Northwest Faces Indestructable Weed

A type of grass that is used to control coastal erosion has taken such a hold on parts of the Pacific Northwest that scientists fear for the future of some of the region's critical wildlife habitat.

The grass is called "Spartina," and don't let its beauty deceive you. As author David Gordon noted in his recent book, Heaven on the Half Shell, it is the plant kingdom's answer to Attila the Hun.

Scientists have poisoned it, dug it up, smashed it into the ground, and yet the grass continues to thrive.

A modest form of ecological warfare has been declared on Spartina, a leathery, tough plant that is turning thousands of acres of mudflats along Washington's coast into salty meadows.

Mudflats are crucial to the survival of everything from shore birds to salmon, according to experts, and unless Spartina can be brought under control, priceless feeding grounds may be lost.

"It's a huge crisis," says Blain Reeves of the Washington state Department of Agriculture. Reeves, who is coordinating a multi-agency attack on Spartina, admits that so far the best that scientists have been able to do is slow the growth of Spartina, which has claimed between 20,000 and 30,000 acres of mudflats over the past few years.

They've tried just about everything, including attacking it with huge "flailing" machines that try to beat it to death. But there's been only limited success.

Strength From Its Roots

To the casual observer, there may not seem to be much of a problem here. Spartina can be "very pretty," says Sally D. Hacker, a biologist at Washington State University at Vancouver.

"It can be lush and green," says Hacker, who is trying to get a handle on the scale of the problem as part of a project sponsored by the Washington Sea Grant Program.

But underneath Spartina's appealing exterior is the root system from hell.

"It accumulates sediments around the roots," Hacker says, rapidly building up the elevation of the land on which it sits, and changing a mudflat into a salty marsh. Lost in the process is the biologically rich intertidal zone that supports so much wildlife.

Spartina has claimed about 15,000 acres of tidelands in southwestern Washington's Willapa Bay, home to one of the richest-oyster producing areas in the nation. Much of the land that has been lost was once used to grow clams and oysters, according to the state's Reeves, and it is critical habitat for migratory birds.

Willapa Bay is one of the last "feeding stations" that nurture the birds on their way north, Reeves says, and if the birds don't find what they need in the bay "they're going to be toast by the time they get to Alaska."

Lush, Green Deserts

But Spartina can turn a nutritious mud flat into a green desert, and longtime resident Dick Sheldon says he's seeing that happen a lot these days.

"I've watched this thing grow from probably half an acre over the last 15 years to 15,000 acres" in Willapa Bay alone, says Sheldon, who claims to have spent about $160,000 trying to keep Spartina from encroaching on tidal flats that his company uses to grow oysters.

But he says he's even more concerned about the impact on wildlife than he is over the future of his oyster beds. "There's millions of ducks" visiting Willapa Bay every year, he says, "and they won't even come close to Spartina."

There's nothing in Spartina for them to eat, he says, and besides, "it looks like a huge duck blind. They won't even fly over it."

According to Hacker, the region's problems with Spartina actually began more than a century ago, but only recently has the plant moved onto center stage. A species called Spartina alterniflora was inadvertently introduced to Willapa Bay when oysters were imported to the region in the late 1800s, she says.

But a different species, Spartina anglica, was brought into northern Puget Sound in 1961 by one farmer who wanted to reduce erosion along coastal dikes that kept seawater from inundating his farm.

The plant, a hybrid from England, didn't do too well at first, but in recent years it has taken over like crabgrass in a suburban lawn.

"And suddenly, there's close to 10,000 acres of Spartina in northern Puget Sound from this one introduction," Hacker says.

Resorting to Rip and Kill

Spartina produces seeds, which can be carried great distances by either wind or water, helping the plant extend its reach.

It grows in clumps, here and there, taking over thousands of acres along hundreds of miles of shoreline. It isn't possible to use powerful chemicals to kill the plants, because the chemicals would cause great damage to the rest of the ecosystem.

In fact, scientists have been limited to the use of one herbicide, Rodeo, which is very similar to Roundup, which is used in many home gardens.

It can cost tens of thousands of dollars to kill Spartina in a single meadow with a herbicide, and quite often the poison kills the part of the plant that is above the surface and leaves the roots to fight another day.

So at the present, the state is leaning toward what Reeves calls the "rip and kill" strategy. It substitutes mechanics for chemistry.

Huge pieces of equipment, including one that looks a little like a tank and is called a Marsh Master, dig across the meadow, ripping at the Spartina as it goes.

That technique was tried last fall, and it seems to work, Reeves says, but he's waiting until May to declare victory, just to make sure the Spartina doesn't pop up again.

One problem with that approach is it's pretty hard to keep the equipment working. Sheldon, the oyster farmer, tried it himself a few years ago. He said it worked, but the salt water really wiped out his tractors.

Now, the state is gearing up for the same approach. Can aerial warfare be far behind?

Lee Dye’s column appears weekly on A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.