scholarly journals Evaluation of isotopes and elements in planktonic foraminifera from the Mediterranean Sea as recorders of seawater oxygen isotopes and salinity

2020 ◽  
Author(s):  
Linda K. Dämmer ◽  
Lennart de Nooijer ◽  
Erik van Sebille ◽  
Jan Haak ◽  
Gert-Jan Reichart
Keyword(s):  
Mediterranean Sea ◽  
Oxygen Isotopes ◽  
Environmental Variability ◽  
Sea Water ◽  
Numerical Models ◽  
Salinity Gradient ◽  
Western Mediterranean ◽  
Ocean Current ◽  
Seawater Salinity ◽  
The Mediterranean

Abstract. The Mediterranean Sea is characterized by a relatively strong west to east salinity gradient, which makes it an area suitable to test the effect of salinity on foraminiferal shell geochemistry. We collected living specimens of the planktonic foraminifer Globigerinoides ruber (white) to analyse the relation between element/Ca ratios, stable oxygen isotopes of their shells and surface seawater salinity, isotopic composition and temperature. The oxygen isotopes of sea surface water correlate with salinity in the Mediterranean also during winter, when sampled for this study. Sea water oxygen and hydrogen isotopes are positively correlated in both the eastern and western Mediterranean Sea, though especially in the eastern part the relationship differs from values reported previously for that area. The slope between salinity and seawater oxygen isotopes is lower than previously published. Still, despite the rather modest slope, seawater and foraminiferal carbonate oxygen isotopes are correlated in our dataset although with large residuals and high residual variability. This scatter can be due to either biological variability in vital effects or environmental variability. Numerical models backtracking particles show ocean current driven mixing of particles of different origin might dampen sensitivity and could result in an offset caused by horizontal transport. Results show that Na/Ca is positively correlated to salinity and independent of temperature. Foraminiferal Mg/Ca increases with temperature, as expected, and in line with earlier calibrations, also in the high salinity environment. By using living foraminifera during winter, the previously established Mg/Ca-temperature calibration is extended to temperatures below 18 °C, which is a fundamental prerequisite of using single foraminifera for reconstructing past seasonality.

scholarly journals Evaluation of oxygen isotopes and trace elements in planktonic foraminifera from the Mediterranean Sea as recorders of seawater oxygen isotopes and salinity

2020 ◽  
Vol 16 (6) ◽  
pp. 2401-2414
Author(s):  
Linda K. Dämmer ◽  
Lennart de Nooijer ◽  
Erik van Sebille ◽  
Jan G. Haak ◽  
Gert-Jan Reichart
Keyword(s):  
Mediterranean Sea ◽  
Oxygen Isotopes ◽  
Environmental Variability ◽  
Numerical Models ◽  
Salinity Gradient ◽  
Western Mediterranean ◽  
Ocean Current ◽  
Eastern Region ◽  
Seawater Salinity ◽  
The Mediterranean

Abstract. The Mediterranean Sea is characterized by a relatively strong west to east salinity gradient, which makes it an area suitable for testing the effect of salinity on foraminiferal shell geochemistry. We collected living specimens of the planktonic foraminifer Globigerinoides ruber albus to analyse the relation between element ∕ Ca ratios, stable oxygen isotopes of their shells, and surface seawater salinity, isotopic composition and temperature. The oxygen isotopes of sea surface water also correlate with salinity in the Mediterranean during winter, which is when sampling for this study took place. Seawater oxygen and hydrogen isotopes are positively correlated in both the eastern and western Mediterranean Sea, although the relationship differs from previously reported values, especially in the eastern region. The slope between salinity and seawater oxygen isotopes is lower than previously published results. Still, despite the rather modest slope, seawater and foraminiferal carbonate oxygen isotopes are correlated in our dataset, albeit with large residuals and high residual variability. This scatter could be due to either biological variability in vital effects or environmental variability. Numerical models backtracking particles show that ocean-current-driven mixing of particles of different origins might dampen sensitivity and could result in an offset caused by horizontal transport. Results show that Na ∕ Ca is positively correlated with salinity and independent of temperature. As expected, foraminiferal Mg ∕ Ca increases with temperature, which is in line with earlier calibrations, and in the high salinity environment. By using living foraminifera during winter, the previously established Mg ∕ Ca–temperature calibration is extended to temperatures below 18 ∘C, which is a fundamental prerequisite of using single foraminifera for reconstructing past seasonality.

