1.2. Topics, issues and a few recent results

1.2.1. Marine Geosciences

General topics and issues

The MG community is active on a very wide range of topics and sites such as how the coastline is evolving, the dynamics of oceanic ridges and formation of the oceanic lithosphere, subduction zones, volcanic arcs, seismic and gravitational hazards, the interface between the oceanic lithosphere and the ocean, analysis of sedimentary archives to study transfer processes and deposit of particles that settle in layers and for paleoclimatic and paleo-oceanographic reconstructions. Society’s concerns regarding the ocean, coasts and associated hazards have been amplified over the last few years by further questioning that is not only scientific but also economic regarding:

  • The type of links between geodynamic and tectonic changes and the oceanic dynamic, climate, erosion and sedimentary recording;
  • Using the sediment and fossil archive, establish a report on the realistic/complete Source-to-Sink material and modelling of the different parameters and forcings that govern this dynamic;
  • Seismic and gravitational hazards possibly in relation to the genesis of tsunamis; coastal hazards linked to anthropic impacts and to climate change (such as coastline erosion);
  • Mineral and marine energy resources (granulates, renewable marine energies)
  • The reconstruction of paleoclimatic and paleo-oceanographic fluctuations working from the study of sediment and coral series; these reconstructions help identify the processes and interactions that control climate change and the ocean’s role in how atmospheric carbon is evolving over time scales associated with the dynamics of the ocean and glacial icecaps or much longer for orbital modifications of exposure to sunlight or from internal geodynamics;
  • The tectogenesis of active or passive margins and the migration of fluids from the mantle and the crust up to the surface in a sedimentary context and associated hazards;
  • The study of processes and water-rock interactions in the ocean depths and the impact of hydrothermal flux on major global biogeochemical cycles and marine ecosystems.

Furthermore, French teams are historically highly implicated in passive margins (Atlantic, Mediterranean, Indian ocean) and active margins (Northern Andes, Japan, Mediterranean, SW Pacific, Indian Ocean, Antilles).

 

Illustrative results

The scientific community has innovated in four booming areas: (1) reducing risks and adapting to climate change in coastal areas, by contributing to quantified assessment of erosion and marine submersion factors modifying the coastline (please also refer to the long-range planning document "Surfaces et interfaces continentales 2013-2017" by the INSU), (2) deep-sea instrumentation, particularly in geophysics, by developing sensors and new devices for electromagnetism (ACEM), gravimetry (GRAVIMOB), geodesics and seismic observation, (3) in-situ data acquisition in the deep-sea environment via innovative instrument developments (PERISCOP, AUV 6000 on-going, ...) and seabed observatories (EMSO programme: 11 marine observatory sites; IR EMSO-France with 3 sites targeting the Azores (MOMAR), in-shore Liguria and Marmara; and (4) the development of very deep core boring that would make France lead the world in terms of mass collection of long sediment series by core boring. This specific aspect has allowed the scientific community to be active within the PAGES/SCOR (IMAGES) programmes by contributing to very important progress concerning climate and oceanographic variability over the last 300,000 years (Waelbroeck et al., 2010; Gottschalk et al., 2016).  The Actions Marges programme (coll. INSU-Ifremer-BRGM-Total; http://actionsmarges.fr) has coordinated national laboratories in three major areas: 1) the continental break in the Gulf of Aden-Afar (Leroy et al., 2011), 2) paleoclimatic reconstructions and the Messinian salt crisis in the western Mediterranean basins (Druissi et al., 2015) and the sedimentary “source to sink” reconstructions of passive margins (Rouby et al., 2013).

 

In parallel, the issue linked to the deep-sea mining exploration permit zones (>3000m) brought about oceanographic campaigns associated with heavy machinery (HOV Nautile, ROV Victor).

