What's a person to make of mixed signals coming from Chesapeake Bay? News reports over the last month cite an ominous, expanding "dead zone" where dissolved oxygen is disappearing.

Yet on Kent Island, where we buy bait, Capt. Teddy Lee says he hasn't seen a year this good for crabbing in a long, long time. He knows plenty about crabs, having grown up on the water, son of the late Capt. Lester Lee, central figure in William Warner's brilliant, Pulitzer Prize-winning treatise of 30 years ago, "Beautiful Swimmers."

"And it's big crabs," says Lee, holding his thick, bronzed hands wide apart and shaking his head in wonder. "Nine inches across, and I'm not kidding."

Size matters, and down at Tilghman Island sport fishermen are likewise marveling over the newest addition to the charter boat fleet, Capt. Buddy Harrison's immense, powerful fiberglass bay-built, the Capt. Buddy. It's 62 feet long, 20 feet wide, tall as a ranch house and powered by a rumbling pair of 660-horsepower diesels.

Harrison says he commissioned the behemoth to answer increasing demand from large groups seeking rockfish trips, and they've been catching their limit almost every day. If the bay is dying, why would he spend hundreds of thousands of dollars on a new boat?

"The only regret I have is that we didn't do this 15 years ago," says Harrison.

So how much trouble can the Bay be in if fishing for Maryland's premier fish is booming and crabs are everywhere? That depends on whom you ask.

The Chesapeake Bay Foundation is deeply concerned about the dead zone, which according to senior CBF scientist John Page Williams can leave up to 40 percent of the water in the bay's main stem either hypoxic (low on oxygen) or anoxic (nearly devoid of oxygen) in high summer.

Bay water loses dissolved oxygen when it's excessively enriched by phosphorus and nitrogen, which come mostly from fertilized farm fields and sewage treatment plants. The nutrients act like bay fertilizer, promoting algae blooms that use up oxygen as the algae die, sink to the bottom and decompose. Williams said in 1650 the bay absorbed about 50 million pounds of nitrogen a year; today the load is about 300 million pounds.

Precise dimensions of the dead zone resulting from that imbalance are hard to pinpoint. "The bad water moves around" on wind and tide, said Williams, and it's bigger some years than others, "but it's out there, and it's much bigger than it was 40 years ago. It starts earlier and lasts a lot longer, and that's the bottom line."

CBF is concerned enough about the dead zone that it threatened last week to sue the federal government for failing to uphold the Clean Water Act by allowing sewage treatment plants to discharge too much nitrogen into the bay. CBF says instead of letting states decide voluntarily how much nitrogen to discharge, the Environmental Protection Agency should set specific, tight limits through its permitting process.

But EPA says CBF's "one-size-fits-all" approach to limiting nutrients is impractical. "Our approach is that states should control nutrients with river-by-river strategies," taking into account farm runoff, sewage plants and other sources, said Jon Capacosa, EPA's director of water protection for the mid-Atlantic region.

Capacosa says if CBF goes ahead with its suit, it won't benefit the bay. "Tying things up in court won't help us move forward," he said.

Who's right? When it comes to the inscrutable Chesapeake, who is ever right about anything? One of the great amusements for watermen this year has been citing the Maryland Department of Natural Resources' preseason prediction for the 2004 crab harvest. DNR said it would be an abysmal year, worse than last, which was the worst on record. Naturally, crabs are thick as fleas in a dog pound.

But no one disputes the existence of the dead zone. EPA's Capacosa says the last two summers were particularly bad. "We've had two incredibly rainy years and rain brings pollution," he said. "It's been the worst of times."

He said federal-state efforts to reduce nutrients nonetheless have worked. Since the 1984 summit that brought together states in the watershed plus the District of Columbia in the common cleanup cause, nitrogen input from sewage plants has been reduced 32 percent and phosphorus is down 54 percent, he said.

CBF reckons the decline is less, and Williams says most of that success came in the first 10 years after the bay summit. "The last decade has been flat," he said.

Both CBF and EPA now are committed to further reducing nitrogen load from sewage treatment plants by more than 100 million pounds, a cut of over one-third, by 2010. "We're after the same thing," said Capacosa. "We just disagree on the method to get there."

As a longtime lover of the bay, I'd like to believe the federal government has the watershed's best interests at heart, but I don't. The Clean Water Act requires EPA to ensure that the permits it issues to states for sewage treatment effluent are adequate and enforceable to ensure water quality is protected. When I look at the state of the bay these days, I can't see how it's done the job.

As for all those crabs and rockfish out there, consider this: They have an advantage. When the dead zone spreads, they're mobile. They can flee.

But what about all the critters that can't -- the worms and clams and oysters and snails? When lesser life forms are in peril, higher life forms like us need to take note, and act.

The Chesapeake Bay Foundation, with a vast treasury of voluntary donations, would do us all a favor by putting some of that money to work by making good on its threat.

Sue 'em!

Capt. Buddy Harrison and Chesapeake Bay's newest, biggest charter boat at 62 feet. "The only regret . . . we didn't do this 15 years ago," he said.