Watercraft inspections began today at Lake Del Valle in Livermore and Contra Loma reservoir in Antioch.
A contractor has been inspecting boats at Lake Chabot in Castro Valley since the spring and those inspections will continue. The park district is also planning inspections at Quarry Lakes in Fremont and Shadow Cliffs in Pleasanton. Those inspections are expected to begin soon.
Boats, trailers and equipment must be clean and dry to pass inspection.
Zebra and quagga mussels can heavily colonize fresh water systems and are known to filter out phytoplankton, zooplankton and other food sources for native species, altering the natural food web and causing plant and fish die offs, according to the California Department of Fish and Game.
The mussels, which are close relatives of each other, also accumulate organic waste in their tissues and generate toxic byproducts, which destroys the natural water system in lakes and rivers. The mussels have also been associated with outbreaks of botulism poisoning in birds, according Fish and Game.
The mussels are mainly spread by boats and trailers that have come into contact with infested waters. The creatures' microscopic larvae can be spread from standing water or even just wet surfaces, according to the park district.
The mussels were first detected in the United States in the 1980s, but were not found west of the Continental Divide until 2007, when they were found in Lake Mead in Nevada.
Quagga mussels have since been found in Lake Mohave and Lake Havasu in Arizona, both of which sit along the Colorado River near Lake Mead. The mussels have also been found in the Colorado River itself and the Colorado River Aqueduct System, which serves Southern California.
Zebra mussels were first found in California in the San Justo Reservoir in San Benito County on Jan. 10, according to Fish and Game.
Neither species of mussel has been detected in any East Bay bodies of water, according to the park district.
During the first week of the new pilot program, watercraft inspections will be conducted at no cost to boaters.
Beginning July 10, a $6 fee will be charged for boats on trailers and a $3 fee will be charged for inspections of boats transported on top of cars, such as kayaks, canoes and rowboats. There will be no charge for float tube inspections.
Boats with any standing water will not be allowed to launch and will be forced to wait five days before returning, according to the park district.