Among vast scientific progress made over the last few years, we might mention the ties between the seismic and gravity hazards and the geodynamic and tectonic changes with the following demonstrations: 1) a correlation between deep-sea or coastal earthquakes and accumulation on the seabed of turbidity current deposits generated by the movement of the seabed and sediment suspension (MARADJA2, PRISME, Figure 1; Babonneau et al., 2016); 2) coupling between dynamics and deep-sea structure of the subduction zones and the origin of major earth tremors (Singh et al., 2011; 2017); 3) ties between volcanic eruptions, neotectonics and collapse of volcanic slopes and tsunamis in the French Antilles (ODEMAR, GWADASEIS, BATHYSAINTES; Escartin et al., 2016; Leclerc et al., 2016).

 

Furthermore, understanding the formation, dynamics and evolution of the oceanic lithosphere remains a fundamental problem issue for geoscience research, revealing complex interactions between magmatism and slow and ultra-slow deformation around oceanic ridges. The results obtained during the latest open-sea campaigns demonstrate that the mechanisms being observed are 1) a local mode with no magmatic feed on the axis where plate divergence accommodation takes place via tectonic blooming of the lithospheric mantle over several tens of km (SMOOTHSEAFLOOR, SWIR, Sauter et al., 2013; Cannat et al., 2009), 2) the rise and exhumation of the mantle all along a transpressive transform fault due to the nature of the subjacent lithospheric mantle rather than a kinematic change (COLMEIA, Maia et al., 2016), and 3) the formation of detachment faults creating “Oceanic Core Complexes” (MOMARDREAM, ODEMAR, Figure 2; Andréani et al., 2014; Escartin et al., 2017).

1.2.2. Physics-Biology-Cycles

General topics and issues

The major aim of research in these fields is to better understand:

  • the physical and biogeochemical oceanic processes
  • their variabilities over different scales of time and space;
  • their possible feedback with other compartments of the earth system (continent, atmosphere, ice, lithosphere):
  • the impact of climate change and anthropic pressure on the physical and biogeochemical ocean, leading to important, fast environmental modifications for some (modification of the stratification, circulation, ice melting, rising sea levels, acidification, change in the volumes of minimum oxygen zones, continental and atmospheric provisions including the arrival of new pollutants, etc.).

To meet these aims, the community is running research projects dedicated to

  • studying the ocean’s internal processes, its interfaces, and its links with external forces;
  • diagnosis of the current average status, of variability and long-term evolutions (trend, break, cycles) of circulation, oceanic content of heat, salt, CO2, and O2, but also large cycles of chemical elements for quantification of the biological pump, etc.

 

So, the Physics-Biology-Cycles community relies on FOF coastal and ocean-going vessels to run major mono-disciplinary (e.g. RREX, CASSIOPEE) or multidisciplinary projects (e.g. AWA, AMOP, GEOVIDE, OUTPACE, JERICO-NEXT, CIGESMED, HYMEX-MERMEX-DEWEX). Without counting Observation Services (Section1.2.5), several tens of projects were run over the last 5 years thanks to the FOF.

Monodisciplinary campaigns, essentially in the field of coastal and open-sea physics, look at the physical processes with an impact on masses of water, their dynamics and their variability in contrasting regions such as the North Atlantic Ocean, the Bay of Biscay, the Austral Ocean or even the Western Pacific. The physical processes being considered are the large-scale circulation and meso-scale structures, current-topography interactions, formation of deep waters, upwellings, turbulent mixture.

Multidisciplinary campaigns look at certain key physical or biogeochemical processes and the role of physical processes on biogeochemistry and the ecosystems.

In the open-sea area, these studies have looked at the minimum oxygen zone in the South East Pacific, the formation of brine in Arctic regions, studies of the carbon processes and flux in the Pacific and Austral Ocean, the hydrology and the biogeochemical features of masses of water in the Mediterranean (MISTRALS site) and the influence of atmospheric contribution (dust), sediments from margins and the physical mixture on the cycles of the trace elements. The contribution of the physical ocean to storage and transport of anthropic carbon, oxygen and the distribution of trace elements and their isotopes has also been studied. The sources, the reaction time and/or the dynamics of the organic matter throughout the continent-ocean continuum, tied into the environmental forces (particularly hydrodynamic and sedimentary hydrodynamic) but also contaminants, have received particular attention on the continental coasts and overseas. The physical-biological link (such as hydrodynamic-zooplankton), the response from ecosystems to climate change and to anthropic pressure (including monitoring contaminants in trophic networks for example) have also been the subject of many research projects.

