SACRAMENTO-SAN JOAQUIN DELTA -- Ask almost any boater or marina manager in the delta, and you'll get the same answer: The water weeds clogging channels and harbors lately are the worst they've ever seen.
The culprit is water hyacinth, a floating plant with shiny leaves and showy purple flowers brought to the United States from the Amazon in the 1880s as an ornamental plant. It reached the Sacramento-San Joaquin Delta in the 1940s, and government officials and the boating industry have been battling it since then mainly by killing it with herbicides.
At Korth's Pirate's Lair Marina near Isleton, owned by the same family for more than half a century, co-owner Kim Korth said the latest infestation exceeds anything she can remember. And that says something: She is 62 and was raised at the marina.
"I've lived here my whole life. It's the worst year we've ever seen," said Korth, who with her three siblings owns the marina at the eastern tip of Andrus Island.
"It's been such an incredible menace to our boaters and our marinas," she said. "Usually the fall is everybody's favorite time for boating. It's calm, it's cool, the sunsets are beautiful. This year, nobody thought it was their favorite time. People just really stayed in their berths, and that was really bad for business."
If left unchecked in the summer, water hyacinth explodes and forms a carpet across the water surface, clogging propellers, rudders and water intakes and discouraging all boating.
That is what happened last year. An annual herbicide spraying program run by the California Department of Boating and Waterways and the U.S. Department of Agriculture did not begin until September, long after the weed exploded in the summer heat. A warm fall allowed it to spread more and hang on longer.
Only in the past few weeks, after persistent frost, did the weed start dying off for the season. Many waterways that were blanketed in hyacinth for months are beginning to clear or are covered in brown leaves killed by the cold.
At Tower Park Marina near Lodi, a cluster of day-use boat slips normally used only in summer was abandoned to the hyacinth, said Sheila Bookwalter, a reservation clerk.
"It looks like a meadow, and it's still basically covered," she said.
A crew labored full days for weeks to keep the rest of the marina clear, shoveling and pitchforking clots of hyacinth out of the water so boats could pass. The team rigged floating booms across critical areas to exclude hyacinth that floats in on the current the weed's typical means of distribution.
Invested in a harvester
Village West Marina, near Stockton, spent more than $70,000 last year hiring extra staff to haul hyacinth off the water and dispose of it on land.
In 2011, the owners purchased a "marine harvester," a floating conveyor belt, to move the weeds from water to shore for disposal. But the hyacinth sometimes got the best of the machine.
"It overworks, it overheats, it breaks down," said Alan Ray, the marina's marketing director. "We got it under control, but it's been a herculean effort by our staff to get that stuff out. It's hurting business."
It got so bad that Recreational Boaters of California, an advocacy group, issued a "call to arms" to its members Jan. 14, urging them to write lawmakers to solve "an infestation of historical proportions."
The government's hyacinth spraying program, funded largely by taxes and fees paid by boaters, normally begins in June. USDA and state Boating and Waterways conduct the spraying program under a five-year permit issued by federal fishery agencies, which review the program to ensure that herbicides do not harm threatened fish species, including chinook salmon and delta smelt.
But the departments waited too long to apply for a permit in 2012, said Kim Turner, assistant field supervisor for the U.S. Fish and Wildlife Service. Additional review was required because the status of the delta smelt had worsened.
The fishery agencies were able to issue the new permit in August, but it meant spraying did not begin until late in the hyacinth growth season.
In addition, the new permit was valid only for the balance of 2012.
Last year's spraying included the same chemicals that have been used in years past: 2,4-D and glyphosate, which are mixed with water and sprayed from boats.
A new five-year permit is in the works, and it is based on a new strategy: spraying as early as March, when hyacinth is more vulnerable, and using new chemicals effective at lower strength.
Spraying historically has not been allowed in March because young salmon are migrating through the delta. It is also breeding season for delta smelt.