scholarly journals Characterizing the surface microlayer in the Mediterranean Sea: trace metal concentrations and microbial plankton abundance

2020 ◽  
Vol 17 (8) ◽  
pp. 2349-2364 ◽  
Author(s):  
Antonio Tovar-Sánchez ◽  
Araceli Rodríguez-Romero ◽  
Anja Engel ◽  
Birthe Zäncker ◽  
Franck Fu ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Negative Correlation ◽  
Salinity Gradient ◽  
Western Mediterranean ◽  
Surface Microlayer ◽  
Dissolved Metals ◽  
Strong Negative Correlation ◽  
Chl A ◽  
Sea Surface Microlayer ◽  
The Mediterranean

Abstract. The Sea Surface Microlayer (SML) is known to be enriched by trace metals relative to the underlying water and harbor diverse microbial communities (i.e., neuston). However, the processes linking metals and biota in the SML are not yet fully understood. The metal (Cd, Co, Cu, Fe, Ni, Mo, V, Zn and Pb) concentrations in aerosol samples in the SML (dissolved and total fractions) and in subsurface waters (SSWs; dissolved fraction at ∼1 m depth) from the western Mediterranean Sea were analyzed in this study during a cruise in May–June 2017. The composition and abundance of the bacterial community in the SML and SSW, the primary production, and Chl a in the SSW were measured simultaneously at all stations during the cruise. Residence times in the SML of metals derived from aerosol depositions were highly variable and ranged from minutes for Fe (3.6±6.0 min) to a few hours for Cu (5.8±6.2 h). Concentrations of most of the dissolved metals in both the SML and SSW were positively correlated with the salinity gradient and showed the characteristic eastward increase in the surface waters of the Mediterranean Sea (MS). In contrast, the total fraction of some reactive metals in the SML (i.e., Cu, Fe, Pb and Zn) showed a negative correlation with salinity and a positive correlation with microbial abundance, which might be associated with microbial uptake. Our results show a strong negative correlation between the dissolved and total Ni concentration and heterotrophic bacterial abundance in the SML and SSW, but we cannot ascertain whether this correlation reflects a toxicity effect or is the result of some other process.

First record of Sphoeroides spengleri (Osteichthyes: Tetraodontidae) in the Mediterranean Sea

2004 ◽  
Vol 84 (5) ◽  
pp. 1089-1090 ◽  
Author(s):  
J.A. Reina-Hervás ◽  
J.E. García Raso ◽  
M.E. Manjón-Cabeza
Keyword(s):  
Alien Species ◽  
Mediterranean Sea ◽  
First Record ◽  
Western Mediterranean ◽  
Alboran Sea ◽  
Total Length ◽  
The Mediterranean ◽  
Alborán Sea

The capture of a specimen of Sphoeroides spengleri (Osteichthyes: Tetraodontidae), 17 December 2000 and 29·7 mm total length, from the Málaga coast (Alborán Sea, western Mediterranean) represents the first record of a new alien species for Mediterranean waters.

scholarly journals First record of Solea (Microchirus) boscanion (Osteichthyes: Soleidae) in the Mediterranean Sea, with data on other sympatric soleid species

2002 ◽  
Vol 82 (5) ◽  
pp. 907-911 ◽  
Author(s):  
Enric Massutí ◽  
J.A. Reina-Hervás ◽  
Domingo Lloris ◽  
L. Gil de Sola
Keyword(s):  
Climate Change ◽  
Mediterranean Sea ◽  
First Record ◽  
Western Mediterranean ◽  
The Other ◽  
The Mediterranean

The capture of five specimens of Solea (Microchirus) boscanion (Osteichthyes: Soleidae), a species previously unrecorded in the Mediterranean, is reported from the Iberian coast (western Mediterranean). The main morphometric and meristic measurements of this species with data of the other sympatric, and morphologically very similar, soleids Microchirus variegatus and Buglossidium luteum are also given. The record is discussed in relation to climate change and competition between species.

