The Sea-Surface Microlayer - Exploratory study of a biofilm-like interface between the ocean and atmosphere

• Applicant: Professor Dr. Oliver Wurl, Ph.D.
• Subject Area: Oceanography
• Term: from 2012 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 223048215

The objective of the proposed study is the exploratory investigation on the fundamental processes and distribution leading to the formation of a biofilm-like matrix within the sea-surface microlayer. The microlayer, the interfacial layer between the ocean and the atmosphere (typically 40-100 micrometer in thickness), plays an important role in air-sea interactions, particle aggregation and biogeochemical cycling. Preliminary work indicates the potential of exopolymer substances (EPS) to accumulate in the microlayer, a fundamental process in the formation of a biofilm-like matrix at the air-water interface. Microlayers are also inhabitated by unique bacterial communities, another shared characteristics with biofilms. The proposed study will address the mode by which a biofilm-like microlayer is formed and distributed, and how it leads to the establishment of bacterial communities adapted to the harsher environment. Through extensive field work biofilm formation and its chemical composition (down to the molecular level) will be monitored and linked to microbiological and meteorological parameter. The proposed work includes investigation of carbon transformations as a greater understanding of the relationship between the formation process and its function can reveal strategies promoting biofilm formation at the oceans surface. The proposed work will answer the question if the recent reported extensive microlayer coverage of the global ocean has generally biofilm-like characteristics. The hypothesis of a biofilm-like coverage of the ocean¿s surface has wide implication on biogeochemical cycles and climate science.

• DFG Programme: Research Grants