of environmental conditions across diverse scenarios. In tandem with these policies, different initiatives, particularly on both sides of the Atlantic, have emerged to provide valuable...
The recent expansion of wild Pacific oysters already had negative repercussions on sites in Europe and has raised further concerns over their potential harmful impact on the balance of biomes within protected areas. Monitoring their colonisation, especially at early stages, has become an urgent ecological issue. Current efforts to monitor wild Paci...
Since the mid-2010s, the abundance and recruitment of the European anchovy Engraulis encrasicolus has significantly increased off Western Iberia, leading to a 5-fold increase in anchovy catches. The potential environmental drivers impacting recruitment variability in anchovy in Atlantic Northwestern Iberian waters (NW Iberia) are unknown. Using dat...
The Atlantic Meridional Transect (AMT) program (www.amt-uk.org) provides the perfect opportunity to observe the phytoplankton community size structure over a long latitudinal transect 50oN to 50oS, thereby covering the most important latitude-related basin-scale environmental gradients of the Atlantic Ocean. This work presents cell abundance data o...
Inland and coastal waters provide key ecosystem services and are closely linked to human well-being. In this study, we propose a semi-analytical method, which can be applied to Sentinel-2 MultiSpectral Instrument (MSI) images to retrieve high spatial-resolution total suspended solids (TSS) concentration in a broad spectrum of aquatic ecosystems ran...
An analysis of multi-satellite-derived products of four major phytoplankton functional types (PFTs-diatoms, haptophytes, prokaryotes and dinoflagellates) was carried out to investigate the PFT time series in the Atlantic Ocean between 2002 and 2021. The investigation includes the 2-decade trends, climatology, phenology and anomaly of PFTs for the w...
The effects of climate change on the estuarine environment are not fully understood. In temperate regions, droughts are expected to increase in frequency and severity, due to lower precipitation, and the mean sea level is expected to rise. This study aimed to assess how the estuarine environment will be affected by river flow's reduction, mean sea...
Estuaries act as nursery for several species, including commercial species. However, these systems are also deeply affected by anthropogenic activities (both directly and by climate change). Phytoplankton is one of the main estuarine primary producers and one of the main bases of the estuarine trophic webs. Phytoplankton responds to several environ...
The Northern Antarctic Peninsula (NAP) shows shifts in phytoplankton distribution and composition along its warming marine ecosystems. However, despite recent efforts to mechanistically understand these changes, little focus has been given to the phytoplankton seasonal succession, remaining uncertainties regarding to distribution patterns of emergi...
The Western Iberian Coast (WIC) is characterized by a dynamic coastal upwelling system with interactions between oceanographic features and continental river run‐off. The present study investigates the spatio‐temporal variability in the concentrations of Chlorophyll a (Chl a ) and turbidity, and their relationships with physical and other biogeoche...
Changes in coccolithophore productivity in response to climate-driven ocean warming are likely to have cascading biogeochemical effects that feed back to the changing climate. This paper investigates the role (and interplay) of large-scale oceanographic and atmospheric processes across the North- and Equatorial Atlantic, including Saharan dust depo...
The European sardine (Sardina pilchardus) is the most abundant and socio-economically important small pelagic fish species in Western Iberia Upwelling Ecosystem. As a result of a long series of low recruitments, sardine biomass off Western Iberia has greatly reduced since the 2000s. Recruitment of small pelagic fish is mainly dependent on environme...
Phytoplankton play a central role in the planetary cycling of important elements and compounds. Understanding how phytoplankton are responding to climate change is consequently a major question in Earth Sciences. Monitoring phytoplankton is key to answering this question. Satellite remote sensing of ocean colour is our only means of monitoring phyt...
A global in situ data set for validation of ocean colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI) is presented. This version of the compilation, starting in 1997, now extends to 2021, which is important for the validation of the most recent satellite optical sensors such as Sentinel 3B OLCI and NOAA-20 VIIRS. The data s...
The estuarine phytoplankton communities are known to respond rapidly to environmental changes, being considered an important water quality indicator; thus, it is crucial to fully under-stand its natural variability. The objective of the present study was to assess the spatial variability of both physicochemical variables and the phytoplankton commu...
