County Teams with City to Breed Mosquito-eating Fish

A new cooperative effort between the County and the City of San Diego is downright fishy. 

The City is allowing the County’s Department of Environmental Health to use a 290,000 gallon pond at its San Pasqual Water Reclamation Plant in North County as a breeding ground for mosquito fish (gambusia affinis). 

Federico (Freddy) Ruiz, Vector Control Technician Aide and Jack Chino, Vector Control Technician II, placed about 20,000 live fish in the new pond.

The diminutive fish, which feast on mosquito larvae, are maintained by DEH as part of its efforts to control West Nile virus. WNV is spread through bites from infected mosquitoes, so by making the fish available to County residents for backyard ponds or swimming pools that are no longer maintained, the fish help keep the mosquito population in check.

For years, DEH has been buying mosquito fish from a breeder or harvesting them from the wild. 

“Purchasing the fish meant not only incurring the cost of the fish, but also of transporting them from Bakersfield,” said Vector Control Program Manager Kerry McNeill.

“And with wild harvesting there was the risk of introducing disease.”

The ball got rolling on the project in June, when DEH approached the City about the possibility of using the site.  The Department of General Services assisted with securing a Right of Entry Permit, Public Works loaned the hose needed to fill the pond, and last week DEH stocked it with 20,000 fish.  In exchange for use of the pond, the County will distribute fish to residents of the region’s cities as well as the unincorporated areas.  The fish are expected to start breeding in the spring, coinciding with the beginning of the mosquito season.

“This new program will save money and provide a reliable source of fish for the residents of San Diego County,” said DEH Director Gary Erbeck. 

"It’s exciting.”