scholarly journals Further spreading of the non-indigenous bryozoan Celleporaria brunnea in the Mediterranean Sea: port to port morphological variations

2015 ◽  
Author(s):  
Jasmine Ferrario ◽  
Agnese Marchini ◽  
Martina Marić ◽  
Dan Minchin ◽  
Anna Occhipinti-Ambrogi
Keyword(s):  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Indigenous Species ◽  
Large Variability ◽  
Morphometric Characters ◽  
Morphological Variations ◽  
The North ◽  
Western Mediterranean Sea ◽  
The Pacific ◽  
The Mediterranean

The Pacific cheilostome bryozoan Celleporaria brunnea (Hincks, 1884), a non-indigenous species already known for the Mediterranean Sea, was recorded in 2013-2014 from nine Italian port localities (Genoa, Santa Margherita Ligure, La Spezia, Leghorn, Viareggio, Olbia, Porto Rotondo, Porto Torres and Castelsardo) in the North-western Mediterranean Sea; in 2014 it was also found for the first time in the Adriatic Sea, in the marina “Kornati”, Biograd na Moru (Croatia). In Italy, specimens of C. brunnea were found in 44 out of 105 samples (48% from harbour sites ad 52% from marinas). These data confirm and update the distribution of C. brunnea in the Mediterranean Sea, and provide evidence that recreational boating is a vector responsible for the successful spread of this species. Previous literature data have shown the existence of differences in orifice and interzooidal avicularia length and width among different localities of the invaded range of C. brunnea. Therefore, measurements of orifice and avicularia were assessed for respectively 30 zooids and 8 to 30 interzooidal avicularia for both Italian and Croatian localities, and compared with literature data, in order to verify the existence of differences in the populations of C. brunnea that could reflect the geographic pattern of its invasion range. Our data show high variability of orifice measures among and within localities: zooids with broader than long orifice coexisted with others displaying longer than broad orifice, or similar values for both length and width. The morphological variation of C. brunnea in these localities, and above all the large variability of samples within single localities or even within colonies poses questions on the reliability of such morphometric characters for inter and intraspecific evaluations.

scholarly journals First record of the sipunculan worm Phascolion (Phascolion) caupo Hendrix, 1975 in the Mediterranean Sea

2012 ◽  
Vol 13 (1) ◽  
pp. 89 ◽  
Author(s):  
L.M. FERRERO-VICENTE ◽  
A. LOYA-FERNANDEZ ◽  
C. MARCO-MENDEZ ◽  
E. MARTINEZ-GARCIA ◽  
J.I. SAIZ-SALINAS ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
First Record ◽  
Western Mediterranean ◽  
High Load ◽  
San Pedro ◽  
Soft Bottoms ◽  
The Mediterranean ◽  
First Time

Specimens of the sipunculan worm Phascolion (Phascolion) caupo Hendrix, 1975 have been collected for the first time in the Mediterranean Sea, thus increasing the number of known sipunculan species of up to 36 in this area. They were encountered on soft bottoms from the coast of San Pedro del Pinatar (Western Mediterranean). Thirty specimens were collected at a depth ranging from 32.6 to 37.2 m, mainly in sandy substrata with high load of silt and clays. 80% of the individuals were found inhabiting empty shells of gastropods or empty tubes of serpulid polychaetes.

scholarly journals Characterization of the Atlantic Water and Levantine Intermediate Water in the Mediterranean Sea using Argo Float Data

2021 ◽  
Author(s):  
Giusy Fedele ◽  
Elena Mauri ◽  
Giulio Notarstefano ◽  
Pierre Marie Poulain
Keyword(s):  
Mediterranean Sea ◽  
Thermohaline Circulation ◽  
Internal Variability ◽  
Warming Trend ◽  
Atlantic Water ◽  
Western Mediterranean ◽  
Water Masses ◽  
Intermediate Water ◽  
Starting Point ◽  
The Mediterranean