Estuaries are highly productive ecosystems, which are strongly affected by several anthropogenic pressures. Phytoplankton is a key element for assessing the ecological quality status in these transitional waters. Moreover, understanding physico-chemical and biological drivers is crucial to disentangle their effect on the structure of phytoplankton...
An analysis of multi-satellite derived products of four major phytoplankton functional types (PFTs – diatoms, haptophytes, prokaryotes and dinoflagellates), was carried out to investigate the PFT time series in the trans-Atlantic Ocean between 2002 and 2021. The investigation includes the two-decade trends, climatology, phenology and anomaly of PFT...
High-resolution satellite data and numerical model solutions are used to document the inner shelf circulation structure during a short upwelling event off NW Portugal in September 2019. A rare sequence of cloud free images of sea surface temperature (SST) and ocean colour show an upwelling cell separated from the coast during the intense wind phase...
In situ and satellite data are used to document the spatial and temporal variability patterns of the phytoplankton pigments off W Iberia.
The in situ data was obtained during the fisheries monitoring surveys carried out by the Portuguese Institute for the Ocean and Atmosphere (IPMA) mainly in the frame of the European Union Data Collection Framewo...
A global in-situ data set for validation of ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI) is presented. This version of the compilation, starting in 1997, now extends to 2021, which is important for the validation of the most recent satellite optical sensors such as Sentinel 3B OLCI and NOAA-20 VIIRS. The data s...
In mesotidal estuaries, the spatial and temporal variation of physicochemical and biological parameters, and thus water quality, is strongly influenced by tidal dynamics. Hence, to improve monitoring and management strategies , it is imperative to understand how tidal conditions affect water quality parameters and the overall water quality assessme...
Chlorophyll-a (Chl-a) underestimation by global satellite algorithms in the Southern Ocean has long been reported, reducing their accuracy, and limiting the potential for evaluating phytoplankton biomass. As a result, several regional Chl-a algorithms have been proposed. The present work aims at assessing the performance of both global and regional...
Phytoplankton biomass, through its proxy, Chlorophyll a, has been assessed at synoptic temporal and spatial scales with satellite remote sensing (RS) for over two decades. Also, RS algorithms to monitor relative size classes abundance are widely used; however, differentiating functional types from RS, as well as the assessment of phytoplankton stru...
As alterações climáticas podem influenciar as variações a longo termo nos estuários. Localizados na interface entre os rios e os oceanos, estes sistemas são altamente dinâmicos e influenciados por processos hidrológicos, atmosféricos e biogeoquímicos. A comunidade fitoplanctónica responde rapidamente a alterações no meio ambiente, sendo considerada...
To establish effective water quality monitoring strategies in estuaries, it is imperative to identify and understand the main drivers for the variation of water quality parameters. The tidal effect is an important factor of the daily and fortnightly variability in several estuaries. However, the extent of that influence on the different physicochem...
While primary productivity is more stable in oceanic regions, it may vary to a great extent with the proximity to coasts, where mesoscale processes may intertwine and shape phytoplankton community composition and biomass. Sometimes, this may lead to the development of anomalous phytoplankton blooms (i.e., episodic blooms that exceed several times t...
The application of Water Quality Indexes (WQI) is an essential part of the water framework directive. One of the main factors of variability in transitional waters is the tidal effect, but knowledge of its effect on WQI is still scarce. Therefore, the objective of this study is to evaluate such effect on the existing metrics (e.g. Chlorophyll’s P90...
Changes in temperature and CO2 are typically associated with climate change, but they also act on shorter time scales, leading to alterations in phytoplankton physiology and community structure. Interactions among stressors may cause synergistic or antagonistic effects on phytoplankton dynamics. Therefore, the main goal of this work is to understan...
Coccolithophores are among the most important calcifying pelagic organisms. To assess how coccolithophore species with different coccolith-carbonate mass and distinct ecological resilience to ocean warming will influence the "rain ratio" and the "biological carbon pump", 1 yr of species-specific coccolith-carbonate export fluxes were quantified usi...
Two ocean colour features in the western Iberian margin (western Europe) were described in present work. They were identified in 10 years (2002–2012) of MODIS-AQUA normalized water-leaving radiance (nLw) at 555 nm and their causes were investigated using complementary satellite, in-situ and model data. One feature was a band of high nLw555 (>0.8 mW...
