Biosecurity in SPF shrimp hatcheries

Prevention of disease introduction requires comprehensive analysis and management of aU aspects of the facUity design and operations. A critical 

It is often said that the three most important factors in real estate valuation are location, location and location. This is also true for an SPF hatchery. The first step in an SPF hatchery biosecurity plan is site selection. A shrimp hatchery requires abundant supplies of high quality sea water. High quality sea water is not polluted with industrial or urban pollutants and is far from other shrimp farming activities. In some countries where a successful hatchery develops others soon follow, and this is a negative factor in SPF hatchery site selection. An extreme example of this can be found in Wenchang, China, a small coastal town on Hainan Island. More than 600 shrimp hatcheries operate in a coastal area less than 50 km in length. It is very difficult for a hatchery operator to maintain good biosecurity in such a location. 

Incoming sea water is the most likely vector for introducing a pathogen to an SPF hatchery. If the hatchery is located in a shrimp-farming region (most 

In large hatcheries where massive quantities (up to 3000 mVday) of sea water are required, the sea water from the well is usually first held in a land-based reservoir system. In some cares, the large reservoirs maybe lined ponds up to 2000 m in area. Such a reservoir must be lined with plastic or other pond liner material to prevent introduction of contaminants from soil. They should be well aerated so water and disinfectants can be thoroughly mixed. This is often done with a paddlewheel or aspirator aerator like those used in grow-out ponds. The reservoir ponds should be surrounded by low fencing to keep walking crabs out of the reservoir. Crabs are well-known vectors of white spot syndrome virus (WSSV). 

At the reservoir stage, sea water has been filtered by the natural filtration system of the well so few or no particles should be present. If significant particles or sand are entrained in the sea water, a filtering system must be added to the system to keep the particles out of the reservoir. A large bag-type filter of 250 pm or less can be used. 

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