Mª.Teresa Moita

Centro de Ciências do Mar | CCMAR

Introduction The production of resting cysts is a key dispersal and survival strategy of many dinoflagellate species. However, little is known about the role of suspended cysts in the benthic nepheloid layer (BNL) in the initiation and decline of planktonic populations. Methods In September 2019, sampling of the dinoflagellate cyst community at di...

We analyse Pseudo-nitzschia abundance off southwest Ire-land collected on weekly basis from January 2003 to December 2010. This study aims at describing Pseudo-nitzschia abundance as a function of the sea surface temperature and the wind index (computed from wind speed and direction). We analyse the influence of the daily wind index on Pseudo-nitzs...

The main meteorological and oceanographic drivers shaping phytoplankton community structure and dynamics are investigated in two wide-open bays influenced by coastal upwelling. Local processes influencing the proliferation of harmful algal bloom species were also investigated. The work was developed during one year in Lisbon Bay (central-west coast...

The Water Framework Directive (WFD) aims at evaluating the ecological status of European coastal water bodies (CWBs). This is a rather complex task and first requires the use of long-term databases to assess the effect of anthropogenic pressure on biological communities. An in situ dataset was assembled using concomitant biological, i.e., chlorophy...

The seasonal and interannual variability of chlorophyll a was studied between 2008 and 2016 in two coastal bays located in the northeastern limit of the Iberia/Canary upwelling ecosystem. The work aims (i) to understand if small latitudinal distances and/or coastline orientation can promote different chlorophyll a seasonal cycles; and (ii) to inves...

This work presents the results of two oceanographic surveys conducted off NW Iberia during successive summer upwelling seasons, aiming at the identification of the physical processes underlying the phytoplankton distribution in the area. Mooring (ADCP and thermistors) and ship-based CTD-F observations corroborate previous results that wind-driven u...

Blooms of Dinophysis acuminata occur every year in Galicia (northwest Spain), between spring and autumn. These blooms contaminate shellfish with lipophilic toxins and cause lengthy harvesting bans. They are often followed by short-lived blooms of Dinophysis acuta, associated with northward longshore transport, at the end of the upwelling season. Du...

The Core Research Project (CRP) HABs in Upwelling Systems was developed as part of the implementation of the international science programme the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB). Progress in addressing eight key questions identified as a requirement for advancing our understanding of the ecology and oceanography of H...

From June 2004 to December 2007, samples were weekly collected at a fixed station located at the mouth of Ria de Aveiro (West Iberian Margin). We examined the seasonal and inter-annual fluctuations in composition and community structure of the phytoplankton in relation to the main environmental drivers and assessed the influence of the oceanographi...

MDS results of the analysis performed on the phytoplankton data from all samples collected; stress value: 0.24. Samples are coded according to the observed values of the upwelling index. (TIF)

List of operational taxonomic units (OTUs) used for organisms unidentifiable at species level, and then grouped within a genus (only genera with size classes defined are included), or at genus level (and then grouped under class- or phyllum-level groups). Size classes were distinguished in most cases. Groups are listed in the following order: Bacil...

%CUM represent the cumulative percentage of most abundant species per season in studied years. Species with less than 0.01% of the total abundance were discarded. (XLS)

Breakdown of percentual contributions from SIMPER analysis for comparisons between assemblages sampled during different oceanographic conditions (all years combined). The taxa listed contribute at least 1%. (DOC)

MDS results of the analysis performed on the phytoplankton data from all samples collected; stress value: 0.24. (A) Samples coded by year; (B) Samples coded by season. (TIF)

Breakdown of percentual contributions from SIMPER analysis for comparisons between assemblages sampled in different seasons (all years combined). The taxa listed contribute at least 1.2%. (DOC)

Dinophysis acuta is a frequent seasonal lipophilic toxin producer in European Atlantic coastal waters associated with thermal stratification. In the Galician Rías, populations of D. acuta with their epicentre located off Aveiro (northern Portugal), typically co-occur with and follow those of Dinophysis acuminata during the upwelling transition (ear...

Dinophysis acuminata and Dinophysis acuta are recurrent species off NW Iberia but their outbreaks occur under different conditions. A decade (2004–2013) of weekly data for each species at two sentinel stations located at the entrance of Rias de Aveiro-AV (NW Portugal, 40°38.6′ N) and Pontevedra-PO (Galicia, Spain, 42°21.5′ N), were used to investig...

Toxic and non-toxic Pseudo-nitzschia blooms are common in coastal waters worldwide including Ireland. Off southwest Ireland, the timing of blooms on a weekly scale is highly variable, while the seasonal pattern is more regular with a bimodal distribution. Upwelling conditions are closely linked to Pseudo-nitzschia blooms. The work presented here de...

