Nutrient monitors could keep closer tabs on bay

By PAMELA WOOD, Staff Writer

by Pamela Wood - The Capital Dean Chigounis, a University of Maryland researcher, takes a water sample from the Patuxent River with Jerry Frank assisting.

SOLOMONS - The Chesapeake Bay may be one of the most studied waterways in the world, but many scientists think there's still room for improvement. In particular, they say the ways of measuring excess nutrients like nitrogen and phosphorus - the ones that lead to oxygen-deprived dead zones each summer - fall short of what's needed.

"We're always going to have a problem of undersampling," said Dr. Lou Codispoti of the University of Maryland.

Right now, nitrogen and phosphorus aren't tested as often as other measures, such as salinity or dissolved oxygen. Samples have to be shipped off to a lab for analysis, so there's a delay in getting information.

But there's promise that tracking the ups and downs of nutrients in the Chesapeake Bay could improve. Several manufacturers have nutrient monitors that can be attached to boats or fixed locations such as piers or buoys, taking regular nutrient measurements.

Though it's known, for example, that nitrogen often increases after rainfall, there's no way to know for sure how much it goes up and how long the spike lasts because there isn't continuous monitoring, Dr. Codispoti said. Knowing those details can be useful in figuring out how to stop - or at least reduce - the nitrogen flow into the water.

"If you're measuring every 10 days, you might miss the whole thing," he said.

Nitrogen and phosphorus wreak havoc on the balance of the Chesapeake's ecosystem. While necessary for life, nutrients flush into the bay in extraordinarily high levels from farms, overfertilized lawns, old sewage plants and septic systems and they drop from the sky from vehicle and power-plant emissions.

Nutrients feed the growth of algae blooms, which block light from reaching vital underwater grasses. And when the algae die, they suck life-sustaining oxygen from the water.

To figure out how to best use new technology, a program located at a University of Maryland lab in Southern Maryland is testing several of the new nutrient monitors.

And as part of the testing regimen, they gave a preview yesterday and today to the kind of people who might one day use the instruments: college researchers and professors, workers for state agencies and private environmental contractors.

The idea is to "get the right tools in users' hands," said Dr. Mario Tamburri, a research professor at the University of Maryland Center for Environmental Science's Chesapeake Biological Laboratory in Solomons. He's also head of the Alliance for Coastal Technology, a federally funded program headquartered in Solomons that evaluates gizmos used in water testing.

"Since we have all the equipment here, why not let them get their hands on them?" he said.

The equipment has names like the NUT 1000, a phosphorus analyzer and a computer monitor packed in a bright yellow case. Or the MBARI-ISUS, a tool for testing nitrogen that comes in a 2-foot-long black tube.

Representatives from the manufacturing companies were on hand to demonstrate their equipment and get feedback from participants. Dr. Tamburri said both sides can benefit from such collaboration.

Dr. Walter Boynton, another University of Maryland professor, said the nutrient monitors hold promise.

"I think we're at the beginning of the learning curve, not the end of the learning curve, of how to use this," he said.

After the two-day workshop, the instruments will be suspended off the end of a dock at CBL for testing starting tomorrow. They'll also make stops on the West Coast, in Alaska and in the Great Lakes - all places that have nutrient pollution problems like the Chesapeake.

(Revised May 2007)