Rescuing Chesapeake Bay

Save the bay - that's been the battle cry in the mid-Atlantic region for two decades, as a unique alliance of federal, state, and local governments has tried to control pollution in the largest estuary in the US, the spectacular Chesapeake Bay.

But it turns out that progress in limiting key pollutants has been significantly overstated by the partnership leading the cleanup effort, the Chesapeake Bay Program.

Relying on a sophisticated computer model - not water samples - to estimate pollution reduction, the partnership reported a near 40 percent drop in major pollutants flowing into the waterway from 1985 to 2000.

Yet water-sample data obtained by The Washington Post from the US Geological Survey showed no decline of the two targeted pollutants - nitrogen and phosphorus - in most of the major rivers feeding the bay. Steep drops in the population of blue crabs and oysters - icons of bay life and the regional economy - also indicate a less rosy picture.

Measuring bay pollution is complicated. For instance, underwater grasses have doubled since the mid-80s - a good sign. And while the partnership does not include water samples in its computer model, it does use them to recalibrate its estimates.

Still, when the partnership revised its computer model in March, the new estimates - a 28 percent fall in phosphorus and 18 percent drop in nitrogen - were considerably lower than the 40 percent estimate of four years ago.

The partnership needs to come up with a more accurate reporting method. Much rides on its assessment, including the political will to curb the fertilizer, animal and human waste, and car pollution that end up in the bay. Bordering states have made serious clean-up efforts, but they have been offset by increased pollution from a rising human population. It looks like a complete rethinking of the bay program, and not just a computer adjustment, is necessary.