The Chesapeake Bay Program’s aerial surveys last year showed that underwater vegetation covered 59,090 acres in the bay, down about 25 percent from 72,263 acres in 2005. Grass coverage last year was the worst since 1989.

Underwater grass beds are important because they filter pollutants and provide habitat and food for blue crabs and other species prized by watermen.

A bright spot in the 2006 survey was the Susquehanna Flats, an area at the extreme northern tip of the bay. Scientists watch that area closely because fresh water that feeds the estuary travels though the Susquehanna Flats. A thick patch of grasses is good news for water quality farther south.

Read (AP via WTOP)