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State's marshes dying for lack of oxygen

By STACY SHELTON
The Atlanta Journal-Constitution
Published on: 08/13/06

Skidaway Island — For 20 years, a scientist near Savannah has taken weekly water samples from the same dock, giving him a composite snapshot of the estuary's health.

Pieced together, the view goes from good to fair, and getting worse. Peter Verity's data tells him the estuary — where rivers wrestle with the sea — is in trouble.

Dissolved oxygen, the breath of life for shrimp, blue crabs, oysters and fish, is declining at an alarming rate. Within 10 years, Verity, a professor at the Skidaway Institute of Oceanography, predicts there won't be enough left for the sea life we love to eat. Those creatures will be replaced by jellyfish, which don't need as much dissolved oxygen and feed on the type of organisms that grow in a polluted estuary, he says.

Verity's already witnessed change. Between 1987 and 2000, his sampling showed a 70 percent increase in jellyfish.

Verity and other scientists who have researched similar changes worldwide say they can sum up the cause in a single word: people.

As more homes, condominiums, marinas and businesses are built on the coast, pollution increases in tidal creeks and estuaries. Treated sewage discharges and stormwater runoff carry fertilizers from lawns, golf courses and farms and oil and other pollutants from pavement and rooftops.

"We need to stop what we're doing now and either mitigate or reduce [the impacts] because we're going downhill in a hurry," Verity said.

Verity presented his dissolved oxygen research in June at an international conference of his peers and published it this month in an academic journal, Estuaries and Coasts. His bottom line: Georgia's bays and inlets, lined with tidal marshes now teeming with infant and juvenile sea life, is headed toward hypoxia, a dead zone incapable of supporting shellfish and fish.

Hypoxia is already severe at times in the Gulf of Mexico off the Louisiana coast and in the Chesapeake Bay near Washington. An associated problem, harmful algae blooms that release fish-killing toxins, has affected virtually every coastal state, threatening human health and dealing economic blows to seafood industries worldwide.

Data collected by the Georgia Department of Natural Resources along the coast tracks Verity's findings. But the state has only been extensively monitoring water quality for about six years.

Spud Woodward, the assistant director of the Georgia Coastal Resources Division, which regulates marine fisheries, said there isn't enough information to know how much shrimp, blue crabs, oysters and fish are suffering from man-made changes to the state's coastal landscape.

"The multimillion-dollar question is what are those effects going to mean for the life support for species that we place great value on? That's what we would like to know," Woodward said. "A lot of that change we want to blame on man, but a lot of that is due to natural fluctuations, I think. It's like the debate on global warming — how much of that is man and how much of it is the natural variation that you're going to see out there?"

State law to be clarified

Not far from where Verity is studying the Skidaway River, a state-appointed group of public officials, business owners, developers, consultants and environmentalists have been debating a seemingly simple question since May: What is waterfront property?

Their answer could have far-reaching impacts on the way the Georgia coast develops — and ultimately on the health of Georgia's estuaries and marshes.

Coastal marshes are green and brown canelike grasses that grow in the salty mixture of tidal waters between the sea-facing barrier islands and the mainland. In Georgia, they form a protective band four to six miles wide and encompass an area of about 378,000 acres. The state's marshlands are considered to be among the nation's most extensive and productive. They are the nursery for young fish and shellfish.

Under the Coastal Marshlands Protection Act, a state law passed in 1970, the state claimed ownership of the tidal marshes and required landowners to seek permission before building community docks, marinas, bridges and causeways across them. It is the state's only tool for regulating development on the coast. But recent court battles pitting developers against environmentalists has called the state's authority into question.

Developers, who have been on the losing end of three separate court decisions, say the state only has the right to regulate the construction of structures in or over the tidal marsh, such as a marina. Environmentalists say the law gives the state the right to regulate development along the entire waterfront, including hotels and swimming pools, single-family homes and condominiums. Their argument is that stormwater runoff from the paved surfaces and rooftops has an impact on the marsh and as such must be regulated by the state.

To help clarify the law, the state Board of Natural Resources earlier this year appointed the Uplands Stakeholder Group — the people who have been debating coast land regulations since May. They are to come up with suggestions for regulating stormwater runoff, limiting paved surfaces and creating buffers, the natural areas that separate the marsh from development. The group is set to vote on recommendations Aug. 21.

While the stakeholders are having a tough time agreeing on all the issues, they have reached consensus on one point. Left unchecked, man-made pollution will ruin Georgia's marshlands.

Committee member Duane Harris, former director of the state's Coastal Resources Division and now a consultant to developers, said at July's meeting, "What we do here is not going to matter unless the Board of Natural Resources and the General Assembly does something to protect the coast."

Samples hold surprises

When Verity arrived at the Skidaway Institute two decades ago after getting his doctorate in biological oceanography from the University of Rhode Island, he decided to keep doing what he'd learned there: sample water for dissolved oxygen levels. At the time, researchers thought a lack of oxygen was unlikely to ever plague Georgia's estuaries and marshes. They assumed constant movement of sea water along Georgia's 90-mile coastline would create enough churn to ensure high oxygen levels.

Still, Verity made water sampling a weekly routine. He figured at least it would be a good technique for his students to learn.

What he discovered over the next two decades surprised him. During hot summer months, dissolved oxygen in the estuary he sampled dropped to levels nearly lethal to sea life.

"People didn't think [dissolved oxygen] could go down," Verity said.

This year, after his research proved the worsening trend, he received a $450,000 National Science Foundation grant to collect another five years' worth of data.

Verity says he'll need a lot more money — he estimates $1.8 million over five years — to track what is causing the decline in dissolved oxygen.

"We need to start taking steps now while the problems are relatively small," he said.

If the blue crabs, shrimp, oysters and finned fish abandon the Georgia coast to bacteria and jellyfish, it could cost millions of dollars to bring them back, he said.

Taxpayers have contributed nearly $4 billion over 10 years to restoring the Chesapeake Bay's health. They'll keep paying. The federal government has demanded the bay be cleaned up by 2010, and recent studies have estimated the cost at between $13 billion and $28 billion.

If Georgia's coastal waters reach a similar crisis, Verity said, "It may be we're not paying for it, but the next generation will."

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