In shrimp larval rearing, possible
contamination with bacteria or other pathogens can come from a number of
sources:
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| The most likely means of transmission (vector) within the hatchery is the activities of people. As such, the above 4 sources need to be controlled and strict measures need to be implemented to maintain hygiene within the hatchery. With the use of probiotics, the original bacteria that caused the problems is probably still present in the environment, so problems can still develop. Hygiene maintenance requires that the area, tanks, equipment and people are routinely sanitized. "Sanitize" means effective bactericidal treatment (bacterial control and reduction) using heat or chemicals (e.g. chlorine) for enough time to reduce the overall bacterial count, including pathogens, to a safe level on all contact surfaces such as tanks and equipment. The traditional, scientific approach was sanitization and antibiotic application. Sterile footbaths, UV treatment of water, the use of surgical gloves and so forth all are aimed at sanitization. |
| Once a week, we use chlorine (around 50 ppm) to sanitize (sterilise) every piece of equipment and all floors, and especially fill and sterilise all spawning tanks. This one-time sterilisation of mops, brooms, siphon pipes etc. seems very effective in reducing Vibrios or other bacterial problems. Afterwards, we keep using the probiotic in the larval rearing and problems diminish. Wherever there is moisture, biofilms will rapidly develop. In some cases this bacterial build-up will be detrimental to the shrimp larvae. The weekly sanitization routine reduces this problem. You will still get some bacterial problems, but your antibiotic use should decrease significantly, possibly completely. |
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E-mail Alken-Murray Corp: aqua@alken-murray.com E-mail author, Laurence Evans: web@ecotao.com | ||||||