Modern organic-walled dinoflagellate cyst distribution offshore NW Iberia; tracing the upwelling system

Abstract

The northwest Iberian ocean margin experiences seasonal upwelling of nutrient-rich water resulting in enhanced primary productivity. The quantitative organic-walled dinoflagellate cyst distribution and that of other palynomorphs has been determined in 37 box core-tops along three transects to trace the upwelling signal. Oligotrophic Impagidinium spp. represent the dominant offshore elements. Cysts of heterotrophic Protoperidinium spp. mainly occur in sediments of the seasonal upwelling area on the shelf and slope and show a sharp decrease offshore. The eutrophic autotrophic taxon Lingulodinium machaerophorum is also abundant in sediments of the seasonal upwelling area on the shelf and slope, and also decreases more offshore. Both relative as well as absolute numbers of these taxa may be used to trace the upwelling system despite potential taphonomic problems. Considering the overall similar environmental conditions with respect to the other two transects, the elevated palynomorph concentrations in the shielded Nazare ¤ Canyon samples may be seen to represent the actual fluxes of palynomorphs along the Iberian coast. If accepted, this would indicate a preservational and transport loss of cysts of an order of magnitude in other transects. ß

Dinoflagellate Cysts in Surface Sediments from Southern Coast of Korea

“…More recently, Smayda and Reynolds (2003) formulated the ecological strategies of marine dinoflagellates, with emphasis on various bloom-forming species. According to their results, L. polyedrum is an upwelling relaxation taxa, and as such their cysts are reported as abundant in upwelling area (Sprangers et al 2004). Upwelling and anthropogenic eutrophied areas generally have different mechanisms of nutrient enrichment.…”

Modern pollen and non-pollen palynomorph assemblages of salt marsh and subtidal environments from the Ría de Vigo (NW Iberia)

“…6b). On the Galician Atlantic coast, Spiniferites species tend to be dominant in some oxygen-rich offshore areas (Marret and Zonneveld, 2003;Sprangers et al, 2004;Muñoz Sobrino et al, 2012, 2014, so they may be pushed into the Ría, especially in upwelling periods. Therefore, we interpret the gradient in the distribution of Spiniferites spp.…”

Upwelling conditions in the Early Miocene Central Paratethys Sea

“…Zonneveld et al 2001;Sprangers et al 2004). Frequent taxa reported from areas of seasonal coastal upwelling include Brigantedinium spp., Operculodinium centrocarpum, Lingulodinium machaerophorum and different Spiniferites species (De Vernal & Marret 2007), all of which are present in the samples of this study.…”