@article{fdi:010070187,
  title = {{I}nfluence of {OSHV}-1 oyster mortality episode on dissolved inorganic fluxes : an ex situ experiment at the individual scale},
  author = {{R}ichard, {M}. and {B}ourreau, {J}. and {M}ontagnani, {C}. and {O}uisse, {V}. and {L}e {G}all, {P}hilippe and {F}ortune, {M}. and {M}unaron, {D}. and {M}essiaen, {G}. and {C}allier, {M}. {D}. and d'{O}rbcastel, {E}. {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{O}streid herpesvirus 1 ({O}s{HV}-1 mu var) infection has caused significant mortalities in juvenile oysters ({C}rassostrea gigas). {I}n contrast to the practices of other animal production industries, sick and dead oysters are not separated from live ones and are left to decay in the surrounding environment, with unknown consequences on fluxes of dissolved materials. {A} laboratory approach was used in this study to test the influence of oyster mortality episode on dissolved inorganic fluxes at the oyster interface, dissociating (i) the effect of viral infection on metabolism of juvenile oysters and (ii) the effect of flesh decomposition on oxygen consumption and nutrient releases at the individual scale. {N}ine batches of juvenile oysters ({I}ndividual {T}otal wet weight 1 g) were infected via injection of {O}s{HV}-1 enriched inoculums at different viral loads (108 and 109 {O}s{HV}-1 {DNA} copies per oyster) to explore infection thresholds. {O}ysters injected with filtered seawater were used as controls ({C}). {O}ysters were maintained under standard conditions to avoid stress linked to hypoxia, starvation, or ammonia excess. {B}efore, after the injection and during the mortality episode, i.e. at days 1, 3, 7, 10 and 14, nine oysters per treatment were incubated in individual metabolic chambers to quantify oxygen, ammonium and phosphate fluxes at the seawater-oyster interface. {N}ine empty chambers served as a reference. {I}njections of the two viral loads of {O}s{HV}-1 induced similar mortality rates (38%), beginning at day 3 and lasting until day 14. {T}he observed mortality kinetics were slower than those reported in previous experimental pathology studies, but comparable to those observed in the field ({T}hau lagoon, {F}rance). {T}his study highlights that oxygen and nutrient fluxes significantly varied during mortality episode. {I}ndeed (i) {O}s{HV}-1 infection firstly modifies oyster metabolism, with significant decreases in oxygen consumption and ammonium excretion, and (ii) dead oysters lead to a strong increase of ammonium (6 fold) and phosphate (41 fold) fluxes and a decrease in the {N}/{P} ratio due to mineralisation of their flesh. {T}he latter may modify the structure of the planktonic community in the field during mortality episode. {T}his study is a first step of the {MORTAFLUX} program. {T}he second step was to in situ confirm this abnormal nutrient loading during a mortality episode and show its impact on bacterio-, phyto-and protozoo-plankton.},
  keywords = {{C}rassostrea gigas ; {M}ortality ; {O}streid herpesvirus 1 ; {J}uvenile ; {S}pat ; {M}ineralisation ; {O}xygen consumption ; {N}utrient fluxes ; {FRANCE}},
  booktitle = {},
  journal = {{A}quaculture},
  volume = {475},
  numero = {},
  pages = {40--51},
  ISSN = {0044-8486},
  year = {2017},
  DOI = {10.1016/j.aquaculture.2017.03.026},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070187},
}