Trouble with gribbles Marine critters chew up pilings at Port of Everett

Published 9:00 pm Tuesday, October 3, 2006

EVERETT – On the television classic “Star Trek,” the crew of the USS Enterprise found themselves up to their tricorders in tribbles, a lovable creature that reproduced at an alarming rate.

At the Port of Everett, there’s trouble with gribbles, a marine borer that’s threatening hundreds of wooden pilings that will eventually have to be replaced.

Gribbles, which look like a wood louse and have seven pairs of legs and four sets of mouth parts, essentially eat all parts of pilings not treated with creosote.

And they’re not alone.

There are also teredos, a nickname often used for Bankia setacea, a shipworm common to Puget Sound that’s also known as the termite of the sea.

Teredos are actually relatives of the clam and look like giant worms.

“They look for a chink in the armor of the treated pilings,” said John Klekotka, the port’s engineer. “They get in and bore up and down in the untreated part of the piling.”

Klekotka said the original bore hole is often hard to see. But the shipworms, which can grow to three feet in length, can destroy a piling from the inside by munching tunnels that are about the width of a finger.

“I’ve seen pilings that look perfect on one side and on the other they have a huge hole,” Klekotka said. “We’re seeing a lot more of these guys and a lot more deterioration.”

The boring critters are also wreaking havoc on Seattle’s seawall.

Klekotka told port commissioners Tuesday that cleaner water in Puget Sound in recent years has led to an explosion of the teredos and gribbles. The critters do better in clean water. During the period from 2001 to 2004, the port had to replace about 18 pilings a year, he said, adding that this year there are 70 gnawed-up pier supports.

The port may have to spend $500,000 to do the job next year, twice what was originally planned for the 2007 budget. The money will be used to replace the creosote-coated wood pilings with steel to eliminate the borer problem.

The 70 damaged pilings need to be replaced immediately, Klekotka said.

“It’s kind of like replacing tires on your car,” he added. “You gotta do it every so often.”

But he said there were “several hundred pilings” that will ultimately need to be replaced because of the borer problem.

In addition to steel pilings, the port will also consider supports made from recycled plastic or concrete.