Institute Ciencias Marinas Of Andalucia

La Roda de Andalucía, Spain

Institute Ciencias Marinas Of Andalucia

La Roda de Andalucía, Spain
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Diez-Minguito M.,University of Granada | Baquerizo A.,University of Granada | Ortega-Sanchez M.,University of Granada | Navarro G.,Institute Ciencias Marinas Of Andalucia | Losada M.A.,University of Granada
Journal of Geophysical Research: Oceans | Year: 2012

This study analyzes tide transformation in the Guadalquivir estuary (SW Spain). When fresh water discharges are less than 40 m3/s, the estuary is tidally-dominated (flood-dominated) and well mixed. Under such conditions, the estuary can be divided into three stretches, each characterized by a different tide propagation process. In the first stretch of 25 km, the dominant process is diffusion. In the next stretch, approximately over 35 km length, convergence and friction processes are in balance. At the head of the estuary, in the last stretch, the tidal motion is partially standing because of tidal reflection on the Alcal del Río dam, located 110 km upstream from the estuary mouth. The reflection coefficient R varies with the frequency; for diurnal constituents its magnitude RD is 0.25; this value increases in the case of semi-diurnal (RS0.40), and quarter-diurnal constituents (RQ0.65), and reaches its minimum at the sixth-diurnal components (RX0.10). The tidal reflection can generate residual currents that have consequences in the bed morphology. Furthermore, when the fresh water discharges are greater than 400 m3/s, the estuary is fluvially-dominated and the water level can be calculated as the linear superposition of tide and river contributions. However, superposition arguments do not hold for currents at any point in the estuary. Copyright 2012 by the American Geophysical Union.

Mantelatto F.L.,University of Sao Paulo | Cuesta J.A.,Institute Ciencias Marinas Of Andalucia
Helgoland Marine Research | Year: 2010

The first zoeal stage of the endemic southern Atlantic pinnotherid crab Austinixa aidae is described and illustrated based on laboratory-hatched material from ovigerous females collected from the upper burrows of the thalassinidean shrimp Callichirus major at Ubatuba, São Paulo, Brazil. The zoeae of Austinixa species can be distinguished from other pinnotherids and especially from zoeae of the closely related species of Pinnixa by the telson structure. © 2010 Springer-Verlag and AWI.

Reuschel S.,University of Regensburg | Cuesta J.A.,Institute Ciencias Marinas Of Andalucia | Schubart C.D.,University of Regensburg
Molecular Phylogenetics and Evolution | Year: 2010

A phylogeographic analysis is carried out for the widely distributed European littoral prawn Palaemon elegans in order to test for potential genetic differentiation and geographic structure. Mitochondrial sequences were obtained from 283 specimens from the northeastern Atlantic, the Baltic, Mediterranean, Black and Caspian Seas. Our study revealed a surprisingly complex population structure. Three main haplogroups can be separated: one from the Atlantic (Type I) and two from the Mediterranean (Types II and III). While the Mediterranean types occur in sympatry, a clear phylogeographic break was observed along the Almería-Oran Front separating Type I and giving evidence for a genetic isolation of Atlantic and Mediterranean populations. Type III represents the most distinct haplogroup with high levels of nucleotide divergence, indicating the occurrence of a cryptic species with a Messinian origin. The colonization of the southeastern Baltic Sea is most likely due to human introduction. © 2010.

Navarro G.,Institute Ciencias Marinas Of Andalucia | Vzquez A.,University of Cádiz | MacIas D.,Institute Ciencias Marinas Of Andalucia | Bruno M.,University of Cádiz | Ruiz J.,Institute Ciencias Marinas Of Andalucia
Geophysical Research Letters | Year: 2011

A singular value decomposition (SVD) analysis was performed to determine the coupled modes of variability of satellite surface chlorophyll (CHL) and absolute dynamic topography (ADT) data for the Alborn Sea (western Mediterranean) during a 12-year period (1998-2009). From this analysis we have been able to detect features of the Alborn Sea dynamics that had not been recognized in previous research on the primary production of this basin. We have found that the two leading SVD modes represent more than 97% of the total squared covariance. The first mode is associated with the inverse barometer and its impact on chlorophyll distribution, whereas the second physical mode can explain the distribution of eutrophic and oligotrophic waters in the Alborn Sea. The results also confirm that the phytoplankton in the basin is very tightly controlled by meteorological and physical processes, via the advection of properties through the Strait, by the influence of Atlantic Jet intensity, which controls the gyres of the basin, and by the activation of up-or down-welling coastal processes by wind. Copyright 2011 by the American Geophysical Union.

