Transcript Milltown 2003 - ScholarWorks

Scale and Permanence
• Dam removal provided a permanent solution in
a way no engineering fix can approach
• Quickly and effectively influenced a huge
geographic area
• Appropriate scale for recovery of species
– context of climate change
– other challenges that other projects lack
– e.g., Bond and Lake 2003 and others
Overview
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•
•
•
•
Background
Dam and sediment removal
Research: Effects of dam
Dam and sediment removal monitoring
Changes since dam removal
Research, 1996-present
• Upstream passage
• Reservoir- northern pike
• Effects of dam removal
Upstream fish passage
• Determined timing, abundance and species
• Captured >50,000 fish/ year
• Estimated >200,000 fish impeded/ year
– 12 species
– Transported westslope cutthroat and bull
trout
Schmetterling & McEvoy 2000, Schmetterling 2003, Schmetterling & McFee 2006
Schmetterling 2003
Schmetterling & McFee 2006
After dam removal
• Reconnected huge areas
– ca. 370 westslope cutthroat and 75 bull
trout annually
– Most to North Fork and Monture
– Increase redds by 20%
• (Schmetterling 2003)*
– 10’s of thousands of suckers
• Transfer of biomass and nutrients
• Benefits transcend fish
• (Schmetterling and McFee 2006)
• “So many crowd the banks …could’ve filmed ‘The Birds’”
• “>20 eagles in 25 mile reach”
• “this time of year, fish are the easiest food for bald
eagles”
Conclusions
• “No fish in this section of river”
• “Young eagles don’t know where to go”
• “Bald eagles like fish, so what are they doing?”
• “Maybe they are eating roadkill”
• “…concern for their safety”
Overview
• Upstream passage
• Reservoir- northern pike
• Effects of dam removal
Adult northern pike population size
3000
(>400 mm)
2000
1500
1000
500
0
M
ar
-0
2
Ju
l-0
2
N
ov
-0
2
M
ar
-0
3
Ju
l-0
3
N
ov
-0
3
M
ar
-0
4
Ju
l-0
4
N
ov
-0
4
M
ar
-0
5
# Pike
2500
Overview
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•
•
•
Upstream passage
Downstream passage
Reservoir- northern pike
Effects of dam removal
– Short term effects
Trout densities, 2004-2008 (> 175 mm, ±SD)
500
450
400
# trout/ km
350
300
250
200
150
100
50
0
04 05 06 07 08
Turah
04 05 06 07 08
Blackfoot
04 05 06 07 08
Milltown
Year/ Location
04 05 06 07 08
Bitterroot
04 05 06 07 08
Huson
Trout densities, 2008-2014 (> 175 mm, ±SD)
500
450
400
# trout/ km
350
300
250
200
150
100
50
0
Turah
Blackfoot
Milltown
Bitterroot
Huson
08 10 12 14 08 10 12 14 08 10 12 14 08 10 12 14 08 10 12 14
Population Monitoring
• Pre– Densities changed, but similar trend regionally
• Dam removal (2008)
– Significant declines
– Movement
• Post- removal (2009-)
– No effect
– Redistribution
– Recovery
Northern Pike in Clark Fork River
• Before removal
– ca. 60/ km
– Handled ca. 70-100/ year
• After dam removal
– too few to estimate
– Handled 2 in 2014
Overview
• Background
• Effects of dam
• Changes since dam removal
Changes
• Location
• Species composition
• Community and ecological changes
Changes
• Location
– Changes will occur on a broad scale
– Diverse populations
• Species composition
• Community and ecological changes
Changes
• Location
• Species composition
– Reservoir
• Drastic lentic to lotic
– River
• Subtle
– Same species present above as
below
• Community and ecological changes
Changes
• Location
• Species composition
– River
• Subtle?
• Community and ecological changes
Changes
• Location
• Species composition
– River
• Subtle?
• No so much
• Community and ecological changes
Species composition changes in river
• Clark Fork Upstream of Milltown Dam
– Historically brown trout dominated
– Up to 95% brown trout
– After dam removal, westslope cutthroat
trout and rainbow trout appeared
• Oncorhynchus species
Bearmouth Section, Clark Fork
120
Brown trout
100
Oncorhynchus
#/ km
80
60
40
20
0
2010
2011
2012
Year
2013
2014
Changes
• Location
• Species composition
• Community and ecological changes
– Resiliency
– Life history expression
• Selected against migrations
– Benefits outside of the water
• We just have to look
Changes
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•
•
•
Location
Species composition
Community and ecological changes
What about bull trout?
– Very few individuals and populations
• Difficult to monitor
• Different lines of evidence
– Redd surveys
Bull Trout ReddsBefore Dam Removal (2001-2007)
160
140
# redds
120
100
Treatment streams
80
60
40
Control Streams
20
0
2001
2002
2003
2004
Year
2005
2006
2007
Bull Trout Redds After Dam Removal
160
140
# redds
120
100
80
60
40
20
0
2008
2009
2010
2011
Year
2012
2013
2014
Bull trout population trends in MT rivers and streams
Bull trout population trends in MT rivers and streams
Conclusions
• What is often viewed as impossible,
doesn’t have to be
• There was a dam in the river that would be
there forever
• And now, the dam’s gone.