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Ecological intensification is a new concept in agriculture that addresses the double challenge of maintaining a level of production sufficient to support needs of human populations and respecting the environment in order to conserve the natural world and human quality of life. This article adapts this concept to fish farming using agroecological principles and the ecosystem services framework. The method was developed from the study of published literature and applications at four study sites chosen for their differences in production intensity: polyculture ponds in France, integrated pig and pond polyculture in Brazil, the culture of striped catfish in Indonesia and a recirculating salmon aquaculture system in France. The study of stakeholders' perceptions of ecosystem services combined with environmental assessment through Life Cycle Assessment and Emergy accounting allowed development of an assessment tool that was used as a basis for co-building evolution scenarios. From this experience, ecological intensifica-tion of aquaculture was defined as the use of ecological processes and functions to increase productivity, strengthen ecosystem services and decrease disservices. It is based on aquaecosystem and biodiversity management and the use of local and traditional knowledge. Expected consequences for farming systems consist of greater autonomy, efficiency and better integration into their surrounding territories. Ecological intensification requires territorial governance and helps improve it from a sustainable development perspective. International audience

Estuaries are essential fish habitats because they provide nursery grounds for a number of marine species. Previous studies in the Bay of Vilaine (part of the Bay of Biscay, France) have underlined the estuarine dependence of juvenile common sole (Solea solea, L) and shown that the extent of sole nursery grounds was positively influenced by the variability of the river flow. In the present study, stable carbon and nitrogen isotopes were used to describe the trophic network until the young-of-the-year sole and to compare interannual variations in the dominant trophic pathways in the sole nursery areas in this bay. Particulate organic matter (POM), sediment organic matter (SOM), microphytobenthos, benthic invertebrate sole prey and young-of-the-year common sole were collected during the summer over 4 years characterised by contrasting river discharges. POM isotopic signatures were used to identify the origins of nutrient and organic matter assimilated into the estuarine food web through benthic organisms to juvenile common sole. Interannual spatial variations were found in the POM carbon stable isotope signatures, with the importance of these variations depending on the interannual fluctuations of the river flow. Moreover, the spatio-temporal variability of this POM isotopic signature was propagated along the food webs up to juvenile sole, confirming the central role of river discharge and terrigeneous subsidy input in the estuarine benthic food web in determining the size of the sole nursery habitat. (C) 2009 Elsevier B.V. All rights reserved.

Developmental changes in myofibrillar protein composition were investigated in the myotomal muscle of the African catfish, Heterobranchus longifilis (Clariidae), by several electrophoretic techniques. The main muscle fibres of larvae and the fast-white muscle fibres of juvenile and adult fish were found to express distinct myosin heavy chain and myosin light chain 2 (LC2) isoforms. Three myosin LC2 chains were successively detected, differing by their isoelectric points. In contrast, the alkali light chains remained qualitatively and quantitatively unchanged during fish growth. Actin, -tropomyosin, and troponin-C (TN-C) were also similar in larval, juvenile, and adult white muscle, but an additional larval tropomyosin isoform was found in the first developmental stages. Two isoforms of troponin-T (TN-T) and troponin-I (TN-I) were synthesised in the course of fish growth. Transition from the larval to the adult isoform was much faster for TN-T than for TN-I. Slow-red muscle myofibrils from adult H. longifilis showed no common component (except actin) with larval, juvenile, or adult fast-white muscle myofibrils. Red myofibrils displayed a single TN-T and a single TN-I isoform, but two isoforms of TN-C. The myofibrillar protein isoforms synthesised at any given developmental stage almost certainly reflect changes in the functional requirements of swimming muscles in the course of fish development.

The influence of riverine inputs on biogeochemical cycling and organic matter recycling in sediments on the continental shelf off the Rhone River mouth (NW Mediterranean Sea) was investigated by measuring sediment oxygen uptake rates using a combination of in situ and laboratory techniques. Four stations were investigated during two cruises in June 2001 and June 2002, with depths ranging from 9 to 192 m and over a distance to the Rhone River mouth ranging from 4 to 36 km. Diffusive oxygen uptake (DOU) rates were determined using an in situ sediment microprofiler and total oxygen uptake (TOU) rates were measured using sediment core incubations. There was good agreement between these two techniques which indicates that the non-diffusive fraction of the oxygen flux was minimal at the investigated stations. DOU rates ranged from 3.7 +/- 0.4 mmol O-2 m(-2) d(-1) at the continental shelf break to 19.3 +/- 0.5 mmol O-2 m(-2) d(-1) in front of the Rhone River mouth. Sediment oxygen uptake rates mostly decreased with increasing depth and with distance from the Rhone mouth. The highest oxygen uptake rate was observed at 63 m on the Rhone prodelta, corresponding to intense remineralization of organic matter. This oxygen uptake rate was much larger than expected for the increasing bathymetry, which indicates that biogeochemical cycles and benthic deposition are largely influenced by the Rhone River inputs. This functioning was also supported by the detailed spatial distribution of total organic carbon (TOC), total nitrogen (TN) and C/N atomic ratio in surficial sediments. Sediments of the Rhone prodelta are enriched in organic carbon (2-2.2%) relative to the continental shelf sediments (< 1%) and showed C/N ratios exceeding Redfield stoichiometry for fresh marine organic matter. A positive exponential correlation was found between DOU and TOC contents (r(2) = 0.98, n = 4). South-westward of the Rhone River mouth, sediments contained highly degraded organic matter of both terrestrial and marine origin, due to direct inputs from the Rhone River, sedimentation of marine organic matter and organic material redeposition after resuspension events. (c) 2008 Elsevier Ltd. All rights reserved.

