LAKE COUNTY — Pam Francis told the county Board of Supervisors Tuesday that the California Department of Food and Agriculture (CDFA) had recently reported major finds of a stealthy invasive aquatic weed.
Francis is the county”s deputy director of Public Works in its Water Resources Department, and said the call from a local CDFA crew chief came too late to put the item on the board”s agenda. So she presented the information in the public input portion of the meeting.
As of Aug. 20, reported Francis, the CDFA had found 18 new hydrilla plants had been found in Clear Lake. The CDFA has been battling the invasive weed on Clear Lake since 1994, and throughout California for longer than that.
Hailing from Africa, the invasive aquatic plant forms dense mats that completely cover a lake surface, Francis explained recently. “It smothers out everything, totally disrupting the ecosystem,” said Francis. In addition, hydrilla can clog water intake valves and ensnare watercraft because of its sheer density.
Record-Bee outdoor columnist Terry Knight said the prolific hydrilla can grow to an are of over 40 acres in size within 24 hours.
The plants are spawned by tubers the size of a navy bean, said Francis, which lay dormant for long periods of time in the mud on the bottom of a water body, waiting for the right conditions to sprout.
And sprout it has. As of Aug. 20, three plants were found at the outlet of State Park, two were found in Buckingham, three around the city of Clearlake and another 10 in Soda Bay.
“The good news is that they”ve sprouted into plants so we don”t have to worry about them. They haven”t formed tubers yet,” said Francis, adding that it would take three weeks for the plants to become mature enough to produce more tubers. “The plants will be eradicated before they have a chance form new ones,” said Francis.
She noted that CDFA would be stepping up its eradication efforts in the areas where the plants were found, although she wasn”t sure what those efforts would entail.
“It would be nice to minimize boating traffic in that area because hydrilla reproduce by fragmentation when boat propellers chop them up,” she said. Something boaters need to be watchful of is that the weed doesn”t get accidentally transported on watercraft from one water body to another.
CDFA, noted Francis, uses air boats, which do not chop up the weed and distribute it. They will be looking for the extent of the infestation in order to determine the best strategy for treating it.
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