Subida M.D.,Institute Ciencias Marinas Of Andalucia | Berihuete A.,University of Cádiz | Drake P.,Institute Ciencias Marinas Of Andalucia | Blasco J.,Institute Ciencias Marinas Of Andalucia
Science of the Total Environment | Year: 2013

A 4-year annual sediment survey was conducted in an organically enriched tidal channel to compare the performance of univariate community descriptors, traditional multivariate techniques (TM) and artificial neural networks (AANs), in the assessment of infaunal responses to moderate levels of sediment metal contamination. Both TM approaches and the SOM ANN revealed spatiotemporal patterns of environmental and biological variables, suggesting a causal relationship between them and further highlighting subsets of taxa and sediment variables as potential main drivers of those patterns. Namely, high values of non-natural metals and organic content prompted high abundances of opportunists, while high values of natural metals yielded typical tolerant assemblages of organically enriched areas. The two approaches yielded identical final results but ANNs showed the following advantages over TM: ability to generalise results, powerful visualization tools and the ability to account simultaneously for sediment and faunal variables in the same analysis. Therefore, the SOM ANN, combined with the K-means clustering algorithm, is suggested as a promising tool for the assessment of the ecological quality of estuarine infaunal communities, although further work is needed to ensure the accuracy of the method. © 2013 Elsevier B.V.

Gonzalez-Ortegon E.,Bangor University | Gonzalez-Ortegon E.,Institute Ciencias Marinas Of Andalucia | Pascual E.,Institute Ciencias Marinas Of Andalucia | Drake P.,Institute Ciencias Marinas Of Andalucia
Journal of Experimental Marine Biology and Ecology | Year: 2013

The respiratory response of six caridean shrimp species under different salinity and dissolved oxygen concentrations (DO) has been carried out at 20 and 25°C. The lowest mean specific oxygen consumption rates (MO2) were found for the less active benthic crangonids Crangon crangon and Philocheras monacanthus; whereas the highest ones corresponded to the two more mobile native palaemonids Palaemon longirostris and Palaemonetes varians. The level of oxygen regulation displayed by the different native species was mainly related with environmental characteristics of their common habitats: species with temporal (C. crangon) or permanent (P. varians) estuarine habitats tended to be more tolerant of salinity changes and/or hypoxia, than are fully marine (P. monacanthus) or freshwater (Atyaephyra desmarestii) species. The estuarine P. longirostris showed moderate oxygen independence, but rather independent of salinity and temperature fluctuations. The exotic shrimp P. macrodactylus seemed to have higher tolerance to hypoxia that its native counterpart P. longirostris at brackish waters, but only under moderate temperature (at 20°C). Results of this study suggest that a simultaneous evaluation of respiration rates and their dependence on DO could be an integrative way of determining the potential effects of increased salinity, temperature and hypoxia on aquatic species with different mobility and/or from different habitats. © 2013 Elsevier B.V.

Garcia-Lopez A.,Institute Ciencias Marinas Of Andalucia | Sanchez-Amaya M.I.,Institute Ciencias Marinas Of Andalucia | Prat F.,Institute Ciencias Marinas Of Andalucia
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology | Year: 2011

A real-time PCR-based gene expression survey was performed on isolated European sea bass follicles from primary growth to late vitellogenesis. Expression levels of 18 transcripts with demonstrated relevance during oogenesis, encoding gonadotropin, thyrotropin, estrogen, androgen, and vitellogenin receptors, steroidogenesis-related as well as growth and transcription factors were measured. Primary oocytes showed high mRNA levels of insulin-like growth factors 1 and 2, bone morphogenetic protein 4, estrogen receptor 2b, androgen receptor b, and SRY-box containing gene 17 together with low transcript amounts of gonadotropin receptors. Follicles at the lipid vesicles stage (i.e., the beginning of the secondary growth phase) showed elevated mRNA amounts of follicle stimulating hormone receptor (fshr) and anti-Mullerian hormone. Early-to-mid vitellogenic follicles showed high mRNA levels of fshr and cytochrome P450, family 19, subfamily A, polypeptide 1a while mid-to-late vitellogenic follicles expressed increasing transcript amounts of luteinizing hormone/choriogonadotropin receptor, steroidogenic acute regulatory protein, and estrogen receptors 1 and 2a. The molecular data presented here may serve as a solid base for future studies focused on unraveling the specific mechanisms orchestrating follicular development in teleost fish. © 2011 Elsevier Inc.

