Abstract
Outbreaks of infection with Ostreid herpesvirus 1 micro variant (OsHV-1 μVar) causing mortalities in Pacific oyster were reported from Europe and Oceania. The Ministry of Agriculture, Forestry and Fisheries issued warnings of the disease to prefectural fisheries divisions and requested them to give the warnings to people and organizations concerned. However, the flow of the warnings was not investigated and it was unclear whether the warnings were actually received by those concerned. We investigated the flow of the warnings by interviews and questionnaire, and found that the warnings were mainly issued to oyster farmers via fisheries cooperatives and that only 30% of oyster farmers knew about the disease. The low rate of oyster farmers with knowledge on the disease seemed to be because some fisheries cooperatives did not relay the warnings to farmers and because not all of the farmers receiving the warnings could understand the risk of this disease probably due to their lack of general knowledge on epidemics of oysters and other mollusks.
