Export flux succession of dinoflagellate cysts and planktonic foraminifera in an active upwelling cell off Cape Blanc (NW Africa)


To extend information about dinoflagellate cysts (dinocysts) and planktonic foraminifera production, succession, excystment and transport in the upper water column, we investigated their fluxes during a 7-day survey in the active upwelling off Cape Blanc (NW Africa) in November 2018 with drifting traps at 100 m, 200 m, and 400 m water depth. The 7-day survey covered a successive change from active upwelling toward stratified conditions. Highest production of organic dinocysts and planktonic foraminifera were observed under active upwelling conditions and decreased drastically towards the end of the survey. Calcareous dinocysts appeared later during upwelling relaxation. Collected cytoplasm bearing (full) dinocysts and foraminifera were produced in the water column above the traps (<100 m depth). Part of the organic-walled empty dinocysts were resuspended implying that sediments below the survey site are likely to contain both local and allochthonous cyst assemblages. We are the first to show that excystment in the upper water column is species-specific. Brigantedinium excysted in the upper water column before reaching deeper depths whereas no upper water column excystment was observed for the other dinoflagellate species. Dinoflagellate and planktonic foraminifera associations showed a clear succession. Echinidinium zonneveldiae, Brigantedinium spp., other peridinioids, Echinidinium spp., cysts of Pentapharsodinium dalei and other photosynthetic organic-walled dinocysts” as well as Neogloboquadrina incompta and Globigerinella calida were collected during active upwelling. Lingulodinium machaerophorum was produced during upwelling relaxation and Gymnodiniaceae cysts (G. microreticulatum, G. catenatum) as well as the foraminifera Globigerina bulloides and Orbulina universa were collected during stratified conditions. Apart from enhancing the biological knowledge of these species, our observations will allow more detailed reconstructions of upwelling history in the Cape Blanc region based on sedimentary archives using fossilised dinoflagellate and planktonic foraminifera assemblages.

DOI https://doi.org/10.1594/PANGAEA.931350
Related Identifier IsSupplementTo https://doi.org/10.1080/09670262.2021.1885066
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.931350
Creator Zonneveld, Karin A F ORCID logo; Meiland, Julie; Donner, Barbara; Versteegh, Gerard J M ORCID logo
Publisher PANGAEA
Publication Year 2021
Funding Reference Deutsche Forschungsgemeinschaft, Bonn https://doi.org/10.13039/501100001659 Crossref Funder ID 413534516 https://gepris.dfg.de/gepris/projekt/413534516?language=en Can patchiness explain habitat variability in planktonic foraminifera?
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 2 datasets
Discipline Earth System Research
Spatial Coverage (-18.000W, 20.729S, -17.788E, 21.163N)
Temporal Coverage Begin 2018-11-19T11:07:00Z
Temporal Coverage End 2018-11-25T08:56:00Z