Spatial Distribution of Living Coccolithophores in the Southern Adriatic Sea During Late Autumn,2000.
Abstract
Water samples for coccolithophorid analyses were collected during the cruise on N/O Italica in the Southern Adriatic Sea in October 2000, from the Albanian slope to the Italian shoreline. The investigated area on the Albanian slope includes the shoreline of Gulf of the Drin to the north of the Corfù island and on the Italian shoreline from the Gulf of Manfredonia to the Capo Santa Maria di Leuca and the southern part of the Otranto Channel. The aim of this work is to understand the ecology of coccolithophorids, one of the major contributors to the carbonate sediment in the Mediterranean Sea, studying their spatial and vertical distribution, species diversity and productivity and try to determinate the relationship of this phytoplankton group with environmental parameters. Sampling was done along several transects from east to west coast (86 stations, 300 water samples). The sampling depths were planned to obtain a regular sample grid. The sampling was finer in the upper photic zone and coarser at depths where both a lower coccolithophorid concentration and species diversity have been observed. For each sampling depth the sea water was filtered on board, on Millipore acetate cellulose filters and immediately oven-dried and stored in petri-dishes. Quantitative and qualitative analyses have been performed on LM and SEM microscope. Here we report the results of 42 selected stations collected at 0m and 10m and of a transect in the southern part of the Otranto Channel. The absolute abundance of total nannoplankton varied between less than several hundreds to 1.7E05 cells/l (station 8). These values are consistent with previous studies in the eastern Mediterranean Sea (1.4E04 cells/l, Knappertbusch, 1993). The distribution and composition of the living coccolithophore communities in the Southern Adriatic Sea can be related to the environmental conditions of surface waters. 60 species have been identified at SEM. The assemblage is mainly dominated by E. huxleyi, and by less abundant Rhabdosphaera spp., Syracophaera spp. and holococcolithophorids. Florisphaera profunda, known as deep-living species, is only present in samples from Santa Maria di Leuca transect below the 100m of depth.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFMPP42B0509B
- Keywords:
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- 4267 Paleoceanography