for National Geographic News
When floodwaters rushed into New Orleans after Hurricane Katrina last August, they filled thousands of swimming pools with fish, pollution, algaeeven the corpses of dead animals.
Experts say the pools may now harbor another hazardmosquitoes.
"We have thousands of pools. We know a bunch of them are breeding mosquitoes, and there's the potential for West Nile virus," said Steve Sackett, an entomologist with the New Orleans Mosquito and Termite Control Board (NOMTCB).
"We're concerned with pest problems, but we're really concerned with disease transmission."
(See National Geographic magazine's "New Orleans: Home No More.")
Using real estate databases, aerial photography, and old-fashioned legwork, Sackett and his team have identified more than 5,000 at-risk pools in the city.
Their research reveals that some abandoned pools harbor not only saltwater fish but mosquito species new to the city, including two of the main carriers of West Nile virus.
"One of the things that we've seen is a change in the mosquito species that were living in the pools. Where they came from I don't know, but we had quite a few of these larvae swimming in some pools," Sackett said.
So far this year, drought has helped prevent a mosquito outbreak in New Orleans. But pools remain a serious health concern, as the summer mosquito breeding season sets in.
To battle the bugs, Sackett has turned to a natural predatorthe western mosquito fish (Gambusia affinis).
The fish can eat up to a hundred mosquito larvae a day. And unlike commercial pesticides, the prolific breeders can replenish themselves.
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