Pesticides, herbicides and fertilizers are among the toxic pollutants that are contaminating the wetlands, fresh water and wildlife of National Wildlife Areas and Migratory Bird Sanctuaries, particularly in the Prairies. Herbicides are killing off the plant species upon which monarch butterflies depend, and these and other toxins can cause reproductive or developmental failure in wildlife. Excess fertilization of lakes and wetlands can cause massive growths of algae, which consumes the available oxygen in the water and results in an increase in fish mortality rates. These toxins may also place birds at greater risk to natural diseases, such as avian botulism, which occurs periodically in prairie wetlands.

More than 28 National Wildlife Areas and Migratory Bird Sanctuaries are contaminated with petrochemicals, oil from fuel drums, sewage, unexploded munitions, and heavy metals. Many northern and coastal sites and those along the St. Lawrence River are at grave risk from oil spills and illegal dumping of bilge water.

Pollutants affecting National Wildlife Areas and Migratory Bird Sanctuaries

Pesticides and fertilizers — 32 sites
Petrochemicals — 23 sites
Sewage — 7 sites
Heavy metals — 4 sites
Solid waste — 2 sites
Unexploded munitions — 1 site
Acid rain — 1 site

Here are two cases of pollution problems.

Pesticides threaten wildlife at Redberry Lake Migratory Bird Sanctuary
The sensitive habitat at Redberry Lake Migratory Bird Sanctuary in Saskatchewan is both unique and vulnerable. Along with the spring run-off, upon which this saltwater lake is so dependent, comes residues of pesticides and herbicides, such as "Triallate,"used extensively in surrounding croplands. Recent studies at Redberry Lake show that Triallate accumulates in the fatty tissues of amphibians and several fish species. This could be harmful for local birds that feed on fish and shrimp in the lake —particularly American white pelicans and white-winged scoters (Canada’s largest known breeding population, currently in decline).

Oil spill from cargo ships a threat to Cap Tourmente National Wildlife Area waterfowl
Each year more than 15,000 cargo ships carrying over 15 million tonnes of petroleum products pass by Cap Tourmente National Wildlife Area along the north shore of the St. Lawrence River. A fuel spill, particularly during fall migration, could kill large numbers of waterfowl and heavily contaminate their habitat. This threat was made evident in 1999 when a cargo ship spilled 15,000 tonnes of a cement compound next to Cap Tourmente. Luckily there was no damage, but it drew attention to the need for better prevention and mitigation measures.