An international laboratory in Norway has said that there is strong evidence of the presence of a serious virus among rainbow trout at a fish farm in Co Mayo, writes Lorna Siggins, Marine Correspondent.
However, it has asked the Marine Institute to carry out more scientific investigations on infectious salmon anaemia, a virus which has hit fish farms in Scotland, Norway and Canada in recent years.
These investigations include determining whether the strain of the virus isolated on the Mayo farm is pathogenic and its effects, if any, on salmon.
The Department of Communications, Marine and Natural Resources said yesterday that those investigations were already under way and it had also initiated a programme of testing wild and ranched salmon returning to the area.
Positive indication of infectious salmon anaemia was isolated during routine testing by the Marine Institute on August 1st at a rainbow trout farm in Clew Bay, which is owned by a local company, Seastream Ltd.
To date there has been no evidence of a clinical outbreak and the trout at the farm have been in good health, a senior Department official said yesterday.
The situation was complicated by the escape of a reported 100 fish from the farm during harvesting on August 2nd. Many of these fish, which ran up the Newport river, were recovered by the Marine Institute and North-Western Regional Fisheries Board.
The Department and the Marine Institute have introduced full disease-control measures at the farm as a precaution, including accelerated harvesting of the fish.
A report on the testing sent to the Office International des Epizooites Reference Laboratory in Oslo was received late this week by the Department and it has notified the European Commission that there is strong evidence of the virus and that there is no clinical outbreak to date.
The Irish Fish and Health Advisory Committee has been convened by the Marine Institute to oversee the continued monitoring at the farm.
All other marine farms are also undergoing routine testing, including the one closest to that on which the virus has been isolated and all tests have been negative, the Department said adding that the company in question had been co-operating fully with the authorities.
Local fishery-owners, notified late last week of the occurrence, have expressed serious concern about the possible impact on wild fish stocks.