Gonzales Maria Lorena

Thesis Title: Organic matter degradability in contrasting marine environments: from oligotrophic ecosystems to fjord highly influenced by aquaculture system.

The general objective of this thesis is to contribute to the understanding of the impact of organic matter input from different sources on the metabolism and diversity of marine microorganisms. The first chapter of this thesis is co-supervised by Dr. Ingrid Obernosterer from Observatoire Oceanologique de Banyuls sur Mer, France. The objective of the first part of the thesis is to determine whether the Low Salinity Water (LSW) detached from Rhone River transport biologically labile dissolved organic matter (DOM) to the offshore NW Mediterranean Sea, and how this DOM affects microbial heterotrophic processes. To address this objective we have worked with data obtained during two annual cycles of microbial activity (Respiration and Production) and amino acid composition of DOM in the NW Mediterranean Sea (MOLA station). The last two chapters of the thesis are conducted under the supervision of Dr. Renato Quiñones from the Interdisciplinary Center for Aquaculture Research (INCAR) of the University of Concepcion (Chile). The aims are to estimate the impact of DOM derived from aquaculture and of an additive used in aquaculture feed on the metabolism (respiration and enzymatic activity) and diversity of the microbial community and their potential effects on the biogeochemistry of the Patagonian fjords. To address these later objectives we are mainly using an experimental approach under controlled conditions (microcosms).

PhD supervisors:

Renato QUINONES (Univ. Concepcion, Chile)

Ingrid OBERNOSTERER (LOMIC, Banyuls)