Studying Hudson River Sturgeon to Promote Conservation Measures for Endangered Species

The New NY Bridge at Tappan Zee


The New NY Bridge at Tappan Zee


Rockland and Westchester Counties, NY


New York State Thruway Authority

One of AKRF’s contributions to the construction of The New NY Bridge at Tappan Zee has been a series of studies to learn more about the ecology of Hudson River sturgeon. These “Net Conservation Benefit” studies are part of the Endangered and Threatened Species Mitigation Plan prepared by AKRF in 2013 on behalf of the New York State Thruway Authority, as required by the New York State Department of Environmental Conservation (NYSDEC). This plan was devised and implemented alongside a series of compensatory mitigation projects required by the NYSDEC permit to offset potential environmental impacts caused during construction and operation of the New NY Bridge.

To ensure a net conservation benefit to shortnose and Atlantic sturgeon, a series of studies was undertaken to provide a better understanding of sturgeon ecology within the Hudson River. These efforts include:

  • Mapping of shallow-water benthic habitats throughout the unmapped portions of the Hudson River to locate foraging habitat for shortnose and Atlantic sturgeon
  • A foraging study to describe the diets of several life stages of shortnose and Atlantic sturgeon in the Hudson River
  • A tagging and tracking study to determine the large-scale and localized movement patterns and benthic-habitat use by Hudson River sturgeon
  • An outreach effort directed at the commercial fishing industry to reduce the impacts of commercial by-catch of Atlantic sturgeon in coastal fisheries

AKRF and NYSDEC are cooperatively conducting tagging and tracking activities. Information on sturgeon movement and distribution in the river will be interpreted using habitat maps that will be produced by AKRF using acoustic data collected during an ongoing shallow benthic-mapping survey of 100 miles of Hudson River between Saugerties and the Battery.

In addition to the sturgeon conservation studies, the compensatory mitigation projects required by the NYSDEC permit include:

  • Oyster Restoration—re-establishment of 13 acres of hard bottom/shell oyster habitat
  • Secondary Channel Restoration—to promote an increase of habitat diversity and function at Gay’s Point
  • Wetlands Enhancement—enhancement and restoration of wetland habitat at Piermont Marsh

Project New NY Bridge illustration

Prior to the start of bridge construction and the initiation of the sturgeon tagging and tracking studies, AKRF led the complex environmental review and permitting process for the Tappan Zee Hudson River Crossing Project. The New NY Bridge will replace this vital link in the regional and national transportation network that carries approximately 134,000 vehicles each day and provides the only interstate Hudson River crossing for a 48-mile stretch between the George Washington Bridge and Newburgh-Beacon Bridge.

Natural Resources Overview