Lake Simcoe - Environmental Problems

Environmental Problems

Lake Simcoe has been victim to significant eutrophication. Lake Simcoe has seen a dramatic decline in these fish species, along with an increase in algae blooms and aquatic weed growth. Phosphorus emissions from both urban and rural sources have upset the lake's ecosystem and fostered excessive aquatic plant growth, raising water temperatures, decreasing oxygen levels, and thereby rendering limited breeding grounds inhospitable.

Lake Simcoe has been victim to zebra mussel, Purple Loosestrife, Black crappie, spiny water flea, round goby, and Eurasian milfoil invasions.

The zebra mussel, which arrived in North American waters in 1985 originated in the Black Sea and Caspian Sea area and is thought to have been brought to North America in the ballast of foreign freighters. Zebra Mussels are particularly harmful to Lake Simcoe because they increase the clarity of the water allowing sunlight to penetrate to the bottom of the lake, where more algae and aquatic weeds can grow accelerating the eutrophication process.

The Rainbow Smelt are another introduced species and they were first observed in the early 1960s. They were believed to compete with native Lake Whitefish and somewhat responsible for a decline in their populations.

Several initiatives, such as the Lake Simcoe Environmental Management Strategy (LSEMS), the Lake Simcoe Conservation Foundation, and the Lake Simcoe Region Conservation Authority, are making efforts to rectify some of the lake's environmental woes. A local activist group, The Ladies of the Lake, are using the $250,000 they raised from the sale of a nude picture calendar to rally government, business, the school system and the local citizenry to rescue the lake. Several towns and communities on the lakeshore depend on Lake Simcoe for their drinking water.

Despite its delicate ecological balance, and its recovering freshwater fishery, the Region of York is currently finalizing plans for a large capacity sewage treatment plant to be located on the Holland River in Cook's Bay. This plant's purpose is to support intensification of development in the Lake Simcoe watershed.