Ocean Watch

Monday, August 31, 1998

USS Missouri is host
to thriving community

Earlier this summer, a tugboat towed the USS Missouri from Washington's Puget Sound to Hawaii's Pearl Harbor.

This famous battleship now rests near her equally famous sunken sister ship, the USS Arizona. Soon, these World War II vessels will be partner museums, somber symbols of the devastating war in the Pacific.

Most people in Hawaii agreed that bringing the Missouri here was a good idea.

But some worried that the move might cause the ship to once again be involved in devastation. This time, however, it could be to Hawaii's marine environment.

The reason for this concern lay on the ship's bottom. The vessel had not moved in six years, and its hull was packed with marine growth up to a foot thick.

Such growth, called a fouling community, is normal on boat bottoms. It begins with a layer of bacteria and one-celled plants and animals, then increases as other plants and animals are attracted to the first.

The resulting buildup is a marvel to biologists but a scourge to boat owners, who must scrape it off or endure slow-going boats.

But organisms living on hulls can be more than just a nuisance. When fouled ships travel from one port to another, there's the chance some will jump off and take hold in a place they don't belong.

In the case of the Missouri coming to Hawaii, the odds of this were low. The ship bore cold water species not likely able to tolerate Hawaii's tropical water temperatures.

Still, the country is currently plagued with accidental species introductions from traveling ships.

The Great Lakes are clogged with the alien zebra mussel, and the European blue crab is creeping its way up the West Coast. This crab eats shellfish, potentially devastating oyster, clam and mussel beds.

So, to be safe, organizers of the Missouri's transfer team asked UH marine researcher Richard Brock to go to Puget Sound and see what was growing on the Missouri's bottom.

Brock swam the entire 886-foot hull and was able to identify only about 60 percent of the species there.

Of these, 14 to 15 were already in Hawaii. The others are found only in the cold waters of Puget Sound, the North Pacific and the North Atlantic.

Brock thought these cold-adapted species would probably die in Hawaii, but still, there were too many unknowns. The bottom needed cleaning before coming to Hawaii.

But hauling the huge boat from the water and cleaning the hull was prohibitively expensive. Estimated costs were $1 million. The Missouri Memorial Association didn't have that kind of money.

As an alternative, Brock suggested they tow the ship up the Columbia River and dock it there for a while. The fresh water would kill most of the species, he reasoned, then Hawaii's warm water would finish them off.

And so the Missouri spent nine days in Astoria, Ore., 12 miles up the Columbia River.

And Brock was right. When he examined the ship's hull in Pearl Harbor, most of it was bare. Nearly all the fouling animals died in the fresh water, then washed off the bottom during the tow.

The six or seven living species left were either dying or already found in Hawaii.

Hawaii's species apparently love the Missouri's large, clean hull. As he worked, Brock saw tiny Pearl Harbor crabs already settling in.

The Missouri will soon be open as a museum, telling the story of the end of the war in the Pacific.

But when you walk her decks, remember the mighty battleship's final journey and the millions of plants and animals moving in down there on the hull.

That's a good story, too.