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The 15th Franco-Japanese Symposium of Oceanography “Marine Productivity, Perturbations and Resilience of Socio-Ecosystems,” organized by the long-standing partners Société franco-japonaise d'Océanographie de France and Société franco-japonaise d'Océanographie du Japon, reviewed the impacts of natural (storms, typhoons, earthquakes, tsunamis, etc.) and man-made (pollution, buildings in coastal areas, aquaculture, tourism, sports, diving, etc.) perturbations inflicted on coastal and marine environments. The Symposium examined the resilience of affected socio-ecosystems along with governance responses for these global/local environments. This book collects 43 selected papers, written by experts from numerous universities and research institutes in both countries. It addresses the needs of marine sciences researchers (natural and social sciences), decision-makers and coastal zone managers, and other stakeholders involved in coastal and marine socio-ecosystems.

The economic systems of production and consumption, as well as the social models that have prevailed so far, are no longer adapted to serious contemporary situations. It is urgent that humans protect the ecosystems on which their present life depends and the existence of future generations, especially marine ecosystems. In France, Japan and other countries, man must now clearly differentiate the disturbances produced by natural phenomena, against which he can do nothing, from those which depend on his own activities. The meetings, the numerous colloquiums, the seminars organized between the members of the two Societes franco-japonaises d’Oceanographie, and especially their fruitful cooperation, had, from the beginning, pragmatic objectives: to better know and compare the marine environments of the two countries and their various uses such as fishing, aquaculture, artificial reefs, shoreline developments. During their recent meetings, members of both societies have deepened many new concepts and made progress on the major changes affecting marine ecosystems and our societies. They are now orienting their future relationships by taking into account the need to study these themes in greater depth in the light of other disciplines. The dialogue between scientists sheds light on the new relationship between man and the marine environment, its resources and their exploitation. Traditions, eating habits, customs and even religions complete the basic scientific knowledge acquired so far. Our current objectives must be clearly defined to provide decision-makers with our knowledge and expertise, to understand the deep motivations and challenges of the professions and organizations that exploit marine resources, to enable man to live in a world in symbiosis with nature. Several new approaches have been identified integrating elements of economy, sociology, demography, law, foresight, culture, studies of traditions and certain religious activities. Beyond anthropocentric approaches, consideration should be given to the possibility of granting legal personality to non-human entities so that they can be protected. This multidisciplinary work will facilitate better integration of man within the ecosystems, especially marine ones and will help his survival.

France and Japan are partners in marine science and technology for a long time. Leonce Verny and Louis-Emile Bertin created and organized the dockyards and the Navy of Japan in the late nineteenth century. This country built many warships on its plans and this new Japanese fleet defeated the Russian fleet in May 1905 at Tsushima. Continuous exchanges took place between the two countries in the marine and maritime fields. Paul Claudel, Ambassador of France in Japan, founded the « Maison Franco-Japonaise » in Tokyo, which is the seat of 26 specialized Franco-Japanese Societies including Franco-Japanese Society of Oceanography of Japan. In marine science and technology, a friendly and effective cooperation extended exchanges with the French bathyscaphes dives during the 1960s, in the depths of Japanese waters and the establishment, at that time, of the French-Japanese Society of Oceanography of Japan. Many other areas of cooperation focused on shellfish, aquaculture of various marine organisms, artificial reefs, coastal development, Law of the Sea, etc. Since 1983, Franco-Japanese symposiums took place between Japanese and French experts, alternately in each country. They all brought new ideas to the participants. These differences always enrich cultural approaches by which selected topics are discussed and addressed in each country. The consideration of the issues in previous conferences shows that participants express similar interests in each country, on the functioning of marine ecosystems, especially coastal ecosystems, exploitation of these ecosystems, changes in operation or under effects of human activities. They provided a good highlight about the human factors involved in the use patterns of marine ecosystems. The necessities are now required to Mankind to make his primitive ecosystems natural abilities, which will require the study of new topics of multidisciplinary research.

