Shrimp seed stock devastated by disease
INDIA
March 12, 2003
Shrimp
seeds production has dropped by at least 50 per cent, according to industry
estimates. This is apparently due to a lack of disease-free brood stock, and
it has sent seed prices soaring, reports Hindu Business Line.
The
subsequent lack of quality shrimp has affected the production of scampi (Macrobrachium
rosenbergii) and black tiger seeds (Penaeus monodon) from hatcheries,
according to industry sources in Chennai.
Concerns
have been raised that the drop in seed availability will hamper the stocking
at farms and production, especially the supplies of scampi, later this year.
If
scampi production is affected, it is estimated that losses could occur of up
to INR 5,000 million. Scampi brooders are usually picked up at the farms,
but it is believed that the disease has spread from the farms, so hatcheries
are using brooders caught in the wild. Farmers believe that these seeds are
of better quality.
The
black tiger brood stock is traditionally caught from the sea, and can be a
lucrative catch. Fishermen have been known to receive up to INR 40,000 per
shrimp during the peak season from the hatcheries.
Unfortunately,
this shrimp has been affected with viral disease, known as white spot or MBV.
Black tiger has been cultivated for more than 15 years, and the crop has,
from time to time, been decimated by viral outbreaks at the hatchery and
farms.
Sampi
is a relatively new species to commercial cultivation and is now facing a
scourge. The disease, which has yet to be identified, broke out in farms
last season and production has subsequently dropped drastically.
Large
amounts of brood stock are infected and are therefore unsuitable for
spawning. The hatcheries are likely to produce just half of the output
achieved last year, when 6-7 billion seeds were produced.
Farmers
are doing what they can to overcome the problem. PCR (polymerase chain
reaction) laboratories are being used to check for the presence of viral
infection. According to hatchery sources, farmers observe at the hatcheries
to keep track of the seed development from the egg stage through to the post
larval stage when they are purchased. Samples are analysed regularly, and
purchase only takes place when the farmer is assured the seed is disease
free.
By
FIS Asia http://www.fis.com/
(From
Aquaculture Newsclips, e-mail: dave.conley@sympatico.ca)