The reserve is located within the York River Basin, approximately one hour north of Norfolk. Like most of the reserves in the national system, Chesapeake Bay-VA is diverse. The source of its diversity is its range of salinity gradient.
Salinity is an important determinate of what species can live in an area.
Located on the freshwater Pamunkey River, northern wild rice grows easily in the Sweet Hall Marsh component of the reserve. However, salinity is too high for it to grow at the Catlett Island component. Conversely, plants like saltwort thrive at the salty Goodwin Island component that would die if transplanted to Sweet Hall Marsh. One of the greatest threats to the Chesapeake Bay region is rapid population growth, which results in residential and commercial development. Research and educational activities at the reserve focus on these complex stresses on the nation's largest estuary.