The Chesapeake Bay Watershed:

Still Cloudy, With a Chance of Clearing

Text by Adam Voiland and Mike Carlowicz.

Visuals by Joshua Stevens, Jesse Allen, and Mike Taylor.

The Chesapeake Bay is the largest estuary in the United States and third largest in the world. Once sculpted by ice, water, and powerful geologic forces over tens of millions of years, today's Bay is shaped by human forces as well.

During the past half century, the watershed (image below) has become a landscape full of fast-spreading cities, suburbs, and farms. That development has clouded the water and reduced the productivity of the habitat. Scientists have been monitoring the Bay closely since the 1980s, and the news has often been troubling—waterways polluted with nitrogen and phosphorous, algae blooms, dead zones, and fish kills.