Botulism | Drainage | Pesticides | Oil | Agriculture | Invasive Weeds

Avian Botulism
Avian Botulism can be viewed as a naturally occurring threat to bird populations, especially waterfowl and shorebirds. Whitewater Lake is susceptible to botulism outbreaks, such as in 1996 with it was estimated that as many as 117,289 bird carcasses were collected after a botulism outbreak. Pratt (1996) reported that during the summer of 1996 approximately 84,220 ducks and 34,240 others (shorebirds, coots, grebes, geese, and others) died of botulism. A high number of American Coots and grebes were collected during the 1996 clean-up efforts. Recent data indicate that 49,000 (1997), 19,000 (1998) and 15,000 (1999) birds were lost to avian botulism at Whitewater Lake.

Avian botulism results from a food poisoning like neurotoxin produced predominately by the bacterium, Clostridium botulinum Type C. The organism is a strict anaerobe which forms dormant spores in the absence of oxygen and other adverse environmental condition. Spores of Type C botulism are widely distributed in wetland sediments and in the tissues of aquatic insects, mollusks and vertebrates. Despite the widespread distribution of Type C botulism spores outbreaks of avian botulism are sporadic and unpredictable.

Drainage
Whitewater Lake is a catchment basin with no water outlet. Some landowners would like to have an outlet for the lake established. Conflicts have existed for many years between landowners and conservation organizations regarding management of water levels. Water levels in the lake determine property lines. There is a continuing interest by some landowners to construct a water outlet.

Pesticides
Pesticide runoff from adjacent agricultural fields is identified as a threat to Whitewater Lake. Fertilizer and pesticides from both surface and subsurface flow is also a threat. It is unknown if any agency is monitoring pesticide levels in the basin. The potential for the herbicides to drift though the air and contaminate wetlands such as Whitewater Lake is also a concern.

Oil and Gas Development
The center portion of Whitewater Lake has partial protection from logging and hydro-electric development but is not protected from oil and gas development. There is interest in oil extraction in the region. Record of oil lease and drilling adjacent to the lake go back to the 1950's and 1960's. Oil and gas developments may have deleterious impacts in avifauna habitat. Possible spills and seepages would degrade the water quality.

Agricultural Practices
Agricultural practices outside the WMA continue to result in the loss of perennial cover as some landowners convert pastureland into annual crops. Grazing has resulted in waterfowl habitat destruction in some years. In 1970, Ransom and Hochbaum (1972) reported several miles of habitat between the waters edge and private lands was heavily grazed, in many cases without permit. The results were stands of barley grass, and gumweed which provide poor nesting cover for waterfowl.

Exotic Invasive Weeds
Globalization has resulted in an accelerated rate of biota transfer between continents. Many of these alien introductions have had economic and ecological consequences. Invasive alien species are the greatest threat to the biological ecosystem second only to habitat loss. weeds of concern include Canada Thistle, Purple Loosestrife, Flowering Rush, Leafy Spruge and Salt Cedar. Kochia is a noxious weed that has proliferated in the general area. Other exotic invasive species of concern include Eurasian water-milfoil which was found in North Dakota along the Sheyenne River in 1996 and Salt Cedar which was introduced from Eurasia in the 1800's as an ornamental.

Purple Loosestrife has Noxious Weed Status and can be found throughout southern Manitoba. Purple Loosestrife is not currently found in Whitewater Lake. Efforts to prevent an invasion of Purple Loosestrife should target awareness activities.

Flowering Rush is an aquatic plant that most often grows as an emergent on wet soil or in shallow water to about one meter deep. The species can also grow as a terrestrial plant on drier area, but emergent and terrestrial plants are identical in appearance. Flowering Rush has invaded several aquatic habitats in Manitoba. Whitewater Lake should be monitored annually for Flowering Rush infestations.

Salt Cedar is a deciduous or evergreen shrub or a small tree, usually 5 to 20 feet tall that can cause enormous damage to aquatic ecosystems. Damage by Salt Cedar includes the displacement of the extremely valuable cottonwood, willow, seepwillow, baccharis, mesquite and other native plant communities, often by dense monotypic thickets of Salt Cedar. Also, it uses great amounts of ground water and lowers water tables, causing springs to dry up and native plants to perish. Salt Cedar infestations can be found in the northern parts of Montana and is expanding its range northward toward the Whitewater Lake area.

Leafy Spruge infestations in southwestern Manitoba already impact several vulnerable species protected under Manitoba Protected Species Act including the Western Spiderwort, Baird's Sparrow and Small White Lady Slipper. A Leafy Spurge infestation around Whitewater Lake degrades available grassland habitat. Current infestation levels in the area are categorized as light.