The main aim of this study was to evaluate the temporal changes in the phytoplankton community of the Tagus Estuary and to identify the stressors involved. Environmental and phytoplankton data were gathered from several studies conducted in the 1960s, 1980s and from 1999 to 2010 (2000s). Phytoplankton data included information on the community comp...

Foi observada pela primeira vez no Arquipélago dos Açores (NE do Atlântico) uma “maré vermelha”, com coloração acastanhada. Este fenómeno natural ocorreu a 2 de Setembro de 2013 na Fajã da Caldeira de Santo Cristo, na ilha de S. Jorge. A microalga responsável pela mudança de cor da água foi identificada como Alexandrium c.f. minutum através de micr...

To investigate whether phytoplankton is the main factor determining mesozooplankton distribution in a continental shelf affected by upwelling, oceanographic surveys were conducted off NW Portugal in 2002 and 2003. During four different seasons, we investigated how the mesoscale relationship between these two communities was forced by environmental...

The Water Framework Directive (WFD) requires the assessment of ecological quality of water bodies based on physico-chemical and biological elements. This paper is focused on the use of phytoplankton as a biological indicator of ecological quality in Portuguese transitional waters (TWs). Phytoplankton is considered to be a sensitive indicator to env...

Shallow coastal lagoons in southern Portugal, such as the Ria Formosa and Alvor, are considered to be highly important both ecologically and economically. Given the impact of phytoplankton in the ecosystem productivity, it is important to understand its dynamics and to consider them for the assessment of ecosystem health. All available phytoplankto...

Ostreopsis siamensis bloom was detected for the first time in 2004, on the central upwelling coast of Morocco by the HAB monitoring program providing an opportunity to analysed the bloom relationship with prevalent winds, sea surface temperature, surface circulation patterns and nutrients rates. In parallel, the effect of O.siamensis blooms on shel...

On Lisbon bay, the annual phytoplankton succession was characterized by a seasonal cycle typical of a temperate area and by short succession cycles associated with the intensity and persistence of upwelling/downwelling events, changes in temperature and salinity and nutrient availability. From July 2001 to May 2005, seawater samples were weekly col...

Phytoplankton in the ocean is composed by unicellular organisms or small colonies that belong to considerably diverse groups (Raymont, 1980). The spatial and seasonal distribution of phytoplanktonic organisms on Condor seamount was studied based on 3 of the 5 scientific cruises that surveyed the seamount from July 2009 to November 2010. A total of...

a b s t r a c t A study of the mesoscale distribution of phytoplankton communities observed along the Portuguese upwelling coast in 1985–1986 made it possible to identify an assemblage composed by the coccolitho-phores Helicosphaera carteri, Syracosphaera pulchra and Coronosphaera mediterranea. The assemblage was consistently present in the coast i...

The upwelling systems of the eastern boundaries of the world's oceans are susceptible to harmful algal blooms (HABs) because they are highly productive, nutrient-rich environments, prone to high-biomass blooms. This review identifies those aspects of the physical environment important in the development of HABs in upwelling systems through descript...

Blooms of Dinophysis spp. associated with lipophilic shellfish toxin outbreaks are common in Northwestern Iberia waters from spring to autumn. Blooms of Dinophysis acuta are very seasonal (late summer-early autumn); they start earlier in Northern Portuguese waters during the upwelling season, and reach their maximum values in the Galician Rías duri...

Marine planktonic diatoms of the genus Pseudo-nitzschia Peragallo have been responsible for amnesic shellfish poisoning (ASP) events worldwide through the production of the neurotoxin domoic acid (DA). In order to better understand the dynamics of the toxic events of Pseudo-nitzschia there is the need to describe their seasonal and spatial patterns...

Dinophysis acuta, which is responsible for diarrhetic shellfish poisoning, reached particularly high concentrations on the north-west coast of Portugal in 2003. In the Ría de Aveiro (40°41'N), the species reached a maximum concentration of 5.0 × 104 cells l−1 on 8 September, the highest value in a 17-year record of monitoring. The bloom followed a...

Sea surface temperature (SST) and chlorophyll (Chl) maps derived from satellite data, together with wind and phytoplankton cell concentration time-series, are used to characterize the wind forcing and the spatio-temporal SST/Chl variability for periods preceding the summer (June–September) diatom and dinoflagellate blooms. The blooms (concentration...

From July 2001 to May 2005, at a fixed station located in Lisbon Bay (Cascais: 38° 41′ N, 09° 24′ W), surface seawater samples were collected on a weekly basis. We aimed to describe at different temporal scales, shortterm to interannual, the phytoplankton community in relation to hydrographic conditions. Maxima of the main phytoplankton groups vari...

