Résumé: The Peruvian hake (Merluccius gayi peruanus) stock has been in a delicate state in the last decades due to overexploitation combined with adverse climatic events. The stock is showing certain signs of recovery since 2012. This work analyses the environmental impacts of current fleet operations and its likely trend. The fleet was divided into coherent segments, per holding capacity and engine power. The validity of both segmentations, as well as the presence of an effect of economies of scale driving fuel use intensity (FUI), was tested. Life cycle assessment was used to calculate environmental impacts, per individual sampled vessel and per segment, complemented with indicators of energy efficiency and biotic resource depletion. The fleet is highly fuel-efficient (120 kg fuel per tonne fish) when compared with other reported values, despite a large overcapacity that increases the impact of the construction and maintenance phases. Significant inter-annual FUI variations were observed (80.0 kg t(-1) in 2008 to 210.3 kg t(-1) in 2006), but no clear trend. Neither significant differences in FUI among fleet segments nor a clear effect of economies of scale were found (but FUI analysis was based on a small sample of 32 values for nine vessels, two of which had data for a single year). Only the largest vessels, featuring 242 m(3) holding capacity and 850 hp engine power, were found to have lower FUI than any of the other vessels, but no statistical test could be applied to validate this difference. Differences in environmental impacts of individual vessels are mostly dominated by their relative FUI. Fuel use and, to a lower extent, maintenance are the main sources of environmental impacts. The most contributing impacts to ReCiPe single score are climate change, human toxicity and fossil depletion. The fishery's impacts on the biotic natural resource were orders of magnitude higher than many other global hake stocks, due to overexploitation. The environmental impacts of the national hake fleet are relatively low during the study period, despite an overcapacity of the fleet. With the perspective of expanding its operations and obtaining better yields on the eventuality that the stock fully recovers, these impacts should decrease. More research based on additional FUI data is necessary to effectively compare the performance of these vessels with larger ones (featuring > 180 m(3) and > 500 hp, of which nine existed in 2016) before possibly recommending their preferential use.

Résumé: Different seafood products based on Peruvian anchoveta (Engraulis ringens) fisheries and freshwater aquaculture of trout (Oncorhynchus mykiss), tilapia (Oreochromis spp.) and black pacu (Colossoma macropomum), contribute at different scales to the socio-economic development, environmental degradation and nutrition of the Peruvian population. Various indicators have been used in the literature to assess the performance of these industries regarding different aspects of sustainability, notably their socio-economic performance. In this study, a novel set of indicators is proposed to evaluate the sustainability performance of these industries in Peru, based on life cycle assessment (LCA) and nutritional profiling, as well as on energy and socio-economic assessment approaches. The emphasis is put on the potential of different products to contribute to improving the nutrition of the Peruvian population in an energy-efficient, environmentally friendly and socio-economically sound way. The set of indicators includes biotic resource use (BRU), cumulative energy demand (CED), energy return on investment (EROI), production costs, gross profit generation, added value, and nutritional profile in terms of vitamins, minerals and essential fatty acids; as well as a number of life cycle impact assessment indicators commonly used in seafood studies, and some recently proposed indicators of resource status (measuring the impacts of fish biomass removal at the species and ecosystem levels). Results suggest that more energy-intensive/highly processed products (cured and canned anchoveta products) represent a higher burden, in terms of environmental impact, than less energy-intensive products (salted and frozen anchoveta products, semi-intensive aquaculture products). This result is confirmed when comparing all products regarding their industrial-to-nutritional energy ratio. Regarding the other attributes analysed, the scoring shows that salted and frozen anchoveta products generate fewer jobs and lower gross profit than canned and cured, while aquaculture products maximise them. Overall, it was concluded that less energy-intensive industries (anchoveta freezing and salting) are the least environmentally impacting but also the least economically interesting products, yet delivering higher nutritional value. Aquaculture products maximise gross profit and job creation, with lower energy efficiency and nutritional values. The proposed set of sustainability indicators fulfilled its goal in providing a multi-criteria assessment of anchoveta direct human consumption and freshwater aquaculture products. As often the case, there is no ideal product and the best trade-off must be sought when making decision regarding fisheries and seafood policy. No threshold for performance of the different indicators is offered, because the goal of the comparison is to contrast the relative performance among products, not of products against reference values.

