WSU/Pend Oreille Extension introduced the Sense of Place series in 1999, with a focus on place-based stewardship education. Since 2001, a partnership with the Kalispel Tribe of Indians Natural Resources Department (KNRD) has supported this newsletter and allowed us to expand class offerings through EPA funding. Further staff support comes through Renewable Resources Extension Act (RREA). Our newest partner, sponsor of the Rain Garden Challenge, is the Pend Oreille Conservation District. Many thanks to our partners and to you, our readers, for your continued enthusiasm for "digging" into the natural history and culture ofthis part of the world.

Native Cutthroat and Non-native Fish

by Joe Maroney, Kalispel Natural Resources Department Fisheries Biologist

Historically, cutthroat trout were distributed widely throughout the lower Pend Oreille River basin. Currently, cutthroat trout populations are depressed or extinct in many of the tributary streams. Non-native fish (mainly rainbow and brook trout) appear to be the primary factor in the decline of native cutthroat trout. Rainbow trout hybridize with cutthroat trout and dilute the unique genetic characteristics that have evolved in our local populations which allow them to adapt to their specific environments.

Brook trout out-compete cutthroat trout and can eventually displace an entire population. Brook trout are fall spawners while cutthroat trout spawn in the spring. As a result, brook trout fry emerge earlier in the spring allowing them to grow while cutthroat trout embryos are still developing. The size discrepancy is maintained throughout the juvenile life stage and the larger more aggressive brook trout juveniles displace the cutthroat juveniles from critical habitat.

Brook Trout Vs. Cutthroat Trout

• Brook trout juveniles are larger than cutthroat trout juveniles
  
• Brook trout mature sexually at an earlier age
  
  • Brook trout females become sexually mature as early as age 1.
    
  • Westslope cutthroat trout mature sexually at 3 to 5 years of age.
    
• Brook trout may live longer than cutthroat trout
  
  • In Montana, cutthroat trout lived a maximum of 8 years.
    
  • In Colorado, brook trout in high elevation streams lived 8 to 14 years.
    
• Brook trout are more tolerant of degraded habitat
  
  • Brook trout can successfully spawn in fine substrate while cutthroat trout have reduced or no survival.
    
  • Brook trout are more tolerant to high water temperatures and appear to have a competitive advantage over cutthroat trout in warm water.
    

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