Papers by Maria R. Miracle
Seasonal distribution of the dinoflagellates in the M a r Menor (Murcia, Spain)
A seasonal study of the phytoplanktonic communities in the Albufera of Valencia, an hypertrophic ... more A seasonal study of the phytoplanktonic communities in the Albufera of Valencia, an hypertrophic coastal lagoon, has been undertaken at the point of its maximum depth ( 3 m ) along the vertical profile. The extreme eutrophy of the Albufera produces notoriously high phytoplanktonic densities; a summer maximum of 5,57 x 1012 individuals/m2 has been registered. The minimum density, five times lower (1,16 x 1012 ind/m2), occurs in winter. Cyanobacteria constitute the dominant phytoplanktonic group, reaching relative abundances above 96% in august, due mainly t o species of the genera Lyngbya and Oscillatoria. The dominance of cyanobacteria is constant during the whole annual cycle constituing more than the 77% of the total phytoplankton, with the only exception of the month of april, in which a relative minimum of 41% was registered. Consequently, in this month, other algal groups reach their maximum representation, mainly chlorophyceae (35%), diatoms ( 1 6%) and cryptophyceae (4,2%). It is interesting to note the presence of Anabaenopsis circularis, a species of tropical distribution, whose growth in the Albufera has only recently been observed. All these results show that an important and recent change on the specific composition of the Albufera phytoplankton has occurred, due to its extreme eutrophication process.
Resumen: La sostenibilidad ambiental está relacionada directamente con el ciclo del agua y las in... more Resumen: La sostenibilidad ambiental está relacionada directamente con el ciclo del agua y las intervenciones del hombre sobre el mismo, tanto en su extracción, uso y eliminación. La conservación del suelo y la vegetación dependen invariablemente del impacto acumulado de este proceso. La perspectiva de un cambio climático mayor, con el subsecuente aumento de las temperaturas en el planeta, implica transformaciones radicales en el ciclo del agua, y por ende, en su disponibilidad y utilización. Para ello se hace imperioso mejorar radicalmente el ahorro del agua, aumentando al mismo tiempo los sistemas de depuración y eficiencia en el regadío. La autora propone una seria de medidas en esta dirección.
EN lAS PágINAS quE SIguEN SE RECogEN lAS INTERVENCIoNES dE 6 ExPERToS SobRE «CIENCIA, PARTICIPACI... more EN lAS PágINAS quE SIguEN SE RECogEN lAS INTERVENCIoNES dE 6 ExPERToS SobRE «CIENCIA, PARTICIPACIÓN, SoSTENIbIlIdAd» EN uN gRuPo dE dISCuSIÓN quE SE REuNIÓ EN bARCEloNA El 8 dE AbRIl dE 2011 EN El MARCo dEl PRoyECTo dE INVESTIgACIÓN CIPARSoS. hE Aquí uNA bREVE CARACTERIzACIÓN INTElECTuAl y ACAdéMICA dE lAS SEIS PERSoNAS PARTICIPANTES.
... Distribución en el espacio y en el tiempo de las especies del zooplanton del lago de Banyoles... more ... Distribución en el espacio y en el tiempo de las especies del zooplanton del lago de Banyoles. Información General. Autores: María Rosa Miracle; Editores: Madrid : sn, 1976; Año de publicación: 1976; País: España; Idioma: Español; ISBN : 84-500-7402-9. Otros catálogos. ...
