Rosa Trobajo

Rosa Trobajo
IRTA Institute of Agrifood Research and Technology | IRTA · Aquatic Ecosystems Programme

PhD

About

92
Publications
30,999
Reads
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2,668
Citations
Citations since 2016
37 Research Items
1906 Citations
20162017201820192020202120220100200300
20162017201820192020202120220100200300
20162017201820192020202120220100200300
20162017201820192020202120220100200300
Additional affiliations
February 2004 - February 2006
Natural History Museum, London
Position
  • Marie Curie Research Fellow
June 1995 - February 2004
Universitat de Girona
Position
  • Research Assistant

Publications

Publications (92)
Article
Full-text available
Implementation of DNA metabarcoding for diatoms for environmental monitoring is now moving from a research to an operational phase, requiring rigorous guidelines and standards. In particular, the first steps of the diatom metabarcoding process, which consist of sampling and storage, have been addressed in various ways in scientific and pilot studie...
Article
Two short diatom rbcL barcodes, 331-bp and 263-bp in length, have frequently been used in diatom metabarcoding studies. They overlap in a common 263-bp region but differ in the presence or absence of a 68-bp tail at the 5′ end. Though the effectiveness of both has been demonstrated in separate biomonitoring and diversity studies, the impact of the...
Article
Full-text available
Recent advances in molecular biomonitoring open new horizons for aquatic ecosystem assessment. Rapid and cost-effective methods based on organismal DNA or environmental DNA (eDNA) now offer the opportunity to produce inventories of indicator taxa that can subsequently be used to assess biodiversity and ecological quality. However, the integration o...
Article
Full-text available
In contrast to surveys based on a few genes that often provide limited taxonomic resolution, transcriptomes provide a wealth of genomic loci that can resolve relationships among taxonomically challenging lineages. Diatoms are a diverse group of aquatic microalgae that includes important bioindicator species and many such lineages. One example is Ni...
Preprint
Full-text available
In contrast to surveys based on a few genes that often provide limited taxonomic resolution, transcriptomes provide a wealth of genomic loci that can resolve relationships among taxonomically challenging lineages. Diatoms are a diverse group of aquatic microalgae that includes important bioindicator species and many such lineages. One example is Ni...
Article
Full-text available
Groundwater pollution has increased in recent years due to the intensification of agricultural and livestock activities. This results in a significant reduction in available freshwater resources. Here, we have studied the long term assessment of a green technology (1–4 L/day) based on a photobioreactor (PBR) containing immobilised microalgae–bacter...
Article
We investigated the advantages and disadvantages of light microscope (LM)-based identifications and DNA metabarcoding, based on a 312-bp rbcL marker, for examining benthic diatom communities from Mediterranean shallow coastal environments. For this, we used biofilm samples collected from different substrata in the Ebro delta bays. We show that 1) E...
Article
Full-text available
In this article we describe Nitzschia anatoliensis Górecka, Gastineau & Solak sp. nov., an example of a diatom species inhabiting extreme habitats. The new species has been isolated and successfully grown from the highly alkaline Van Lake in East Turkey. The description is based on morphology (light and scanning electron microscopy), the sequencing...
Article
Our study evaluates differences in the distribution and ecology of genetic variants within several ecologically important diatom species that are also key for Water Framework Directive monitoring of European rivers: Fistulifera saprophila (FSAP), Achnanthidium minutissimum (ADMI), Nitzschia inconspicua (NINC) and Nitzschia soratensis (NSTS). We use...
Conference Paper
Full-text available
The feeding behavior of nudibranchs has always been regarded as carnivorous and this group is often referred to as an exam- ple of specialized predators. In the Alfacs Bay (Ebro Delta, NW Mediterranean), the small sized, cryptic nudibranch Polycere- lla emertoni and its egg masses are found associated with the pseudo-indigenous bryozoan Amathia ver...
Article
Full-text available
DNA barcoding and metabarcoding is increasingly used to effectively and precisely assess and monitor biodiversity in aquatic ecosystems. As these methods rely on data availability and quality of barcode reference libraries, it is important to develop and follow best practices to ensure optimal quality and traceability of the metadata associated wit...
