First evidence of European eels exiting the Mediterranean Sea during their spawning migration

Abstract The migration route and the spawning site of the European eel Anguilla anguilla are still uncertain. It has been suggested that the Mediterranean eel stock does not contribute to spawning because there is no evidence of eels leaving the Mediterranean Sea. To test this hypothesis, we equipped eight female silver eels from the south of France with pop-up satellite tags during escapement from coastal waters. Once in deeper water, the eels quickly established diel vertical migration (DVM) between the upper and lower mesopelagic zone. Five tagged eels were taken by predators within the Mediterranean, but two eels reached the Atlantic Ocean after six months and at distances greater than 2000 km from release. These eels ceased their DVM while they negotiated the Gibraltar Strait, and remained in deep water until they reached the Atlantic Ocean, when they recommenced DVM. Our results are the first to show that eels from Mediterranean can cross the Strait of Gibraltar and continue their migration into the Atlantic Ocean. This finding suggests that Mediterranean countries, as for other EU states, have an important role to play in contributing to conservation efforts for the recovery of the European eel stock.

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De cerca medieval islámica a frente abaluartado: génesis y evolución del Frente de Tierra de Ceuta

X ◽

10.4995/fortmed2020.2020.11403 ◽

2020 ◽

Author(s):

Fernando Villada Paredes

Keyword(s):

Sixteenth Century ◽

Atlantic Ocean ◽

Mediterranean Sea ◽

Archaeological Research ◽

Strait Of Gibraltar ◽

Research Project ◽

Southern Shore ◽

Archival Documents ◽

Gibraltar Strait ◽

The Mediterranean

From Medieval Islamic Wall to Bastioned Land Front: Genesis and evolution of the Land Front of CeutaCeuta is built on a peninsula at the southern shore of the Strait of Gibraltar. It’s a strategic point for communications between the Mediterranean Sea and the Atlantic Ocean and between two continents: Europe and Africa. As Ceuta ships rule the Gibraltar Strait in Medieval and Modern Ages, main defensive efforts were tuned of to Land Front. Consequently, in 950 ‘Abd al-Rahman III built a new fence in order to protect the madina reusing Roman and Byzantine fortifications. Although repaired and enlarged by Almohads, Marinids, and Portuguese, these walls and towers protected the Land Front of Ceuta until the sixteenth century. But, at this moment, pirobalistic artillery development had made this defensive device obsolete and a new bastioned front, an early and outstanding example of the new Renaissance ideas for the defense of the cities, was built. Archival documents, cartographic sources, etc., let us follow the main lines of this evolution. Recently, an archaeological research project has added new data on how this evolution, from Medieval to Renaissance fortifications, took place.

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A Near-Uniform Basin-Wide Sea Level Fluctuation of the Mediterranean Sea

Journal of Physical Oceanography ◽

10.1175/jpo3016.1 ◽

2007 ◽

Vol 37 (2) ◽

pp. 338-358 ◽

Cited By ~ 56

Author(s):

Ichiro Fukumori ◽

Dimitris Menemenlis ◽

Tong Lee

Keyword(s):

Atlantic Ocean ◽

Mediterranean Sea ◽

Sea Level ◽

Ocean Circulation ◽

Large Scale ◽

Circulation Model ◽

Level Fluctuation ◽

Strait Of Gibraltar ◽

Sea Level Fluctuation ◽

The Mediterranean

Abstract A new basin-wide oscillation of the Mediterranean Sea is identified and analyzed using sea level observations from the Ocean Topography Experiment (TOPEX)/Poseidon satellite altimeter and a numerical ocean circulation model. More than 50% of the large-scale, nontidal, and non-pressure-driven variance of sea level can be attributed to this oscillation, which is nearly uniform in phase and amplitude across the entire basin. The oscillation has periods ranging from 10 days to several years and has a magnitude as large as 10 cm. The model suggests that the fluctuations are driven by winds at the Strait of Gibraltar and its neighboring region, including the Alboran Sea and a part of the Atlantic Ocean immediately to the west of the strait. Winds in this region force a net mass flux through the Strait of Gibraltar to which the Mediterranean Sea adjusts almost uniformly across its entire basin with depth-independent pressure perturbations. The wind-driven response can be explained in part by wind setup; a near-stationary balance is established between the along-strait wind in this forcing region and the sea level difference between the Mediterranean Sea and the Atlantic Ocean. The amplitude of this basin-wide wind-driven sea level fluctuation is inversely proportional to the setup region’s depth but is insensitive to its width including that of Gibraltar Strait. The wind-driven fluctuation is coherent with atmospheric pressure over the basin and contributes to the apparent deviation of the Mediterranean Sea from an inverse barometer response.