This research is run on different scales of space and time. Certain campaigns cover thousands of km to study the successions of dynamic regions and trophic regimes (e.g. OUTPACE 5000km) whilst others focus on restricted and yet extremely key zones such as the North West Mediterranean (MISTRALS programme), the Bay of Biscay, the Pacific islands or the Gulf of Guinea when considering the sub-basin scale. At an even smaller scale, research has been run alongside coasts by proposing to study a specific ecosystem such as the upwelling region in West Africa (AWA, EPURE) or a set of ecosystems. Certain campaigns are carried out just once whilst others are performed several times a year to study the seasonal cycle (SPOT, MOOSE-GE), or even, for those based on observation services, they are run frequently and interannually (e.g. MOSLIT project). Others, without being labelled as Observation Services, have existed for almost 20 years (OVIDE). This research is generally associated with other platforms deployed at sea (autonomous machines, moorings) and are joined on to satellite observations and modelling work.

Finally, these projects fall within the scope of the aforementioned international programmes such as GO-SHIP, CLIVAR, GEOTRACES, SOLAS, etc. where the French community is highly implicated, active and acknowledged

Illustrative results

The study of the annual hydrological and biogeochemical cycle in the north-west Mediterranean within the DEWEX-MERMEX/HYMEX project (Figure 3) illustrates the beauty of getting the Ocean and Atmosphere communities to work together, the point of seasonal monitoring and an important validation of the use of several FOF ships.

The MOSLIT project (EC2CO-DRIL Figure 4) illustrates the link between research projects, observation services and the French Oceanographic Fleet as it relies on data and logistics from the SNO SOMLIT and so over around 900 sea trips from FOF station and in-shore boats between 2007 and 2014.

The results illustrate 1) the dominance of phytoplankton outside the estuaries, 2) the importance of diazotrophs in the Mediterranean (oligotrophic system), 3) the continent-ocean gradient within the same ecosystem or along a continuum (black arrows), and 4) the major forcings: sediment hydrodynamics (in itself linked to the meteorology and the climate) and the trophic status (oligotrophy vs merso/eutrophy) of the ecosystems (Liénart et al., 2017).

 

 

 

 

 

1.2.3. Biology-Ecology-Biodiversity

Topics and issues

Although the fundamental concepts of biology remain identical on land or sea, the marine environment features impose different ways of working and specific reactivity of the ecosystems. As for other areas, exploration and experimentation are strongly constrained by access and specific resources, particularly the fleet, structure the community into a coherent and interactive group.

The major issue remains to characterise the biodiversity and its dynamic, in a context of global changes and diversified anthropic impacts, an issue that the sequencing technologies (NTS), just like real-time, non-invasive observation methods (such as biologging, sensors placed on animals) and high-resolution space and time sensors such as those associated with the JERICO-Next joint European coastal infrastructures network, can allow us to envisage whether it is for research on biological evolution, the biogeography or how the ecosystems work. The integration of this important flood of data with physical and chemical oceanography contributions is on-going on different scales which are pertinent to be able to include ecology in holistic models.

In the pelagic area, the study of the biological component (plankton) is generally included in the multidisciplinary biogeochemical campaigns (e.g. KEOPS2, MERMEX, etc.) including biodiversity studies in the wider sense: phylogeography, trophic network, adaptive mechanisms.

The exploration of biodiversity in deep-sea environments by French teams remains at the international forefront particularly thanks to the FOF’s submersible machines (section 2.4.1 and Appendix 5). This concerns chemosynthetic ecosystems (e.g. MESCAL, BIG, BIOBAZ, BICOSE, WACS, CONGOLOBE), often linked in with geoscience campaigns, and ecological studies associated with the EMSO-MOMAR (MOMARSAT) deep-sea observatory. However, there are also deep ocean floor ecosystems on continental slopes or sea mounts (particularly the current Tropical Deep Sea Benthos programme by the MNHN http://www.mnhn.fr/fr/recherche-expertise/lieux/tropical-deep-sea-benthos that provides access to 40 years of sampling during the MUSORSTOM campaigns on deep-sea environments around large tropical islands with a focus on French overseas territories but also BOBECO, MAD, etc.) that are being developed.

