Dissemin is shutting down on January 1st, 2025

Published in

Micropaleontology Press, Micropaleontology, 5(54), p. 377-396, 2008

DOI: 10.47894/mpal.54.5.01

Links

Tools

Export citation

Search in Google Scholar

Coccolithophore communities in the Gulf of Manfredonia (Southern Adriatic Sea): Data from water and surface sediments

This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Red circle
Preprint: archiving forbidden
Red circle
Postprint: archiving forbidden
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

Living coccolithophore distributions from the Gulf of Manfredonia (Southern Adriatic Sea) were investigated and com-pared with the coccolith assemblages in the underlying surface sediments. In total, 55 samples from 13 stations in four transects collected at the end of October 2000 were analyzed to determine spatial and vertical distribution of individual taxa in the coastal environment. At all stations, the maximum coccosphere densities were between 10m and 30m of water depth (maximum values were ~4x10 4 coccospheres per litre of seawater). Coccolithophore absolute abundances show a vertical stratification and spatial variation, as well as variable species diversity, increasing from the coast to the open sea and decreasing with depth. Different coccolithophore communities are recorded in the shallow and deep photic zone. Emiliania huxleyi, Syracosphaera spp., Rhabdosphaera spp., Coronosphaera spp., Umbellosphaera tenuis and holococcolithophores are present mainly in the surface waters, above the thermocline between 25-30m depth. In the deeper water samples, there is a significant increase in coccospheres of Florisphaera profunda. The coccolithophore cell density variability is compared with in situ measurements of environmental parameters (temperature, salinity, nitrates and phosphates). Cell densities of all dominant taxa are most highly correlated with temperature variability. The low correlations of cell densities with ni-trates and phosphates may be caused by insufficient sampling resolution, nutrient levels close to detection limits, or both. The compari-son of the living assemblage with surface sediment records shows significant differences in the presence and abundance of some species. The recognised fossil record in the surface sediments is mainly represented by Cretaceous-Pleistocene reworked species, showing stron-ger dynamic processes at the bottom, such as terrigenous input and resuspension, than phytoplankton growth. Most marked correspon-dence between living and fossil assemblages has been found in the deeper and open sea sediments.