|Utilization of a Submersible Ultra-Violet Fluorometer For Monitoring Anthropogenic Inputs in the Mediterranean Coasts |
Conference: 13th French-Japanese Oceanography Symposium (, FR, 2008)
Ref HAL: hal-00942931_v1
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The Mediterranean Sea Coast is subject to strong anthropogenic pressure because of an intensification of urban, industrial, agricultural and tourist catchment (UNEP, 2000). This anthropogenic pressure is reflected in the direct (from coastal sources) and indirect (via rivers) discharge of terrigenous materials and pollutants (Tolosa et al., 1996; UNEP, 1996). These contributions promote transformations of ecosystems and associated biogeochemical cycles. In order to assess environmental changes, discrete measurements at fixed observation site (i.e. SO-COM, SOMLIT station) are useful but remain insufficient to describe the synoptic extension and the impact of these released terrigenous inputs. An objective of the laboratory is to develop and use in situ UV fluorimeters for quantification at high spatial and temporal frequency of terrigenous and anthropgenic tracers such as polycyclic aromatic hydrocarbons (PAHs, index of chemical contaminations) and “tryptophan-like” material (index of bacterial contaminations). An in situ UV fluorometer (EnviroFlu-HC, TriOS optical sensor) was deployed in the coastal area of Marseille-Sud since January 2008. The fluorescence signal of this probe (Ex/Em: 254±25 / 360±50 nm) was compared to the spectrofluorimetric Excitation Emission Matrices (EEMs) of discrete samples taken from the same area. The probe signal, due to its relative “large” Excitation and Emission bands, covers the EEMs signature of several groups of compounds: PAHs, tryptophan-like material, humic substances. This study is part of a laboratory program that aims at developping observation tools for operational oceanography and urban marine zone management: The project SEA EXPLORER (leader ACSA-Meyreuil, partnerships: ACRI, ISITIV, IFREMER, LMGEM-COM, LOV) funded by the Ministery of Industry (Fond de Compétitivité des Entreprises, FCE). Other partners: Agence de l’Eau Rhône-Méditerranée (IBISCUS project).