The ecology of communities and trophic networks provides a specific response to the demand for diagnosis on the ecological status of coastal environments, and soon further out to sea, to monitor the overall marine space (WFD or MSFD) and more particularly for Marine Protected Areas (MPA) that are currently under development. Clarifying indicators requires access to reference zones that are not affected by humans using FOF resources (cf. PRISTINE programme and Scattered Islands). The population connectivity study, using marking and telemetric monitoring or genetic tools, constitutes an essential element for establishing and monitoring MPAs.

All these approaches are also implemented in the intertropical belt, where the exceptional concentration of biodiversity in the coral ecosystems and the threats looming over them due to climate change draw particular attention (POSTBLANCO campaign monitoring coral whitening in New Caledonia and SUPERNATURAL, CARIOCA campaigns on the effect of acidification on the ocean in the coral reef ecosystem).

Illustrative results

Among the numerous biology, ecology and biodiversity campaigns carried out in all oceans and at all latitudes or depths, here are two contrasted examples. One from the coastal area using a station vessel to study parasitism in a commercial species, the cockle; the other in the deep benthic area, using an ocean-going vessel and a submersible to study the adaptation to an extreme environment of a chemotrophic symbiosis.

 

Competition vs. Parasitism in cockles

Since 1998, the cockle population (bivalve) has been sampled monthly on the Arguin bench (Gironde) from missions organised on the station vessel Planula 4. It has been demonstrated that there is a reverse relationship between cockle density and the number of trematode parasites infesting them (Figure 5-A). Thereby a strong density of cockles, classically demonstrating competition (less growth, accrued mortality) can also have beneficial effects for the host population by removing certain parasites from them. The underlying mechanism being proposed relies on the effect of dilution: for a given parasite stock in water, the larger the number of hosts the more parasites will be diluted among the cockle population and the less individuals will be infested (Figure 5-B).

Bringing up hydrothermal fauna in isobar conditions

One of the major criticisms of studying the biology of deep-sea organisms is that when bringing up the samples, the pressure variation affects their physiology in supposedly damaging proportions. For the last fifteen years, B-Shillito’s team (UPMC) has been developing a set of hyperbaric instruments to attempt to get around this problem. For the first time, during the BIOBAZ campaign in 2013, the ROV Victor was able to sample mussels on Mid-Atlantic ridge sites between 800 and 2400m down, and place them in PERISCOP, a device that can maintain seabed pressure until on board the ship, the Pourquoi-Pas? The first analyses show an abundance of bacterial symbiots from these mussels that do not vary compared to mussels brought up without pressure control (Szafranski et al., 2015). However, analysis of the differential expression of genes between these two conditions clearly shows an effect of bringing them up without controlling the pressure for the deeper site, but not below, thereby validating certain studies carried out to date but encouraging us to consider the effect of bringing samples up from more than 2000m (Tanguy et al., comm. pers.). 

1.2.4. Fisheries

General topics and issues

In addition to one-off research campaigns, most fishery campaigns run over the last few years are providing data for long chronological series (the longest date from the 70s), in annual time steps. Most of them are institutional (IBTS, PELGAS, EVHOE, CGFS…), funded in a community framework and not assessed by the scientific community. However, a few upgrading actions are assessed. They can be carried out on an ocean-going vessel (RV Thalassa for IBTS campaigns for example), or coastal vessels (they can also be financed locally). The coastal campaigns are carried out on board the RV Thalia for scallops, Côtes de la Manche for ORHAGO campaigns and Europe in the Mediterranean. Small professional vessels might be required for estuary areas, when an oceanographic vessel is required with capacity for basket trawling on the Channel-Atlantic sides. All these campaigns must be run in the imposed periods (linked to the species’ biological cycle) and explained in detail in international protocols, when appropriate. This refers mainly to biological data collection that will provide the basis of the diagnosis on the state of the main stocks of species being exploited. Over time, these campaigns have diversified and now allow us to also collect data on all sampled species and on the environment; this refers more generally to contributing to observation of all compartments of the continental shelf ecosystems (from hydrology to primary production, right up to top-level predators).

