The physical processes that drive the Chesapeake Bay ecosystem sustain the many habitats and organisms found there. Complex relationships exist among the living resources of the Bay watershed. Even the smallest of creatures plays a vital role in the overall health and production of the Bay. Forests and wetlands around the Bay and the entire watershed filter sediments and pollutants while supporting birds, mammals and fish. Small fish and crabs find shelter and food among lush beds of underwater Bay grasses. Unnoticed by the naked eye, phytoplankton and microzooplankton drift with the currents, becoming food for copepods and small fish. Clams and oysters pump Bay water through their gills, filtering out both plankton and sediment. During the fall and winter, waterfowl by the thousands descend upon the Bay, feeding in wetlands and shallow waters. Bald eagles and osprey, perched high above the water, feed perch, menhaden and other small fish to their young. The spectrum of aquatic environments, from freshwater to seawater, creates a unique ecosystem abundant with life.

Cover title. "EPA 903-R-04-003." "CBP/TRS 232/00." "July 2004." "Update of the 1994 edition and includes information through January 2004"--T.p. verso.