Impacts of Behavioral, Organizational, and Spatial Factors on the Carbon Footprint of Traditional Retail and E-commerce in the Paris Region.

Carbon footprint assessment of retail is necessary to optimize procurement strategies and adopt sustainable shopping habits. However, estimating carbon footprints is a complex task, given the diversity of existing distribution channels. Average values for carbon emissions of "conventional" retail (i.e., purchasing and receiving the product directly at the physical point of sale) found in most studies mask a heterogeneous reality: different retail strategies entail diverse shopping behavior for consumers, as well as varied procurement processes for outlets. In this paper, we propose a methodology to assess greenhouse gas (GHG) impacts of different distribution systems related to the consumption of goods in the Paris Region by coupling traditional transport modeling with a life-cycle assessment (LCA) approach. We model and compare six distribution systems, including five traditional retail formats (hypermarkets, supermarkets, small generalist retail, small food retail, and small nonfood retail) and E-commerce home deliveries. Our model includes warehouse activity, shop and home delivery, shop energy consumption, consumer mobility, and goods packaging. Overall, we conclude that E-commerce emits fewer GHG emissions than retail outlets per kilogram of product purchased. This result is in line with the existing literature on the topic. However, the carbon footprint varies greatly within the case study depending on the characteristics of the logistics procurement processes of outlets, the behavior of shoppers, and spatial characteristics.

Toward reference intervals for shellfish: An illustrative case of feeding and respiratory activities in the Pacific cupped oyster, Crassostrea gigas.

BACKGROUND: The Quality Assurance and Laboratory Standards Committee of the American Society for Veterinary Clinical Pathology and the guidelines of the Clinical and Laboratory Standards Institute provide a framework for establishing reference intervals of physiological parameters in reputedly healthy individuals, humans, and terrestrial animals, respectively. This framework was applied for the first time to the Pacific cupped oyster, Crassostrea gigas. Reference intervals (RIs) would, first, be of interest for research purposes, including pathophysiology studies. RI determination is the first step before considering the use of RIs for field applications by farmers and marine shellfish health services. OBJECTIVES: The purpose of this study was to propose reference intervals of feeding and respiration parameters, the clearance rate (CR), and oxygen consumption rate (OCR), in a reference population of hatchery-reared diploid Pacific oysters. METHODS: A de novo, a priori, and a direct approach were applied. The reference values acquired from 214 healthy diploid C gigas (total wet weight 6.23-83.64 g, DW 0.06-1.87 g) were analyzed using a non-parametric statistical method. RESULTS: Reference intervals were proposed for CR, 0.7-4.1 L/h/g dry flesh weight (DW), and OCR, 0.4-1.3 mg O2/h/g DW in C gigas in a seawater at a temperature of 22℃ and a salinity of 32‰. Animals were fed 30-40 cells/µL of Isochrysis affinis galbana. The confidence intervals at 90% of the upper limits of the two parameters were found to be higher than those of the Clinical and Laboratory Standards Institute (CLSI) recommendations. CONCLUSIONS: Obtaining reference intervals is an important step and must be completed by proposed decision limits to facilitate the early detection of health disorders in C gigas.

Harmful or harmless: Biological effects of marennine on marine organisms.

Marennine is a water-soluble blue-green pigment produced by the marine diatom Haslea ostrearia. The diatom and its pigment are well known from oyster farming areas as the source of the greening of oyster gills, a natural process increasing their market value in Western France. Blooms of blue Haslea are also present outside oyster ponds and hence marine organisms can be exposed, periodically and locally, to significant amounts of marennine in natural environments. Due to its demonstrated antibacterial activities against marine pathogenic bacteria (e.g. Vibrio) and possible prophylactic effects toward bivalve larvae, marennine is of special interest for the aquaculture industry, especially bivalve hatcheries. The present study aimed to provide new insights into the effects of marennine on a large spectrum of marine organisms belonging to different phyla, including species of aquaculture interest and organisms frequently employed in standardised ecotoxicological assays. Different active solutions containing marennine were tested: partially purified Extracellular Marennine (EMn), and concentrated solutions of marennine present in H. ostrearia culture supernatant; the Blue Water (BW) and a new process called Concentrated Supernatant (CS). Biological effects were meanwhile demonstrated in invertebrate species for the three marennine-based solutions at the highest concentrations tested (e.g., decrease of fertilization success, delay of embryonic developmental stages or larval mortality). Exposure to low concentrations did not impact larval survival or development and even tended to enhance larval physiological state. Furthermore, no effects of marennine were observed on the fish gill cell line tested. Marennine could be viewed as a Jekyll and Hyde molecule, which possibly affects the earliest stages of development of some organisms but with no direct impacts on adults. Our results emphasize the need to determine dosages that optimize beneficial effects and critical concentrations not to be exceeded before considering the use of marennine in bivalve or fish hatcheries.

