Genetic homogeneity of the critically endangered fan mussel, Pinna nobilis, throughout lagoons of the Gulf of Lion (North-Western Mediterranean Sea)

AbstractThe fan mussel, Pinna nobilis, endemic to the Mediterranean Sea, is a critically endangered species facing mass mortality events in almost all of its populations, following the introduction of the parasite Haplosporidium pinnae. Such a unique pandemic in a marine organism, which spreads rapidly and with mortality rates reaching up to 100%, could lead to the potential extinction of the species. Only few regions, involving lagoon habitats, remain healthy throughout the entire Mediterranean Sea. This study describes the genetic structure of P. nobilis across the Gulf of Lion, including confined locations such as lagoons and ports. A total of 960 samples were collected among 16 sites distributed at 8 localities, and then genotyped using 22 microsatellite markers. Genetic diversity was high in all sites with mean allele numbers ranging between 10 and 14.6 and with observed heterozygosities (Ho) between 0.679 and 0.704. No genetic differentiation could be identified (FST ranging from 0.0018 to 0.0159) and the percentages of related individuals were low and similar among locations (from 1.6 to 6.5%). Consequently, all fan mussels, over the entire coastline surveyed, including those in the most geographically isolated areas, belong to a large genetically homogeneous population across the Gulf of Lion. Considering the ongoing mass mortality context, this result demonstrates that almost all of the genetic diversity of P. nobilis populations is still preserved even in isolated lagoons, which might represent a refuge habitat for the future of the species.

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S.O.S. Pinna nobilis: A Mass Mortality Event in Western Mediterranean Sea

Frontiers in Marine Science ◽

10.3389/fmars.2017.00220 ◽

2017 ◽

Vol 4 ◽

Cited By ~ 42

Author(s):

Maite Vázquez-Luis ◽

Elvira Álvarez ◽

Agustín Barrajón ◽

José R. García-March ◽

Amalia Grau ◽

...

Keyword(s):

Mediterranean Sea ◽

Western Mediterranean ◽

Mass Mortality ◽

Mortality Event ◽

Pinna Nobilis ◽

Mass Mortality Event ◽

Western Mediterranean Sea

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Population trends of the fan mussel Pinna nobilis from Portofino MPA (Ligurian Sea, Western Mediterranean Sea) before and after a mass mortality event and a catastrophic storm

The European Zoological Journal ◽

10.1080/24750263.2020.1850891 ◽

2020 ◽

Vol 88 (1) ◽

pp. 18-25

Author(s):

F. Betti ◽

S. Venturini ◽

L. Merotto ◽

V. Cappanera ◽

S. Ferrando ◽

...

Keyword(s):

Mediterranean Sea ◽

Western Mediterranean ◽

Mass Mortality ◽

Population Trends ◽

Ligurian Sea ◽

Mortality Event ◽

Pinna Nobilis ◽

Mass Mortality Event ◽

Western Mediterranean Sea ◽

Before And After

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On the termination of deep-sea fan channels: Examples from the Rhône Fan (Gulf of Lion, Western Mediterranean Sea)

Geomorphology ◽

10.1016/j.geomorph.2020.107368 ◽

2020 ◽

Vol 369 ◽

pp. 107368

Author(s):

L. Droz ◽

I. Jégou ◽

H. Gillet ◽

B. Dennielou ◽

M. Bez ◽

...

Keyword(s):

Mediterranean Sea ◽

Deep Sea ◽

Western Mediterranean ◽

Western Mediterranean Sea ◽

Gulf Of Lion ◽

Sea Fan

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Repeated fluid expulsions during events of rapid sea-level rise in the Gulf of Lion, western Mediterranean Sea

BSGF - Earth Sciences Bulletin ◽

10.1051/bsgf/2017190 ◽

2017 ◽

Vol 188 (4) ◽

pp. 24 ◽

Cited By ~ 3

Author(s):

Aurélien Gay ◽

Thibault Cavailhès ◽

Dominique Grauls ◽

Bruno Marsset ◽

Tania Marsset

Keyword(s):

