Rose Valley, Saskatchewan
Ponass Lake is located 8 km west of the town of Rose Valley in the Aspen Parkland Ecoregion of central Saskatchewan. In 1981 Ponass Lake was designated by the Province as Saskatchewan's first Heritage Marsh. Water levels for the marsh are controlled by a series of dams built and operated by Ducks Unlimited Canada (DUC). The 2,995 ha marsh complex consists of 6 basins ranging in size from 98 ha to 1,631 ha, and has approximately 162 km of shoreline. The basin is rectangular in shape, approximately 15km long and 10 km wide. Adjacent to this marsh project within the IBA are several other large marshes some of which are also managed by DUC. The lake is shallow with an irregularly-shaped, much-indented shoreline. Lake water levels can fluctuate greatly between years, as Ponass Lake is dependent on drainage from intermittent creeks, spring runoff and seasonal rainfall; however this has been changing with increased wetland drainage into the marsh. Most of the land surrounding the lake is cultivated, but there is native prairie and some aspen groves along the north and west shore of the lake. The Lake and the 1,600 ha of native uplands that surround it is mostly Crown Agricultural land leased to ranchers for hay and pasture. The Crown land is protected from sale, breaking, and clearing by the Saskatchewan Wildlife Habitat Protection Act. The private lands surrounding the marsh, while dotted with small potholes, are primarily cultivated for cereal grain production. The upland vegetation is dominated by native wheatgrasses and fescues with scattered bluffs of snowberry, willow, and trembling aspen. Aquatic vegetation consists of cattail, hardstem bulrush, water milfoil, and pondweed. According to Environment Canad,a Ponass Lake is located within an area that is rated as nationally important for migratory birds, breeding ducks, staging ducks, geese, and shorebirds, and regionally important for colonial waterbirds. Duck breeding densities range from 20 to 60 breeding pairs per square mile and pintail breeding densities range from 2 to 10 per square mile. Ducks at Ponass Lake Marsh number in the tens of thousands, while Canada Geese and Sandhill Cranes number in the thousands, and snow geese number in the hundreds of thousands. Other noteworthy birds include migrating endangered species such as Whooping Crane and Peregrine Falcon. Other wetland birds include American Coot, Black-crowned Night-heron, American Bittern, Sora, American White Pelican, Black Tern, Common Tern, Pied-billed Grebe, Red-necked Grebe, Great Blue Heron, and Franklin's Gull.
Ponass Lake is a globally significant site for staging waterfowl and nationally significant for staging Sandhill Cranes. On September 12, 1994, 2,740 Canada Geese, 30 Greater White-fronted Geese, 360 Snow Geese, 15,270 ducks and 635 Sandhill Cranes were observed at the lake. By the time a second survey was conducted on October 5, 1994, Snow Geese numbers had increased to 17,550, but duck numbers had decreased. In total, 18,400 waterfowl were recorded in the earlier survey and 24,650 waterfowl were counted in the later. Additionally, a separate survey of an unknown date noted over 12,000 ducks in the fall.
Small numbers of Canada Geese breed at this site (15-30 pairs) and Ponass Lake is locally important for moulting ducks.
The threats to the site include loss of upland habitat, overgrazing, and pollution by agricultural pesticides and fertilizers. The main threat to the area is the drainage of wetlands surrounding Ponass Lake and the flooding it causes on the lake. Over 70% of the wetlands surrounding the lake have already been drained and drainage continues unabated. A provincial wetland drainage policy exists but it is rarely enforced. Land prices in this area are very high and increasing land values and high agricultural commodity prices in recent years have provided additional incentives to private landowners to drain wetlands, clear land, and cultivate them. Ponass Lake drains into the Quill Lakes IBA which adds additional threats to those lakes. In addition, changes to the Saskatchewan Wildlife Habitat Protection Act in 2014 will allow for the sale of Crown land with or without the protection of a no break / no drain Conservation Easement (CE). It is unknown at this time if any of the Crown Lands within the Ponass Lake IBA will require a CE as a condition of sale.Catégories ZICO Habitats Usages Menaces Potencielles ou Existantes Status de Protection