Benthic foraminifera in sapropels of the eastern Mediterranean Sea

DOI

High-resolution benthic foraminiferal and geochemical investigations were carried out across sapropels S5 and S6 from two sediment cores in the Levantine Sea to evaluate the impact of climatic and environmental changes on benthic ecosystems during times of sapropel formation. The faunal successions indicate that eutrophication and/or oxygen reduction started several thousand years prior to the onset of sapropel formation, suggesting an early response of the bathyal ecosystems to climatic changes. Severest oxygen depletions appear in the early phases of sapropel formation. The initial reduction of deep-water ventilation is caused by a warming and fresh water-induced stratification of Eastern Mediterranean surface waters. During the late phase of S5 formation improved oxygenation is restricted to middle bathyal ecosystems, indicating that at least some formation of subsurface water took place. During S6 formation oxygen depletions and eutrophication were less severe and more variable than during S5 formation. Estimated oxygen contents were low dysoxic at middle bathyal to anoxic at lower bathyal depths during the early phase of S6 formation but never dropped to anoxic values in its late phase. The high benthic ecosystem variability during S6 formation suggests that water column stratification at deep-water formation sites was in a very unstable mode and susceptible to minor temperature fluctuations at a millennial time-scale.

Supplement to: Schmiedl, Gerhard; Mitschele, A; Beck, S; Weldeab, Syee; Schulz, Hartmut; Hemleben, Christoph; Sperling, Michael R; Emeis, Kay-Christian (2003): Benthic foraminiferal record of ecosystem variability in the eastern Mediterranean Sea during times of sapropel S5 and S6 formation. Palaeogeography, Palaeoclimatology, Palaeoecology, 190, 139-164

Identifier
DOI https://doi.org/10.1594/PANGAEA.736661
Related Identifier https://doi.org/10.1016/S0031-0182(02)00603-X
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.736661
Provenance
Creator Schmiedl, Gerhard ORCID logo; Mitschele, A; Beck, S; Weldeab, Syee ORCID logo; Schulz, Hartmut; Hemleben, Christoph; Sperling, Michael R; Emeis, Kay-Christian (ORCID: 0000-0003-0459-913X)
Publisher PANGAEA
Publication Year 2003
Funding Reference Sixth Framework Programme https://doi.org/10.13039/100011103 Crossref Funder ID 36949 https://cordis.europa.eu/project/id/36949 Southern European Seas: Assessing and Modelling Ecosystem Changes
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 16 datasets
Discipline Earth System Research
Spatial Coverage (27.288W, 32.609S, 34.139E, 34.814N); E of Crete
Temporal Coverage Begin 1998-01-23T00:00:00Z
Temporal Coverage End 1999-04-18T00:00:00Z