So, the major areas of research tackled by the campaigns cover a very wide field: individual-environment interactions, spatial distribution, habitats and connectivity of fish populations, dynamics of fish populations, space-time dynamics of ichthyological communities and their diversity, how marine trophic networks work, fishery resources-fishing fleet interactions, ecosystem-multiuse interactions, etc. Observation method issues are also tackled by certain campaigns (study on observability, the acoustic “Target Strength” of pelagic fish, etc.) plus automation methods for sampling and determination (e.g. the CUFES combination on RV Thalassa and ZooCAM for continuous sampling and semi-automated recognition of fish eggs and zooplankton).

 

Illustrative results

 

In the Mediterranean

Historically, fishery campaign protocols were built to supply the databases used to produce indicators on stock status. These chronological series are then used in a wider scientific framework and constitute basic data for research work with widely-diffused results (doctoral dissertations, M2, referenced publications, symposiums, etc.).

As an example, data from the PELMED campaigns revealed demographic and biological changes in the small pelagic populations in the Gulf of Lion over the last twenty years. Whilst anchovy biomass has fallen considerably, leading to a fishing crisis, the abundance of sardines has remained the same or even increased. At the same time, an important change in the size structure of these species has been observed. The sardines and the anchovies were a lot smaller after 2008 than before. This drop in sardine size is the result of a drop in growth and a loss of the oldest individuals (loss of 2+ years age brackets; Van Beveren et al., 2014, Figure 7, opposite), whilst only growth seems to be questioned for anchovies.

 

Fisheries and marine biodiversity in the South-West Pacific

The IRD has been working actively with the CPS since 2005 on the topic of pelagic fishery resources. Tuna is a primordial resource for most small countries in the Pacific and represents an important proportion of the local economy in the territories of New Caledonia and French Polynesia. The total tuna captures in the western and central Pacific have been constantly increasing since the 1980s, reaching a total of 2.7 million tonnes in 2015 (namely 80% of captures in the Pacific and 56% of worldwide captures). The work focusses on understanding how the pelagic ecosystem works and on interactions between tuna and its environment. Since 2011, in particular, studies have looked at trophic intermediate levels (zooplankton and micronekton) that represent the food of superior predators such as tuna and marine birds. On the topic of micronekton for which there is very little field data, the NECTALIS (1 to 5) series of multidisciplinary oceanographic campaigns was performed around New Caledonia between 2011 and 2016 on board the Alis. The MOM-ALIS and INTERCASTEAUX campaigns were able to enlarge our work to marine birds. This data-collection work was performed within the BIOPELAGOS project (Best 2.0 programme funded by the European Union) that took place over 3 years (2016-2019) in New Caledonia and in Wallis and Futuna with 2 other campaigns: PUFFALIS programmed in 2017 and WALLALIS requested for 2018, always on board the Alis collecting physical, chemical, biological (phytoplankton, zooplankton, micronekton) and acoustic data. 

 

 

1.2.5. Observation services

General topics and issues

In Environmental Sciences, regular observations made over long periods were and appear to be an increasingly essential device to accompany the research and support contractual commitments to the State. For each of the natural environments, it is actually necessary to understand the fundamental mechanisms of how they work, to foresee possible changes on different scales and to build forecasting models that should assimilate reliable data. To run this research properly and meet society’s expectations, the Environmental Science community is involved in systematic observation of natural environments, in order to follow their evolution, understand it and model it. This mission is the basis for forecasts within the ambition of this scientific work.

