Mediterranean Oran

Author(s):  
Joshua Schreier

This chapter recounts Oran’s history over the longue durée. It speaks of a city situated on the northern coast of Africa, but also on the southern coast of the Mediterranean Sea. Oran was a creation of Spain and southern Europe as well as of Tlemcen, the Sahara, and the African sources of goods that lay beyond it. Indeed, in the first century or two of its existence, Oran owed its existence to its proximity to the Iberian Peninsula. The westernmost section of the Mediterranean, stretching from Cape Tenès in the east to the Straights of Gibraltar in the west, has been described as a medieval “Ibero-African English Channel,” linking North Africa and Spain with a constant flow of commercial ships. Oran’s dependence on larger circuits of western Mediterranean commerce would continue into the nineteenth century.

2020 ◽  
Vol 41 (1) ◽  
pp. 49-62
Author(s):  
Josep Francesc Bisbal-Chinesta ◽  
Karin Tamar ◽  
Ángel Gálvez ◽  
Luís Albero ◽  
Pablo Vicent-Castelló ◽  
...  

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.


2017 ◽  
Author(s):  
María del Carmen García-Martínez ◽  
Manuel Vargas-Yáñez ◽  
Francina Moya ◽  
Patricia Zunino ◽  
Begoña Bautista

Abstract. The Mediterranean Sea transforms Atlantic Waters inflowing through the Strait of Gibraltar into saltier, cooler and denser Mediterranean Waters that outflow into the Atlantic Ocean. A theoretical steady state functioning of the Mediterranean Sea would be the result of the balance between the net heat and volume transports through the Strait of Gibraltar and the heat loss to the atmosphere through the sea surface and the net evaporation. The salt transport for the inflow and outflow should be balanced. Changes in the heat content, temperature and salinity of the Mediterranean waters reveal that the present Mediterranean functioning is out of this equilibrium state. A new analysis for MEDAR data shows that the temperature and salinity averaged for the Mediterranean Waters in the whole basin increased at rates of 0.0020 ± 0.0018 ºC/yr and 0.0007 ± 0.0003 psu/yr. This temperature trend is equivalent to a 0.43 ± 0.38 W/m2 heat absorption. This warming trend would have increased during the beginning of the twenty first century at the Western Mediterranean, maybe linked to the Western Mediterranean Transition. Results from a simple box model using heat, volume and salt conservation laws indicate that the observed changes cannot be attributed only to an increase of the net evaporation, nor to a salinity increase of the Atlantic Waters flowing through the Strait of Gibraltar as previous hypotheses suggested. An increase of the net evaporation ranging between 5 and 7 % combined with a reduction of the heat losses to the atmosphere ranging between 0.4 and 0.5 W/m2 could explained the observed changes.


2021 ◽  
Author(s):  
Alba de la Vara ◽  
William Cabos ◽  
Dmitry V. Sein ◽  
Claas Teichmann ◽  
Daniela Jacob

AbstractIn this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean.


Author(s):  
J.A. Reina-Hervás ◽  
J.E. García Raso ◽  
M.E. Manjón-Cabeza

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.


Author(s):  
Sergio Ragonese ◽  
Giovan Battista Giusto

The occurrence in the Strait of Sicily of the saddled snake eel, Pisodonophis semicinctus (Osteichthyes: Ophichthidae), a rare finding for the Mediterranean Sea, is confirmed on the basis of one specimen caught off the northern coast of Tunisia in 1991. The specimen, 800 mm in total length and 457 g in body weight (preserved condition), was captured during a commercial bottom trawl hauled at 30 m next to Cape Bon (north of Tunisia). This represents the second and fourth documented record of this Atlantic intruder within the Strait of Sicily and the Mediterranean Sea, respectively.


Author(s):  
Enric Massutí ◽  
J.A. Reina-Hervás ◽  
Domingo Lloris ◽  
L. Gil de Sola

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.


2015 ◽  
Author(s):  
Jasmine Ferrario ◽  
Agnese Marchini ◽  
Martina Marić ◽  
Dan Minchin ◽  
Anna Occhipinti-Ambrogi

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.


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 ◽  
...  

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.


2021 ◽  
Author(s):  
Giusy Fedele ◽  
Elena Mauri ◽  
Giulio Notarstefano ◽  
Pierre Marie Poulain

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.


2019 ◽  
Author(s):  
Piero Lionello ◽  
Dario Conte ◽  
Marco Reale

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.


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