Abstract. The Atlantic Water (AW) and Levantine Intermediate Water (LIW) are important water masses that play a crucial role in the internal variability of the Mediterranean thermohaline circulation. In particular, their variability and interaction, along with other water masses that characterize the Mediterranean basin, such as the Western Mediterranean Deep Water (WMDW), contribute to modify the Mediterranean Outflow through the Gibraltar Strait and hence may influence the stability of the global thermohaline circulation. This work aims to characterize the AW and LIW in the Mediterranean Sea, taking advantage of the large observational dataset provided by Argo floats from 2001 to 2019. Using different diagnostics, the AW and LIW were identified, highlighting the inter-basin variability and the strong zonal gradient that characterize the two water masses in this marginal sea. Their temporal variability was also investigated focusing on trends and spectral features which constitute an important starting point to understand the mechanisms that are behind their variability. A clear salinification and warming trend have characterized the AW and LIW in the last two decades (~0.007 and 0.008 yr−1; 0.018 and 0.007 °C yr−1, respectively). The salinity and temperature trends found at subbasin scale are in good agreement with previous results. The strongest trends are found in the Adriatic basin in both the AW and LIW properties. A subbasin dependent spectral variability emerges in the AW and LIW salinity timeseries with peaks between 2 and 10 years.

scholarly journals The effect of cyclones crossing the Mediterranean region on sea level anomalies at the Mediterranean Sea coast

2019 ◽  
Author(s):  
Piero Lionello ◽  
Dario Conte ◽  
Marco Reale
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Eastern Mediterranean ◽  
Storm Track ◽  
Western Mediterranean ◽  
Residual Water ◽  
Positive Anomaly ◽  
Western Basin ◽  
Sea Level Anomalies ◽  
The Mediterranean

Abstract. Large positive and negative sea level anomalies at the coast of the Mediterranean Sea are linked to intensity and position of cyclones moving along the Mediterranean storm track, with dynamics involving different factors. This analysis is based on a model hindcast and considers nine coastal stations, which are representative of sea level anomalies with different magnitude and characteristics. When a shallow water fetch is present, the wind around the cyclone center is the main cause of sea level positive and negative anomalies, depending on its onshore or offshore direction. The inverse barometer effect produces a positive anomaly at the coast near the cyclone pressure minimum and a negative anomaly at the opposite side of the Mediterranean Sea, because a cross-basin mean sea level pressure gradient is associated to the presence of a cyclone. Further, at some stations, negative sea level anomalies are reinforced by a residual water mass redistribution within the basin, which is associated with a transient response to the atmospheric pressure forcing. Though the link between presence of a cyclone in the Mediterranean has comparable importance for positive and negative anomalies, the relation between cyclone position and intensity is stronger for the magnitude of positive events. Area of cyclogenesis, track of the central minimum and position at the time of the event differ depending on the location where the sea level anomaly occurs and on its sign. The western Mediterranean is the main cyclogenesis area for both positive and negative anomalies, overall. Atlantic cyclones mainly produce positive sea level anomalies in the western basin. At the easternmost stations, positive anomalies are caused by Cyclogenesis in the Eastern Mediterranean. North Africa cyclogeneses are a major source of positive anomalies at the central African coast and negative anomalies at the eastern Mediterranean and North Aegean coast.

Trade and stowaways: molecular evidence for human-mediated translocation of eastern skinks into the western Mediterranean

2020 ◽  
Vol 41 (1) ◽  
pp. 49-62
Author(s):  
Josep Francesc Bisbal-Chinesta ◽  
Karin Tamar ◽  
Ángel Gálvez ◽  
Luís Albero ◽  
Pablo Vicent-Castelló ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Molecular Evidence ◽  
Long Distance ◽  
Human Movements ◽  
Allochthonous Species ◽  
The Mediterranean ◽  
Chalcides Ocellatus ◽  
The Impact

