Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigas

Mortalities of oyster Crassostrea gigas seed associated with ostreid herpesvirus OsHV-1 μVar have been observed in many oyster-producing countries since 2008. The present study, comprised of 4 complementary experiments, aimed to identify factors associated with disease-induced oyster mortality in or...

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Main Authors: B Petton, P Boudry, M Alunno-Bruscia, F Pernet
Format: Article
Language:English
Published: Inter-Research 2015-03-01
Series:Aquaculture Environment Interactions
Online Access:https://www.int-res.com/abstracts/aei/v6/n3/p205-222/
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author B Petton
P Boudry
M Alunno-Bruscia
F Pernet
author_facet B Petton
P Boudry
M Alunno-Bruscia
F Pernet
author_sort B Petton
collection DOAJ
description Mortalities of oyster Crassostrea gigas seed associated with ostreid herpesvirus OsHV-1 μVar have been observed in many oyster-producing countries since 2008. The present study, comprised of 4 complementary experiments, aimed to identify factors associated with disease-induced oyster mortality in order to propose mitigation strategies. Our first experiment compared survival of oysters from natural spatfall with others sampled from nurseries, after thermal elevation in the laboratory from <14 to 21°C. A total of 60% of the tested wild seed batches (n = 51) were infected by OsHV-1, exhibited mortality and were able to transmit the disease to cohabited naïve oysters. Comparatively, only 1 out of the 32 tested batches sampled from nurseries presented similar characteristics. In a second experiment, we studied the effects that timing and duration of exposure to field conditions had on risk of infection and mortality in the laboratory at 21°C. Naïve oysters deployed in the field during winter and spring, when seawater temperatures were <14.7°C, showed no mortality in the laboratory, and OsHV-1 DNA was not detected by PCR. However, in oysters transferred to the field, OsHV-1 was observed when seawater temperature reached ~15.3°C. Our third experiment showed that the odds of mortality decreased with age of oysters when facing the disease. Further, we observed that odds of disease mortality decreased with water renewal and increased with the biomass of neighbouring infected oysters under controlled conditions. Based on these findings, we propose mitigation strategies in terms of the regulation of oyster movements between sites, timing of seeding and spatial planning, taking into account seawater temperature and seed origin.
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spelling doaj.art-026cd104f7534829863642531939a6212022-12-21T19:29:05ZengInter-ResearchAquaculture Environment Interactions1869-215X1869-75342015-03-016320522210.3354/aei00125Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigasB Petton0P Boudry1M Alunno-Bruscia2F Pernet3Ifremer, UMR LEMAR 6539 (UBO/CNRS/IRD/Ifremer), 11 presqu’île du Vivier, 29840 Argenton-en-Landunvez, FranceIfremer, UMR LEMAR 6539 (UBO/CNRS/IRD/Ifremer), Technopole de Brest-Iroise, BP 70 29280 Plouzané, FranceIfremer, UMR LEMAR 6539 (UBO/CNRS/IRD/Ifremer), 11 presqu’île du Vivier, 29840 Argenton-en-Landunvez, FranceIfremer, UMR LEMAR 6539 (UBO/CNRS/IRD/Ifremer), Technopole de Brest-Iroise, BP 70 29280 Plouzané, FranceMortalities of oyster Crassostrea gigas seed associated with ostreid herpesvirus OsHV-1 μVar have been observed in many oyster-producing countries since 2008. The present study, comprised of 4 complementary experiments, aimed to identify factors associated with disease-induced oyster mortality in order to propose mitigation strategies. Our first experiment compared survival of oysters from natural spatfall with others sampled from nurseries, after thermal elevation in the laboratory from <14 to 21°C. A total of 60% of the tested wild seed batches (n = 51) were infected by OsHV-1, exhibited mortality and were able to transmit the disease to cohabited naïve oysters. Comparatively, only 1 out of the 32 tested batches sampled from nurseries presented similar characteristics. In a second experiment, we studied the effects that timing and duration of exposure to field conditions had on risk of infection and mortality in the laboratory at 21°C. Naïve oysters deployed in the field during winter and spring, when seawater temperatures were <14.7°C, showed no mortality in the laboratory, and OsHV-1 DNA was not detected by PCR. However, in oysters transferred to the field, OsHV-1 was observed when seawater temperature reached ~15.3°C. Our third experiment showed that the odds of mortality decreased with age of oysters when facing the disease. Further, we observed that odds of disease mortality decreased with water renewal and increased with the biomass of neighbouring infected oysters under controlled conditions. Based on these findings, we propose mitigation strategies in terms of the regulation of oyster movements between sites, timing of seeding and spatial planning, taking into account seawater temperature and seed origin.https://www.int-res.com/abstracts/aei/v6/n3/p205-222/
spellingShingle B Petton
P Boudry
M Alunno-Bruscia
F Pernet
Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigas
Aquaculture Environment Interactions
title Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigas
title_full Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigas
title_fullStr Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigas
title_full_unstemmed Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigas
title_short Factors influencing disease-induced mortality of Pacific oysters Crassostrea gigas
title_sort factors influencing disease induced mortality of pacific oysters crassostrea gigas
url https://www.int-res.com/abstracts/aei/v6/n3/p205-222/
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AT fpernet factorsinfluencingdiseaseinducedmortalityofpacificoysterscrassostreagigas