Sea Level Rise ◽

Mediterranean Sea ◽

Sea Level ◽

Western Mediterranean ◽

Unconsolidated Sediments ◽

Geometrical Parameters ◽

Near Surface ◽

Western Mediterranean Sea ◽

Gulf Of Lion ◽

Potential Fluid

Based on a High-Resolution 3D seismic block acquired in the Gulf of Lion in 2004–2005 we investigated fluid pipes and pockmarks on the top of the interfluve between the Hérault canyon and the Bourcart canyon both created by turbidity currents and gravity flows from the shelf to the deep basin in the north-western Mediterranean Sea. Combining the geometry of the potential fluid pipes with the induced deformation of surrounding sediments leads then to the ability to differentiate between potential fluid sources (root vs source) and to better estimate the triggering mechanisms (allochtonous vs. autochtonous cause). We linked together a set of derived attributes, such as Chaos and RMS amplitude, to a 3D description of pipes along which fluids may migrate. As previously shown in other basins, the induced deformation, creating cone in cone or V-shaped structures, may develop in response to the fluid pipe propagation in unconsolidated sediments in the near surface. The level at the top of a cone structure is diachronous. It means that stratigraphic levels over this surface are deformed at the end of the migration. They collapse forming a depression called a pockmark. These pipes are the result of repeated cycles of fluid expulsion that might be correlated with rapid sea-level rise instead of sediment loading. The most recent event (MIS 2.2 stage) has led to the formation of a pockmark on the modern seafloor. It has been used as a reference for calculating the effect of a rapid sea-level rise on fluid expulsion. As all physical and geometrical parameters are constrained, we were able to define that a + 34 m of sea level rise may account for triggering fluid expulsion from a very shallow silty-sandy layer at 9 m below seafloor since the last glacial stage. This value is consistent with a sea level rise of about 102 m during this period. This study shows that the episodic nature of fluid release resulted from hydromechanical processes during sea-level rise due to the interactivity between high pressure regimes and principal in situ stresses.

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Sedimentological imprint on subseafloor microbial communities in Western Mediterranean Sea Quaternary sediments

Biogeosciences ◽

10.5194/bg-9-3491-2012 ◽

2012 ◽

Vol 9 (9) ◽

pp. 3491-3512 ◽

Cited By ~ 11

Author(s):

M.-C. Ciobanu ◽

M. Rabineau ◽

L. Droz ◽

S. Révillon ◽

J.-F. Ghiglione ◽

...

Keyword(s):

Community Structure ◽

Microbial Communities ◽

Mediterranean Sea ◽

Microbial Community Composition ◽

Western Mediterranean ◽

Depositional Environments ◽

Ligurian Sea ◽

Western Mediterranean Sea ◽

Quaternary Climate ◽

Gulf Of Lion

Abstract. An interdisciplinary study was conducted to evaluate the relationship between geological and paleoenvironmental parameters and the bacterial and archaeal community structure of two contrasting subseafloor sites in the Western Mediterranean Sea (Ligurian Sea and Gulf of Lion). Both depositional environments in this area are well-documented from paleoclimatic and paleooceanographic point of views. Available data sets allowed us to calibrate the investigated cores with reference and dated cores previously collected in the same area, and notably correlated to Quaternary climate variations. DNA-based fingerprints showed that the archaeal diversity was composed by one group, Miscellaneous Crenarchaeotic Group (MCG), within the Gulf of Lion sediments and of nine different lineages (dominated by MCG, South African Gold Mine Euryarchaeotal Group (SAGMEG) and Halobacteria) within the Ligurian Sea sediments. Bacterial molecular diversity at both sites revealed mostly the presence of the classes Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria within Proteobacteria phylum, and also members of Bacteroidetes phylum. The second most abundant lineages were Actinobacteria and Firmicutes at the Gulf of Lion site and Chloroflexi at the Ligurian Sea site. Various substrates and cultivation conditions allowed us to isolate 75 strains belonging to four lineages: Alpha-, Gammaproteobacteria, Firmicutes and Actinobacteria. In molecular surveys, the Betaproteobacteria group was consistently detected in the Ligurian Sea sediments, characterized by a heterolithic facies with numerous turbidites from a deep-sea levee. Analysis of relative betaproteobacterial abundances and turbidite frequency suggested that the microbial diversity was a result of main climatic changes occurring during the last 20 ka. Statistical direct multivariate canonical correspondence analyses (CCA) showed that the availability of electron acceptors and the quality of electron donors (indicated by age) strongly influenced the community structure. In contrast, within the Gulf of Lion core, characterized by a homogeneous lithological structure of upper-slope environment, most detected groups were Bacteroidetes and, to a lesser extent, Betaproteobacteria. At both site, the detection of Betaproteobacteria coincided with increased terrestrial inputs, as confirmed by the geochemical measurements (Si, Sr, Ti and Ca). In the Gulf of Lion, geochemical parameters were also found to drive microbial community composition. Taken together, our data suggest that the palaeoenvironmental history of erosion and deposition recorded in the Western Mediterranean Sea sediments has left its imprint on the sedimentological context for microbial habitability, and then indirectly on structure and composition of the microbial communities during the late Quaternary.