Hydrobiologia, Oct 31, 2003
The seasonal features of the water chemistry in the saline shallow lakes Laguna de Manjavacas and... more The seasonal features of the water chemistry in the saline shallow lakes Laguna de Manjavacas and Laguna del Pueblo (Castilla -La Mancha, Central Spain) were studied during 1990-1991 and in 1997. These lakes were both affected by sewage inputs driving them to a high trophic status. However, whereas sewage inputs entered Laguna del Pueblo directly, wastewater reached Laguna de Manjavacas after running for 8 km through a small riverbed, where natural processes caused partial mineralisation of organic matter. Moreover, water quality was further improved before entering the main water body of Laguna de Manjavacas, since water crossed through a wetland and high amounts of organic matter and inorganic nutrients were retained there. Anyway, in both lakes spatial heterogeneity was mainly associated with the distance to sewage inputs, and this was also reflected by the sediment chemistry. The patterns of water evaporation and precipitation-dissolution of salts strongly determined the salinity of their waters. During the warmest period (which coincided with the main drought period) water losses by evaporation increased water salinity, whereas a higher dilution was found during the cold rainy period. However, the relatively higher amount of low-salinity sewage inputs in Laguna del Pueblo allowed this lake to maintain its hyposaline characteristics. In contrast, Laguna de Manjavacas shifts from hyposaline to hypersaline following the seasonal cycle with different rain and temperature regimes, as the relative importance of the permanent wastewater inputs was lower here than in Laguna del Pueblo. Inorganic nutrient dynamics was determined in both lakes both by the sewage supply and by consumption by phytoplankton, with soluble P depletion following algal blooms.
Hydrobiologia, Feb 28, 1994
Climatic Change, Jan 5, 2011
We present the first winter (December to March) rainfall reconstruction based in a novel proxy, t... more We present the first winter (December to March) rainfall reconstruction based in a novel proxy, the thickness of annual calcite laminations preserved in Lake La Cruz (central-eastern Spain). A previous calibration analysis between laminae thickness and the instrumental data series (1950 to present) indicated a highly significant correlation with winter rainfall. Therefore this study attempts the winter rainfall reconstruction since the onset of laminations (1579 a.d.) by means of the calibration function previously developed. The verification analysis between inferred annual values and earlier instrumental data confirms the suitability of this novel proxy and the reliability of the series reconstructed. The reconstructed series show the fluctuating character of winter rainfall in the western Mediterranean area; interdecadal dry periods alternated with wetter periods following, in a board sense, the pattern recorded by documentary sources in other regions of the Iberian Peninsula. At present times regional winter rainfall anomalies are highly correlated with the phase of the North Atlantic Oscillation (NAO). However the time series analysis showed the dominance of nonstationary components at high frequencies of the climate signal over the last four centuries suggesting that the connection between
Hydrobiologia, 1994
... in a shallow hypertrophic lake (Albufera of Valencia, Spain) S. Romo & MR Miracle Area de... more ... in a shallow hypertrophic lake (Albufera of Valencia, Spain) S. Romo & MR Miracle Area de Ecologia, Fact&ad de Ciencias Biologicas, Universidad de Valencia, 46100-Burjasot,Valencia, Spain ... The Albufera of Valencia is a shallow, hyper-...
Limnetica
Recent studies on the Albufera of Valencia show that this shallow oligohaline coastal lagoon is a... more Recent studies on the Albufera of Valencia show that this shallow oligohaline coastal lagoon is an ecosystem under stress. Domestic and industrial waters loaded with phosphorus and ammonium reach the lagoon from the northern side.
Hydrobiologia, 2000
The main limnological features of Lake Arcas-2 were followed through two consecutive stratificati... more The main limnological features of Lake Arcas-2 were followed through two consecutive stratification periods. Its morphometrical characteristics, such as the high relative depth (31%) and steep basin walls, enhance the sharp water stratification with the formation of an oxic-anoxic boundary at 8.8-9 m and a sulphide-rich hypolimnion during the thermal stagnation. The ionic sequence was SO 2− 4 >Alkal.>Cl − and Ca 2+ >Mg 2+ >Na + >K + and the mineralization was high, with water conductivity higher than 2500 µS cm −1 . It is mesotrophic with epilimnetic chlorophyll a concentrations of 2-5 µg l −1 and metalimnetic of 8 µg l −1 . The depth of the euphotic zone was established at around 8 m. Phosphorus concentration in the oxic waters was low but largely accumulated in the anoxic hypolimnion, together with other compounds such as ammonium, silicate, sulphide, etc. Nitrate was abundant in the oxic waters and is related to the use of fertilizers in the surrounding fields. A fine-layer sampler was used to study the oxic-anoxic interface where a dense plate of Chromatiaceae developed. The dominant species, Chromatium weissei, reached a maximum integrated biomass of 121 gWW m −2 during August. Thiocapsa sp., representing less than 1% of total purple bacteria, had an integrated biomass of 0.8 gWW m −2 and Amoebobacter sp. (1%) had 1 gWW m −2 . Other populations were sharply stratified i.e. Oscillatoria cf. ornata and Cryptomonas erosa. Those organisms, and mainly the cyanobacterium, accounted for the high chlorophyll a concentrations (>100 µg l −1 ) recorded in the anoxic waters of the hypolimnion. Green bacteria were scarcely developed due to the shadowing effect caused mainly by the purple bacterial bloom.