Gonzalez-Ortegon E.,Institute Ciencias Marinas Of Andalucia | Drake P.,Institute Ciencias Marinas Of Andalucia
Aquatic Sciences | Year: 2012

The aim of this 6 year study was to assess whether freshwater inputs (rainfall and dam discharges) were acting as physical, physiological or trophic forcing factors on phytoplankton pigment concentrations and the dominant mysids of a temperate estuary (Guadalquivir estuary; SW, Spain). The effects of natural and human-controlled freshwater inputs modified the physico-chemical conditions and consequently biological production (bottom up control). Nutrient (nitrogen hypernutrification), suspended particulate matter and allochthonous photosynthetic pigment imports linked to freshwater inputs from adjacent habitats were observed, as well as light-limited autochthonous primary production. Seasonal and/or spatial patterns were shown by all study variables, including mysids. Freshwater management effects on dominant mysids differed depending on the species' salinity tolerance (physiological forcing) and preferred prey availability (trophic forcing). Moreover, high inorganic matter content had a negative effect on the density of Mesopodopsis slabberi (physical forcing), which led to an increased detritivory/herbivory ratio (Neomysis integer/M. slabberi ratio). In conclusion, freshwater inputs appeared to effect estuarine lower trophic levels via a combination of different forcing mechanisms. Although several general patterns can be derived, the response of the system to freshwater inputs was not always univocal. © 2011 Springer Basel AG.

Caballero I.,Institute Ciencias Marinas Of Andalucia | Morris E.P.,Institute Ciencias Marinas Of Andalucia | Ruiz J.,Institute Ciencias Marinas Of Andalucia | Navarro G.,Institute Ciencias Marinas Of Andalucia
Remote Sensing of Environment | Year: 2014

Measurements of Total Suspended concentrations (TSS) are critical for monitoring geomorphological processes as well as ensuring the "good status" of transitional and coastal waters. Here, we explore the potential of the new DEIMOS-1, multi-spectral, medium-resolution satellite sensor for quantifying TSS dynamics within the large, turbid Guadalquivir estuary (SW Iberian Peninsula). Eight scenes were atmospherically corrected using various image-based procedures (apparent reflectance; Dark Object Subtraction, DOS; and solar zenith angle approximation, COSTZ). In-situ measurements (100 to 1400mgL-1) from three campaigns coinciding (±15min) with satellite overpasses were used to assess the semi-analytical algorithm from Nechad et al. (2010) relating water-leaving reflectance (ρw) to TSS. All bands were very sensitive to TSS, however saturation of the visible wavelengths was observed at the highest sediment loads. The best correlation was obtained for the NIR band (755-906nm) using the simple band-reflectance model at the top of atmosphere reflectance (ρw(TOA)), TSS (mgL-1)=21428.77 ρw(TOA)/(1-ρw(TOA)/0.21)-346.17 (r2=0.864, p<0.001, εr=25.411%, n=53), which was used to generate maps. This approach revealed detailed spatio-temporal variability in sediment concentrations within the river plume, near to shore and far up the river channel. We demonstrate that DEIMOS-1 has a high capability as a valuable tool for the frequent, synoptic monitoring of water-quality parameters needed for the optimum management of coastal and transitional waters. © 2013 Elsevier Inc.

Gonzalez-Ortegon E.,Institute Ciencias Marinas Of Andalucia | Cuesta J.A.,Institute Ciencias Marinas Of Andalucia | Pascual E.,Institute Ciencias Marinas Of Andalucia | Drake P.,Institute Ciencias Marinas Of Andalucia
Biological Invasions | Year: 2010

Results of field surveys, stomach content analysis, and laboratory measurements of oxygen consumption at different salinities in the exotic shrimp Palaemon macrodactylus and its native counterpart P. longirostris from the Guadalquivir estuary (SW Spain) were used to assess interaction between both species. After its first record in this estuary in 1998, P. macrodactylus has shown a gradual increase in density and its estuarine population has been clearly dominated by juveniles. Feeding habits of both shrimps indicated a strong trophic overlap between them, with mysids as main prey. Their salinity-related and spatial distribution patterns show that maximal inter-specific overlap between the two populations occurs in the inner, less saline part of the estuary. Specific oxygen consumption rates under different salinities and water oxygen concentrations suggest a more efficient metabolism and a higher tolerance to hypoxic conditions in brackish waters by P. macrodactylus than by P. longirostris. Such inter-specific physiological differences could have made it possible for the exotic P. macrodactylus to invade an estuarine stretch that, prior to its arrival, was infra-utilized by native species. © Springer Science+Business Media B.V. 2009.

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