Our Estuarine Sanctuary


In 1998, State Legislation designated the 400 acres of in-water area within the Park’s boundaries as an Estuarine Sanctuary. These protected waters are supported by a multi-faceted management plan to preserve and enhance the Park’s aquatic habitat and promote awareness and stewardship of the estuarine environment for the millions of New Yorkers who enjoy the Park each year. 

  • The Hudson River spans 315 miles from its source in the Adirondack Mountains to its terminus at New York Harbor.
  • Nearly half of the Hudson River’s waters, from New York City to Troy, NY are considered a tidal estuary.  An estuary is a valuable ecosystem where fresh and salt water mix, resulting in a dynamic nutrient-rich habitat with high biodiversity.
  • The Hudson Estuary provides essential habitat for many juvenile populations, including striped bass and blue crabs.


Park waters are home to a dynamic underwater world of fish, crustaceans and invertebrates.  A trademark of Hudson River Park is its many pile fields - clusters of aging wooden fragments that remain from bygone piers. The Park’s pile fields are some of the most notable elements of Hudson River Park’s Estuarine Sanctuary because of the dynamic habitat that they create and the complex food web they support. 

  • Hudson River Park is home to more than 70 different species of fish. Many of these species are highlighted in our Park Field Guide.

  • Frequently observed fish in recent years include the white perch, bluefish, striped bass, oyster toadfish and American eel.

  • Many people are also surprised to learn that our Estuarine Sanctuary is also home to a thriving population of lined seahorses!  These endearing residents wrap their tails around aquatic vegetation for support as they delicately flutter around hunting for food.


The Park’s Sanctuary waters and the ecological abundance they support have informed virtually every aspect of park planning and operations to date. Hudson River Park Trust and the New York State Department of Environmental Conservation created the Park’s Estuarine Sanctuary Management Plan to guide the decision-making and maintenance practices that affect these waters. Below are some of the ways the Park accomplishes the goals of this management plan: 


  • Each year, Hudson River Park provides hundreds of enriching and hands-on environmental education programs. In addition to creating access to the River itself, this includes communicating the River’s vital ecological role to everyone from school children to the general public.
  • In 2018, Hudson River Park hosted 410 education programs reaching over 27,000 people.


  • Hudson River Park conducts a series of environmental monitoring projects focused on studying wildlife and water quality in the Park. These projects provide data for Park managers to make informed decisions about Park planning and operations.
  • From oyster restoration stations to water quality testing, numerous citizen science projects give students and members of the general public the opportunity to engage in hands-on field science.


  • Using an Integrated Pest Management system for maintaining the Park’s green spaces reduces the use of chemicals and protects the health of the park ecosystem and its many users. For example, each spring staff manually removes invasive bagworm moth egg casings rather than applying chemical pesticides.
  • The Park’s industrial composting machine transforms plant debris and food scraps into nutrient rich soil, significantly reducing the Park’s waste stream and improving the health of its plants.


  • When reconstructing deteriorating piers into park space, in-water construction and pile driving is not allowed during winter months when sensitive juvenile fish populations are overwintering in the park.  
  • Hudson River Park has transformed Manhattan’s west side waterfront from a completely impervious concrete landscape into a stormwater buffer zone – a green space capable of absorbing rainwater and runoff.