Potential ways to address the issues that relate to the techniques for analyzing food and environmental samples for the presence of enteric viruses are discussed. It is not the authors' remit to produce or recommend standard or reference methods but to address specific issues in the analytical procedures. Foods of primary importance are bivalve molluscs, particularly, oysters, clams, and mussels; salad crops such as lettuce, green onions and other greens; and soft fruits such as raspberries and strawberries. All types of water, not only drinking water but also recreational water (fresh, marine, and swimming pool), river water (irrigation water), raw and treated sewage are potential vehicles for virus transmission. Well over 100 different enteric viruses could be food or water contaminants; however, with few exceptions, most well-characterized foodborne or waterborne viral outbreaks are restricted to hepatitis A virus (HAV) and calicivirus, essentially norovirus (NoV). Target viruses for analytical methods include, in addition to NoV and HAV, hepatitis E virus (HEV), enteroviruses (e.g., poliovirus), adenovirus, rotavirus, astrovirus, and any other relevant virus likely to be transmitted by food or water. A survey of the currently available methods for detection of viruses in food and environmental matrices was conducted, gathering information on protocols for extraction of viruses from various matrices and on the various specific detection techniques for each virus type.

Three scenarios for the future of the French agro-food system were specified for the territory draining into the Seine Bight, comprising Paris megacity and the Seine watershed. The first scenario assumes the pursuit of the current trend of opening and specialization of agriculture, as well as of concentration of population within the Paris agglomeration. The second scenario assesses the generalization of agro-ecological practices and a healthier human diet. A third, hybrid, scenario was elaborated assuming that agro-ecological practices were implemented in some protected areas (namely Regional Natural Parks and drinking water protection areas, making up about one-third of the total watershed area), while the rest of the territory will follow the trends of the first scenario. We use a unique modelling chain (GRAFS-Riverstrahler-ECOMARS3D) that couples the biogeochemical functioning of the river basin, the estuary and the adjacent bay. It allows exploring the implications of changes in terrestrial activities throughout the aquatic continuum in a consistent way and assessing to what extent changes in population, agricultural practices, food consumption, and sanitation may sustain the current trend of recovery in the Seine River or either increase stress on the system. Results show that only the full agro-ecological scenario would be able to restore good water quality everywhere in the river network, as well as decrease significantly the risks of toxic algal blooms in the coastal zone. Intermediate situations, such as the protection of specific areas, however attractive as a solution, are not enough to offset the impacts of intensive human activities unless the protected areas dedicated to compensating for damage are sufficiently large.

While research has extensively investigated the dynamics of CO2 water partial pressure (pCO2) and planktonic food webs (PFWs) separately, there has been limited exploration of their potential interconnections, especially in marsh typologies. This study’s objectives were to (1) investigated if pCO2 and atmospheric CO2 flux can be elucidated by PFW topologies, and (2) ascertain if these potential relationships are consistent across two distinct “Blue Carbon” ecosystems. Abiotic and biotic variables were measured in two contrasting wetlands at the Atlantic French coast: a saltwater (SM, L’Houmeau) and a freshwater marsh (FM, Tasdon). SM acted as a weak carbon source, with pCO2 between 542 and 842 ppmv. Conversely, FM exhibited strong atmospheric CO2 source or sink characteristics, varying with seasons and stations, with pCO2 between 3201 and 114 ppmv. Five PFW topologies were linked to varying pCO2 across the two ecosystems: three stable topologies ('biological winter', 'microbial', 'multivorous' PFW) exhibited consistently high pCO2 values (FM: 971, 1136, 3020 ppmv; SM: 'biological winter' not observed, 842, 832 ppmv), while two transient topologies ('weak multivorous' and 'weak herbivorous') displayed lower and more variable pCO2 values (FM: from 127 to 1402 ppmv; SM: from 638 to 749 ppmv). Seasonality emerged as an influencing factor for both pCO2 dynamics and PFW. However, PFW in FM did not demonstrate a seasonal equilibrium state, potentially hindering a clearer understanding of the relationship between pCO2 and PFW. This is the first documented association between PFW topologies and pCO2 dynamics in “Blue Carbon” marsh environments.

