Mosquitoes, Fish, Pools and Foreclosure

What do these four have in common? More than you might think.

July 14, 2008 — -- We're advised to eat things that are green and buy cars that are green. Green is the buzzword of today's world.

But nobody wants a green swimming pool.

As the foreclosure crisis deepens by the day, an unsightly and potentially deadly consequence of homes without owners are neglected swimming pools. An abandoned pool can become contaminated with algae within two weeks. Shortly after that, the mosquitoes follow … in the millions.

It's a mess far too pervasive to stave off without daily work with a skimmer and a dash of chlorine.

It's times like these that neighbors and homeowner associations turn to a 2-inch fish with a big appetite. Gambusia affinis, more commonly known as mosquito fish, have been used in this way since the 1920s. They are released into green pools in small batches of about 100, and they breed and eat hundreds of mosquito larvae a day.

"These fish are an awesome ally," said Jon Miller a 22-year veteran technician at the Orange County Vector Control District. "I've had to treat over 200 pools in the last three months and with these [fish] I don't need to come back."

The government agency -- which is charged with stopping the transmission of diseases spread by insects and animals -- abandoned its policy of using only pesticides when it became clear that foreclosed homes were sitting unoccupied for months rather than weeks. They still use chemical agents but only in small amounts, and they specifically target mosquitoes, leaving other aquatic life unaffected.

Mosquito fish have a life expectancy of more than two years and can survive with very little oxygen, making them the perfect long-term treatment for mosquitoes breeding in backyards.

Specialists say the only real problem with using mosquito fish in unnatural waterways like swimming pools is the public's lack of knowledge regarding them.

"It breaks my heart to come back to a pool we've just treated and see all the fish dead because somebody has used bleach thinking that they're helping," said Mike Hearst, director of communications at Orange County Vector Control

Luckily for Hearst, the supply of mosquito fish is plentiful. The amorous fish could put rabbits to shame by multiplying at an astounding rate. Hundreds can become thousands in a matter of weeks. Water hazards at golf courses are used as ideal breeding grounds throughout the county.

Green pools are not just an eyesore and mosquitoes not just a nuisance. According to figures from the Center for Disease Control and Prevention, the mosquito-transmitted West Nile virus has killed 1,068 Americans since 2002. The disease is spread when a mosquito feeds from an infected animal and then goes on to bite a human. With weakened immune systems, the very young and very old are most at risk, but Hearst said no one is impervious.

Because data also show that 80 percent of those bitten and infected with the virus never show any symptoms or become ill, the dangers of West Nile can go overlooked. But for those who are susceptible, the consequences can be dire.

"If people see a green pool, they need to report it to us and not attempt to treat it themselves," Hearst said. "I've seen formerly healthy 35-year-old men have to learn to walk and talk again. Few will know they ever had the disease, but a few will never forget they had it."

In California, vector control districts like the one in Orange County have numerous means of identifying which properties have pools posing a risk. They can use the Multiple Listing Service and pay a visit to any recently foreclosed homes or use a sheriff's helicopter to take pictures from the sky that clearly highlight green pools.

But the most effective source of information is the good old-fashioned nosey neighbor.

"I called the police last night [Wednesday] because I heard noises and thought someone was breaking in next door," said Anaheim, Calif., resident Bill Milo. "When I looked over the fence to see what was going on I saw the green pool and instantly thought 'mosquito,' so I called code enforcement."

The burglars turned out to be the former residents returning for their belongings, but Milo and his eagle eye are just what the authorities rely on.

"We need these calls so we can come to the property," Hearst said. "Some think that emptying the pool will solve the problem. But with the high water table in Orange County, the pools just rise up out of the ground and split if we drain and leave them."

With money tight and pools in constant need of attention, San Gabriel Valley Mosquito and Vector Control District's Alfonso Melgoza said it's the busiest he's been since starting out in the profession in the late 1990s.

"Maintenance is the first thing people let go when they're trying to save their homes," Melgoza said. "If they can't pay their loans they're not going to pay the pool guy. So that's where we come in."

Instead of mosquito fish, the valley district uses a thin layer of a basic oil specially refined for the pool can stifle the wiggling larvae within minutes before stalling them once and for all.

To avoid having his agency foot the bill for residents' willful neglect, Melgoza posts a notice on properties on his rounds and attempts to contact either the bank or the owner. If there is no response, then a public nuisance order is mailed with the threat of fines.

Melgoza said that some are more cooperative than others.

"If we track down the owner and it's a bank, then they'll nearly always do what they say, whether it's drain the pool or make sure it's maintained," Melgoza told ABC News. "But if it's a realtor, then it's 50-50 whether they help us." shows that there are currently 2,431 single-family homes in Los Angeles County with swimming pools that are foreclosed. This number more than doubles to 5,263 when preforeclosure homes are added, according to county records and research by Kate Middleton of San Gabriel Valley vector control.

With thousands more pools across California and other sunny states like Florida and Arizona -- all of which have been hit hard by the nation's housing slump -- it seems that the battle against backyard mosquitoes is going to be a long one.

Authorities are keen to stress that wearing repellant, making sure no bodies of water are left to stagnate and using window screens are the keys to success.

Calling vector control, they say, is also a far better solution than taking matters into one's own hands, no matter how tempting. Milo, the neighbor of the green pool in Anaheim, admitted that he'd considered his own approach before calling vector control.

"When I saw it," he said, "I was thinking of throwing a hand grenade in there."