Description: 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.

Description: This Atlas summarises the global distribution of extant organic-walled dinoflagellate cysts in the form of 61 maps illustrated by the relative abundance of individual cyst taxa in recent marine sediments from the Atlantic Ocean and adjacent basins, the Antarctic region (South Atlantic, southwestern Pacific and southern Indian Ocean sections), the Arabian Sea and the northwestern Pacific. This synthesis is based on the integration of literature sources together with data from 835 marine surface sediments prepared on a comparable methodology and taxonomy. The relationships between distribution patterns of cyst species and the surface-water parameters (temperature, salinity, phosphate and nitrate concentrations) are documented with graphs depicting the relative abundance of species in relation to seasonal and annual values of the above mentioned parameters at the sample sites. Two ordination techniques (detrended correspondence analysis and canonical correspondence analysis) have been carried out to statistically illustrate the relationships between species distribution and sea-surface conditions. Results have been compared with previously published records and an overview of the ecological significance of each individual species is presented. Characterisations of selected environments as well as a discussion about how additional processes such as preservation and transport could have affected the present dataset are included.

Description: To extend the understanding of dinoflagellate cysts production, excystment and vertical/ lateral transport in the water column, upper water dinoflagellate cyst export production have been compared with cysts associations and concentrations in the subsurface nepheloid layer, bottom nepheloid layer and deeper water column during active upwelling off Cape Blanc (NW Africa) in August 2020. Export production was collected by two drifting trap surveys; one in an active upwelling cell for 4 days and the other in an offshore drifting upwelling filament for 2 days. Subsurface and bottom nepheloid layers as well as the deeper waters were sampled by in-situ pumps along two transects perpendicular to the shelf break. The dataset represents the count data on species level of organic-walled dinoflagellate cysts in drifting trap and in-situ pump collected samples as well as information about the sampling time, sampling volume and collection surface.

Description: We report on the succession of selective degradation of dinoflagellate cyst species that can be considered representative for discrete particulate organic matter (POM) classes of different degradability. The effects of anaerobic and aerobic degradation as well as bioturbation in a natural setting are documented in high resolution by means of palynological and geochemical analyses on Madeira Abyssal Plain A- and F-turbidites. These turbidites are unique as their initial ungraded sediments are affected by a downward penetrating oxydation front. The dataset covers the density, porosity, water content and dinoflagellate cysts content of sediments from the so called A- and F-turbidite.