The main objective of this paper is to implement a coupled three-dimensional physical and ecological model for the Aveiro coast, and to apply it to study the temperature and the phytoplankton biomass spatial distributions along the coastal ecosystem. The Aveiro coast is located at Portugal within the upwelling system of the Atlantic Iberian coast,...

Satellite-derived sea surface temperature (SST) and chlorophyll ([Chl]) concentration maps are used together with numerical models to study the advection patterns observed during a summer upwelling event off central Portugal, a region characterized by a complex coastline and bathymetry. It is shown that the model solutions realistically reproduce t...

A study of the Calcidiscus genus in Lisbon Bay has revealed the presence of Calcidiscus quadriperforatus and Calcidiscus leptoporus. Samples were collected continuously on a weekly basis for four years (July 2001–May 2005) and on a cruise carried out in summer 2005, covering Lisbon Bay. Calcidiscus quadriperforatus and C. leptoporus developed in th...

From July 2001 to May 2005, seawater samples were collected once a week at a fixed station in Lisbon bay (38°41′N, 09°24′W) in order to describe the ecological dynamics of the coccolithophore community. The seasonal and interannual distribution patterns of the different species and their relationships with environmental parameters are addressed. Th...

The abundance of Dinophysis acuta in the digestive contents of five copepod taxa was studied in situ during a thin-layer bloom on the NW upwelling coast of Portugal, when D. acuta reached 24x10 3 cells.L-1. The copepod community, sampled in two depth strata, was abundant and reached a maximum of 17800 ind.m-3. The concentration of D. acuta in the c...

This paper reviews relevant investigations conducted in the Western Iberia Upwelling Ecosystem (WIUE) on the dynamics of small pelagic fish (SPF), its relationship to climate changes and processes related to the ‘ocean triad’ (enrichment, concentration, transport/retention). In the last decades, a decline in the productivity of several SPF species...

The different hydrodynamic and ecological conditions that favour the development of Gymnodinium catenatum and Lingulodinium polyedrum blooms along the upwelling coast of Portugal are discussed based on previous results on satellite images and on resting cyst distributions. Results indicate that each species benefits from particular ecological niche...

The composition and the distribution patterns of phytoplankton were studied during the early stages of an upwelling event in Lisbon Bay, in September 1999. The distribution of chlorophyll a and phytoplankton assemblages was asymmetric about the upwelling centre, with the highest abundance of chlorophyll a observed at the inner (coastal) side of the...

To understand the processes controlling the formation of the sediment record, seasonal variations of living communities, fluxes through the water column, and sediment accumulation rates of diatoms, coccolithophores (phytoplankton), and planktic foraminifera (zooplankton) were studied through seasonal water-column sampling, sediment traps, and box-...

On 11 September 1996, the HAB monitoring program detected the presence of Lingulodinium polyedrum in Setubal Bay. One week later, a brownish discoloration of seawater was noticed and the species reached concentrations of 700 000cells/L. The bloom lasted 10 days and the accompanying assemblage was dominated by Prorocentrum micans. A hydrographic/ ph...

The traditional interpretation of Coccolithus pelagicus as a cold water proxy is examined based on its distribution patterns in the water column off the Portuguese coast (using data from eleven cruises) and in Holocene surface sediment samples and Quaternary cores from the same region.Coccolithus pelagicus is common in the Portuguese upwelling syst...

Diatom and coccolithophorid abundance and diatom assemblage composition found in the water column along the Portuguese margin, during upwelling and non-upwelling conditions, are compared to the distribution patterns observed in the recent sediments from the same area. The water column results indicate a one order of magnitude increase in phytoplank...

Diatom and coccolithophorid abundance and diatom assemblage composition found in the water column along the Portuguese margin, during upwelling and non-upwelling conditions, are compared to the distribution patterns observed in the recent sediments from the same area. The water column results indicate a one order of magnitude increase in phytoplank...

During monthly synoptic surveys in a dry year, physicochemical and biological data were collected at 15 stations throughout the Tagus estuary. A Principal Component Analysis (PCA) was used to identify the major sources of variation in the data. The most important variations in the Tagus estuary were the spatial variations, mainly the longitudinal o...

The eggs and larval stages of sardine Sardina pilchardus (Walb.), were studies to establish the spawning seasonality and the spawning area off Portugal. Sampling was carried out during a period of two years (August 1985 to Sptember 1987). Three different sampling designs correspondent to three distinct programs were analysed. The data seem to indic...

Data from AVHRR (Advanced Very High Resolution Radiometer), MODIS (MODerate Resolution Imaging Spectroradiometer) and MERIS (MEdium Resolution Imaging Spectrometer) are used together with field data from a survey carried out off NW Iberian Peninsula in February/March 2006 to study the effect of wind and river runoff on sea surface temperature (SST)...