Breeding fish to eat larvae not always suitable

Reply from NEA, Straits Times Forum 22 Feb 08;

WE REFER to the letter, 'Breed fish that devour mozzie larvae' (Feb 13).

Using natural predators has always been part of the World Health Organisation's (WHO) integrated vector management strategy which the National Environment Agency (NEA) supports.

In Singapore, such natural predators like the Gambusia holbrooki fish (also known as Gambusia affinis or the mosquito-fish) are already commonly found in our rural streams, canals, drains, ponds and reservoirs.

The Tilapia is another fish present in our water bodies, which also helps to remove mosquito larvae. There is also a common understanding that the Gambusia helps to remove mosquito larvae along the edges of the water bodies that cannot be reached easily by the larger Tilapia.

While the use of fish as a natural predator is suitable for large water bodies, it is not suitable for small pockets of stagnant water.

Mosquitoes can breed in a drop of stagnant water as small as the size of a 20-cent coin. NEA's primary strategy for mosquito control is to reduce and remove any potential mosquito breeding sites. Source reduction is the most effective way to control mosquitoes.

We urge everyone to prevent Aedes mosquito breeding by removing all stagnant water at home. Dengue or chikungunya can be made less of a threat if everyone takes steps to prevent mosquito breeding. This is the most effective 'weapon' in our fight against mosquito-borne diseases.

We thank your reader for the suggestion and appreciate his concern.

S. Satish Appoo
Director, Environmental Health Department
National Environment Agency