Dinoflagellate cysts in western equatorial Atlantic surface sediments

DOI

In contrast to the wide range of studies carried out in temperate and high-latitude oceanic regions, only a few studies have focused on recent and Holocene organic-walled dinoflagellate cyst assemblages from the tropics. This information is, however, essential for fully understanding the ability of species to adapt to different oceanographic regimes, and ultimately their potential application to local and regional palaeoenvironmental and palaeoceanographic reconstructions. Surface sediment samples of the western equatorial Atlantic Ocean north of Brazil, an area greatly influenced by Amazon River discharge waters, were therefore analysed in detail for their organic-walled dinoflagellate cyst content. A diverse association of 43 taxa was identified, and large differences in cyst distribution were observed. The cyst thanatocoenosis in bottom sediments reflects the seasonal advection of Amazon River discharge water through the Guyana Current and the North Equatorial Countercurrent well into the North Atlantic. To establish potential links between cyst distribution and the environmental conditions of the upper water column, distribution patterns were compared with mean temperature, salinity, density and stratification gradients within the upper water column (0–100 m) over different times of the year, using correspondence analysis and canonical correspondence analysis. The analyses show that differences in these parameters only play a subordinate role in determining species distribution. Instead, nutrient availability, or related factors, dominates the distribution pattern. The only possible indicators of slightly reduced salinities are Trinovantedinium applanatum and Lingulodinium machaerophorum. Four assemblage groups of cyst taxa with similar environmental affinities related to specific water masses/currents can be distinguished and have potential for palaeoenvironmental reconstruction.

Supplement to: Vink, Annemiek; Zonneveld, Karin A F; Willems, Helmut (2000): Organic-walled dinoflagellate cysts in western equatorial Atlantic surface sediments: Distributions and their relation to environment. Review of Palaeobotany and Palynology, 112(4), 247-286

Identifier
DOI https://doi.org/10.1594/PANGAEA.55922
Related Identifier https://doi.org/10.1016/S0034-6667(00)00046-4
Related Identifier https://nbn-resolving.org/urn:nbn:de:gbv:46-ep000102797
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.55922
Provenance
Creator Vink, Annemiek ORCID logo; Zonneveld, Karin A F ORCID logo; Willems, Helmut
Publisher PANGAEA
Publication Year 2000
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 1938 data points
Discipline Geosciences; Natural Sciences
Spatial Coverage (-59.388W, -31.615S, -16.330E, 18.195N); Mid Atlantic Ridge; Vema Channel; Continental slope off Brazil; Brazil Basin; Equatorial Atlantic; Northeast Brasilian Margin; Amazon Shelf/Fan; Atlantic Caribbean Margin; Midatlantic Ridge; Northern Brasil Basin; Ceara Rise; Amazon Fan; Guayana continental slope
Temporal Coverage Begin 1996-03-01T00:00:00Z
Temporal Coverage End 1997-04-04T13:54:00Z