Authorities in Vietnam are on guard to prevent illegal trading of shrimp broodstock, commercial shrimp products, and feeds from China that may spread the Decapod iridescent virus 1 (DIV1) to the country.
The Vietnamese Ministry of Agriculture and Rural Development said in a recent letter that DIV1 was first detected in 2014 and, since then, has spread throughout China. The virus was believed to have affected about a quarter of shrimp farming area in the Chinese province of Guangdong during an outbreak in February of this year, according to a statement from Vietnam’s General Department of Fisheries on 22 May.
DIV1 can infect various kinds of shrimp in different growth stages, and can also harm crayfish.
At present, the virus has not been detected in Vietnam, though the country shares more than 1,400 kilometers of a land border with China, with busy cross-border trading of agriculture and fisheries products.
The Vietnamese ministry, however, has called on the National Steering Committee against Smuggling, Trade Fraud, and Counterfeit Goods to take measures against the illegal cross-border trading of shrimp broodstock, commercial shrimp products, and feeds from China. The steering committee is headed by a deputy prime minister of Vietnam and has units in several border provinces.
The ministry also asked seven provinces that have borders with China to intensify checks against the illegal imports of shrimp and aquaculture feeds from China.
Director General of the Network of Aquaculture Centres in Asia-Pacific (NACA) Huang Jie said the virus can cause high mortality – above 80 percent – in whiteleg shrimp (P. vannamei) and giant river prawns (Macrobrachium rosenbergii) in particular. Symptoms of DIV1 infection in whiteleg shrimp include empty stomach and guts. A slight loss of color on the surface and section of the hepatopancreas, as well as a soft shell, is usually observed in partially infected shrimp, with one-third of infected individuals also showing slightly reddish bodies.
According to Global Aquaculture Alliance President George Chamberlain, the virus has serious implications for shrimp producers throughout Southeast Asia, especially considering new reports that it has been detected in wild monodon shrimp in the Indian Ocean, which is a major a source of broodstock for many regional operations.
Photo courtesy of Chuchai/Shutterstock
