San Luis Obispo County's Parks and Recreation Department is applying for a grant to prevent invasive mussels from infesting Lopez and Santa Margarita Lakes. Quagga and zebra mussels disrupt food chains and clog water pipelines across California.
The mussels first appeared in California in the 1980s and reached Southern California by 2007.
Cara Roderick, a senior environmental scientist with the California State Parks Division of Boating and Waterways, explained how they have spread over the years.
“Once they got into California because of our water systems, canals, pipelines — they spread from one water body to another in Southern California, and then likely boaters are the ones that continue the spread of them,” Roderick said.
The mussels latch onto boats and hide in hard-to-reach areas. Their larvae can survive in pools of water inside boats.
According to Roderick, in their larvae form, they can be undetectable to the human eye. She said they spread quickly, feeding on bacteria and plankton essential to native organisms.
“That means they can out-compete any of the native lower part of the ecosystem organisms, so they'll out-compete native mussels as well as invertebrates and other other organisms,” Roderick said.
The mussels affect fisheries by altering which fish survive. They also clog water systems for drinking and agriculture.
“You can imagine, the adult mussels, they encrust and can pile on top of each other,” Roderick said. “It’s quite a system that in an extreme case, they even have to have divers that go down and scrape dams and the filters.”
Roderick said prevention is crucial since there has not been a successful eradication of the mussels from any infested waterway. That's why the State Division of Boating and Waterways created a grant program to help counties prevent the spread of the species.
Zebra and quagga mussels have not yet reached San Luis Obispo County waters like Lopez Lake and the Santa Margarita Lake. The County is taking measures to keep it that way.
“Our park rangers are really the front line to keep the mussels out through recreation and preventing boats coming in that could potentially have the mussels,” Supervising Lopez Lake Park Ranger Craig Duprey said.
Every boat entering Lopez Lake is inspected thoroughly.
“Any water in the boat is an automatic fail because the larvae can survive for several days in the water,” Duprey said.
Duprey explained that if the mussels infest Lopez Lake, state officials could ban visitors from enjoying the reservoir.
“That would be catastrophic on many fronts because of the economic impact and people using it for recreation and how it impacts our parks,” Duprey said.
If the County receives the $400,000 grant, it would fund hiring dogs to detect larvae, employing more rangers, and supporting Public Works' efforts to monitor water quality and pH levels.
SLO County officials expect to hear back from the state on their grant application this September.