The spatial distribution of heterotrophic prokaryotes was investigated during the Tokyo–Palau cruise in the western part of the North Pacific subtropical gyre (NPSG) along a north–south transect between 33.60 and 13.25° N. The cruise was conducted in three different hydrological areas identified as the Kuroshio region, the subtropical gyre area and the transition zone. Two eddies were crossed along the transect: one cold-core cyclonic eddy and one warm-core anticyclonic eddy and distributions of the heterotrophic prokaryotes were recorded. By using analytical flow cytometry and a nucleic acid staining protocol, heterotrophic prokaryotes were discriminated into three subgroups depending on their nucleic acid content (low, high and very high nucleic acid contents labelled LNA, HNA and VHNA, respectively). Statistical analyses performed on the data set showed that LNA, mainly associated with low temperature and low salinity, were dominant in all the hydrological regions. In contrast, HNA distribution seemed to be associated with temperature, salinity, Chl a and silicic acid. A latitudinal increase in the HNA / LNA ratio was observed along the north–south transect and was related to higher phosphate and nitrate concentrations. However, the opposite relationship observed for the VHNA / HNA ratio suggested that the link between nucleic acid content and oligotrophic conditions is not linear, underlying the complexity of the biodiversity in the VHNA, HNA and LNA subgroups. In the Kuroshio Current, it is suggested that the high concentration of heterotrophic prokaryotes observed at station 4 was linked to the path of the cold cyclonic eddy core. In contrast, it is thought that low concentrations of heterotrophic prokaryotes in the warm core of the anticyclonic gyre (Sta. 9) are related to the low nutrient concentrations measured in the seawater column. Our results showed that the high variability between the various heterotrophic prokaryote cluster abundances depend both on the mesoscale structures and the oligotrophic gradient.

Marine protected areas (MPAs) were created in reaction to large-scale disturbance that humankind has caused to the equilibrium, productivity, and production of marine ecology. This chapter considers some specific characteristics of different types of MPAs. It attempts to assess how the protection of these areas allows them to return to close to their original state after disturbance. It also attempts to discern the ways in which societies whose existence or activities depend on these protected areas may adapt their total conservation or use the environment more or less aggressively.

The distribution of ultraphytoplankton was investigated in the western North Pacific Subtropical Gyre (NPSG) during La Niña, a cold phase of El Niño Southern Oscillation (ENSO). Observations were conducted in a north-south transect (33.6–13.25° N) along the 141.5° E meridian in order to study the ultraplankton assemblages in various oligotrophic conditions. Analyses were performed at the single cell level by analytical flow cytometry. Five ultraphytoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes, nanoeukaryotes and nanocyanobacteria-like) defined by their optical properties were enumerated in three different areas visited during the cruise: the Kuroshio region, the subtropical Pacific gyre and a transition zone between the subtropical Pacific gyre and the Warm pool. Prochlorococcus outnumbered the other photoautotrophs in all the investigated areas. However, in terms of carbon biomass, an increase in the relative contribution of Synechococcus, picoeukaryotes and nanoeukaryotes was observed from the centre of the subtropical gyre to the Kuroshio area. In the Kuroshio region, a peak of abundance of nanoeukaryotes observed at the surface suggested an increase in nutrients likely due to the vicinity of a cold cyclonic eddy. In contrast, in the salinity front along the isohaline 35 and anticyclonic eddy located around 22.83° N, the mainly constant distribution of Prochlorococcus from the surface down to 150 m characterised the dominance by these microorganisms in high salinity and temperature zone. Results suggested that the distribution of nanocyanobacteria-like is also closely linked to the salinity front rather than low phosphate concentration. The maximum abundance of ultraphytoplankton was located above the SubTropical Counter Current (STCC) at depths > 100 m where higher nutrient concentrations were measured. Finally, comparison of the ultraphytoplankton concentrations during El Niño (from the literature) and La Niña (this study) conditions seems to demonstrate that La Niña conditions lead to higher concentrations of Synechococcus in the Subtropical gyre and a lower abundance of Synechococcus in the Kuroshio region. Our results suggest that the west part of NPSG is a complex area, where different water masses, salinity fronts and eddies lead to a heterogeneous distribution of ultraphytoplankton assemblages in the upper layer of the water column.

In the history of deep diving in the oceans, bathyscaphs have played an eminent role. For the first time in the exploration of the earth, mankind constructed machines with the capability to reach depths of several thousand meters and the capacity to carry observers in order to collect information on an unknown world: the deepest parts of the seas.

