Search results for "plankton"
showing 10 items of 549 documents
Diversity and Distribution of the Dinoflagellates Brachidinium, Asterodinium and Microceratium (Brachidiniales, Dinophyceae) in the open Mediterranea…
2011
Diversity and Distribution of the DinoflagellatesBrachidinium, AsterodiniumandMicroceratium(Brachidiniales, Dinophyceae) in the open Mediterranean SeaBrachidiniacean dinoflagellates have been investigated in the open waters of the Mediterranean Sea, along a transect from the south of France to the south of Cyprus (20 June-18 July 2008).BrachidiniumandKarenia papilionaceaoften co-occurred,B. capitatumpredominating in the surface waters. The highest abundance ofBrachidiniumwere found in the upper 25min the western Mediterranean with amaximum (24 cells L-1) at a depth of 5 m in the Balearic Sea.Asterodinium(up to 4 cells L-1) was recorded below of deep chlorophyll maxima. The genusMicroceratiu…
That twenty years is nothing for gravel-pit limnology
2020
[EN] The past twenty years have witnessed a rise in the analysis of long-term limnological data given the need to know whether global warming is affecting freshwaters, and if so, how. Previous studies indicated that processes affecting ecosystem function-ing may develop slowly, thus requiring long-term study, as in the case of the eutrophication-oligotrophication gradient. Here we report annual averages and seasonal variability of meteorological data (air temperature, solar radiation, rainfall) and the main limnological variables (lake level, water temperature, euphotic depth, mixing depth, nitrogen and phosphorus compounds and phytoplankton biomass) for a gravel-pit, seepage lake close to …
Mediterranean Neogene planktonic foraminifer biozonation and biochronology
2019
Abstract Planktonic foraminifera are widely used for biostratigraphy and correlation of Mediterranean Neogene marine sediments, and are a fundamental component in the astronomical tuning of the Neogene Time Scale. Recent developments in high-resolution studies, focused on the astronomical calibration of cyclically marine sediments cropping out in land-based sections and recovered from deep-sea successions, increased the accuracy of stratigraphic ranges of planktonic foraminiferal species improving the biostratigraphic resolution and biochronology. The large amount of data on planktonic foraminifera obtained through quantitative/semiquantitative analyses, published in the recent years, allow…
Metagenomes of Mediterranean Coastal Lagoons
2012
Coastal lagoons, both hypersaline and freshwater, are common, but still understudied ecosystems. We describe, for the first time, using high throughput sequencing, the extant microbiota of two large and representative Mediterranean coastal lagoons, the hypersaline Mar Menor, and the freshwater Albufera de Valencia, both located on the south eastern coast of Spain. We show there are considerable differences in the microbiota of both lagoons, in comparison to other marine and freshwater habitats. Importantly, a novel uncultured sulfur oxidizing Alphaproteobacteria was found to dominate bacterioplankton in the hypersaline Mar Menor. Also, in the latter prokaryotic cyanobacteria were almost exc…
Microcrustacean and Rotiferan Communities of Two Close Mediterranean Mountain Ponds, Lagunas de Bezas and Rubiales (Spain)
2010
ABSTRACT We compared two freshwater mountain ponds during an annual cycle by focusing on Rotifera and Crustacea. These ponds, Laguna de Bezas and Laguna de Rubiales, are located only 4.5 kilometers apart and share a similar altitude (ca. 1200 m.a.s.1) on the Iberian Mountain range, in Teruel (Spain). Bezas is near-permanent and dries out only in severe droughts; Rubiales is temporary, drying out periodically. They also show important differences in other limnological traits. Bezas has transparent water, harbors a fish population, and has a dense macrophyte cover, whereas Rubiales has elevated turbidity and neither fish nor macrophytes during most of the hydroperiod. These differences are pr…
Trace and minor element records in aragonitic bivalve shells as environmental proxies
2019
Abstract Investigation of the geochemical composition of bivalve shells can provide information on changes in the marine environment occurring during the lifespan of an organism. Three species, locally abundant in the Adriatic Sea, were chosen in this study, namely Glycymeris pilosa, Callista chione, and Venus verrucosa. Of these, G. pilosa has the longest lifespan, exceeding 50 years, and therefore presents a potential archive of decadal climate variability. The other two species, C. chione and V. verrucosa, are commercially important. Samples were collected alive by SCUBA diving in the North Adriatic Sea, near Barbariga, Istria. Major growth increments in these shells form on an annual ba…
Does lake age affect zooplankton diversity in Mediterranean lakes and reservoirs? A case study from southern Italy
2010
Zooplankton assemblages of 51 lacustrine environments located in the middle of the Mediterranean Region were analysed to evaluate the existence of an ‘age effect’ in determining their structure. The analysed datasets refer to two different geographic areas, one comprising 30 natural and artificial lakes in Sicily and the other an arrangement of 21 analogous aquatic ecosystems located at the bottom of the Italian Peninsula, a more pristine area called Southern Apennine region. Most of the natural lakes are of post-glacial origin. The artificial lakes in both datasets were built in the last century and offer the opportunity to evaluate the possible short-term effects of ageing on the structur…
Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary impli…
2007
CONCENTRACIÓN DE ISÓTOPOS ESTABLES DE C Y N EN VARIOS TEJIDOS DE LA TORTUGA BOBA CARETTA CARETTA DEL MEDITERRÁNEO OCCIDENTAL E IMPLICACIONES SOBRE LA DIETA. – La concentración isotópica de escudos del caparazón, piel, músculo y sangre de tortuga boba (Caretta caretta) fueron analizados para investigar el patrón de variación entre tejidos y para evaluar la posición de esta especie en las redes tróficas de la cuenca Argelina. La piel presentaba valores más altos de δ13C que el músculo o los escudos del caparazón y éstos presentaban valores más altos que la sangre. En cambio, el músculo presentaba valores más altos de δ15N que la piel, ésta valores más altos que la sangre y ésta valores más al…
Calcareous nannofossil surface sediment assemblages from the SicilyChannel (central Mediterranean Sea): palaeoceanographic implications.
2008
Quantitative analysis of 67 calcareous nannofossil assemblages from surface sediments recovered in a wide area across the Sicily Channel has been carried out in order to improve the interpretation of palaeontological data based on this planktonic group in a key area for Mediterranean palaeoceanographic studies. The investigation focused on three case studies that demonstrate the high potentiality of such a combined approach, taking into account the recent distribution of taxa or groups of taxa on the sea floor and the palaeontological record. The distribution of reworked specimens over the northern Sicily Channel sea floor validates the role of southern Sicily as a source region for reworke…
Distribution of Brachionus species in Spanish mediterranean wetlands
1987
In this study 200 zooplankton samples were Burjassotcollected (1979–1980), from 57 different wetlands in coastal Mediterranean Spain (CMS) and examined for the occurrence of Brachionus species. Data on 17 separate physical and chemical features of these water bodies were obtained from samples collected at the same time. Ten different Brachionus species were found in these wetlands, but only six occurred frequently enough to allow further examination of their distributional patterns using multivariate discriminant analysis. To separate these species, three analyses were performed using the 17 physical and chemical parameters, or their ratios. Three discriminant functions accounted for 80% or…