Bair Island restoration would reduce biters' breeding pools

Bay water will flood larva-friendly mud flats

By Justin Jouvenal


Monday, June 16, 2003 - MILLIONS and millions of mosquitoes. Without the dogged efforts of the County Mosquito Abatement District, they would rise like a malevolent cloud from this 3,000-acre chain of old salt ponds looking for one thing -- blood. The quest could send them buzzing for 20 miles in search of prey or, in other words, to nearly every swimming pool, backyard barbecue or tennis court in the County. The stagnant waters of these old ponds are the largest breeding ground for mosquitoes in the County, but this decades old sanctuary for a summer nuisance could soon be wiped out. The state Department of Fish and Game is studying a $22 million plan to restore the ponds to a tidal salt marsh, which would flood the mud flats and standing pools of rain water the mosquitoes lay their eggs in. "A small area the size of a 55-gallon drum can produce thousands and thousands of mosquitoes. Now look at the vastness of this place," said James Counts, a field-operations supervisor for the district. Counts looked out over a 525-acre stretch of Bair Island Friday. It's a flat expanse punctuated by pickle weed, shallow dirt basins that fill with rain water, and dikes that hold back the Bay. The island is cut into three pieces by narrow, winding sloughs. It was originally grazing land in the early 1900s. Later the island was bought by the Leslie Salt Company, which used it to evaporate salt until the 1960s. The island has been part of the Don Edwards San Francisco Bay National Wildlife Refuge since 1998. Reducing the numbers of a pesky insect has a health benefit. Several of the mosquito species that breed on Bair Island could potentially carry West Nile Virus. District biologists expect the disease to arrive in the County this summer.

Man vs. insect The district devotes 600 man-hours a year to battling mosquitoes on the island. Teams trudge through knee-deep muck to treat the mud flats and catch ponds that are home to mosquito larvae.

Larger breeding grounds are tackled with a helicopter that sprays the formula from two 30-foot booms. The area requires constant vigilance to kill the mosquitoes before they take wing.

Different species hatch at different times of the year and the larva stage can be as short as five days. Mosquito eggs can lie dormant in mud for up to 10 years before hatching.

In 1996, a spring helicopter crash prevented the district from spraying Bair Island from the air for a week. The District received 200 calls a day for two weeks after, as a swarm of mosquitoes descended on the southern half of the County.

"People in San Mateo, Redwood City and San Carlos were getting eaten alive," Counts said. "We're hoping that the restoration takes care of 75 percent of the mosquito problem."

A draft environmental review of the project should be released this fall. The actual restoration will take place in phases over the next five to six years.

This fall, the state Department of Fish and Game will begin uprooting an invasive species known as smooth cordgrass. The East Coast import has gained a foothold on Bair Island and could choke the restored tidal salt marsh if it is not removed.

The department will then restore the outer, middle and inner portions of the island in succession. The process involves breaking the dikes to let Bay water flow through the salt ponds.

Saving species The primary goal of the restoration is to provide a habitat for two endangered species native to the Bay: the California Clapper Rail and the Salt Marsh Harvest Mouse. There are fewer than 1,000 of the clapper rail birds in existence.

"This is going to be one of the largest restoration projects for endangered species on the Bay," said Clyde Morris, manager of the Don Edwards wildlife refuge.

But the project that is a centerpiece of Bay restoration nearly became the next Foster City. The Redwood City City Council approved a plan in the early '80s to develop the island into a residential and office complex known as "South Shores."

The move drew the ire of some local residents who mounted a grassroots campaign to stop the development. In 1982, Redwood City residents passed Measure O putting the plans off. It won by a scant 40 votes.

"These are virgin wetlands," said Ralph Nobles, the Redwood City resident who led the campaign. "They clean the air, clean the water and provide shelter for animals."

The Bair Island restoration could be the last great battle in a long war between the County and mosquitoes -- a war which often went the mosquitoes' way.

County bites back In the early 1900s, the ferocity of County insects regularly drove residents from the area. The problem culminated in 1912 with a mosquito D-Day of sorts.

Several levees broke in the County that year because of poor maintenance, creating prime breeding pools for the pests. When summer rolled around, the mosquitoes descended on Peninsula residents in swarms.

One newspaper account said the mosquitoes were so thick "life was unbearable." The Peninsula Hotel, an upscale resort in San Mateo, was shuttered and property values began to drop.

At that point, three Peninsula cities decided to bite back. San Mateo, Burlingame and Hillsborough formed a mosquito control committee to repair the levees and fight the mosquitoes with an unusual tool -- kerosene.

The fuel was poured into standing pools, where it formed an oily slick that suffocated mosquito larvae. It was effective, but extremely destructive for the environment.

By 1930, humans started to get the upper hand on mosquitoes through yearly abatement. The increasing pace of development on the Peninsula also robbed the mosquito of breeding grounds during the '30s and '40s.

These days, the war is waged with high-tech weapons, from hovercraft to helicopters. But some things haven't changed.

"You're sure tired at the end of the day," Counts said.

If residents have problems with mosquitoes, call the County Mosquito Abatement District at 650-344-8592. The state Health Department is collecting dead crows, ravens and blue jays to track the spread of West Nile Virus. If you find one, call 877-WNV-BIRD.

San Mateo County Times