The Nelson River empties into western Hudson Bay about 150 km downstream from Gillam, Manitoba. Marsh Point protrudes into Hudson Bay between the outlets of the Nelson River on the west and the Hayes River on the east. The substrate of this area consists of fine sand and gravel deposits. The land between the estuaries of these two rivers is known as Marsh Point and is extremely flat. It contains extensive tracts of grasses and willows interspersed with many bogs and small clumps of Black Spruce. There are no major rock outcroppings in the area. The land behind the Nelson River estuary is boggy and has extensive expanses of stunted spruce. The gently sloping tidal flats receive tides that reach four metres.
Mammals found at this site include Polar Bear, Caribou, Timber Wolf and Beluga Whale. This site is a major summer staging, breeding and calving area that contains as many as a few thousand Belugas on peak days.
Over 1,000 Black Scoters have been recorded here in the spring. If these birds are all of the eastern Black Scoter population then this represents about 1.5% of this population.
In the fall, this site supports congregations of North American Ruddy Turnstones (ssp. morinella), with 600 or more being reported in one day; the total for the fall season would be much higher considering turnover rates. Other species of shorebirds found at this site in the fall include Semipalmated Sandpiper (1,000), Dunlin (400), and Least Sandpiper (650). Other waterbirds found include White-winged Scoter (1,000), Surf Scoter (300), Sandhill Crane (75) and Bonaparte's Gull (850). Bald Eagles are also frequently seen.
BirdLife International (2020) Important Bird Areas factsheet: Nelson River Estuary and Marsh Point. Downloaded from http://www.birdlife.org on 04/12/2020.