IIOSC - 2025

IIOSC - 2025

International Indian Ocean Science Conference - 2025

Celebrating 10 years of the Second International Indian Ocean Expedition

01-05 December 2025
INCOIS, Hyderabad, India.

Summary of Abstract Submission



Abstract Submission No.ABS-06-0120
Title of AbstractSources of suspended matter in the Bay of Bengal and the equatorial Indian Ocean
AuthorsBirgit Gaye*, Gesa Schulz, Jonas Leonhardt, Ramazan Cetin, Joanna Waniek, Kirstin Dähnke, Niko Lahajnar
OrganisationInstitute of Geology, Universität Hamburg
AddressInstitute for Geology, University of Hamburg
Hamburg, Hamburg, Germany
Pincode: 20146
E-mail: birgit.gaye@uni-hamburg.de
CountryGermany
PresentationOral
AbstractSuspended particulate matter (SPM) was sampled at various depths along transects in the Bay of Bengal and the equatorial Indian Ocean. Large volumes of water were filtered at up to seven different water depths. The SPM on filters was analyzed for organic carbon, nitrogen and amino acids (AA) to improve our understanding of sources and degradation processes of organic matter in the SPM pool as AA are the main nitrogenous compounds in fresh organic matter of plankton and sinking particles of the epipelagic ocean. As food-sources to microbes and zooplankton, AA undergo rapid qualitative and quantitative changes with depth and time. While sinking particles show indications of degradation with water depth, the AA spectra of SPM change with increasing residence time of SPM in the ocean. This is probably due to sorption processes and exchange with the dissolved AA pool. Such changes can be traced by using biogeochemical indicators based on AA content and spectra, providing fine-tuned markers of organic matter cycling processes and SPM sources. In this study we found that significant differences in AA-based biogeochemical indicators may be related to the age of water masses. We further show that SPM from several stations in the deep Bay of Bengal originates from a sediment source, indicating resuspension or downslope transport within the channel system on the Bengal deep-sea fan.
Are you part of IIOE-2 endorsed projectyes
Endorsed Project NumberIIOE2-EP52, IIOE2-EP07
KeywordsSuspended particulate matter, amino acids, Bay of Bengal, Equatorial Indian Ocean
For Awardsno