Thesis Title «Microbial response coupled to marine snow formation following crude oil pollution and application of remediation techniques»

Thursday 3 October 2019, at: 12:00, Venue: Hall Κ2.A3

Examination Committee

• Professor Nicolas Kalogerakis (advisor)
• Dr Evina Gontikaki
• Dr Elefteria Antoniou

Abstract:

The explosion of the Deepwater Horizon (DWH) rig in the Gulf of Mexico in April 2010, resulted in the largest marine oil spill in the history of the United States. As part of treating the oil spill, huge amounts of chemical dispersants were discharged both at surface and at the point of discharge at 1500 m. Dispersants are thought to stimulate the microbial degradation of crude oil by breaking it down into smaller droplets. The application of dispersants in the DWH region played a key role in the formation of 'marine oil snow' (MOS). MOS is formed by biological activity and is defined as aggregates of biomass, organic matter and inorganic particles which 'trap' oil. It is estimated that up to 14% of the oil from DWH has reached the seabed through MOS sedimentation. This thesis investigates the possibility of MOS formation in the surface waters of the Eastern Mediterranean, as well as the factors that trigger the appearance of aggregates. At the same time, the role of microbial communities that degrade crude oil in the formation of MOS is studied. During the experiment, surface water conditions were simulated in a continuous stirring hybridization incubator at a temperature corresponding to surface water and 3 scenarios were tested: 1. contamination with crude oil, 2. crude oil and dispersant, 3. crude oil, dispersant and nutrients, to investigate in detail how each factor affects the microbial community and MOS formation.