 |
| Titel |
Environmental variations in a semi-enclosed embayment (Amvrakikos Gulf, Greece) – reconstructions based on benthic foraminifera abundance and lipid biomarker pattern |
| VerfasserIn |
S. Naeher, M. Geraga, G. Papatheodorou, G. Ferentinos, H. Kaberi, C. J. Schubert |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 12 ; Nr. 9, no. 12 (2012-12-11), S.5081-5094 |
| Datensatznummer |
250007458
|
| Publikation (Nr.) |
 copernicus.org/bg-9-5081-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| The evolution of environmental changes during the last decades and the
impact on the living biomass in the western part of Amvrakikos Gulf was
investigated using abundances and species distributions of benthic
foraminifera and lipid biomarker concentrations. These proxies indicated
that the gulf has markedly changed due to eutrophication. Eutrophication has
led to a higher productivity, a higher bacterial biomass, shifts towards
opportunistic and tolerant benthic foraminifera species (e.g. Bulimina elongata, Nonionella turgida,
Textularia agglutinans, Ammonia tepida) and a lower benthic species density. Close to the Preveza Strait
(connection between the gulf and the Ionian Sea), the benthic assemblages
were more diversified under more oxygenated conditions. Sea grass meadows
largely contributed to the organic matter at this sampling site. The
occurrence of isorenieratane, chlorobactane and lycopane supported by oxygen
monitoring data indicated that anoxic (and partly euxinic) conditions
prevailed seasonally throughout the western part of the gulf with more
severe oxygen depletion towards the east. Increased surface water
temperatures have led to a higher stratification, which reduced oxygen
resupply to bottom waters. Altogether, these developments led to mass
mortality events and ecosystem decline in Amvrakikos Gulf. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|