INVASIVE SPECIES TAKING OVER CALIFORNIA WATERS

Tiny mussels pose huge threat to county’s lakes

If pipe-choking, poison-discharging zebra and quagga species surface in reservoirs, officials could close the waters — a blow to recreational users and to county coffers

By Bill Morem

These zebra mussels were found in the San Justo Reservoir in San Benito County. PHOTO COURTESY OF THE CALIFORNIA DEPARTMENT OF FISH AND GAME

Click any image to enlarge.

Mussels’ toxic effects travel up food chain

Besides choking water systems, mussels can starve a lake or reservoir of its native stock.

First, they target the zooplankton and phytoplankton that’s the base food for small fish, explains Alexia Retallack, a spokeswoman for the Department of Fish and Game.

As bivalves, they filter the water of its plankton and suck in and store toxins such as PCBs up to 300,000 times greater than their surrounding environment. The mussels then discharge this toxic-concentrated waste in mucous- coated pellets called pseudofeces.

The pellets work their way up the food chain and poison untold numbers of animals in the process.

HOW BOATERS CAN STEM THE SPREAD OF INVASIVE MUSSELS

• Inspect all exposed surfaces of boats, trailers and vehicles. Small mussels feel like sandpaper to the touch.

• Use a high-pressure hose, preferably with hot water, to wash down all watercraft, whether it’s a boat, personal watercraft or windsurfing board.

• Remove all plants and animal materials from boats and leave them in a trash can — that includes bait.

• Drain all water and dry all surfaces.

• Drain and dry the lower outboard unit; run the engine for five to 10 seconds once on the trailer.

• Clean and dry all live-wells; empty and dry any buckets.

• Wait five days — and keep the craft dry — between launches into different bodies of water.

WHAT TO LOOK FOR

Zebra and quagga mussels are triangular and have dark and light bands. They’re relatively small, from microscopic to fingernail size for the quagga; up to two inches for the zebra.

— California Department of Fish and Game

California’s reservoirs and lakes are under siege by an invasive species that’s been migrating west after being brought to the Upper Midwest from Ukraine.

The pernicious little animals, from microscopic to 2 inches in length, are zebra and quagga mussels, believed to have hitched a ride to the Great Lakes in the blown bilge water of an Eastern European freighter in the mid-1980s.

The mussels have cost public utilities in the Great Lakes region billions of dollars in damage to water delivery systems, costs that are then shouldered by ratepayers.

If the mussels were to establish a beach head in this county, officials may close lakes — which would cost the county thousands of dollars in recreational income, not to mention the anger that it would cause in the fishing, boating and windsurfing communities.

“They pose a threat anywhere,” said John Hollenbeck, project manager of the $173 million Nacimiento pipeline project. “If they got into Nacimiento, we couldn’t get them out.”

That’s the thinking that led Ventura County’s Casitas Municipal Water Board on March 4 to close one of the top three bass fishing lakes in the nation to outside boaters. (Boats stored at the lake, as well as marina rentals, can still get out on the water.)

The water officials feared that if the mussels got a foothold in the lake, it could financially ruin the district.

Santa Barbara County decided Tuesday to wait two weeks before deciding to follow Ventura’s lead or leave Cachuma Lake open to outside boaters. San Luis Obispo County has yet to schedule any meetings on the possible mussel invasion of its lakes and streams.

With the zebra capable of spawning anywhere from 30,000 to 100,000 offspring a year—and the quagga up to a million a year—an infestation has the capacity to “completely cripple any water system,” Hollenbeck said.

The animals grow in such thick masses that they’d first completely choke the lake screens on the water system’s intake pipe, he adds. Those would have to be cleaned regularly.

“If we get them in the main pipe,” he explains, “that increases friction of the water moving through the pipe; that means a need for larger pumps to push the water. Smaller pipes — from 3 to 4 inches in diameter — will be completely shut tight and have to be replaced.”

Don’t move a mussel

In their larval stage, these mussels are adept little hitchhikers. They like nothing more than to attach themselves to hard surfaces like boat hulls. From there, they can migrate into a boat’s motor and cooling system, bait wells, trailers and even bumpers of trucks that back into lakes for launching.

And that’s why after zebra mussels were found in San Justo Reservoir in San Benito County a month ago, the reservoir was closed to public boating.

Endangered recreation?

Lake closings trouble Pete Jenny, manager of the San Luis Obispo County Parks Division, which oversees boating and camping at Lopez and Santa Margarita lakes.

“As recreation providers, we’re concerned,” he explained. “So we’re trying methods of education. We have fliers at the lakes, marinas and launch ramps, telling people what to look for. We’re doing spot inspections, but we don’t have the resources to go over every boat.”

Jenny’s concern is if the invaders are found at either or both of the lakes, the county Public Works Department — which oversees domestic water production for Lopez and Margarita—could close them to recreational use.

Such a move would be a recreational and financial hit to the county parks program: Santa Margarita brings in about $50,000 a year in launch fees and annual passes with more than 4,000 launches per year.

Lopez draws an average of 450,000 visitors a year, with about 7,500 annual launches that run the gamut of boats, personal watercraft, wind surfers and canoes. When those launches are combined with the 550 people who buy passes for unlimited launches, annual revenue there totals about $95,000.

The impact of having to close Lopez “would be huge to us,” Jenny said. “And imagine the impact on local sporting goods, from selling bait to boats to rods and reels.”

Maintenance or prevention?

Paavo Ogren is the county’s top engineer of Public Works. As such, he oversees water supplies at Lopez and Margarita. He attended a state Department of Water Resources conference on mussels about six months ago and left with a sense of wary resignation.

“We weren’t given a lot of optimism at the conference,” he recalled. “Preventive programs have been attempted; it’s been limited—and usually means delaying the infestation.

“Is there any reason to believe we can be more successful than others who have tried prevention?” he asked. “Probably not. It’s going to be a maintenance program; it’s just a matter of time.”

Fish and Game spokeswoman Alexia Retallack doesn’t agree. As part of an educational blitz, her agency sent out mussel educational material to all of the state’s registered boaters, in addition to about 1.2 million boaters who are reregistering their boats.

“Food and Agriculture has stopped every boat coming into the state since January 2007,” she noted. “Out of 82,000 inspected boats, they’ve had 104 confirmed cases of mussels. We’ve trained hundreds of boat inspectors throughout the state, including state and federal employees, as well as marina operators.”

The state even uses mussel-sniffing dogs in its detection efforts and is thinking about using a passport-type of identification system for pinpointing where boats have been launched.

“Education is working,” she said. “The angler at San Justo knew something wasn’t right when he found a clump of mussels. He brought them in. People are looking for this creature; notifying and reporting is awesome.”

Don Melin, supervising ranger at Lopez Lake, has taken note of the Casitas Lake decision: “The bottom line is this: Simply closing our lakes for a few months isn’t the answer. If they’re closed, it would be for a long, long time.”