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The Honolulu Advertiser
Posted on: Thursday, February 20, 2003

State blamed for neglecting situation

 •  Work to eradicate weed shuts down Lake Wilson

By Jan TenBruggencate
Advertiser Science Writer

O'ahu residents watching the cleanup efforts in Lake Wilson yesterday said the state was negligent in not responding to the salvinia weed infestation earlier.

"Everything in Hawai'i has to get to epidemic proportions before anybody does anything about it," said Kim Seleska, a business machine repairman from the North Shore who fished the lake for peacock bass for eight years until the weed took over.

Seleska said he had called state officials about the problem for more than a year.

"How much would it have cost the taxpayers if they went after the first few patches with some herbicide more than a year ago?" he said. "A couple of hundred dollars?"

"Somebody fell asleep somewhere," agreed Joe Mahina of Wahiawa, a 76-year-old retired heavy-equipment operator who came to the lake yesterday to watch the fancy floating backhoe at work.

State officials say they responded aggressively last year to the salvinia infestation in Lake Wilson, but they concede that in retrospect, it wasn't nearly aggressive enough.

"Last August, we did have people clearing mechanically and spraying (the herbicide) Rodeo. We had already diverted three people, and that's a substantial portion of our budget," said Bill Devick, head of the state Division of Aquatic Resources.

But despite previous experience with it, and despite its reputation as a superweed worldwide, the state did not fully understand how severe Salvinia molesta was as a pest.

"If we had been aware beforehand of just how vicious this weed is, we could have done more," Devick said. Officials here have never had to deal with a plant so invasive that it can double its coverage in less than a week.

Today, state crews face spending hundreds of thousands of dollars to control a weed that covers the 300-acre surface of the Central O'ahu reservoir, in some places a foot thick. Devick said it may take three giant excavators working daily just to keep ahead of it.

Residents watching the cleanup at Lake Wilson asked how state officials could so badly have underestimated the weed that the Corps of Engineers has dubbed "possibly the world's worst weed."

Partly, that may be because invasive species have become a hot issue only in the past few years, with the attention focused on miconia, noisy tree frogs and other aggressive invaders. The programs to identify and respond to them are in development.

For example, the state has contracted with The Nature Conservancy of Hawai'i to prepare an aquatic species management plan, which will provide guidance for preventing, detecting and controlling alien aquatic species. Also, University of Hawai'i researchers are working with the state Division of Forestry and Wildlife and the U.S. Forest Service to develop a system to identify the most dangerous invasive plant species.

But responding to a problem that becomes a crisis presents a familiar problem for government, said state forester Michael Buck. Even though managing a mature plant pest invasion is much more expensive than responding early, agencies can't raise the money to marshal the needed resources until a weed is at the crisis stage.

"It's another example of, if you prevent it, that surely is the best thing, but it is so much harder to get the resources to prevent things," Buck said. "In invasive species, we need to be like a fire department — we have to have the ability to detect early and to respond."

Ultimately, salvinia will be expensive, but it may be easier to control than some land weeds, like the escaped nursery plant miconia, which forms dense stands in native forest on several islands, he said.

"We're dealing with miconia on over 100,000 acres of the most pristine rainforest in the whole world," Buck said.

Two primary issues are recognizing a serious invader early enough, and having the money to combat it. The former may be easier than the latter, said Teya Penniman, biologist and manager of the Maui Invasive Species Committee.

"There are folks working on weed risk assessment, looking at whether a weed is likely to spread quickly, to threaten native plants, to challenge economically valuable plants. Then, it's always a question of, we only have so many resources," Penniman said.

University of Hawai'i botanist Curt Daehler, who is among those working on identifying hazardous species, said that while the federal government has listed Salvinia molesta as a noxious weed, illegal to move between states, Hawai'i does not have it on the noxious weed list.

"Because we don't have it on our list in Hawai'i, people can sell it and move it around," he said.

The plant probably got to the Islands as an aquarium plant many years ago. It likely got into Lake Wilson when someone dumped the contents of an unwanted aquarium, but it could also have arrived during a flood that washed salvinia from someone's backyard pond, or it could even have arrived on the feet of ducks.

It had already been noted as a problem in Kailua's Enchanted Lake, where state officials and community volunteers tried to eradicate it three years ago. Kailua resident Scott Lautner noted one helpful factor there. Whenever salvinia drifted into brackish water, it died, he said. But that is unlikely to be of assistance in upland, freshwater Lake Wilson.

Advertiser staff writer Walter Wright contributed to this report. Reach Jan TenBruggencate at jant@honoluluadvertiser.com or (808) 245-3074.