San Joaquin River DOTMDL -- Technical Working Group

Pacific studies on river science go deep

Stockton Record - February 22, 2005
By Dana Nichols

Pacific studies on river science go deep

Stockton Record - 2/22/05
By Dana Nichols, staff writer

STOCKTON -- This is a story about tiny bubbles.

First, there are the kind that matter to fish -- tiny bubbles of oxygen that experimental aerators spew into the Stockton Deep Water Channel.

Then there are the other kind, in a glass an engineering professor might raise to salute University of the Pacific's emergence as a player in environmental research.

Pacific researchers currently have millions of dollars in grants from the California Bay Delta Authority to study problems like algae growth and low oxygen levels in the San Joaquin River. Also, Pacific last year recruited Lawrence Berkeley National Laboratory scholar William Stringfellow to head Pacific's new environmental research program.

And officials at the campus expect the university's role in studying the area's troubled rivers to grow.

"We are just at the perfect place and time to take advantage of these opportunities," said Garry Litton, a professor of civil engineering at Pacific.

Litton and his students often can be seen cruising the Deep Water Channel in his 18-foot aluminum-hulled Duckworth outboard, taking samples of water and algae and using dye to trace water flows.

Stringfellow, the most recent addition to Pacific's environmental research team, brought $3.1 million in CALFED funding with him, university officials said.

"UOP is in a very good position, both in terms of location and in terms of their prior experience doing research with the state," Stringfellow said. "It's right in the middle of a critical area for environmental restoration."

Pacific's work is getting attention even from some perennial critics of CALFED and its research priorities.

"Garry Litton has been doing some of the more imaginative and scientifically sound work on the San Joaquin River," said Bill Jennings of DeltaKeeper, a water pollution watchdog group.

 "Kudos to the university for finally understanding that they have the responsibility and the opportunity to play a role in protecting this estuary on their doorsteps," Jennings said.

Back to the bubbles.

On the day before Thanksgiving, Litton was out with students in his trusty Duckworth.

They were trying to figure out if a machine could solve the dissolved oxygen problem near the Port of Stockton.

Fish need oxygen to live. But several problems cause oxygen levels to drop right in the middle of Stockton. One is the depth of the river where the ship channel carves through it. The deeper channel means less surface area to absorb oxygen.

Also, very little fresh water flows into the area from upstream. And then there is the problem of algae coming in from shallow waters. When the algae falls into the depths of the channels, it dies and decays. That absorbs oxygen.

"It looks like aeration may be one of the cheapest strategies around for solving the problem," Litton said.

So he and his students injected dye along with the oxygen bubbles coming from an aerator under a dock at the Port of Stockton. Then they used instruments dangling from the boat to watch the dye and see how long it took the oxygen-rich water from the aerator to mix through the rest of the channel.

But the results were disappointing. Computer-generated images showed the oxygen reaching only about 300 feet, or halfway across the channel. And most of it continued to hug the edge right near the aerator.

So Litton checked the tides. It turned out that tidal action was weak that day.

Even though it was a holiday, Litton and his students decided to come back on the next day -- Thanksgiving Day -- during a stronger tide.

This time the tests showed the oxygen reaching all the way across the channel.

"Since these things will be operating for days on end, we have pretty good confidence that if we had a battery of these things operating on one side of the channel, we'll have pretty good mixing," he said.

Celebration was in order.

"We had champagne at Thanksgiving dinner," Litton said.

Which raises another question. Litton eagerly reads studies by other scientists who analyze the tiny bubbles of carbon dioxide in beer and sparkling wines.

So why does he prefer studying the murky and unpalatable waters of the Delta?

"There's a lot more money in turbid slough water," he said. #

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