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Marine Environment and Sustainable-fisheries: Observation-Model in the Northern West Mediterranean Sea

Final Report Summary - MESOMED (Marine Environment and Sustainable-fisheries: Observation-Model in the Northern West Mediterranean Sea)

FINAL PUBLISHABLE SUMMARY REPORT

The MESOMED, funded to Professor Meng Zhou hosted at the CNRS–Marseille Oceanographic Center (COM) – Laboratory of Physical and Biological Oceanography (LOPB), focused on 2 objectives associated with marine ecosystem structure, function and modeling under human impacts and climate change:
1) Developing sensor package configurations in studying small–mesoscale distributions and transport of zooplankton and fish larvae associated with currents and eddies in coastal and shelf areas,
2) Developing and verifying mathematical models for zooplankton and fish larvae based on measurements from sensor packages.

To address the first objective, we developed three sensor packages:
1) An integrated Laser Optical Plankton Counter (LOPC) – Conductivity, Temperature and Depth sensors (CTD) –fluormeter–Data logger on a CTD frame for measuring mesozooplankton and fish larvae within the size range in equivalent spherical diameter (ESD) between 100 µm and 30 mm deployable on a small ship,
2) An integrated towed Acrobat platform–LOPC–CTD–fluorometer for measuring mesozooplankton and fish larvae within the size range in equivalent spherical diameter (ESD) between 100 µm and 30 mm deployable on a medium ship,
3) An integrated Laser In-Situ Scattering and Transmissometery (LISST) (ESD between 1 and 250 µm) – LOPC (ESD between 100 µm and 30 mm)–CTD–fluorometer–water sampler on a rosette frame deployable on a medium–large ship,

These sensor packages were deployed on
(1) the RV Antedon at the SOFCOM Station (Service d’Observation du Frioul du Centre d’Océanologie de Marseille) in the Bay of Marseille for developing and testing methods in monitoring seasonal variability of hydrographic, biogeochemical and zooplankton (during several one day cruises), and to validate size structure from captors and from samples. Several researchers of LOPB were involved together with Meng Zhou).
(2) the RV Tethys for 2 weeks cruise (from October 2 to October 17, 2009) in the Gulf of Lions to map physical and biological fields spatial, to quantify stock distributions of nutrients, phytoplankton and zooplankton, and to study advection and dispersion processes, and to identify linkages between size structure and community structure for phyto- and zooplankton. Several researchers, technicians and students of LOPB were involved together with Meng Zhou, as well as one researcher and one engineer from University of Massachusetts Boston.
(3) RV Gould in the Gerlache Strait, Antarctica for 6 weeks cruise (from April 21 to June 11, 2009) to map distributions of zooplankton, krill and whales, and to study whale feeding behavior and krill overwintering strategies. One PhD student of LOPB was involved together with Meng Zhou.

To address the second objective, we have developed:
1) Mesozooplankton size relationships between their length and ESD,
2) Ecosystem size spectrum models between 1 and 250 µm for LISST, between 250 µm and 35 mm for Optical Plankton Counter (OPC), and between 100 µm and 30 mm for LOPC,
3) A growth rate model for zooplankton based on literature data and theoretical approaches,
4) Plankton trophic dynamics model based on sizes for carbon flux, recycling and export.

Specific research activities include:
• Analyzing hydrographic, biogeochemical and zooplankton data collected at the SOFCOM time series station in last 10 years for developing zooplankton growth and trophic dynamics models.
• Developing and testing an instrument package (LOPC–CTD–fluorometer) for potential expansion of the SOFCOM monitoring program.
• Developing a 2-week COSTEAU (“Contaminants dans le système trophique phytoplanktonzooplankton-anchois dans le Golfe du Lion”) cruise including the installation of a winch and towed Acrobat–LOPC–CTD–fluorometer system and a rosette–LISST system on the RV Tethys, participation in the cruise, operating the instrument package and data–processing.
• Participating in a 6 week US Antarctic cruise using an integrated rosette–LOPC–CTD system and a ship–mounted acoustic Doppler current profiler (ADCP) for studying krill aggregation and feeding behavior in a US funded krill-whale interaction project (a PhD student at the LOPB participated in the cruise and is using the data and samples for his PhD thesis) During the project, several scientists, technicians and students of LOPB were involved in sensor integration, training and cruises. Boris Espinasse, a PhD student (2009-2011) funded by CNRS, has been using the data collected in this project for his thesis.

The project has produced a peer reviewed journal article, three manuscripts in preparation, two meeting abstracts and presentations, one workshop, three sensor integration configurations and one funded French national project.

The significant impacts of this project on the CNRS–COM–LOPB include:
• New capability and capacity to conduct mesoscale physical and biological surveys for studying freshwater plumes, coastal currents and cross–shelf exchange;
• New sensor packages to integrate physical and biological measurements addressing ecosystem structure and bio–carbon fluxes between trophic levels
• Mathematical theories and models based on sensor packages developed to study seasonal variations of plankton communities and bio–carbon fluxes and burials applicable to end–to–end modeling for fisheries and carbon export flux for climate studies.