Stretching from near Morristown to the Moses Saunders Dam,
approximately 60 miles downriver, the Lower St. Lawrence River
encompasses a range of wetland and upland habitats. This site is
primarily privately owned, but significant acreage is administered by
the New York State Power Authority. Additional land is administered
by NYS OPRHP and NYS DEC. Two undeveloped islands, Croil
Island State Park and Long Sault Island, totaling 1,100 acres, are the
largest undeveloped islands in the lower Great Lakes. These islands
contain old growth oak forests and significant natural communities,
identified by the NY Natural Heritage Program. There are a number
of state parks in the area and one state Wildlife Management Area
(WMA)?the 3,450-acre Wilson Hill WMA.
This site supports large numbers of breeding Common Terns (over 450
nests in 12 colonies). There is a very large and globally significant Bank
Swallow colony (3,000 plus pairs in 1992; larger than 95% of all Bank
Swallow colonies in North America) at Sparrowhawk Point, north of
Ogdensburg. Bald Eagles winter along the river (up to 64 counted in
2001), and the area is very important for wintering waterfowl as well.
Additional at-risk species supported at the site include the American
Black Duck (winter), Common Loon, Pied-billed Grebe, Least Bittern,
Northern Harrier, Wood Thrush, and Cerulean Warbler.
This site is listed in the 2002 Open Space Conservation Plan as a priority
site under the project name St. Lawrence River Islands, Shorelines, and
Wetlands. A major factor affecting the health of Common Terns and
other fish-eating species is the level of toxins found in the ecosystem.
Studies of Common Tern eggs and forage fish in the St. Lawrence from
1986 to 1989 documented the presence of organochlorines, including
PCBs, dieldrin, metal and trace elements, including mercury, selenium,
copper, aluminum, and cadmium. The levels of several organochlorines
and mercury exceeded the no-observed-adverse-effect level and the
lowest-observed-adverse-effect level for sensitive species, and may
have contributed to low levels of reproductive success. Further work is
needed to monitor the reproductive success of other fish-eating birds,
and the levels of environmental toxins in the river. The river is a very
popular area for recreational boating and fishing, which can potentially
disturb birds, especially terns and herons at breeding colonies. Airboats
and hovercraft may also disturb wintering birds. Continuing land
development pressure is a threat wherever waterfront property exists.
Inventory and monitoring, especially of at-risk bird species, should