The Tagus Estuary is one of the largest estuaries in Europe and merges large urban and industrial areas. Understanding phytoplankton community variability is key for an appropriate assessment of the estuarine ecological status. The objective of the present study was to assess the importance of the tidal influence over the phytoplankton community an...
Monitoring water quality parameters and their ecological effects in transitional waters is usually performed through in situ sampling programs. These are expensive and time-consuming, and often do not represent the total area of interest. Remote sensing techniques offer enormous advantages by providing cost-effective systematic observations of a la...
Phytoplankton bloom phenology studies are fundamental for the understanding of marine ecosystems. Mismatches between fish spawning and plankton peak biomass will become more frequent with climate change, highlighting the need for thorough phenology studies in coastal areas. This study was the first to assess phytoplankton bloom phenology in the Wes...
Reliable satellite estimates of chlorophyll-a concentration (Chl-a) are needed in coastal waters for applications such as eutrophication monitoring. However, because of the optical complexity of coastal waters, retrieving accurate Chl-a is still challenging. Many algorithms exist and give quite different performance for different optical conditions...
Um dos fatores de variação mais importante em águas de transição é o ciclo de maré, mas o seu efeito sobre as métricas utilizadas para a classificação do estado de massas de água é ainda pouco estudado. O objetivo deste estudo foi analisar a influência da maré nos resultados da classificação de diferentes métricas. Duas estações com diferentes níve...
Early detection of dense harmful algal blooms (HABs) is possible using ocean colour remote sensing. Some algorithms require a training dataset, usually constructed from satellite images with a priori knowledge of the existence of the bloom. This approach can be limited if there is a lack of in situ observations, coincident with satellite images. A...
The phytoplankton comprises different shapes and sizes, having different impacts on the biogeochemical cycles. The development of models for Phytoplankton Size Classes ( is based mainly on the empirical relationship between marker pigments and chlorophyll a
The present study sought to investigate the PSC's spatial variability along the Portuguese c...
The Northern Antarctic Peninsula (NAP), located in West Antarctica, is amongst the most impacted regions by recent warming events. Its vulnerability to climate change has already led to an accumulation of severe changes along its ecosystems. This work reviews the current findings on impacts observed in phytoplankton communities occurring in the NAP...
Monitoring lakes in high-latitude areas can provide a better understanding of freshwater systems sensitivity and accrete knowledge on climate change impacts. Phytoplankton are sensitive to various conditions: warmer temperatures, earlier ice-melt and changing nutrient sources. While satellite imagery can monitor phytoplankton biomass using chloroph...
Monitoring lakes in high-latitude areas can provide a better understanding of freshwater systems sensitivity and accrete knowledge on climate change impacts. Phytoplankton are sensitive to various conditions: warmer temperatures, earlier ice-melt and changing nutrient sources. Satellite imagery can monitor algae biomass over large areas. The detect...
Aquaculture has become the fastest-growing sector of the food industry worldwide. The increase of intensive aquaculture practices, however, has been raising global concern about economic and social impacts, but mostly due to the associated potential environmental impacts. The aim of this report is to make a preliminary assessment of the impact of a...
Diatoms usually dominate microphytobenthic biofilms in coastal and estuarine intertidal environments. Yet, functional studies on biofilms often skip species analysis because benthic diatoms are notoriously difficult to extract from sediments and challenging to identify at that taxonomic level. Valid, less time-consuming alternatives would surely be...
Surface sediments were sampled at 18 stations from 7 to 64 m depth off the SE coast of Algarve to characterize the organic matter contents in the inner and middle shelf. For each sediment sample, grain size, mineralogy and total organic carbon analyses were carried out, as well as pigment analyses (19’ but-fucoxanthin, fucoxanthin, 19’ hex-fucoxant...
Ocean colour is recognised as an Essential Climate Variable (ECV) by the Global Climate Observing System (GCOS); and spectrally-resolved water-leaving radiances (or remote-sensing reflectances) in the visible domain, and chlorophyll-a concentration are identified as required ECV products. Time series of the products at the global scale and at high...
Spectrally resolved water-leaving radiances (ocean colour) and inferred chlorophyll concentration are key to studying phytoplankton dynamics at seasonal and inter-annual scales, for a better understanding of the role of phytoplankton in marine biogeochemistry; the global carbon cycle; and the response of marine ecosystems to climate variability, ch...