TRANSCRIPT - Bunjonk Nissapavanich
Nissapavanich is a Hatchery Owner and Shrimp Farmer at
the Bunjonk Farm in Amphur Ban Poh, Cha Choung Sao Province,
How do you clean your bottom soil?
pump air and water to the bottom soil and this aerates the sediment.
By this technique, the water turns turbid and we can control the
pH of the water.
You have to do this everyday, right?
we have to do it everyday. The bottom soil will be clean and shrimp
will be healthy.
Does it cause danger to the shrimp?
the shrimp can swim away. The shrimp pond uses a biological process
for controlling the water. This is the way we treat the bottom
sediment. Usually, there is a lot of organic matter accumulated
in the shrimp pond. This sediment is composed of organic matter,
hydrogen sulfide, which causes the problem to the shrimp. Shrimp
like to lie down on bottom sediment during periods of temperature
changes. If the sediment is not clean, shrimp will stress and
become fragile to the disease. That’s why we have to treat
we pump the air and water to mix with the sediment, hydrogen sulfide
will turn to sulfuric acid which then reacts with calcium to become
gypsum. Gypsum is neutral and helps to buffer the water and control
the pH of the water. By this method, shrimp will stay healthy
because the toxic gases are neutralized. The suspension of sediment
decreases the photosynthesis process and pH will not get too high
in the afternoon. If photosynthesis is too strong, afternoon pH
will be high and shrimp will stress.
After you use this technique, do you have problems with
we have no disease problem. The growth rate is normal and survival
rate is 80%.
What do you think about the natural water? Is it still
suitable for shrimp culture?
the years 1957-1967, shrimp culture was still an extensive culture
that relied on natural water. There was no organic matter. The
water was good; there was no sewage or any industrial pollution.
Then in 1987, the shrimp culture system changed to intensive culture.
There was more organic matter, more chemicals used, and more sewage
and industrial pollution. That is why we had to change from an
open system to a closed system. With high density in a closed
system and a lack of appropriated water treatment, it finally
caused failure in shrimp culture. It was the high organic matter
and the pollution from community and industries.
Your system is natural, right?
Yes, it is a natural treated system. They already had one in nature,
but when we put too much organic matter in it, it caused imbalance
in nature. Some organisms disappeared. That is the reason why
we have to rebalance nature again.
Why don’t shrimp farmers in the southern part of
Thailand, who have disease problems, use this system?
reason why people do not use this system is because they want
to use 100 % of their area for shrimp production. If they have
to change to the natural system, they think it will increase their
operation costs and complicate and decrease their profit. But
it is not true.
What is the density you use here compared with the others?
use 30 pieces per square meter; generally, people use 60 to 100
pieces per square meter. They just think that if they raise 30
pieces per square meter, they will gain 1 ton per rai, so if they
double the density they think they will double production. But
they forget that shrimp culture and mathematics is very different.
Could you tell us about your name and where we are now?
am at the Bunjonk Farm, the address is 59 Moo3, Tumbol Bang Chorn,
Amphur Ban Poh, Cha Choung Sao province.
What is your opinion about the future of shrimp culture?
Do you think people will turn to use the natural system?
farmers both in Thailand and other countries encounter disease
problems. Some can’t raise shrimp anymore, while the natural
system has no problem. I think in the future all the shrimp farmers
will turn to use this system.
If there are foreign markets for those who raise high
quality shrimp, do you think it will help promote this system
there are markets that require shrimp culture from natural systems
that avoid using chemicals or anything that’s toxic to the
consumers, the demand from the market will push farmers to change
to this system faster.
Why does low density culture have better chance to survive?
we raise shrimp at 30 pieces/m2 compared with those who raise
60 pieces/m2, the lower densities cause less waste, are easier
to manage, and the shrimp are more likely to be healthy and grow
How does low density culture affect the price of shrimp
Every pond is limited in its capacity, if you put many shrimp
into the pond you get the same production but with a smaller size
of shrimp production compared with when you put lower density
in which creates bigger shrimp. Bigger shrimp get a better price
that affects a lot of your cost and benefits the crop.
What do you think about your system compared to the others?
think every system has the same target: to produce quality shrimp.
But the ways to approach the target may be different. It is difficult
to say which one is better, but the lower cost should be the good
index. The one that produces with the lowest cost will be the
one who survives.