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Management Strategies for Seabream Sparus aurata Cultivation in Floating Cages in the Mediterranean Sea and Atlantic Ocean

Journal of the World Aquaculture Society ◽

10.1111/j.1749-7345.2003.tb00036.x ◽

2003 ◽

Vol 34 (1) ◽

pp. 29-39 ◽

Cited By ~ 6

Author(s):

Eucario Gasca-Leyva ◽

Carmelo J. León ◽

Juan M. Hernández

Keyword(s):

Atlantic Ocean ◽

Mediterranean Sea ◽

Sparus Aurata ◽

Management Strategies ◽

The Mediterranean

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High genetic differentiation of red gorgonian populations from the Atlantic Ocean and the Mediterranean Sea

Marine Biology Research ◽

10.1080/17451000.2017.1312005 ◽

2017 ◽

Vol 13 (8) ◽

pp. 854-861 ◽

Cited By ~ 1

Author(s):

Joanna Pilczynska ◽

Silvia Cocito ◽

Joana Boavida ◽

Ester A. Serrão ◽

Henrique Queiroga

Keyword(s):

Genetic Differentiation ◽

Atlantic Ocean ◽

Mediterranean Sea ◽

The Mediterranean

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Characterizing the Evolution of the Container Traffic Share in the Mediterranean Sea Using Hierarchical Clustering

Journal of Marine Science and Engineering ◽

10.3390/jmse6040121 ◽

2018 ◽

Vol 6 (4) ◽

pp. 121 ◽

Cited By ~ 1

Author(s):

Manel Grifoll ◽

Thanassis Karlis ◽

M. Ortego

Keyword(s):

Mediterranean Sea ◽

Hierarchical Clustering ◽

System Analysis ◽

Compositional Data ◽

Eastern Mediterranean ◽

Compositional Data Analysis ◽

Mediterranean Countries ◽

The Mediterranean ◽

Combination Of Methods ◽

Port Infrastructure

This research investigates the traffic share evolution of the container throughput in the Mediterranean ports from 2000 to 2015 considering hierarchical clustering and concentration indexes. Compositional Data analysis techniques are used to illustrate periods with similar traffic share composition. Two different regions (East and West) in the Mediterranean Sea (Med) are selected in the function of the long haul services. The standard concentration indexes (i.e., concentration ratio, Gini coefficient, and Normalized Herfindahl-Hirschman) reveal a gentle decreasing of the concentration with relevant fluctuations mainly in the East region. This is due to the investment in port infrastructure in the area resulting from privatization initiatives in many Eastern Mediterranean countries. The periods obtained from the hierarchical clustering show a differentiated pattern in traffic share composition. For these periods, the shift-share results are consistent with traffic fluctuations and in line with the evolution of the concentration indexes. The combination of methods has allowed a good interpretation of the spatial and temporal evolution of the Med ports’ traffic being the methodology applicable elsewhere in the context of port system analysis.

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Echinoderes pterus sp. n. showing a geographically and bathymetrically wide distribution pattern on seamounts and on the deep-sea floor in the Arctic Ocean, Atlantic Ocean, and the Mediterranean Sea (Kinorhyncha, Cyclorhagida)

ZooKeys ◽

10.3897/zookeys.771.25534 ◽

2018 ◽

Vol 771 ◽

pp. 15-40 ◽

Cited By ~ 10

Author(s):

Hiroshi Yamasaki ◽

Katarzyna Grzelak ◽

Martin V. Sørensen ◽

Birger Neuhaus ◽

Kai Horst George

Keyword(s):

Atlantic Ocean ◽

Arctic Ocean ◽

Distribution Pattern ◽

Mediterranean Sea ◽

Deep Sea ◽

Wide Distribution ◽

The Arctic ◽

Sea Floor ◽

The Arctic Ocean ◽

The Mediterranean

Kinorhynchs rarely show a wide distribution pattern, due to their putatively low dispersal capabilities and/or limited sampling efforts. In this study, a new kinorhynch species is described,Echinoderespterussp. n., which shows a geographically and bathymetrically wide distribution, occurring on the Karasik Seamount and off the Svalbard Islands (Arctic Ocean), on the Sedlo Seamount (northeast Atlantic Ocean), and on the deep-sea floor off Crete and on the Anaximenes Seamount (Mediterranean Sea), at a depth range of 675–4,403 m. The new species is characterized by a combination of middorsal acicular spines on segments 4–8, laterodorsal tubes on segment 10, lateroventral tubes on segment 5, lateroventral acicular spines on segments 6–9, tufts of long hairs rising from slits in a laterodorsal position on segment 9, truncated tergal extensions on segment 11, and the absence of any type-2 gland cell outlet. The specimens belonging to the populations from the Arctic Ocean, the Sedlo Seamount, and the Mediterranean Sea show morphological variation in the thickness and length of the spines as well as in the presence/absence of ventromedial sensory spots on segment 7. The different populations are regarded as belonging to a single species because of their overlapping variable characters.

