Written by: nicholas davies
A few small mangrove fish (Anaphius dispar) were collected from the mangrove area, north of Garden Residential District, and kept in a jar with mosquito larvae overnight to test if fish will feed on larvae.
After finding successful results on the short test, more small mangrove fish were collected and released in Lake 4, 5a, and 5b on June 23, 2020. The weekly monitoring of lakes continued as routine to test the water for mosquito larvae and the adaptation of fish to new their environment. No larvicides (Bacillus thuringiensis) had been applied to the lakes since June 23.
Finding the lakes and the stream negative from mosquito larvae during the last 11 weeks of inspection is a sign that fish released on those lakes may have helped in the control of mosquito breeding. However, it would be confirmed only by the end of the year during the peak of mosquito season, if fish introduced will successfully control the mosquito breeding, without the use of any biocides.
This generates savings of an average of ~ 37 kg of Vectobac WDG (Bacillus thuringiensis: Bti) in one year. This action has proved 100% successful.