Publication Abstract

Monitoring for viral haemorrhagic septicaemia virus and infectious salmon anaemia virus at contaminated and reference areas in the North Sea

Monitoring for fish viruses

P.F. Dixon, C.B. Longshaw, G.J. Jones and D.M. Stone

These studies were carried out under the Biological Effects in Pelagic Ecosystems programme. Until recently, viral haemorrhagic septicaemia (VHS) was considered to be a serious disease that primarily affected cultivated rainbow trout in Europe. However, the causative virus (VHSV) has been isolated from an increasing number of marine or anadromous fish species, and the isolations from marine fish in Europe have all been from the North Sea, or waters linked to the North Sea such as the Baltic Sea. Rather than the virus being transferred from the freshwater environment to the marine environment, there is evidence that the reverse may have occurred and that there is a reservoir for VHSV in marine fish, particularly the herring. It has been suggested that exposure of fish to polynuclear aromatic hydrocarbons and other pollutant may reactivate a subclinical infection with VHSV, or make fish more susceptible to the virus. The herring has also been implicated as a possible reservoir of infectious salmon anaemia virus (ISAV). That virus causes infectious salmon anaemia which is a serious disease of salmon, particularly those in seawater. Amongst other countries, the disease occurs in Norway and Scotland, both of which border the North Sea. The objectives of this project were to take tissue samples from herring from contaminated and reference areas in the North Sea, try to detect VHSV or ISAV, and if successful, determine whether there is any correlation between virus incidence and sampling area. As it was not possible to catch the required number of herring from each sampling station, other fish, predominantly whiting were sampled as well. A total of 401 fish were tested but neither VHSV nor ISAV were isolated, and there was no evidence for the presence of VHSV by the polymerase chain reaction. An aquabirnavirus was isolated from whiting from the German Bight reference area, a new host record. The findings are discussed.

Reference:

P.F. Dixon, C.B. Longshaw, G.J. Jones and D.M. Stone (2006) Monitoring for viral haemorrhagic septicaemia virus and infectious salmon anaemia virus at contaminated and reference areas in the North Sea. Biological Effects of Contaminants in Marine Pelagic Ecosystems.  Hylland, K., Lang, T. and Vethaak, D. (Eds). p 111-120. SETAC Press, Brussels, Belgium.

P.F. Dixon*, C.B. Longshaw*, G.J. Jones and D.M. Stone*

Biological Effects of Contaminants in Marine Pelagic Ecosystems. Hylland, K., Lang, T. and Vethaak, D. (Eds). p 111-120. SETAC Press, Brussels, Belgium.