Effects of lumichrome, L-tryptophan, and curcumin on fouling organisms were examined on panels immersed in a near-shore aquatic environment. These products showed effective action in aquariums in preliminary screening tests for promoting different steps of fouling. Lumichrome showed metamorphosis-inducing activity for ascidian larvae (Halocynthia), L-tryptophan was a settlement-inducer for larvae of barnacles (Balanus), and curcumin showed attachment-promoting activity on the blue mussel (Mytilus). In order to establish that these tests are helpful in screening actual fouling or antifouling compounds, we examined the action of these three compounds in a coastal environment by following the first steps of biofouling, that is, by studying the quantity of chlorophyll, the number of bacterial cells, and the larvae settled. These experiments on the seashore indicated that these compounds did not act as promoters for the target organisms; however, they did show promoting effects on some nontarget organisms.

Variations of the total free amino acid (FAA) pool and the content of specific amino acids have been measured in the muscle and hepatopancreas of adult shrimps, Penaeus japonicus , acclimatized at five water salinities: 38, 32, 26, 20 and 14%‰ The FAA content is always higher in muscle than in hepatopancreas at all tested salinites. On the other hand, the hepatopancreas exhibits the highest concentrations of essential amino acids. Two steps in the evolution of FAA content can be observed, the first one regarding decrease in salinity from 38 to 20%‰ and the second one, when salinity goes below 20% ° . The first step can be characterized by a 16% decrease of total FAA content in the muscle and a 36% increase in the hepatopancreas. In muscle, the variations are mainly due to changes in non-essential FAA content, whereas in the hepatopancreas, they are linked to variations in essential FAA content. The other step is characterized by a drastic increase in moisture and decrease in FAA content in both studied organs when water salinity is 14%‰ The total FAA content is about 40% lower in shrimps at 14% ° compared to 38%‰ seawater salinity. During adaptation, the FAA pool (mainly NEFAAs) of muscle seems to be directly related to osmoregulation, whereas in the hepatopancreas, its evolution seems to be linked with energy expenditure and protein synthesis. The results are evaluated in order to elucidate the role of FAA in intracellular osmoregulation and in relation to animal ecology.

Proceedings of the 15th French-Japanese Oceanography Symposium; International audience; Considerable research has been conducted in the past 15 years around the Eastern English Channel ecosystem. Data collected since the 1970s on the biotic and abiotic compartments have been collated and mapped out in the mid-2000. This spatially explicit information formed a sound basis to improve knowledge on, and model, the functioning and dynamics of key ecosystem compartments, with a focus on flatfish species and fisheries and their interactions with other sectors of activity (aggregate extractions, maritime traffic). The more recent ongoing works are dedicated to the integration of those processes into several complementary end-to-end ecosystem models.

International audience; Biodiversity is often defined erroneously as the number of species. The higher the number of species, the better the status or the health of a habitat is considered to be. Managers, stakeholders and environmentalists worldwide often prioritize the ‘species approach’. The protection of an iconic and endearing species is obviously easier than that of tiny zooplankton species, although the latter may play a far more important role than the former in the functioning of healthy ecosystems. The species approach has been widely favoured compared to the ecosystem approach. However, ‘species-by-species’ management is unrealistic. The problem is that the management of natural habitats is often driven by environmentalist lobbies on the basis of taxonomy (e.g. mammals, turtles, birds, iconic fish, flowering plants, etc.) and disciplinary lobbies (biology, benthos, pelagos, contaminants, currents, etc.). Ecosystems are units of biological and spatial organization that include all the organisms, their interactions, the functional compartments they belong to, along with the components of the abiotic environment. The concept of the socio-ecosystem is useful insofar as it emphasizes the fact that man is part of ecosystems. Here, the authors make use of four case studies, in the Mediterranean Sea, in an attempt to demonstrate the interest of a comprehensive, socio-ecosystem-based approach in the field of environmental management. They also highlight the importance of tackling the coupling between benthic and pelagic ecosystems and between terrestrial and marine ecosystems.

The Channel programme is a collation of interlinked multidisciplinary projects supporting ecosystem-based management in the English Channel by integrating works carried out in the past thirty years including novel approaches to the spatial modelling of ecosystems. The Channel programme has required a coordination of efforts and expertise by both scientists and stakeholders to address the challenges of the Marine Strategy Framework Directive and of its national implementations. The Channel programme has also consisted of harmonising information, regulations and habits in terms of ecosystem management in the English Channel.