Oyster Herpesvirus in Wadden Sea, the Netherlands

Gepubliceerd op
9 april 2013

Research shows that Japanese oysters in the Wadden Sea are infected with Oyster Herpesvirus OsHV-1 μvar. In the Wadden Sea, a UNESCO World Heritage site, young Japanese oysters were collected in the summer of 2012. When tested for the presence of DNA of the OsHV three of the five examined spots proved to be infected. This implies that the virus has settled in the Wadden Sea.

Oyster Herpesvirus OsHV-1 μvar was first discovered in Europe in 2008. Since then it appears this virus is responsible for an increased juvenile mortality among young Japanese oysters along the French, English and Irish coasts. The EU advises to take measures to stop further spread of this virus. With the measures the following methods of spread should also be taken into account: shellfish transports, oysters attached to ships, infected oyster larvae in the ocean currents along the European coast.

OsHV-1 herpesvirus μvar was found in the Netherlands for the first time in 2010 in the Zeeland Delta; an increased juvenile mortality was seen. How and when the virus was introduced into the Wadden Sea is not known. The oyster herpesvirus can only be detected by DNA testing. Previously the presence of this virus in the Wadden Sea was not investigated, so further research is needed to find out to which extent the virus causes increased mortality among the oysters in the Wadden Sea. The only host for Oyster Herpesvirus is the Japanese oyster. People are not susceptible to the virus, so there is no risk to the public health.


Dr. A. Gittenberger (GiMaRIS, Marine Research, Inventory & Strategy solutions); /

Dr. M.Y. Engelsma (Central Veterinary Institute, part of Wageningen UR, Vis- en Schelpdierziektenlaboratorium)

See also IMARES, part of Wageningen, for research on marine environment, fishery activities, aquaculture and maritime sector.