The Extent of NonnativeFish & Amphibians in Oregon & the West

Slide 1: (illustration) A Few Oregon Non-natives

Slide 2: Title: The Extent of NonnativeFish & Amphibians in Oregon & the West

Thom Whittier – OSU
Gregg Lomnicky – Dynamac, Inc.
Bob Hughes – OSU
Dave Peck – U.S. EPA

Slide 3: Those Questions

Are they

Valid?
Interesting?
Useful?

Slide 4: Answering Those Questions

• Ask a professional
• Gather existing data
  • More is better (go for lots of dots on maps)
  • Good Luck
    • Finding it
    • Checking for quality/consistency
    • Making it fit together
  • When you’re done, you still won’t have a statistically valid answer

Slide 5: Answering Those Questions

• Apply Statistical Survey Methods
  • aka Probability Design
  • analogue to a Gallup survey of voters
• Infer condition of entire population from a small sample
• Answer with known confidence
• Can be applied at range of scales

Slide 6: Answering Those Questions

Basic Rules

• Involve a Survey Statistician – up front
• Define “population” of interest
• Determine how many sites you can afford
• Randomly select sites to sample
• Determine sites’ Inclusion Probabilities
  (Inverse = Site Weight)
• Understand & follow the Design!!

Slide 7: EMAP Western Survey

• Target Population = all perennial flowing streams & rivers in 12 western states
  • Except mainstem Colorado, Columbia & Missouri Rivers
  • Excluded impoundments & diversions
• 965 Probability Design Sites
  • 119 sites with inadequate fish samples
  • 66 sites with no fish or amphibians
• 711 sites for this analysis

Slide 8: (map) EMAP Western Survey

Slide 9: Fish & AmphibianSampling

• Wadeable Streams
  • 40 x wetted width (150 m minimum)
  • single pass backpack electrofishing
• Non-Wadeable Streams & Rivers
  • 100 x wetted width
• 5000 W electrofisher on raft with rowing frame
• alternate sides every 20% of length
  

Slide 10: Most Widespread Non-Native Fish in the West?

Slide 11: Most Widespread Non-Native Fish in the West?

#1 – Brook Trout 17% (+ 3%)

Slide 12: Most Widespread Non-Native Fish in the West?

#2 – Brown Trout 16%

Slide 13: Most Widespread Non-Native Fish in Oregon?

Slide 14: Most Widespread Non-Native Fish in Oregon?

#1 – Smallmouth Bass

Slide 15: Most Widespread Non-Native Fish in Oregon?

#2 – Brown Bullhead

Slide 16: What portion of Oregon stream & river length

• Has at least one non-native fish or amphibian?

Slide 17: What portion of Oregon stream & river length

Has at least one non-native fish or amphibian?
20% ( + 9%)

Slide 18: Skip ahead to Question 4

• Which western States are most invaded by non-native fish?
• Which are least invaded?
• Stream length with non-natives
  • Colorado 86%
  • Montana 86%
  • Arizona 83%
  • Utah 74%
  • S. Dakota 70%
  • Nevada 70%
  • N. Dakota 66%
  • Wyoming 63%
  • Idaho 41%
  • California 34%
  • Washington 21%
  • Oregon 20

Slide 19: (map) EMAP Western Stream & River Survey

Slide 20: Why is Oregon So Different?

Slide 21: Why is Oregon So Different?

• Most of West has 1or 2 native trout

Slide 22: Why is Oregon So Different?

• Most of West has 1or 2 native trout
• Oregon has 3 native trout plus steelhead, Coho & Chinook salmons

Slide 23: Why is Oregon So Different?

• Most of West has 1or 2 native trout
• Oregon has 3 native trout plus steelhead, Coho & Chinook salmons
• Rainbow trout is native in Oregon

Slide 24: What portion of Oregon stream & river length

• Has any non-native fish or amphibians?
  • 20% ( + 9%)
• Has common carp?

Slide 25: What portion of Oregon stream & river length

• Has any non-native fish or amphibians?
  • 20% ( + 9%)
• Has common carp?
  • 2%

Slide 26: What portion of Oregon stream & river length

• Has any non-native fish or amphibians?
  • 20% ( + 9%)
• Has common carp?
  • 2%
• Is dominated by Non-Native Fish?

Slide 27: What portion of Oregon stream & river length

• Has any non-native fish or amphibians?
  • 20% ( + 9%)
• Has common carp?
  • 2%
• Is dominated by Non-Native Fish?
  • 6%
  • Compared with 22% in the West

Slide 29: Oregon Stream Length with Non-Native Fish & Amphibians

• Smallmouth Bass 5%
• Brown Bullhead 5%
• Bullfrog 4%
• Largemouth Bass 4%
• Brook Trout 3%
• Black Bullhead 2%
• Common Carp 2%

Slide 30: Oregon Stream Length

• Non-Natives
  • Smallmouth 5%
  • Brn Bullhead 5%
  • Bullfrog 4%
  • Largemouth 3%
  • Brook Trout 3%
  • Blk Bullhead 2%
  • Carp 2%
• Natives
  • Rainbow Trout 54%
  • Cutthroat Trout 42%
  • Tailed Frog 36%
  • Gnt Salamander 30%
  • Speckled Dace 28%
  • Retic. Sculpin 22%
  • Redside Shiner 21%

Slide 31: Oregon Stream Length

• Non-Natives
  • Smallmouth 5%
  • Brn Bullhead 5%
  • Bullfrog 4%
  • Largemouth 3%
  • Brook Trout 3%
  • Blk Bullhead 2%
  • Carp 2%
• Natives
  • Rainbow Trout 54%
  • Cutthroat Trout 42%
  • Tailed Frog 36%
  • Gnt Salamander 30%
  • Speckled Dace 28%
  • Retic. Sculpin 22%
  • Redside Shiner 21%

Slide 32: Slide 1: (illustration) A Few Oregon Non-natives

Slide 33: "Angling for spiny-rayed fishes has been slow to take in hold in Oregon.  In the past, Waltonians were prone to look askance at the abundant warm-water fishes.  To those anglers, trout were the supreme fish in Oregon and to be caught angling for the lowly crappie or sunfish was indeed a blow to their fishing prestige. 

"Today, thousands of anglers - many who were confirmed trout addicts - are finding pleasure and recreation in fishing for the warm-water denizens.  They have found that it not only takes fishing skill, but that on light tackle these fishes are indeed scrappers in the finest sense, and their table delicacy is unsurpassed." -- http://www.dfw.state.or.us/swwd/warmwater.html

(For more information contact the author at thomas.whittier@oregonstate.edu