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Corrigendum: In the Wake of the Ongoing Mass Mortality Events: Co-occurrence of Mycobacterium, Haplosporidium and Other Pathogens in Pinna nobilis Collected in Italy and Spain (Mediterranean Sea)

Frontiers in Marine Science ◽

10.3389/fmars.2020.00382 ◽

2020 ◽

Vol 7 ◽

Cited By ~ 1

Author(s):

Francesca Carella ◽

Elisabetta Antuofermo ◽

Simone Farina ◽

Fulvio Salati ◽

Daniela Mandas ◽

...

Keyword(s):

Mediterranean Sea ◽

Mass Mortality ◽

Pinna Nobilis

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Tectonic evolution of the Sicilian Maghrebian Chain inferred from stratigraphic and petrographic evidences of Lower Cretaceous and Oligocene flysch

Geologica Carpathica ◽

10.2478/geoca-2014-0020 ◽

2014 ◽

Vol 65 (4) ◽

pp. 293-305 ◽

Cited By ~ 5

Author(s):

Diego Puglisi

Keyword(s):

Lower Cretaceous ◽

Western Mediterranean ◽

Geological Evidence ◽

The Balkans ◽

Early Oligocene ◽

Gulf Of Lion ◽

Tectonic Development ◽

Thinned Continental Crust ◽

Almost All ◽

Back Arc

Abstract The occurrence of a Lower Cretaceous flysch group, cropping out from the Gibraltar Arc to the Balkans with a very similar structural setting and sedimentary provenance always linked to the dismantling of internal areas, suggests the existence of only one sedimentary basin (Alpine Tethys s.s.), subdivided into many other minor oceanic areas. The Maghrebian Basin, mainly developed on thinned continental crust, was probably located in the westernmost sector of the Alpine Tethys. Cretaceous re-organization of the plates triggered one (or more) tectonic phases, well recorded in almost all the sectors of the Alpine Tethys. However, the Maghrebian Basin seems to have been deformed by Late- or post-Cretaceous tectonics, connected with a “meso-Alpine” phase (pre-Oligocene), already hypothesized since the beginning of the nineties. Field geological evidence and recent biostratigraphic data also support this important meso- Alpine tectonic phase in the Sicilian segment of the Maghrebian Chain, indicated by the deformations of a Lower Cretaceous flysch sealed by Lower Oligocene turbidite deposits. This tectonic development is emphasized here because it was probably connected with the onset of rifting in the southern paleomargin of the European plate, the detaching of the so-called AlKaPeCa block (Auct.; i.e. Alboran + Kabylian + Calabria and Peloritani terranes) and its fragmentation into several microplates. The subsequent early Oligocene drifting of these microplates led to the progressive closure of the Maghrebian Basin and the opening of new back-arc oceanic basins, strongly controlled by extensional processes, in the western Mediterranean (i.e. Gulf of Lion, Valencia Trough, Provençal Basin and Alboran Sea).

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