Chesapeake: The Twilight Estuary (2014)

A detective story about the investigation of an environmental mystery: What was killing the seagrasses in the Chesapeake Bay, the country's largest and richest estuary? Beneath the surface of the Chesapeake Bay, in a twilight world where shafts of light barely pierce the water, a blanket of seagrasses once flourished. These grassbeds were feeding grounds for geese and wild swans and ducks.