2007
Volume 6, Numbers 3 & 4
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THINKING DEEPLY ABOUT THE SHALLOWS
By Jack Greer

Special 30th Anniversary Issue
The Bay around Us

Contents

The Past Is Prologue

From Microbes to
Mute Swans

Biocompexity & the Bay


On the Threshold

Preparing for the Future

Last light of an autumn afternoon settles on the West River. Gone are hot summer days that brought unlooked-for algae blooms and turbidity. Scientists are tracking water quality in the Bay's tributaries as never before to find out where all those algae come from. Above Photograph by
Sandy Rodgers.

The setting sun shoots light straight down the West River. Autumn's last leaves ignite all along the shore. Summer is ending on this quiet Western Shore river just south of Annapolis.

It should have been a better summer.

With drought conditions sending little runoff into the river all summer long, the waters should have looked cleaner, clearer. Instead, warm weather brought an unwanted crop of algae blooms.

"I've never seen so many mahogany tides," says Bob Gallagher. Gallagher is the riverkeeper for the West River and Rhode River. He oversees a team of citizen monitors to watch water quality and to look out for the rivers' health. One thing he doesn't want to see is a mahogany tide — a reddish-brown algal bloom that can cause fish kills.

For the past couple of years Gallagher and his team have measured the vital signs of these two rivers — oxygen levels, bacteria, suspended sediment. They also consult data collected by the Maryland Department of Natural Resources and others, including the Smithsonian Environmental Research Center and the National Oceanic and Atmospheric Administration.

For Gallagher, this summer raised questions that the data don't seem to answer. "This was a strange summer," he says. In particular, they expected to see clearer water because of the drought. "That's not the way it turned out," he says. Even though dissolved oxygen levels were slightly better than the year before, the water was cloudy, and there were those worrisome mahogany tides.

With so little runoff, why didn't the rivers run a little clearer in the summer of 2007? Where did all those algae come from — not only in the main Bay, but in the shallower water of the tributaries? Why wasn't it a better summer?

Thirty years ago we could not have answered these questions. Can we answer them now?

The Productivity Puzzle

Tom Malone looks out the window of his 12th story office in Silver Spring, Maryland. Behind him loom other steel-and-glass office towers wrapped with dark windows, as if the buildings themselves were wearing sunglasses.

He swivels back to his desk and pokes at his computer's keyboard. He's trying to get on the network, and it's not working. He knows there's a sharp irony in this, given why he's here.

Malone, whose longish hair and beard are going gray, is a key figure in the fight for global advanced observing systems. He has taken time from his position as a university researcher to serve as the Deputy Director of Research for the National Office for Integrated and Sustained Ocean Observations. He's leading a charge to expand the nation's capacity to observe changes in the world's oceans and coastal waters, using buoys, satellites, ships, and underwater vehicles. He testifies before Congressional committees. He wrangles with policy makers and officials at every level. In about an hour he has a conference call with two admirals. And his computer's not working.

Malone's leg jiggles as he speaks. He seems in a hurry even when sitting still. There must be times when he wishes he were back on the water, doing the research that's been his life for more than thirty years.

Malone's career in oceanography began back in the 1960s working in the blue waters of the Pacific. There he studied the effects of nutrients on tiny floating plants called phytoplankton, from the equator to the California coast. He found that when currents brought up nutrients from deeper waters — known as upwelling — larger forms of plankton thrived. It is these larger forms that support food chains leading directly to fish. He was also among the first to discover the importance of very small phytoplankton (or picoplankton) in the ocean's overall productivity, something previously overlooked.

During this period, Malone saw that to understand how marine food webs work as part of the earth's carbon cycle meant understanding how ocean physics and biology interact. And to do that required close observations — at least once a month, he says, or more often if possible. That posed a challenge in the open ocean.

Malone had a chance to get closer to his subject when he accepted his first academic appointment back East, at the City College of New York. There he started a research program on the Hudson River estuary and the coastal waters of the New York Bight. In these shallower waters he could study how phytoplankton respond to nutrients from human sources — mostly from sewage discharge. He could observe up close how they move through the estuary and onto the continental shelf.

Here in the shallows Malone discovered the delicate dance of nutrients, phytoplankton, and estuarine currents that leads to the summertime loss of oxygen. With this new understanding he was able to show, for example, that a harmful algal bloom that developed over several months and spread over the entire New York Bight was not caused by nutrients from sewage discharges, as many assumed. Instead, it was fed by an unusual circulation pattern that brought nutrients into the Bight from deep waters of the North Atlantic.

He had turned his training as a blue water oceanographer toward the shallows.

Malone first came to the Chesapeake in 1983 after persuasive conversations with a gregarious Welshman named Ian Morris, then President of the University of Maryland Center for Environmental and Estuarine Studies (now the UM Center for Environmental Science, UMCES). Part of the attraction, he says, was that Morris was also wooing a physical oceanographer named Bill Boicourt. Here was another researcher interested in how physics and biology interact to shape shallow-water ecosystems.

That Morris recruited a biological and a physical oceanographer at the same time was no accident. In addition to their individual accomplishments, Morris saw in them the future of estuarine science. He saw the importance of understanding how circulation patterns and mixing affect the Bay's biological productivity — especially of phytoplankton — and how this in turn determines how too many nutrients affect the health of the Chesapeake.

Understanding these interactions could help explain why algal blooms occur in some places and not in others, why they would occur in some years more than others. Even in a dry summer.

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