Year of compilation: 2001
In addition to the numerous species that stopover at the site during fall migration, several bird species breed at this site in significant numbers. Franklins Gulls nest in large colonies within the marsh, in numbers exceeding 4,500 pairs. This represents at least 1.3% of the North American population, based on upper level population estimates. In the late 1970s, 325 Forsters Tern nests were recorded in the marsh (about 1.5% of the global population). In addition, over 100 pairs of Black-crowned Night-Herons have been observed nesting in the marsh, which account for 2% of the estimated national population. Species that breed in large, though not significant numbers at the site include the Eared Grebe (100+ pairs) and the Western Grebe (125+ pairs). At least twelve species of ducks breed here mostly dabbling ducks.
Because the water levels of Lake Winnipeg are regulated by Manitoba Hydro, the physical structure of the marshes has been altered, leading to the loss of wetland habitat. Part of this change can be seen in the number of water bodies comprising the marsh: in 1960 there were 50 individual waterbodies, whereas in 1980 the number had decreased to 17. The control and maintenance of water levels also means that natural drawdowns, which encourage new plant species, are eliminated. Large floods that sweep through the Netley Marsh are a natural phenomenon that occur from time to time. These floods tend to discourage development such as urbanization and agriculture.
Other threats to the area include Purple Loosestrife, this site having the provinces largest infestation, and carp, which destroy marsh vegetation thereby removing food sources for some duck species. Rainbow Smelt and Zebra Mussels are also concerns at this site.
BirdLife International (2023) Important Bird Areas factsheet: Netley-Libau Marsh. Downloaded from http://www.birdlife.org on 29/03/2023.