Daily food intake of young soles, from 8 to 30 am length, was measured in the labo­ratory at five constant temperatures from 10 to 26°C. The daily consumption (C) was correlated with length (L, cm) and weight (W, g) of the fish, which resulted in the following exponen­tial relationships with temperature (T, °C) : c = O.OOOOll e°'Zb TJ3.20-0.0096T-0.0026T2) n - n nna 0.18T „(1.12-0.013T-0.00055T2) C — 0.Quo e , w . It appears that the daily food consumption of small soles is maximal at high tempe­ratures (26°C for 10 cm fish). With increasing size of the fish the temperature for maximum feeding shifts to lower values (16°C for a 50 am fish). The daily food consumption expressed as percentage of the metabolic weight of the fish (C = % 8) appears to be independant of fish size at about 16°C. Higher temperatures are more favourable for the smaller fish, lower temperatures for the larger fish. This may explain why young soles need coastal nurseries with a high summer temperature and a rich food supply, while the adult fish find optimum conditions at lower temperatures offshore | La consommation quotidienne en nourriture de jeunes soles, de 6 à 30 cm de long, a été mesurée au laboratoire, à 5 températures constantes, de 10 à 26°C. Cette consommation quo­tidienne (C) a été reliée à la longueur (L, cm) et au poids (W, g) des poissons, fournissant avec la température (T, °C) les relations exponentielles suivantes : C = 0.000011 e0-35 T.l(3-20-0.0096T-0.C026t2) C = 0.006 eO.18Tjl.l2-O.Ol3T-O.O0O55T2) Il apparaît que la consommation quotidienne de petites soles est maximale à de hautes températures (26°C pour un poisson de 10 cm). Lorsque la taille du poisson augmente, la température de consommation maximale glisse vers des valeurs plus basses (16°C pour un poisson de 50 cm). La consommation de nourriture quotidienne, exprimée en pourcentage du poids métabolique du poisson (C = % \fi>8) se montre indépendante de sa taille aux environs de 16°C. Des températures plus élevées sont plus favorables à des poissons plus petits, des températu­res plus basses à des poissons plus grands. Cela peut expliquer pourquoi les jeunes soles ont besoin de nurseries côtières, avec une température estivale élevée, et une nourriture abondan­te, tandis que l'adulte trouve des conditions optimales à des températures plus basses, au large.

Environmental parameters, such as food level and water temperature, have been shown to be major factors influencing pearl oyster shell growth and molecular mechanisms involved in this biomineralization process. The present study investigates the effect of food level (i.e., microalgal concentration) and water temperature, in laboratory controlled conditions, on the last stages of pearl mineralization in order to assess their impact on pearl quality. To this end, grafted pearl oysters were fed at different levels of food and subjected to different water temperatures one month prior to harvest to evaluate the effect of these factors on 1) pearl and shell deposition rate, 2) expression of genes involved in biomineralization in pearl sacs, 3) nacre ultrastructure (tablet thickness and number of tablets deposited per day) and 4) pearl quality traits. Our results revealed that high water temperature stimulates both shell and pearl deposition rates. However, low water temperature led to thinner nacre tablets, a lower number of tablets deposited per day and impacted pearl quality with better luster and fewer defects. Conversely, the two tested food level had no significant effects on shell and pearl growth, pearl nacre ultrastructure or pearl quality. However, one gene, Aspein, was significantly downregulated in high food levels. These results will be helpful for the pearl industry. A wise strategy to increase pearl quality would be to rear pearl oysters at a high water temperature to increase pearl growth and consequently pearl size; and to harvest pearls after a period of low water temperature to enhance luster and to reduce the number of defects.

In this study, surface seawater, sediment and zooplankton samples were collected from three different sampling stations in Marseille Bay (NW Mediterranean Sea) and were analyzed for both microplastics and organic plastic additives including seven phthalates (PAEs) and nine organophosphate esters (OPEs). PAE concentrations ranged from 100 to 527 ng L-1 (mean 191±123 ng L-1) in seawater, 12 to 610 ng g-1 dw (mean 194±193 ng g-1 dw) in sediment and 0.9 to 47 μg g-1 dw (mean 7.2±10 μg g-1 dw) in zooplankton, whereas OPE concentrations varied between 9-1013 ng L-1 (mean 243±327 ng L-1) in seawater, 13-49 ng g-1 dw (mean 25±11 ng g-1 dw) in sediment and 0.4-4.6 μg g-1 dw (mean 1.6±1.0 μg g-1 dw) in zooplankton. Microplastic counts in seawater ranged from 0 to 0.3 items m-3 (mean 0.05±0.05 items m-3). We observed high fluctuations in contaminant concentrations in zooplankton between different sampling events. However, the smallest zooplankton size class generally exhibited the highest PAE and OPE concentrations. Field-derived bioconcentration factors (BCFs) showed that certain compounds are prone to bioaccumulate in zooplankton, including some of the most widely used chlorinated OPEs, but with different intensity depending on the zooplankton size-class. The concentration of plastic additives in surface waters and the abundance of microplastic particles were not correlated, implying that they are not necessarily good indicators for each other in this compartment. This is the first comprehensive study on the occurrence and temporal variability of PAEs and OPEs in the coastal Mediterranean based on the parallel collection of water, sediment and differently sized zooplankton samples.