Article
The paraphyletic diatom genus Nitzschia comprises over 1000 morphologically distinct pennate taxa, known from the benthos and plankton of freshwater, brackish and marine environments. The principal diagnostic characters for delimitation of Nitzschia species include valve shape, the position and structure of the raphe, presence/absence and shape of...
Article
The Bacillariaceae is a very species-rich family of raphid diatoms and includes the large and taxonomically difficult genus Nitzschia, whose species are often small-celled and finely structured and have few discrete morphological characters visible in the light microscope. The classification of Nitzschia is still mostly based on one developed in th...
Article
Nudibranchs have always been regarded as a group of specialized predators. In Alfacs Bay (Ebro Delta, Spain), the cryptic nudibranch Polycerella emertoni is found associated with the pseudo-indigenous bryozoan Amathia verticillata, which has been thought to be its target prey. Here, we assessed the trophic ecology of P. emertoni using a combination...
Article
Our study of 164 diatom samples from Catalonia (NE Spain) is the first to evaluate the applicability of DNA metabarcoding, based on high throughput sequencing (HTS) using a 312-bp rbcL marker, for biomonitoring Mediterranean rivers. For this, we compared the values of a biotic index (IPS) and the ecological status classes derived from them, between...
Article
Full-text available
Nitzschia is common in the phytoplankton of several East African lakes. A new species, Nitzschia fenestralis, sp. nov. D. Grady, D.G. Mann et Trobajo was encountered at numerous depths in a 16 m sediment core from Lake Babogaya, Ethiopia and is described using light and scanning electron microscopy. It is compared with several other morphologically...
Article
Full-text available
Diatoms (Bacillariophyta) are ubiquitous microalgae which produce a siliceous exoskeleton and which make a major contribution to the productivity of oceans and freshwaters. They display a huge diversity, which makes them excellent ecological indicators of aquatic ecosystems. Usually, diatoms are identified using characteristics of their exoskeleton...
Article
Full-text available
A monophyletic group of dinoflagellates, called ‘dinotoms’, are known to possess evolutionarily intermediate plastids derived from diatoms. The diatoms maintain their nuclei, mitochondria, and the endoplasmic reticulum in addition with their plastids, while it has been observed that the host dinoflagellates retain the diatoms permanently by control...
Article
We describe here a protocol for cleaning diatoms when time is short and the amount of sample is very limited. Essentially, the method consists of drying material onto coverslips and cleaning it directly in situ using nitric acid (or hydrogen peroxide), which is evaporated to dryness. After washing twice or a few times with deionized water, the cove...
Article
Full-text available
Background and aims – The diatom genus Simonsenia has been considered for some time a minor taxon, limited in its distribution to fresh and slightly brackish waters. Recently, knowledge of its diversity and geographic distribution has been enhanced with new species described from brackish-marine waters of the southern Iberian Peninsula and from inl...
Article
Full-text available
Current biomonitoring approaches are widely used but have some limitations. • DNA metabarcoding provides a new complementary tool for biomonitoring. • Metabarcoding allows extending the range of taxa used as bioindicators. • Metabarcoding data could be used to establish molecular metrics and indices. • Future work should standardise procedures and...
Article
Diatoms are used routinely to assess pollution level in rivers and lakes. Current methods are based on identification by light microscopy, which is laborious. An alternative is to identify species based on short DNA fragments and High–Throughput Sequencing (HTS). However a potential limitation is the incomplete coverage of species in reference barc...
Article
In recent years, remarkable progress has been made in developing environmental DNA metabarcoding. However, its ability to quantify species relative abundance remains uncertain, limiting its application for biomonitoring. In diatoms, although the rbcL gene appears to be a suitable barcode for diatoms, providing relevant qualitative data to describe...
Article
A previously unknown member of the Bacillariaceae was discovered almost simultaneously in four different brackish coastal wetlands on the Atlantic and Mediterranean coasts of the Iberian Peninsula. It appears to tolerate a wide range of salinities but was never common in samples where it occurred. The frustules were consistently hantzschioid (i.e....