Antimicrobial Compounds from Eukaryotic Microalgae against Human Pathogens and Diseases in Aquaculture.

The search for novel compounds of marine origin has increased in the last decades for their application in various areas such as pharmaceutical, human or animal nutrition, cosmetics or bioenergy. In this context of blue technology development, microalgae are of particular interest due to their immense biodiversity and their relatively simple growth needs. In this review, we discuss about the promising use of microalgae and microalgal compounds as sources of natural antibiotics against human pathogens but also about their potential to limit microbial infections in aquaculture. An alternative to conventional antibiotics is needed as the microbial resistance to these drugs is increasing in humans and animals. Furthermore, using natural antibiotics for livestock could meet the consumer demand to avoid chemicals in food, would support a sustainable aquaculture and present the advantage of being environmentally friendly. Using natural and renewable microalgal compounds is still in its early days, but considering the important research development and rapid improvement in culture, extraction and purification processes, the valorization of microalgae will surely extend in the future.

Ostreid herpesvirus 1 detection and relationship with Crassostrea gigas spat mortality in France between 1998 and 2006.

Since its molecular characterisation, Ostreid herpesvirus 1 (OsHV-1) has been regularly detected in Crassostrea gigas in France. Although its pathogenicity was demonstrated on larval stages, its involvement during mortality outbreaks at the juvenile stage was highly suspected but not evidenced. To investigate mortality outbreaks, the French National Network for Surveillance and Monitoring of Mollusc Health (REPAMO) carried out two surveys in juvenile C. gigas. The first survey lasted from 1998 to 2006 and was an epidemiological inquiry occurring when oyster farmers reported mortality outbreaks. The second survey, a longitudinal one, was set up in 1998 to complete the network observations on OsHV-1. Data analysis showed a specific pattern of mortality outbreaks associated with OsHV-1 detection. Ostreid herpesvirus 1 detection mainly appeared during the summer, suggesting the influence of the seawater temperature on its occurrence. It mostly presented a patchy distribution in the field in contrast to the nursery. Significant relationship between OsHV-1 detection and spat mortality was found, preferentially in sheltered and closed environments. The longitudinal survey confirmed most of the network observations. Although subsequent works particularly epidemiological surveys would be useful to confirm the causal link between the detection of OsHV-1 and the mortality outbreaks in juvenile C. gigas, the role of OsHV-1 in oyster mortality is progressing.

Can the protozoan parasite Bonamia ostreae infect larvae of flat oysters Ostrea edulis?

Bonamia ostreae is an intracellular protistan parasite affecting flat oysters Ostrea edulis. It can be detected in juveniles but mortalities mainly affect oysters which are more than 2 years old. The parasite is usually observed inside haemocytes and sometimes free, notably in gill epithelia suggesting a parasite release through this organ. However, the infective form and ways of entry and release remain undetermined. Flat oysters incubate their larvae in their pallial cavity for 8-10 days before releasing them into the water column. Flat oysters in Bay of Quiberon in South Brittany (France) are known to be infected with B. ostreae since 1979 and is the most important area in France for O. edulis spat collection. Flat oysters incubating larvae were sampled in this area during summertime between 2007 and 2009. Both adults and larvae were preserved and assayed by PCR and in situ hybridisation (ISH). PCR tests revealed the presence of parasite DNA in some adults and larvae. Specific labelling could be detected by ISH in gills, digestive system, gonad and mantle in adults and in the epithelium surrounding the visceral cavity of some larvae. Our results demonstrate that larvae can be infected with B. ostreae. Larvae might thus contribute to the spread of the parasite during their planktonic life. In addition, their transfer for aquaculture purpose should be controlled especially when they are exported from infected zones.

Molecular detection and quantification of the protozoan Bonamia ostreae in the flat oyster, Ostrea edulis.

Bonamia ostreae is an intracellular protozoan which is recognized as a cause of mortality in European populations of flat oysters (Ostrea edulis). Based on the recent characterization of actin genes of B. ostreae, specific primers were designed for real-time PCR using SYBR Green chemistry. Specificity was demonstrated by the unique melting temperature peak observed in positive samples and by the lack of amplification in samples of oysters infected by closely related parasites, including Bonamia exitiosa. A calibration curve using a cloned template was defined to estimate copy number. The assay had a 6 log- dynamic range, mean inter- and intra-assay variation coefficients of <1% and a minimum detection limit of 50 gene copies per reaction. Using infected oyster samples as templates, the assay was at least 10-fold more sensitive than conventional PCR. The quantitative assay was applied to test 132 oysters, and results were compared with the heart imprint method. There was a strong correlation between both techniques, and the results showed that the real-time PCR assay should be useful for studies of the ecology of B. ostreae and its host-parasite relationship.