Distribution of modern dinocysts and pollen in the western Mediterranean Sea (Algerian Margin and Gulf of Lion)

Date 2022
Author(s) Coussin Vincent1, Penaud AurelieORCID1, Combourieu-Nebout NathalieORCID2, Peyron OdileORCID3, Schmidt SabineORCID4, Zaragosi SebastienORCID4, de Vernal AnneORCID5, Babonneau NathalieORCID1
Affiliation(s) 1 : Univ Brest, CNRS, Ifremer, Geo-ocean, UMR6538, F-29850 Plouzané, France
2 : HNHP, CNRS, UMR 7194, Département de Préhistoire du Muséum d’Histoire Naturelle, F-75013 Paris, France
3 : Univ Montpellier, CNRS, UMR 5554, Institut des Sciences de l’Evolution de Montpellier (ISEM), 34095 Montpellier cedex 05, France
4 : Univ Bordeaux, CNRS, UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), F-33615 Pessac, France
5 : Geotop, Université du Québec à Montréal (UQAM), 201 Avenue du Président Kennedy, Montréal, Québec, H3C 3P8, Canada
DOI 10.17882/87317
Publisher SEANOE
Keyword(s) western Mediterranean Sea, Gulf of Lion, Algerian Margin, dinoflagellate cysts, productivity, fluvial discharge, upwelling cells, pollen and spores, vegetation gradients, non-pollen palynomorphs
Abstract

The Mediterranean Sea is generally described as an oligotrophic area where primary productivity is limited to a few coastal environments with nutrient-enriched fluvial input. However, several studies have revealed that the hydrology of the western Mediterranean has major seasonal productive patterns linked either to significant riverine input or to seasonal upwelling cells. This study aims to: i) discuss organic microfossils (i.e. pollen and dinoflagellate cyst assemblages, as well as other non-pollen palynomorphs) from two different productive areas of the western Mediterranean Sea, and ii) examine the importance of the interconnections between marine and continental influences responsible for modern palynomorph distributions. Based on 25 samples from the Gulf of Lion (GoL) and Algerian Margin, this study key findings are: i) that GoL marine productivity is driven by the combination of discharges from the Rhône River and seasonal upwelling mechanisms, ii) that the strong productive pattern of the northern African coast is driven by water density front mixings and related upwellings. These two patterns are discussed in the light of major links that provide a better understanding of the signatures of marine and continental bio-indicators. The dinocyst Lingulodinium machaerophorum can be considered as a tracer of Rhône River plume influence in the GoL. Brigantedinium taxa are shown to be upwelling-sensitive in both studied areas. Typical differences in vegetation across the north–south climate gradient in the western Mediterranean Basin are highlighted by the larger ratio of Euro-Siberian to Mediterranean pollen taxa in the northern sector. Synoptic maps also illustrate the complex interactions of environmental drivers determining the distributions of continental and marine palynomorphs in the western Mediterranean Sea.

Licence CC-BY
Acknowledgements This work was part of a PhD thesis (Coussin V.) financed by the Région Bretagne and UBO (University of Brest). This work was supported by the French national programme (CNRS) LEFE-EC2CO (‘DATAPOL’), by the ‘ISblue’ project (Interdisciplinary graduate school for the blue planet; ANR-17-EURE-0015), and was co-funded by a grant from the French government under the program Investissements d'Avenir. We thank the captains, crews and scientific teams of the cruises that collected studied cores: GMO1 (Pierre Cochonat, Bernard Dennielou), GMO2-CARNAC (Nabil Sultan, Michel Voisset), BEACHMED (Catherine Satra Le Bris) and RHOSOS (Serge Berné, Bernard Dennielou). We also thank the Ifremer for access to the sedimentology laboratory and Marion Genet for the sample sharing. We acknowledge the ANR BRAISE project, grant ANR-19-CE01-0001-01, for the funding of the 210Pbxs measurements of the Gulf of Lion sediments. We thank Yannick Miras for his help with the determination of non-pollen palynomorphs and discussion about their ecological signature.
Sensor metadata

Datation data of the study samples, exctracted and used environmental parameters at samples coordinates (from Levitus.org), palynological counts for dinoflagellates cysts and pollen

Data
File Size Format Processing Access
Datation data, used environmental parameters and palynological data (rough counts) 42 KB XLS, XLSX Raw data Open access
Top of the page

How to cite 

Coussin Vincent, Penaud Aurelie, Combourieu-Nebout Nathalie, Peyron Odile, Schmidt Sabine, Zaragosi Sebastien, de Vernal Anne, Babonneau Nathalie (2022). Distribution of modern dinocysts and pollen in the western Mediterranean Sea (Algerian Margin and Gulf of Lion). SEANOE. https://doi.org/10.17882/87317