Poster
Full-text available
In this communication we present some of the results of the benthic diatom community study. Diatom samples were obtained from 17 sites distributed across the two coastal lagoons, both before (2011) and one and two years after habitat restoration actions were taken to restore (2012 and 2013)
Article
Major Mediterranean deltas began to develop during a period between 8000 and 6000 yr BP when the rate of fluvial sediment input overtook the declining rate of sea-level rise. However, different authors have argued that the Ebro Delta primarily formed during the late Middle Ages as a consequence of increased anthropogenic pressure on its river basin...
Article
1. Studies quantifying the content of fine particulate matter (organic and inorganic) retained in macrophyte stands are scarce. Thus, little is known about the relationship between retention of fine particulate matter and macrophyte architecture, especially in rivers. Here, we quantified the amount of organic and inorganic fine particulate matter r...
Chapter
River-dominated estuaries (also known as salt-wedge or highly stratified estuaries) are transitional water bodies occurring in micro-tidal coasts such as the Mediterranean. Their hydrological and ecological particularities make difficult the assessment of the ecological status using either the procedures for rivers or estuaries. For instance, river...
Article
Full-text available
The genus Simonsenia is reviewed and S. aveniformis described as new for science by light and electron microscopy. The new species originated from estuarine environments in southern Iberia (Atlantic coast) and was isolated into culture. In LM, Simonsenia resembles Nitzschia, with bridges (fibulae) beneath the raphe, which is marginal. It is only el...
Article
sochrysis galbana and Selenastrum capricornutum, marine and freshwater microalgae species respectively, were co-digested with sewage sludge under mesophilic and thermophilic conditions. The substrates and the temperatures significantly influenced biogas production. Under mesophilic conditions, the sewage sludge digestion produced 451 ± 12 mLBiogas/...
Chapter
Full-text available
River-dominated estuaries (also known as salt-wedge or highly stratified estuaries) are transitional water bodies occurring in micro-tidal coasts such as the Mediterranean. Their hydrological and ecological particularities make difficult the assessment of the ecological status using either the procedures for rivers or estuaries. For instance, river...
Article
Nitzschia inconspicua is an ecologically important diatom species, which is believed to have a widespread distribution and to be tolerant to salinity and to organic or nutrient pollution. However, its identification is not straightforward and there is no information on genetic and ecophysiological diversity within the species. We used morphological...
Article
The contemporary distribution of benthic diatoms and their use as ecological indicators were examined in a coastal wetland, the Ebro Delta, as a representative of environmental conditions in Mediterranean coastal wetlands. A total of 424 diatom taxa were identified across 24 sites encompassing a wide range of wetland habitat types (coastal lagoons,...
Conference Paper
Our study combines modern foraminiferal distribution from a Mediterranean wetland (the Ebro Delta, NE Iberian Peninsula) and their present-day environmental requirements as a basis for interpreting the Holocene fossil record in the context of the natural and anthropogenic changes occurred in this coastal area through time. The benthic foraminiferal...
Conference Paper
Full-text available
Our study combines modern foraminiferal distribution from a Mediterranean wetland (the Ebro Delta, NE Iberian Peninsula) and their present-day environmental requirements as a basis for interpreting the Holocene fossil record in the context of the natural and anthropogenic changes occurred in this coastal area through time. The benthic foraminiferal...
Article
The distributions of Nitzschia inconspicua Grunow and N. soratensis E. Morales & Viz in response to environmental variables were compared using a dataset composed of samples from 46 locations in UK streams and rivers; they were also investigated using laboratory experiments. There were only three samples in which both species occurred with a relati...
Article
A microalgal growth model has been developed based upon experiments using three species – (Cylindrotheca closterium, Nannochloropsis gaditana and Phaeodactylum tricornutum) – at three different levels of carbon dioxide (provided by aeration with ambient air, ambient air enriched with 0.5% carbon dioxide, and ambient air enriched with 1% carbon diox...
Article
Present-day altered distribution of the natural habitats in the Ebro Delta is consequence of intensive human settlement in the last two centuries. We developed spatial predictive models of potential natural wetland habitats of the Ebro Delta based on ecogeographical predictors and presence/ pseudo-absence data for each habitat. The independent vari...
