1. TROUBLE IN THE SWEET SEAS:
THE SAGA OF GREAT LAKES POLLUTION
Chicago, Jan. 23, 2013
James P. (Jim) Bruce, O.C., FRSC

9. Lake Erie Lake Huron Lake Superior
Seasonal Average Ice Cover (%)
Seasonal Average Ice Cover (%)
Seasonal Average Ice Cover (%)
60 60 60
50 50 50
40 40 40
30 30 30
20 20 20
10 10 10
0 0 0
1970 1980 1990 2000 2010 1970 1980 1990 2000 2010 1970 1980 1990 2000 2010
Winters 1973 -2008 Winters 1973 -2008 Winters 1973 -2008
Lake St. Clair Lake Michigan Linear Trends
Seasonal Average Ice Cover (%)
Seasonal Average Ice Cover (%)
Seasonal Average Ice Cover (%)
60 60 5-year moving average
50 50 50 St. Clair
40 40 40
Erie
30 30 30
Huron
20 20 20
10 10 10 Michigan
0 0 0 Superior
1970 1980 1990 2000 2010 1970 1980 1990 2000 2010 1970 1980 1990 2000 2010
Winters 1973 -2008 Winters 1973 -2008 Winters 1973 -2008

14. Tens of thousands of dead fish rotting on Lake Erie shore
Toronto Star 4 September 2012

17. August 2010 ⁰C above Temps near
normal Surface ⁰C
Superior 8 21
Michigan 4
Erie 27
Ontario 24
(Austin, 2010, U. of Minn. Duluth)