Shellfish Breeding and Hatchery Management (2+1)

26.1.1 Disinfection and Disease Prevention

Generally there are lot of doubts on the need for disinfection and the process of disinfection. The following text will help in getting a fair understanding on this topic

What is Disinfection?

The technique or method of selectively controlling or removing organisms that enter into aquaculture system is called disinfection. In the process of disinfection, the unwanted microorganisms are removed from the water.

Why it is required in the hatchereis?

In hatcheries, the major input is the formulated and prepared feed for the breeders and larvae, which is purely organic in nature. This feed results in the production of fecal matter by the fishes. The uneaten feed is another fraction to add with the fecal matter offer good scope for the growth of microbes, as they are the principal feed for the heterotrophic bacteria. The nutrients released or leeched from the feed and fecal matter also encourage the growth of diverse microorganisms. In many instances these microbes turn to be pathogens causing or leading to disease outbreak in the population. Therefore it is very much essential to disinfect to reduce or remove the bacterial load in the culture water.

In practice, disinfection is commonly adopted in hatcheries as a separate treatment measure. Disinfection can be accomplished by using one or a combination of readily accepted methods. To minimize the outbreak and transmission of disease causing organisms and parasites, disinfection is becoming one of the promising methods in the super intensive aquaculture system.

Disinfection methods

Basically, 4 methods can disinfect the water. They are,

a. Heat disinfection,

b. Chlorination,

c. Ultraviolet irradiation &

d. Ozone treatment

The agent or chemical used for the disinfection process is referred as disinfectant. The effectiveness of a given disinfectant depends on some of the basic factors, viz.,

i. Contact time

ii. Temperature

iii. Turbidity

iv. Particulate concentration

v. Characteristics or type of the of the target organisms