Abstract Human movements in the regions surrounding the Mediterranean Sea have caused a great impact in the composition of terrestrial fauna due to the introductions of several allochthonous species, intentionally or not. Reptiles are one of the groups where this anthropic impact is most evident, owing to the extensive intra-Mediterranean dispersals of recent chronologies. Chalcides ocellatus is a widespread skink with a natural distribution that covers almost the entire Mediterranean Basin. Two hypotheses have been proposed to explain its origin: natural dispersions and human translocations. Previous molecular data suggest the occurrence of a recent dispersal phenomenon across the Mediterranean Sea. In this study we present the first record of this species in the Iberian Peninsula, in Serra del Molar (South-east Spain). We combined molecular analyses and archaeological records to study the origin of this population. The molecular results indicate that the population is phylogenetically closely related to specimens from north-eastern Egypt and southern Red Sea. We suggest that the species arrived at the Iberian Peninsula most likely through human-mediated dispersal by using the trade routes. Between the Iron to Middle Ages, even now, the region surrounding Serra del Molar has been the destination of human groups and commercial goods of Egyptian origins, in which Chalcides ocellatus could have arrived as stowaways. The regional geomorphological evolution would have restricted its expansion out of Serra del Molar. These findings provide new data about the impact of human movements on faunal introductions and present new information relating to mechanisms of long-distance translocations.

scholarly journals Summertime surface PM<sub>1</sub> aerosol composition and size by source region at the Lampedusa island in the central Mediterranean Sea

2019 ◽  
Vol 19 (17) ◽  
pp. 11123-11142 ◽  
Author(s):  
Marc D. Mallet ◽  
Barbara D'Anna ◽  
Aurélie Même ◽  
Maria Chiara Bove ◽  
Federico Cassola ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Ammonium Sulfate ◽  
Organic Aerosol ◽  
Western Mediterranean ◽  
Central Mediterranean ◽  
Aerosol Composition ◽  
Air Masses ◽  
Westerly Winds ◽  
Central Mediterranean Sea ◽  
The Mediterranean

Abstract. Measurements of aerosol composition and size distributions were taken during the summer of 2013 at the remote island of Lampedusa in the southern central Mediterranean Sea. These measurements were part of the ChArMEx/ADRIMED (Chemistry and Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate) framework and took place during Special Observation Period 1a (SOP-1a) from 11 June to 5 July 2013. From compact time-of-flight aerosol mass spectrometer (cToF-AMS) measurements in the size range below 1 µm in aerodynamic diameter (PM1), particles were predominately comprised of ammonium and sulfate. On average, ammonium sulfate contributed 63 % to the non-refractory PM1 mass, followed by organics (33 %). The organic aerosol was generally very highly oxidized (f44 values were typically between 0.25 and 0.26). The contribution of ammonium sulfate was generally higher than organic aerosol in comparison to measurements taken in the western Mediterranean but is consistent with studies undertaken in the eastern basin. Source apportionment of organics using a statistical (positive matrix factorization) model revealed four factors: a hydrocarbon-like organic aerosol (HOA), a methanesulfonic-acid-related oxygenated organic aerosol (MSA-OOA), a more oxidized oxygenated organic aerosol (MO-OOA) and a less oxidized oxygenated organic aerosol (LO-OOA). The MO-OOA was the dominant factor for most of the campaign (53 % of the PM1 OA mass). It was well correlated with SO42-, highly oxidized and generally more dominant during easterly air masses originating from the eastern Mediterranean and central Europe. The LO-OOA factor had a very similar composition to the MO-OOA factor but was more prevalent during westerly winds, with air masses originating from the Atlantic Ocean, the western Mediterranean and at high altitudes over France and Spain from mistral winds. The MSA-OOA factor contributed an average 12 % to the PM1 OA and was more dominant during the mistral winds. The HOA, representing observed primary organic aerosol, only contributed 8 % of the average PM1 OA during the campaign. Even though Lampedusa is one of the most remote sites in the Mediterranean, PM1 concentrations (10 ± 5 µg m−3) were comparable to those observed in coastal cities and sites closer to continental Europe. Cleaner conditions corresponded to higher wind speeds. Nucleation and growth of new aerosol particles was observed during periods of north-westerly winds. From a climatology analysis from 1999 to 2012, these periods were much more prevalent during the measurement campaign than during the preceding 13 years. These results support previous findings that highlight the importance of different large-scale synoptic conditions in determining the regional and local aerosol composition and oxidation and also suggest that a non-polluted surface atmosphere over the Mediterranean is rare.

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