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Conséquences tectoniques de l'existence d'une anomalie de conductivité électrique au nord du Maroc

Canadian Journal of Earth Sciences ◽

10.1139/e82-130 ◽

1982 ◽

Vol 19 (7) ◽

pp. 1507-1517 ◽

Cited By ~ 10

Author(s):

Michel Menvielle ◽

Jean-Claude Rossignol

Keyword(s):

Atlantic Ocean ◽

Mediterranean Sea ◽

Geomagnetic Field ◽

Southern Spain ◽

Electric Currents ◽

Anomalous Field ◽

Conductivité Électrique ◽

The Mediterranean ◽

Transient Variations

Anomalous transient variations of the geomagnetic field in northern Morocco and southern Spain have been described previously for periods ranging from 10 min to 2 h. These results have been reinvestigated with regard to their tectonic implications.The main result obtained is evidence for a conductive structure that electrically connects the Atlantic Ocean to the Mediterranean Sea. This conductive structure coincides with a zone of fractures, extending over several hundreds of kilometres and deeply penetrating the crust, that may form the southeastern boundary of the Alboran block.We also show that the deviation and channeling of electric currents by lateral contrasts of conductivity may account for most of the features of the observed anomalous field in southern Spain and northern Morocco.

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Anthropogenic and natural CO<sub>2</sub> exchange through the Strait of Gibraltar

Biogeosciences ◽

10.5194/bg-6-647-2009 ◽

2009 ◽

Vol 6 (4) ◽

pp. 647-662 ◽

Cited By ~ 48

Author(s):

I. E. Huertas ◽

A. F. Ríos ◽

J. García-Lafuente ◽

A. Makaoui ◽

S. Rodríguez-Gálvez ◽

...

Keyword(s):

Time Series ◽

Atlantic Ocean ◽

Mediterranean Sea ◽

Mediterranean Basin ◽

Inorganic Carbon ◽

Strait Of Gibraltar ◽

Anthropogenic Carbon ◽

The Mediterranean ◽

The Mediterranean Basin ◽

Mediterranean Water

Abstract. The exchange of both anthropogenic and natural inorganic carbon between the Atlantic Ocean and the Mediterranean Sea through Strait of Gibraltar was studied for a period of two years under the frame of the CARBOOCEAN project. A comprehensive sampling program was conducted, which was design to collect samples at eight fixed stations located in the Strait in successive cruises periodically distributed through the year in order to ensure a good spatial and temporal coverage. As a result of this monitoring, a time series namely GIFT (GIbraltar Fixed Time series) has been established, allowing the generation of an extensive data set of the carbon system parameters in the area. Data acquired during the development of nine campaigns were analyzed in this work. Total inorganic carbon concentration (CT) was calculated from alkalinity-pHT pairs and appropriate thermodynamic relationships, with the concentration of anthropogenic carbon (CANT) being also computed using two methods, the ΔC* and the TrOCA approach. Applying a two-layer model of water mass exchange through the Strait and using a value of −0.85 Sv for the average transport of the outflowing Mediterranean water recorded in situ during the considered period, a net export of inorganic carbon from the Mediterranean Sea to the Atlantic was obtained, which amounted to 25±0.6 Tg C yr−1. A net alkalinity output of 16±0.6 Tg C yr−1 was also observed to occur through the Strait. In contrast, the Atlantic water was found to contain a higher concentration of anthropogenic carbon than the Mediterranean water, resulting in a net flux of CANT towards the Mediterranean basin of 4.20±0.04 Tg C yr−1 by using the ΔC* method, which constituted the most adequate approach for this environment. A carbon balance in the Mediterranean was assessed and fluxes through the Strait are discussed in relation to the highly diverse estimates available in the literature for the area and the different approaches considered for CANT estimation. This work unequivocally confirms the relevant role of the Strait of Gibraltar as a controlling point for the biogeochemical exchanges occurring between the Mediterranean Sea and the Atlantic Ocean and emphasizes the influence of the Mediterranean basin in the carbon inventories of the North Atlantic.

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