International audience; Since 2005, wind-driven 'sporadic' coastal upwelling events have been identified off the southwestern reef of New Caledonia. Several studies have described the main physical processes and induced surface patterns using 1D and 3D modelling, as well as in situ measurements. Previous models were applied at the mesoscale without taking into account the lagoon. Using a recently developed 3D coupled physical-biogeochemical model that considers the complex ocean-lagoon interface, we aim to understand better the impact of the upwelling on the lagoon. The model was found to be in good agreement with measured data reported in previous publications about two upwelling events. However, in general, levels of surface chlorophyll-a were overestimated by the model in the upwelling area when compared to ocean colour data and several hypotheses have been proposed to explain the discrepancy. We then tracked rich upwelled water using a forward Lagrangian transport analysis. Upwelled waters from the upper nutricline were found to be able to reach the South West lagoon. An anti-cyclonic eddy was detected near the upwelling area, potentially responsible, in part, for the rich water intrusions into the lagoon.

The giant clam Tridacna maxima has been largely overexploited in many tropical regions over the past decades, and was therefore listed in appendix II of the Convention of International Trade in Endangered Species (CITES) in 1985. In French Polynesia, several atolls and islands harbor the world's highest stocks of giant clams in very shallow and accessible areas, which are therefore highly vulnerable to fishing pressure. The local fishery authority (i.e., Direction des Resources Marines or "DRM") implemented several management schemes in 2002 to control and regulate fishing pressure. However, for further decisions DRM was missing a sensitivity analysis on the effectiveness of the possible management actions. Here, we report on the use of a deterministic Viable Population Analysis (VPA) and spatially-explicit age-based population model that simulated the 30-year trajectory of a Tridacna maxima stock under different management approaches. Specifically, given various scenarios of intra-island larval dispersal, we tested which of No-take-Areas (NTAs), rotational closures, size limits, quotas, and restocking schemes would lead to the highest future stocks in Tubuai and Raivavae, two exploited islands of the Austral archipelago. For both islands, stock abundances were estimated in 2004/2010 and 2005/2010 respectively, and natural mortalities were assessed previously only in Tubuai. When compared to field data, the model successfully predicted the 2010 stocks for Tubuai, but proved to be less reliable for Raivavae, where natural mortality rates may well be different from those on Tubuai. For Tubuai, the spatial model suggested that reducing fishing effort (through fixed quotas) and banning fishing below the 12 cm size limit (as currently implemented) were the most effective management actions to sustain T. maxima populations into the future. Implementing NTAs was of poor effectiveness. NTAs increased giant clam stock inside the protected area, but also increased overfishing in the neighboring areas, and were ineffective overall.

It cannot be said that aquaculture has ignored sustainable development (SD), judging by the number of standards, guides and indicators devoted to it, produced mainly under the aegis of international organizations such as FAO, The European Union and sorne NGOs. However, these continue to be perceived in large measure as constraints rather than as shared objectives by actors. Faced with this situation, which is not specific to aquaculture but on the contrary quite general regardless of sector, context or scale, the authors seek to propose a generic approach that through a collective process, i.e. a co-construction, promotes the implementation and appropriation of SD. What makes this approach original is not only the participatory nature of the construction, but also the regional nature of the approach which includes both aquaculture systems and their host area. It is based on a selection process that nests princip les, criteria and linking indicators to the actors' issues and representations, encourages their appropriation of both SD and the indicators produced. This approach is the fruit of fieldworks undertaken by a group of French researchers in partnership with teams of scientists and actors in France, in Europe and in Southern countries (Cameroon, Indonesia and Philippines). Aquaculture systems, representative of a broad range of farming systems and governance mechanisms, were studied. Designed in a form of an instruction manual that is as flexible as possible, the approach alternates various sequences in order to modulate the range and the involvement of stakeholders and to emphasise the collective learning process. In this paper, the authors first present the postulates which underlie the adaptive and participatory nature of the approach and then outline the linking phases. They conclude with sorne of the results obtained from the implementation of the method.

AbstractAccelerating the description of biodiversity is a major challenge as extinction rates increase. Integrative taxonomy combining molecular, morphological, ecological and geographical data is seen as the best route to reliably identify species. Classic molluscan taxonomic methodology proposes primary species hypotheses (PSHs) based on shell morphology. However, in hyperdiverse groups, such as the molluscan family Turridae, where most of the species remain unknown and for which homoplasy and plasticity of morphological characters is common, shell‐based PSHs can be arduous. A four‐pronged approach was employed to generate robust species hypotheses of a 1000 specimen South‐West Pacific Turridae data set in which: (i) analysis of COI DNA Barcode gene is coupled with (ii) species delimitation tools GMYC (General Mixed Yule Coalescence Method) and ABGD (Automatic Barcode Gap Discovery) to propose PSHs that are then (iii) visualized using Klee diagrams and (iv) evaluated with additional evidence, such as nuclear gene rRNA 28S, morphological characters, geographical and bathymetrical distribution to determine conclusive secondary species hypotheses (SSHs). The integrative taxonomy approach applied identified 87 Turridae species, more than doubling the amount previously known in the Gemmula genus. In contrast to a predominantly shell‐based morphological approach, which over the last 30 years proposed only 13 new species names for the Turridae genus Gemmula, the integrative approach described here identified 27 novel species hypotheses not linked to available species names in the literature. The formalized strategy applied here outlines an effective and reproducible protocol for large‐scale species delimitation of hyperdiverse groups.