Article
The large diatom genus Nitzschia and the morphologically similar Hantzschia are currently distinguished on the basis of cell symmetry and division. In Hantzschia, the eccentrically placed raphe systems of the two valves are always on the same side of the frustule (‘hantzschioid’ symmetry), never diagonally opposite (‘nitzschioid’ symmetry). Althoug...
Article
DNA barcoding, being developed for biomonitoring, requires a database of reference sequences and knowledge of how much sequences can deviate before they are assigned to separate species. The molecular hunt for hidden species also raises the question of species definitions. We examined whether there are objective criteria for sequence-based species...
Article
Knowledge concerning the ability of microalgae to produce metabolites of interest such as toxins or high-value secondary metabolites requires exhaustive details to be supplied on how the research was conducted. These should include the microalgal species and strain characterization, the culture conditions, the cell density, and physiological state...
Conference Paper
Species belonging in the genus Simonsenia, including S. delognei, have been studied by means of light and electron microscopy. One of them, from estuarine environments in the Guadiana River (Atlanticcoast, close to the border of southern Portugal) has also been maintained in culture, making it possible to use molecular (rbcL gene) data to study its...
Article
Paedogamy (fusion of gametes produced within the same gametangium following meiosis) has rarely been reported in diatoms, with fewer than 10 confirmed examples. One of these, reported by L. Geitler, was in a diatom from Illmitz, Lake Neusiedl (Austria), identified as ‘Nitzschia frustulum var. perpusilla’. We observed uniparental auxosporulation in...
Article
Full-text available
Cylindrotheca is one of the main model diatoms for ecophysiological and silicification research and is among the few diatoms for which a transformation protocol is available. Knowledge of its life cycle is not available, however, although sexual reproduction has been described for several related genera. In this study, 16Cylindrotheca closterium str...
Article
Full-text available
The taxonomy of several small-celled, ecologically significant Nitzschia species, which are frequently confused with each other or whose names are misapplied, is clarified. Following an examination of type material and modern samples by light and electron microscopy, it was concluded that N. frustulum (Kützing) Grunow, N. inconspicua Grunow, N. sor...
Conference Paper
The potential of the two microalgal strains, i.e., Selenastrum capricornutum and Isochrysis galbana, as a co-substrate for biogas production was studied via anaerobic biodegradability test. Mesophilic and thermophilic digestion and different percentages of microalgae in the reactors feed were tested. The amount and quality of biogas produced was an...
Article
This study of the distribution of benthic diatom assemblages and their relationship with environmental factors in a highly stratified Mediterranean estuary, i.e. the Ebro Estuary, shows the importance of hydrological dynamics to explain the features of the diatom community in such an estuary, where river flow magnitude and fluctuations imply strong...
Article
Diatom indices are used to evaluate the ecological status of rivers but they have been rarely applied in estuaries. This study aimed to identify the diatom species indicating the main environmental gradients and pressures in a highly stratified estuary; and to evaluate the applicability of existing freshwater diatom indices. Marine influence due to...
Article
The type material of Nitzschia abbreviata Hustedt ex Simonsen (Nitzschia sect. Lanceolatae) has been examined with light and electron microscopy in order to clarify the structure and identity of this species which may have been largely neglected and possibly identifi ed as N. inconspicua Grunow or N. frustulum (Kützing) Grunow. We illustrate some o...
Article
Full-text available
The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutr...
Article
The purpose of this study was to explore efficient methods of harvesting the microalga Phaeodactylum tricornutum. Natural sedimentation experiments, performed at different light and temperature conditions, did not yield significant improvements in efficiency even after 1 week. When alkalinity-induced flocculation was performed, both the flocculatio...
Article
This study describes the diatom species Planothidium iberense sp. nov. from a salinity gradient of the Ebro River Estuary in northeastern Spain. A detailed description is given based on light and scanning electron microscopy observations, and the diatom species is compared with morphologically similar Planothidium species. Planothidium iberense is...
Article
The effects of salinity on the growth and valve morphology of five benthic estuarine diatoms (Nitzschia pusilla, N. frustulum, N. palea, N. filiformis var. conferta and Eolimna subminuscula), isolated from both freshwater and brackish/marine habitats, were investigated. The four Nitzschia strains grew well over a broad salinity range, though some (...