Ask almost any boater or marina manager in the Delta – one of California's top boating destinations – 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 large, shiny leaves and showy purple flowers brought to America 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 years old 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 solid carpet across the water surface, clogging propellers, rudders and water intakes and discouraging any kind of boating activity.
And that is exactly 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 farther and hang on longer.
Only in the last couple of weeks, after a persistent January frost, did the weed finally start dying off for the season. Many waterways that were blanketed in hyacinth for months are beginning to clear or are covered in shriveled brown hyacinth leaves killed by the cold.
At Tower Park Marina in Lodi, a cluster of day-use boat slips normally used only in summer was abandoned to the hyacinth, said Sheila Bookwalter, a reservation clerk at the marina.
"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 also rigged floating booms across critical areas to exclude hyacinth that floats in on the current – the weed's typical means of distribution.
Village West Marina, also 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 kind of 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. Our fuel dock receipts are down because people just aren't taking their boats out and gassing up."
It got so bad that Recreational Boaters of California, an advocacy group, issued a "call to arms" to its members on Jan. 14, urging them to write lawmakers to solve "an infestation of historical proportions."
Boater fees fund spraying
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 new permit in 2012, said Kim Turner, assistant field supervisor for the U.S. Fish and Wildlife Service. Additional review also was required because the status of the Delta smelt had worsened since the previous permit was issued.
The fishery agencies were able to issue the new permit in August within their normal turnaround time, 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 the calendar year and has now expired.
"They kind of tied our hands by coming in so late in the first place," Turner said.
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.
Between 2007 and 2011, an average of 772 gallons of herbicide was sprayed over 812 acres of water surface each year. The spraying volume was similar in 2012, despite the compressed season, said Gloria Sandoval, a spokeswoman for Boating and Waterways.
The chemicals have been used for years on hyacinth and are effective at beating back the weed if applied annually. But it is now generally accepted that hyacinth will never be eradicated because it has adapted to the Delta and is so widespread.
"You're talking about something that's very invasive, that grows fast, and that has a pretty good, long life," said Devery Stockton, who operates Owl Harbor Marina on Andrus Island with her husband.
Permit changes possible
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 that are effective at lower concentrations.
Spraying historically has not been allowed in March because it is a time when young salmon, which may be more vulnerable to herbicides, are migrating through the Delta. It is also breeding season for Delta smelt, and the herbicides may be harmful to their eggs and larval fish.
The new chemicals proposed for use are penoxsulam and imazamox. They are effective against hyacinth at much lower concentrations, said Patrick Moran, a research entomologist at the USDA's exotic and invasive weeds research unit in Albany, so their use might be allowable in March. They have not yet been approved for use by the state Water Resources Control Board, but that is expected soon and the agencies want to be ready.
"The idea is to treat some of the hyacinth when they're just starting to grow in March and April with a small amount of chemical that is still enough to kill them," Moran said, "and that would actually reduce the number of acres that have to be sprayed each year."
A third new herbicide, imazapyr, is also proposed for the program. But it requires still more layers of approval and would be added later.
So far, all parties say the new permit is proceeding smoothly through the review process.
"We have some questions and concerns, but it doesn't look like there's going to be any hang-ups this year," said Fish and Wildlife's Turner.
That will be a relief to the boating community, which doesn't want another year like 2012.
Devery Stockton, who has operated Owl Harbor Marina with her husband for four years, declined to say how much the hyacinth battle cost them last year, saying only that "it was costly."
At one point, Stockton hired a crew of four men with a work skiff. They worked for five straight days to clear hyacinth from Sevenmile Slough, a public waterway, so their boating tenants could come and go from the marina. The workers collected the floating hyacinth and towed it out to the San Joaquin River so it would drift away.
During this time, Stockton added three tenants and had to tow their boats through the blockade of weeds so their propellers and engines would not be fouled by the plants.
Stockton's husband, an engineer, built a 36-foot-long, 6-foot-wide conveyor-belt device that can be towed to a hyacinth clog and lowered into the slough to lift the weeds out of the water and onto dry land for disposal. They are still testing the contraption and will deploy it this year, if necessary, to keep the slough clear.
"We're new here and put a lot of energy into building this marina into an area that people will want to visit, because we think the Delta is an incredible place," Stockton said. "To not stay on top of it and have this lapse in applying the spray has been very detrimental to all of our businesses out here."