Résumé: Studies considering the biology and ecology of the toxic bloom-forming species, Alexandrium pseudogonyaulax, are rare. Our results highlight five features not described before in A. pseudogonyaulax life cycle: (i) A. pseudogonyaulax gametes showed two modes of conjugation, anisogamy and isogamy, (ii) sexual conjugation occurs either in the dark or in the light phase by engulfment or a fusion process, (iii) the presence of planozygote and newly formed cysts in monoclonal culture suggests homothallism, (iv) newly formed cysts have very dark vesicular content and are mostly unparatabulated when observed under light microscope and (v) natural resting cysts are able to give either a planomeiocyte or two vegetative cells. Cyst viability was enhanced after 5 months of cold storage (4°C), with excystment rate reaching 97% after 3 d of incubation. Excystment rate was highest (43%–79%) in Enriched Natural Sea Water diluted culture medium, whereas few germling cells were able to survive without the culture medium (0%–13%). Salinity-irradiance experiments revealed that the highest cell concentrations occur at high irradiances for all the tested salinities. Vegetative growth rates generally increased with increasing irradiance, and were less dependent on salinity variations. The relatively low growth rate, low cell densities in the laboratory, and the notable capacity of producing cysts along growth phases of A. pseudogonyaulax could explain the occurrence of high resting cysts densities in the sediment of Bizerte lagoon and the relatively low abundances of vegetative cells in the water column.

Résumé: The Peruvian anchoveta fishery is currently targeted by a large fleet featuring a wide range of vessel sizes (segments), with highly variable capacities. In addition, the landings of the industrial fleet are used exclusively by the reduction industry, while those performed by small- and medium-scale vessels are destined mainly for direct human consumption. Despite these differences, the entire fleet is made up of purse seiners that perform similar operations when at sea. Therefore, the main aim of this study is to identify the differences in eco-efficiency between the different fleet segments in order to delve into the potential environmental improvements that could be attained through operational benchmarking. To this end, the combined use of Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) was applied to the Peruvian anchoveta fleet. More specifically, a modified 5-step LCA + DEA method, whose particularities are broadly discussed throughout the study, was computed to obtain the desired operational benchmarks and, thereafter, estimate the target environmental gains. Results led to an average efficiency score of 86% throughout the segments, with a total of eight fleet segments out of 13 (62%) operating inefficiently. Nevertheless, no clear pattern was identified through the segments, although certain correlations with stock abundance, fuel use intensity, overcapacity and climatic conditions are discussed. Reduction in material inputs based on operational benchmarks translated into environmental gains that ranged from 26% to 53% for inefficient segments. Finally, it is expected that the findings in this study may aid stakeholders and policy makers when revising fuel use optimisation and overcapacity management strategies.

Résumé: SUMMARY The paramyxean parasite Marteilia refringens infects several bivalve species including European flat oysters Ostrea edulis and Mediterranean mussels Mytilus galloprovincialis. Sequence polymorphism allowed definition of three parasite types ‘M’, ‘O’ and ‘C’ preferably detected in oysters, mussels and cockles respectively. Transmission of the infection from infected bivalves to copepods Paracartia grani could be experimentally achieved but assays from copepods to bivalves failed. In order to contribute to the elucidation of the M. refringens life cycle, the dynamics of the infection was investigated in O. edulis, M. galloprovincialis and zooplankton over one year in Diana lagoon, Corsica (France). Flat oysters appeared non-infected while mussels were infected part of the year, showing highest prevalence in summertime. The parasite was detected by PCR in zooplankton particularly after the peak of prevalence in mussels. Several zooplanktonic groups including copepods, Cladocera, Appendicularia, Chaetognatha and Polychaeta appeared PCR positive. However, only the copepod species Paracartia latisetosa showed positive signal by in situ hybridization. Small parasite cells were observed in gonadal tissues of female copepods demonstrating for the first time that a copepod species other than P. grani can be infected with M. refringens. Molecular characterization of the parasite infecting mussels and zooplankton allowed the distinguishing of three Marteilia types in the lagoon.

Résumé: Life Cycle Assessment(LCA) was applied to evaluate the global environmental impact of two scenarios of trout production systems based on the operational information from an operational farm using a flow through system (FFF) and an experimental pilot low head recirculating system (RSF) located on the same site. The main differences between the environmental balances of the two systems were relative to water use, eutrophication potential and energy use. Independently of the system used, feed is the key indicator in determining the environmental balance (notwithstanding eutrophication potential and water dependence) monitored by fish production, chemical products, buildings and energy consumption. Consequently, when considering the RSF with a lower feed conversion ratio (0.8 versus 1.1 for FTF), the environmental balance of the RSF is more favourable at both global and regional levels, except with regards to energy use. RSF water dependence is 93% lower than the FTF and its eutrophication potential is 26-38% lower due to reduced waste release. On the other hand, at 57,659 MJ per ton of fish produced ( 16 kWh per kg), the RSF consumes 24-40% more energy than the FTF, especially for aeration and water treatment. Nevertheless, the RSF has significant potential for energy reduction through improvements to airlift and biofilter designs which Would reduce RSF energy use to a level similar to that of the FTF (34,869-43,841 MJ per ton of fish produced, corresponding to 10 and 12 kWh respectively). LCA is therefore a powerful tool which can be used on fish farms to define and prioritise the most promising potential improvements to the system. (C) 2008 Elsevier B.V. All rights reserved.