The Florida Department of Health in Orange County (DOH-Orange) has enlisted the assistance of mosquito fish in the fight against mosquitoes. Known as Gambusia holbrooki in the scientific world, their common name is the eastern mosquito fish.  This native Florida aquatic species has been the focus of a DOH-Orange Environmental Health Community Initiative.  Introduced into abandoned green swimming pools, the mosquito fish live up to their name by feeding on mosquito larvae. 

DOH-Orange’s Zoonosis team deployed the first 50 fish into a local green pool in September 2016. Signs were also posted on site to inform the public that mosquito fish were hard at work on the property. After a few days, Zoonosis team members returned and verified the green pool was free of mosquito larvae. Furthermore, staff noted the mosquito fish had reproduced, thus ensuring continued elimination of future mosquitoes.

“Initially, staff were putting ‘mosquito dunks’ into abandoned green pools to kill the mosquito larvae,” said Kari Lara-Murabito, the Zoonosis team leader.  “However, that process requires a staff member to go out to each pool once a month to re-apply the dunks.” 

The concept of using mosquito fish as a mosquito biological control agent is not new. Mosquito control districts and backyard water garden enthusiasts have utilized the species in untreated/abandoned swimming pools as well as artificial ponds, ditches and swales. 

However, what is new is a public health department using this method. Employing the mosquito fish not only reduces mosquitoes, but also frees up staff to complete other tasks and saves money spent on mosquito dunks. 

Success of the project has been more than promising. Today, the fish have been deployed in eight pools. Two of which were at the request of property-owners because they were unable to maintain the pool properly.

According to Florida Statute 386.041, the department is authorized to investigate any condition determined to constitute a sanitary nuisance and take action to abate the said condition. Anything that is capable of breeding mosquitoes, like abandoned pools, is a sanitary nuisance. After investigating any valid complaint, staff sends notices to property owners to abate the green pool nuisance. If there is no response, DOH-Orange staff begins the abatement process. 

To inquiry about the project, contact DOH-Orange Environmental Health at 407-858-1497. 

Drain and Cover

Mosquito fish are just one element of an overall approach to combating mosquitoes. DOH-Orange encourages the public to utilize the “Drain and Cover” approach to fighting mosquitoes. Routinely drain any standing water in and around your home. Wear long sleeves and long pants when you go outside, and apply insect repellent to bare skin and clothing. Use netting to protect children younger than 2 months. Finally, repair broken screening on windows, doors, porches and patios.