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Researchers haul their inflatable dinghy across the tideflats of Skagit Bay. Photo by John Ryan. More photos on Flickr.

Researchers haul their inflatable dinghy across the tideflats of Skagit Bay. Photo by John Ryan. More photos on Flickr.


Researchers Explore Link Between Skagit Bay and North Korea

John Ryan

The tideflats of the Skagit River stretch for miles into Puget Sound. But the winding channels of the mud flats could extend their reach as far as North Korea. Scientists funded by the U.S. Navy are studying the shallows of Skagit Bay. The Navy is supporting the work in part to learn how it might invade similar estuaries on the other side of the North Pacific. KUOW's John Ryan tagged along with the tideflat researchers as they head to work in a small rubber boat.


It's just about low tide as the researchers motor across Skagit Bay from the town of La Conner. Britt Raubenheimer is the team leader. She's an oceanographer living in Idaho, of all places. She works for the Woods Hole Oceanographic Institution in Massachusetts.

Raubenheimer: "We have 2 kilometers to go still? 1.5? We're not going to make it all the way in."

We've got more than a mile to go before we reach dry land. But the bay is already too shallow for us to motor any farther. So the four female scientists on board the inflatable boat hop out. And start to tow it by hand.

Raubenheimer is out front in the calf–deep water. Her dog Whit is just behind her. He stands at the bow with his front paws on the pontoons. He looks like a hood ornament or the figurehead on an ancient sailing ship.

Once the inflatable has run aground in less than a foot of water, an anchor is set. We continue walking toward a still–distant shore.

For the past two summers, Raubenheimer's been leading teams onto this tideflat to study what makes it tick. Scientists understand why the Skagit has a massive tideflat: Puget Sound's biggest river dumps huge loads of sediment here. And Whidbey Island, just off shore, protects the sediment from wave action.

But they don't know why the deep channels cutting through the tideflats form where they do. Or what makes the channels move around over time. Raubenheimer says such basic science could, some day, have military applications.

Raubenheimer: "It's of interest because of North Korea, actually. During the Korean War, where the soldiers landed in Han River estuary, near Seoul, there are very large extensive tidal flats in the area."

The Han delta sits along one of the world's most heavily militarized borders. Raubenheimer says the peaceful Skagit delta is quite similar, at least physically. Both estuaries have very large tides and very large rivers discharging into them.

Raubenheimer: "If you look around yourself right now, we are definitely surrounded, everything around us is higher, we're the lowest point around. So soldiers, if they're crossing a tideflat, whether they're in the water going by boat or whether they're going on foot, they are exposed."

She says the best way for troops to minimize their exposure is to head up a deep channel at high tide. The Navy would like to be able to predict where those channels will form, so they can get personnel and equipment ashore as quickly as possible. The Office of Naval Research has been putting about a million dollars a year into the Skagit studies.

The work is considered non–classified, basic research, with no practical military application expected for a decade. Raubenheimer says understanding the tideflats' dynamics should have more immediate benefits for efforts to protect species like Dungeness crab and chinook salmon.

Raubenheimer: "You might have noticed walking, there's a lot of crabs that live in here. The crabs spend a lot of their time up on these mudflats."

In fact, what I've noticed as we wade in the shallows is tiny young flatfish about the size of a poker chip. They kick up underwater clouds of sediment as they rocket away from our approaching boots.

Raubenheimer says I might have noticed crabs because she can't see the crabs herself. She's blind. Whit is her seeing–eye dog.

Raubenheimer: "I lost my vision seven years ago now. It was an interesting change, a lot to learn, a lot to adapt to."

At first, she thought her career as a scientist was over. But she was wrong. A talking computer lets her do her office work now. With some help and some extra effort, she still does a lot of the field work.

Raubenheimer: "With my dog, Whit, he will guide me across marshes, and across the downed trees, up and over this little island. Once I get out on flats, I can walk with a partner, just listening to them, as long as they let me know if I'm about to trip over a log."

Her team has peppered the bay with waterproof gadgets. They measure the temperature, speed, saltiness and muddiness of the water. The researchers spent much of the past two months removing clumps of seaweed from their instruments. Raubenheimer scraped seaweed and changed batteries along with everyone else.

Raubenheimer: "What I've learned I can't do is clean the O rings, which is a really critical job. You have to use vision because just a tiny piece of hair or a tiny piece of dust on the O rings will cause a leak and then you ruin a $15,000 instrument and lose the data."

Tom Frank with the U.S. Office of Naval Research has been funding Raubenheimer's work for more than a decade.

Frank: "She was not blind when she got started and has gradually gone blind. She's an extraordinary person, still able to scuba dive and do all kinds of things that one might not normally expect from a blind person."

Members of Raubenheimer's research team say in some ways, her blindness makes her the best at scuba diving in the murky water of the tideflats. To her, working without seeing your hand in front of your face is no big deal.

Raubenheimer: "We should also probably wander over in the boat direction, the water does come up fairly quickly, you don't want to be in over the top of your hip waders."

Reporting from Skagit Bay, I'm John Ryan, KUOW News.

© Copyright 2009, KUOW

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