An estuary is a body of water where rivers meet the sea and salt
meets fresh water. The unique characteristics of these waters
make estuaries rich, productive, and diverse ecosystems where
many types of plants and animals live. The geologic history and
physical characteristics of the Harbor Estuary particularly
contribute to this diversity. Positioned at the confluence of
the Hudson River and many smaller rivers such as the East,
Hackensack, and Raritan, the estuary opens into the New York
Bight and Long Island Sound. Its complex physical history
includes a diversity of landforms, bedrock types, and plant and
animal communities. Stones and boulders left over from the most
recent glacial advance span from Long Island northwest into the
New York-New Jersey Highlands (such as in Palisades Interstate
Park) and southwest to the southern tip of Staten Island. The
Harbor Estuary is home and essential habitat to many resident
and migratory species. A rich human history also surrounds the
harbor, as people have been d