 

Structuring of national observation (SNO, SOERE, Research Infrastructures) has helped support long term studies of marine environments that might be mainly affected by changes in the climate (ocean/atmosphere interaction), directly subject to the influences of human activity such as coastal or in-shore waters or even in specific benthic environments. The observatories and observation networks are now acknowledged as essential to obtain long term data to determine changes in the environment and in the processes (physical, biodiversity, ecosystems, biogeochemical cycles) linked to global change and the anthropic impact. Over the 2011-2016 period, over 600 days a year have been dedicated to observatory operations labelled from ocean-going, in-shore and station vessels. For the time being, very few national observation structures cover the French overseas EEZ, leaving an important vacuum.

In parallel, the ramp-up of operational oceanography (MERCATOR/Coriolis project) requires a greater flow of data in almost real time via automated observation systems (moorings, surface measurements in transit, ARGO profilers, CTD station profiles, XBT probes, SVP derived buoys, etc.). These developments require boat time, particularly to implement and maintain autonomous equipment.

 

Observations using the station fleet (marine stations and OSU) 

Observations made from easily-accessible areas (after a few hours of sailing at the most) essentially use the INSU and IFREMER in-shore vessels but also constantly use the Marine Stations vessels. The current total for the station fleet, regarding the number of days dedicated to observation operations is around 260 days (Table 1).

These in-shore and coastal studies are also increasingly often multidisciplinary to correctly apprehend the physics-chemistry-biology couplings in these anthropized environments with complex dynamics. This flotilla is also requested to maintain moorings and instrumented sites in the coastal environment (CoastHF national network from the ILICO Research infrastructure). Its local programming helps it react quickly which is an essential quality to ensure the logistics associated with autonomous measuring equipment (instrumented moorings, AUV, gliders, floats), new technology that is currently integrated in all on-going programmes. The flexible, user friendly programming mode for this fleet is generally satisfactory. It is imperative to maintain this flexibility for use and the quality of this flotilla that on its own provides support for recurring research and teaching activities in marine stations and ensures diving missions for biological and ecological observations.

To date, there is no actual station vessel located overseas. Currently, a single OSU has been set up and could be used for support, in La Réunion, but there is no boat. On the other hand, two ships cover or have covered this function, but this cover is sporadic or under-sized (Amborella from the government of New Caledonia and La Curieuse in La Réunion).

 

Observations using the in-shore fleet 

Programming of so-called in-shore vessels (essentially coastal) is currently evolving with an increase in recurring requests within the labelled scientific observation services but also from public service development (e.g. MSFD). Apart from regular sampling (monthly to annually) on reference stations (SOMLIT and MOOSE networks), the needs refer to maintenance of instrumented sites, increasingly numerous and complex, particularly in the north-west Mediterranean (BOUSSOLE, MOLA, ANTARES, …). The current overview shows a need for around 70 days.

The in-shore fleet must necessarily be modernised to implement “seabed” stations and to meet emerging needs from operational oceanography, particularly on-board installation of automated measurement systems (ferry box type) and fast communications.

 

Observations using the ocean-going fleet 

The ocean-going fleet is also in great demand to cover operations linked to scientific observation activities with a demand of around 180 days per year:

  • For specifically dedicated campaigns (PIRATA, MOOSE, OVIDE…)
  • For added-value transits (MINERVE, OISO, SURVOSTRAL…).
  • For “seabed” observatories overseen by France and included in a Europe Consortium ERIC (European Research Infrastructure Consortium), which ensures creating a network between 11 multidisciplinary marine observation sites (geoscience, biology, oceanography), EMSO-France has become a Research Infrastructure (IR) with 3 target sites: Azores (MOMAR), Liguria and Marmara shore. These three sites involve around 120 users over 15 labs, of which almost 2/3 are working on marine geosciences.
  • It should be noted that all these observation operations allow transits to be made the most of (see below). Consequently, the total number of days reported for the OISO-CARAUS, MEMO, NIVMER, SONEL… services is given as a guide.

 

Ocean-going observation campaigns regularly host other operations by pooling ship time and upgrading transits. 

