Tilapia and Pathogens
Tilapia has always performed exceptionally well in recirculation systems and has long been a popular fish for use in aquaponics. Unfortunately so have disease-producing microorganisms called pathogens.
The introduction of a pathogen into a recirculating system can be quite destructive as eradication is almost impossible. Even after the removal process which consists of depopulating the system; purifying it; and them repopulating it, some pathogens may not have been destroyed. Even with 100% success the outcome can be disastrous to farmers who are depending on their tilapia farm for revenue.
Pathogens can reach clean recirculating systems by the introduction of contaminated young fish bought from hatcheries. Another method of spreading disease is by water from contaminated facilities coming onto the property. Pathogens can be distributed on a live-hauler’s dip net, on the soles of shoes or boots, or on someone’s hands. The warm, nutrient-rich water provides just the atmosphere for pathogens to reproduce quickly.
Some ways to reduce the risk of disease are: (1) buy clean fish, (2) question the provider about the health of the fish, (3) be sure the fish are maintained nutritionally, (4) do not overcrowd the tanks, (5) have clean hands, (6) be sure live-haul trucks are clean and (7) limit visitors.
Tilapias Environment It is important to screen your fish regularly to become familiar with their normal look and habits, paying special attention to new fish. Through familiarity you may be better able to detect parasitical problems while at an early stage.
In the best of conditions a healthy tilapia is less likely to be attacked by parasites. Healthy fish are more inclined to survive an infestation and handle any treatment. It is very vital to the survival of the fish that they are not exposed to elements that can endanger their immune systems. Hazard conditions include improper water chemistry and sudden environmental changes. The water must be checked on a regular basis for waste such as ammonia, nitrite, nitrate; for temperature content and oxygen content. If any changes are necessary, they must be done gradually so that the fish may adapt.
Overcrowded Conditions Though filling your tanks(s) with as much tilapia as it can hold sounds like a fantastic thing to do, overcrowding will put them at risk for parasite attacks. Overcrowded conditions promote stress which breaks down the immune system making them worthy hosts for parasites. You could lose a lot of fish due to overcrowding. In a densely stocked tank parasites, and their offspring reproduce quickly because they can easily find suitable hosts.
Tilapia Diets Your tilapia should be given a diet containing adequate amounts of all the essential nutrients in order for the immune system to remain strong. On an inadequate diet the fish are more vulnerable to parasitical attacks. This is particularly true for young fish.
Preventing Infestation If you maintain multiple units it is advisable to use separate sets of equipment and do not allow water to flow from one unit to another. In doing so disease will be contained in the affected unit rather than spreading back and forth between units.
Dangerous Stages Handling, transportation, moderation of water chemistry, even seasonal changes can generate stressful situations for fish, weakening their immune systems and putting them at risk for parasitical attacks. Markedly susceptible to protozoan parasites are fingerlings and juvenile tilapia. Younger fish are more at risk of infection than mature fish.
Tilapia has constantly functioned very well in recirculation systems and has long been a popular fish for usage in aquaponics. Unfortunately so have disease-producing microorganisms called pathogens. You just should be aware that tilapia does have its vulnerabilities.. Unique version for reprint here: Tilapia and Pathogens.
