Spawn Timing

• Spawn Timing:

• • Influenced & constrained
  • • Temps > ~13C
  • Delayed spawning, pre-spawn mortality
  • • - (Andrew, Green 1960 as cited by McCullough 1999)
  • Acting mechanism
  • Salmon continue upstream migration
  • • Suitable temperatures
    • Commonly spawn earlier at higher latitudes

• Examples:

• • American River spring Chinook
  • • Four weeks earlier than Naches
    • Six weeks earlier than upper Yakima
  • Okanogan summer Chinook
  • • Shift in distribution
    • • Higher to lower elevation reaches