  • PIRATA, in view of its annual campaigns and according to the radials repeated in the same region, constitutes a platform to carry out opportunity operations (instrumented mast, radio-sounding, collection of CARBOCHANGE samples, deployment of gliders, SVP derived buoys and Argo floats, continuous measurement of isotopes).
  • For the last 5 years, MOOSE-GE has been providing pooled maintenance of hydrological open-sea moorings of the north west Mediterranean shore. From 2017 onwards, this maintenance pooling was expanded to two ODAS buoys from Météo-France, subject to scientific relevance. Many research programmes rely implicitly on long-lasting observation services (e.g. MISTRALS site with MOOSE and FiXO3).

Without being labelled National Observation Service, the OVIDE project has been contributing since 2002 to observation of subpolar gyre circulation elements in the North Atlantic by carrying out a section of hydrography-geochemistry-currentometry every two years between Greenland and Portugal and by deploying Argo profilers.  The OVIDE section was firstly carried out as part of the OVIDE project (every two years from 2002 to 2010) then by the Spanish CSIC lab in 2012 and 2016 and in 2014 during the GEOVIDE campaign by GEOTRACES/France. The OVIDE section is one of the “high frequency” lines on the international Go-Ship programme and contributes to the TGIR Euro-Argo by deploying profilers and to the international OSNAP project.  Like PIRATA, OVIDE contributes to the SNO SSS and to GOSUD by systematic sampling to measure salinity and to CARBOCHANGE by taking samples for the CO2 parameters. Certain observations are sent in almost real time to CORIOLIS (CTD and XBT profiles).

 

Finally, certain services (SSS, Argo) that rely on the FOF also call on foreign oceanographic vessels or merchant ships to get regular access to zones that are rarely explored by research vessels. Within the framework of SNO Argo France, 56% of floats run by France were deployed by FOF ships, 33% by foreign oceanographic ships and 11% from opportunity vessels (sailing boats, etc.). The SSS service relies uniquely on opportunity vessels, but regrouping can be envisaged in the mid-term with equivalent data released by research ships.

 

Fisheries

The fishery campaigns, known as “public service”, not scientifically assessed and not funded by the FOF budget, are part of the long-running campaigns carried out using both ocean-going and coastal vessels supplying long chronological series (since the 80s and 90s) and they contribute to the Ifremer Fishery Information System observation network (SIH). They also support complementary observations, essentially concerning marine fauna. The use of the fleet for these state missions covers more than 150 days at sea (Table 2).

Illustrative results

 

PIRATA:

The utility and accuracy of rain and salinity measurements obtained from ATLAS buoys in the PIRATA network are now well-established, and it is now proven that salinity is an extremely important parameter in the tropics for the heat budget in the mixture layer and the air-sea interface exchanges (severe desalting has been observed in the tropical Atlantic due to strong precipitation and discharge from the world’s main rivers - Amazon, Congo, Niger). Since 1999, PIRATA measurements have been able to demonstrate the salt barrier phenomenon in the west tropical Atlantic (Pailler et al., 1999). Understanding the impact of salinity variations on the SST has become a major goal over the last few years. The use of PIRATA data (particularly for validation of new dedicated satellite measures - SMOS Aquarius) has provided a better understanding of the respective impact of precipitation and discharge from major rivers on the mixture layer and the SST and to draw up salt budgets in the Gulf of Guinea (Figure 8, Da Allada et al., 2013, 2014).

 

OISO-CARAUS

The OISO observations, conducted on board the Marion-Dufresne II since 1998, have improved assessment of the ten-year variability of oceanic CO2 wells (Landschützer et al., 2015). Under the influence of wind variability and heating up or cooling down of surface water in certain sectors of the Austral Ocean and depending on the year, the carbon well dropped over the 1990-2000 period, but it rose between 2002 and 2011 (Figure 9). These estimations specifically allow us to review the planetary carbon balance (Le Quéré et al., 2016).

SOMLIT

In coastal ecosystems, regional climate (AMO, NHT, SST) and local climate (wind, precipitation, etc.) have a direct influence on how ecosystems work. In particular, a shift in the early 2000s appeared on both climate indices and parameters and on hydrological data on the scale of the three French maritime shores but also more locally (Gironde estuary) on the ichthyological communities (Figure 10). These examples give a perfect illustration of coastal ecosystems’ sensitivity to climate change. This sensitivity concerns both abiotic and biotic compartments.