Not logged in
PANGAEA.
Data Publisher for Earth & Environmental Science

Romero, Oscar E; Lange, Carina Beatriz; Wefer, Gerold (2002): Siliceous phytoplankton fluxes off northwest Africa. PANGAEA, https://doi.org/10.1594/PANGAEA.736513, Supplement to: Romero, OE et al. (2002): Interannual variability (1988-1991) of siliceous phytoplankton fluxes off NW Africa. Journal of Plankton Research, 24(10), 1035-1046, https://doi.org/10.1093/plankt/24.10.1035

Always quote above citation when using data! You can download the citation in several formats below.

RIS CitationBibTeX CitationShow MapGoogle Earth

Abstract:
Four years of observations (1988-1991) of downward fluxes of diatoms and silicoflagellates at a trap site off Cape Blanc (ca. 20°N, 20°W), northwest Africa, are presented. Significant variations in flux and species composition were observed as well as a marked drop in the export of biogenic opal (and diatoms) from 1988 to 1989; fluxes remained low thereafter. We hypothesize that this diminution might be related to decreased coastal upwelling intensity and offshore spreading of the typical chlorophyll filament, and/or a lesser silicate content of upwelling waters off Cape Blanc. In addition, the more seaward positioning of the mooring may have influenced the fluxes. At all times, diatoms were the most prominent contributors to the biogenic opal flux, and diatom fluxes closely paralleled total mass flux fluctuations. Although species composition varied seasonally, no significant qualitative variations were observed from year to year. In general, the dominance of neritic diatoms, such as Thalassionema nitzschioides var. nitzschioides, resting spores of Chaetoceros and Cyclotella litoralis, reflected the continuous offshore influence of coastal upwelling at the Cape Blanc trap site, with stronger intensity in spring/summer. In contrast, the occurrence of pelagic diatoms (e.g. Nitzschia bicapitata, N. interruptestriata, T. nitzschioides var. parva and Fragilariopsis doliolus), and high silicoflagellate fluxes (mainly Dictyocha messanensis) were linked to inshore transport of oceanic waters, generally in winter. With the exception of some fragile, pelagic diatoms, dominant species found in the settled material also occurred in the underlying sediments, suggesting that diatom thanatocoenosis downcore (Organisms preserved from the top to the bottom in sediment core) can be used as a reliable indicator of the intensity and persistence of the offshore spreading of coastal upwelling.
Coverage:
Median Latitude: 21.045750 * Median Longitude: -20.447000 * South-bound Latitude: 20.755000 * West-bound Longitude: -20.687000 * North-bound Latitude: 21.145000 * East-bound Longitude: -19.742000
Date/Time Start: 1988-03-22T12:00:00 * Date/Time End: 1991-11-09T00:01:00
Event(s):
CB1_trap * Latitude: 20.755000 * Longitude: -19.742000 * Date/Time Start: 1988-03-22T00:00:00 * Date/Time End: 1989-03-08T00:00:00 * Elevation: -3646.0 m * Campaign: M6/6 * Basis: Meteor (1986) * Device: Trap (TRAP)
CB2_trap * Latitude: 21.145000 * Longitude: -20.687000 * Date/Time Start: 1989-03-15T00:00:00 * Date/Time End: 1990-03-24T00:00:00 * Elevation: -4092.0 m * Campaign: M9/4 * Basis: Meteor (1986) * Device: Trap (TRAP)
CB3_trap * Latitude: 21.138000 * Longitude: -20.672000 * Date/Time Start: 1990-04-08T00:00:00 * Date/Time End: 1991-04-30T00:00:00 * Elevation: -4094.0 m * Campaign: M12/1 * Basis: Meteor (1986) * Device: Trap (TRAP)
Size:
12 datasets

Download Data

Download ZIP file containing all datasets as tab-delimited text (use the following character encoding: )

Datasets listed in this publication series

  1. Romero, OE; Lange, CB; Wefer, G (2002): Neritic/pelagic diatom ratio of mooring CB1_trap. https://doi.org/10.1594/PANGAEA.107765
  2. Romero, OE; Lange, CB; Wefer, G (2002): Neritic/pelagic diatom ratio of mooring CB2_trap. https://doi.org/10.1594/PANGAEA.107766
  3. Romero, OE; Lange, CB; Wefer, G (2002): Neritic/pelagic diatom ratio of mooring CB3_trap. https://doi.org/10.1594/PANGAEA.107767
  4. Romero, OE; Lange, CB; Wefer, G (2002): Neritic/pelagic diatom ratio of mooring CB4_trap. https://doi.org/10.1594/PANGAEA.107768
  5. Romero, OE; Lange, CB; Wefer, G (2002): Percentage abundant of neritic and pelagic diatoms of mooring CB1_trap. https://doi.org/10.1594/PANGAEA.107726
  6. Romero, OE; Lange, CB; Wefer, G (2002): Percentage abundant of neritic and pelagic diatoms of mooring CB2_trap. https://doi.org/10.1594/PANGAEA.107727
  7. Romero, OE; Lange, CB; Wefer, G (2002): Percentage abundant of neritic and pelagic diatoms of mooring CB3_trap. https://doi.org/10.1594/PANGAEA.107728
  8. Romero, OE; Lange, CB; Wefer, G (2002): Percentage abundant of neritic and pelagic diatoms of mooring CB4_trap. https://doi.org/10.1594/PANGAEA.107763
  9. Romero, OE; Lange, CB; Wefer, G (2002): Seasonal flux patterns of mooring CB1_trap. https://doi.org/10.1594/PANGAEA.107721
  10. Romero, OE; Lange, CB; Wefer, G (2002): Seasonal flux patterns of mooring CB2_trap. https://doi.org/10.1594/PANGAEA.107722
  11. Romero, OE; Lange, CB; Wefer, G (2002): Seasonal flux patterns of mooring CB3_trap. https://doi.org/10.1594/PANGAEA.107723
  12. Romero, OE; Lange, CB; Wefer, G (2002): Seasonal flux patterns of mooring CB4_trap. https://doi.org/10.1594/PANGAEA.107724