Phytoplankton and Trophic Gradients, 1998
Summer phytoplankton assemblages are described and characterised according to their prevalence in... more Summer phytoplankton assemblages are described and characterised according to their prevalence in a series of hardwater reservoirs of eastern Spain that had been classified in trophic categories on OECD criteria. Distribution patterns of phytoplankton species were ordinated statistically by principal components analysis (PCA). The first component was strongly related to trophic gradient and it particularly discriminated the eutrophic and hypertrophic reservoirs. The second component segregated life-forms, so that (1), on the oligo-mesotrophic side, large dinoflagellates were separated from small centric diatoms, unicellular chrysophytes and filamentous ullotrichales and, on the euhypertrophic side (2), colonial greens and large desmids were separated from unicellular volvocales and small centric diatoms.
Archiv Fur Hydrobiologie, 1992
Recent studies on the Albufera of Valencia, Spain, have shown the effects of the ever-increasing ... more Recent studies on the Albufera of Valencia, Spain, have shown the effects of the ever-increasing pollution. In a study of the seasonal distribution of zooplankton in this hypertrophic coastal lagoon the copepod Acanthocyclopos robustus and the rotifer ...
Hydrobiologia, 1993
Hydrobiologia 255/256: 145-152, 1993. JJ Gilbert, E. Lubzens & MR Miracle (ed... more Hydrobiologia 255/256: 145-152, 1993. JJ Gilbert, E. Lubzens & MR Miracle (eds), Rotifer Symposium VI. © 1993 Kluwer Academic Publishers. Printed in Belgium . ... Relationships between mixis in Brachionus plicatilis and preconditioning of culture medium by crowding
Archiv Fur Hydrobiologie, Jan 31, 2003
Biochemical Systematics and Ecology, 1989
... Total Protein Analysis in Rotifer Populations MARIA JOSe: CARMONA, MANUEL SERRA and MARIA ROS... more ... Total Protein Analysis in Rotifer Populations MARIA JOSe: CARMONA, MANUEL SERRA and MARIA ROSA MIRACLE Departamento de Ecologia, Universidad de Valencia, 46100Burjassot (Valencia), Spain Key Word IndexBrachionus plicatilis; Rotifera; Brachionidae; rotifers ...
Journal of Experimental Marine Biology and Ecology, 1994
Effects of population density on mictic response and the population dynamics of 13 clones of Bruc... more Effects of population density on mictic response and the population dynamics of 13 clones of Bruchionus plicatilis were investigated by culturing isolated females at two different population densities. Results from the experiments did not provide general support for the dependence of mictic response on population density. Only six clones, isolated amictic females cultured at a density of 5 females*ml-', produced higher proportions of mictic female offspring than females grown at a density of 1 female.ml-', indicating that mictic-female production in these clones of B. plicatilis is density-dependent. High population density affected other life-history traits: lifespan (e,) and fertility per female lifetime (R,) decreased with density. Interclone differences in the mictic response to density were detected, which may be caused by genetic differences in the capacity to undergo mixis. High variabilities for mictic rates and life-table parameters were found among clones derived by selting from a clone. These results indicate that age of the parental female is also a signiticant internal factor that affects the production of mictic daughters.
Limnology and Oceanography, 1995
Uploads
Papers by Maria R. Miracle