Saturday, June 28, 2008

last updated: February 25, 2008 01:59:04 AM

A tiny invader has found its way into Northern California that could have a devastating impact on our water system -- from San Luis Reservoir to New Melones to delta pumps and water treatment plants. This invader is hard to kill, breeds fast and spreads quickly. In infested areas, damage to pipes, pumps, piers and other structures has been measured in the billions of dollars. It even damages boat motors.

The zebra mussel -- a freshwater mollusk about a half-inch long -- was found in late January in San Justo Reservoir south of Hollister. San Justo is small, getting its water from San Luis Reservoir -- the real concern. Through the attached O'Neill Forebay, San Luis also sends water into the State Water Project, which supplies the rest of our valley. Zebra mussels in San Justo is an emergency; zebra mussels in San Luis would be a crisis.

"It's a significant potential impact to the state of California," said Alexia Retallack of the Department of Fish & Game.

How significant? Zebras got to the Great Lakes by the early 1990s and were followed by a sister species called quagga a short time later; after six years, damage to infrastructure was put at $3.1 billion, total costs at $5.1 billion.

A single mussel can spawn 40,000 eggs. They turn into larvae that then become "villagers," which attach and congregate by the hundreds of thousands on any smooth structure, then begin to spawn. In the Great Lakes region, zebras and quaggas spawn twice a year. But in warmer water, like ours, a mussel can spawn up to six times a year -- meaning the threat grows exponentially.

They travel by boat. Larvae attach to hulls, fenders and lines and can live in half a cup of water -- so bait boxes and even small puddles can carry them. As anglers move from lake to lake, so do the mussels. They can live as long as five days out of water, but they don't like summer heat.

The lower Colorado River was first found to be carrying quagga mussels a little more than a year ago. Now, around 20 Southern California reservoirs are infested. Finding adult mussels 350 miles north was startling. Guessed to be a year old, they had plenty of time to reproduce. That's why State Department of Fish & Game divers checked San Luis Reservoir.

"Quagga and zebra mussels have the same impacts -- clogging water pipes, killing off the fishery by removing the phytoplankton," said Retallack, who said quagga often follow zebra into an environment. "When you get the mussels, the water gets really clear, but that lets sunlight to the bottom of the lake and vegetation grows, which causes oxygen deprivation. Then you get fish kills."

Both types of mussels also carry botulism, putting shorebirds and other wildlife at risk.

The most expensive damage is caused by their concentration on equipment, piers, pipes, pumps or anything smooth. In the Great Lakes region, they have clogged intake pipes 3 feet wide and shut down entire water systems. They have been found from Ohio to the Mississippi River.

East Bay Municipal Utilities District, which operates Camanche and Pardee reservoirs east of Lodi, isn't taking any chances. It will "severely restrict" boating in all its reservoirs this year. No boats from out of state, or licensed in San Benito or Santa Clara counties or in any Southern California county, will be allowed in East Bay MUD reservoirs. Of 1,000 boats trying to launch last weekend, 30 were turned away. Every boat was inspected before it was allowed to launch.

This is not an overreaction. Fish & Game has trained 700 inspectors and has deployed five mussel-sniffing dogs with six more to join them soon. One will be assigned to Stockton.

Pre-launch boat inspections are important, but so is education.

Neither mussel likes chlorine, so there is little threat to drinking water. Both types can be killed with high-pressure flows of at least 140 degrees. Still, the best defense is to keep the mussels out, meaning boaters and anglers must understand the risks and take precautions.

"Don't take a chance on losing your fishery," DFG's Retallack said. "You don't want to have it closed because you brought mussels in."

Carol Russell, director of Don Pedro Recreation Agency, is keenly aware of the threat. "I'm watching what is going on at San Luis and looking at it from an enforcement standpoint and what steps would be involved in ... keeping certain vessels out of the water."

To act, she needs direction from the reservoir's owners -- the Turlock and Modesto irrigation districts. They should be considering inspectors at boat launches and high-pressure washing systems.

The Bureau of Reclamation partners with the state to operate San Luis Reservoir and runs New Melones on the Stanislaus River. It is "working very closely with the DFG ... to see what's (in San Luis), how long it's been there and how we can keep it there," bureau spokesman Jeff McCracken said. His agency, too, should be considering preventative measures at New Melones.

"Water districts will have to start implementing plans to prevent them from clogging their pipes," Retallack said. "The irrigation districts will have to look at something similar ... to keep water flowing to farmers."

The invaders are here; it's time to act.

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