6.9 Making Connections

LAKE ERIE: A NOT SO GREAT LAKE

Background: The Great Lakes are located in a highly populated area of North America and are susceptible to pollution from both urban and agricultural sources. In the 1960s and 1970s, Lake Erie became notorious for being heavily polluted by industrial contaminants, agricultural runoff, and raw sewage. Rivers flowing into the lake were known to catch fire owing to oil contamination, and elevated phosphorus and nitrogen led to algal blooms and massive fish kills. Following the signing of an International Water Quality Agreement in 1972 by Canada and the United States, pollution regulations were developed. By the late 1990s there was significant improvement in Lake Erie. However, a dead zone persists in Lake Erie, where hypoxic conditions prevail every year in late summer.

Case: Environment Canada is very concerned about the persistence of the Lake Erie dead zone and the threat it poses to this Great Lake ecosystem. The company where you work wants to apply for a grant from Environment Canada to investigate possible solutions to the annual dead zones.

Research the issue and write a report that includes:

1. An introduction explaining the causes of the dead zone. Be sure to take into account the following factors which can affect nutrient cycling in Lake Erie:
   1. Agricultural activities, including both crop and livestock farming in Ontario and Ohio
   2. Large cities, such as Detroit and Cleveland
   3. Industrial activities in Ontario, Ohio, and Michigan
2. A possible course of action that you think your company might want to pursue, such as greatly slowing or eliminating the pollution generated by one of the three sources listed above.