June 1991, Mount Pinatubo erupts sending enough ash into the atmosphere to cool northern hemisphere temperature by 1 to 3C in 1992.  This resulted in poor spawning for walleye. 1998 was the warmest year in the last 150 years in Ontario.  This resulted in phenomenal spawning success for walleye! Click here to view a larger version Click here to view a larger version Year class strength in Lake Nipissing and the French River follow these major climatic events (i.e. few to no age 9 fish and many age 3 fish!) The French River also shows what happens when you protect spawners during periods of favorable climate...good reproduction from 1998 to 2001 (also warm years). The Delta does not show this pattern...why?  Best guess is it has to do with growth and fishing regulations. To show this reproduction pattern is global in nature, here are two lakes FWINed in 2001 by the State of Washington.  Even in their moderate climate, the year-class effect is apparent. Click here to view a larger version Proactive Management  Biological Reference    Points Resource Implications     Status - Georgian Bay FWIN DATABASE | STATUS OF THE RESOURCE | REGULATORY DIRECTIONS | BEYOND OUR CONTROL

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