September 30, 2008

 

 

Scientists have warned aquaculture farmers not to raise vannamei shrimps without proper planning since the country is not yet prepared for any diseases they might acquire.

 

Last month, farmers in Dong Hoa District of Phu Yen Province discovered their vannamei shrimps were covered with red spots.

 

The disease then caused some of the shrimps to lose their appetite and die while the rest stopped growing.

 

Initial tests revealed that the water on the farms was polluted and the quality of breeding low.

 

At present, little is known of the shrimp's resistance to disease.

 

Ly Vinh Phuoc of the Agriculture Expansion Centre of HCM City said there is much uncertainty surrounding the vannamei shrimps and without proper preparation and control, epidemics may recur to cause huge damage, as in the case of the black tiger prawn.

 

Le Ngoc Phuoc, vice chairman of the Vietnam Association of Fishing, said countries that had previously raised vannamei shrimps, such as Thailand and India, were planning to return to black tiger shrimps.

 

Vannamei shrimps are now being raised in many southern provinces thanks to their high profitability and adaptability, but officials have warned that farmers should not rush to abandon black tiger prawns.

 

In recent years, black tiger prawn farms in southern provinces have been experiencing epidemics and farmers have suffered major losses.

 

Many farm owners then shifted to vannamei shrimps after initial models showed that this variety brings a higher profit.

 

Currently, out of a total 600,000 hectares used for shrimp farming in the country, 14,000 hectares, or 2.3 percent, is used for vannamei shrimp breeding, according to the Department of Aquaculture,

 

Vannamei shrimps seem to be growing well in Ho Chi Minh City, according to Nguyen Thanh Luong, head of the Department of Economy of Can Gio District in HCM City.

 

Farmers can grow and harvest the shrimps in as little as two-and-a-half months, with each tonne bringing VND2-3 million (US$ 176), a higher profit than black tiger prawns.

 

Deputy Minister of Agriculture and Rural Development Nguyen Viet Thang said at a conference that developing vannamei shrimp farming would have to be carried out at the same time as the search to treat black tiger prawn diseases.

 

Thang said each province should gather farmers who raise vannamei shrimp into a group and set out certain criteria, techniques for breeding and find a stable consumption market.

 

He also emphasised the need to plan a breeding area to prevent spontaneous reproduction.

 

Meanwhile, reports from provinces reveal that more than 75,000ha of black tiger prawn or 21 percent of the total area of shrimp breeding in the country - has been affected by diseases, and about 1.8 billion breeding prawns have died.

 

Some provinces can hardly cope with the costs of quarantine. For example, in Khanh Hoa Province, which focuses on producing breeding prawns only one third of the shrimps is quarantined due to the lack of resources.

 

Quarantine costs are high. For example, with 7 billion breeding prawn, farmers would have to pay VND7 billion (US$411,000).

 

Though there are subsidies to farmers to cut quarantine costs, this is often not enough and many farmers avoid quarantine altogether, leading to epidemics.

 

Officials suggested amendments to be made to policies to mitigate quarantine costs in order to gain control of epidemic diseases which affect black tiger prawns, arguing that the prawn species should not be abandoned and a diversification of aquaculture products should be considered.