Climate Change, Recreational Demand and the
Future of Lake Champlain Game Fisheries
Chris Childers, Cara Schacher, Jeffrey Passman,
Lauren Schmitt, Cody Warren
Game Fisheries
The fish people fish
for
In Lake Champlain,
that’s




Trout
Bass
Perch
Salmon
Questions
Whats the status of the game fish pops in the
lake (Are they self-sustaining? endangered?)
How do people place a demand on these
populations?
How are these populations managed?
How will climate change affect the
communities these fish live in?
What factors are most important to managers
in the face of climate change?
Why is it important?
People like fishing
Economic draw to
the region
The fish were here
first
Approach
3 angles



basic response of typical Lake Champlain fish to
changing water temperatures
present and predicted changes in community
structure resulting from range shifts and altered
food webs
the importance of VT’s fish and wildlife service,
providing an economic draw to the region through
management of the fisheries
Climate Change
Climate Modeling
Start with SRES
-IPCC’s Special Report on Emission
Scenarios
A1F1 – 1000 ppm CO2
B2 – 500 ppm CO2
(Nakićenović, N., et al. 2000.)
Climate Modeling
AOGCM
- Atmospheric Ocean General Circulation
Model
Inputs – SRES and Physical Processes of Cell
Outputs – Temp. Precip. Humidity
Hayhoe et al., 2007.
Climate Models
•Heat Waves
•Precipitation
•Extreme Events
•Soil Moisture
•Drought
•Stream Flow
•Winter Storms
•Timing of Seasons
•Sea Level Rise
NECIA, 2006
Climate Models
Connection from Air
to Water?
As Air Temp Rises,
Water Temp Rises
Not a linear function
Logistics Curve suggest evaporative cooling in
warmer temps
Two lines reflect seasonal heating and cooling
‘hysteresis’
Mohseni et al. 2003
Climate Models
Heat Index and Migrating States
Mary Watzin Presentation
NECIA, 2006
Effects on Individual Habitat
Cold Blooded – Temperature Controls
Metabolism
Optimal Ranges and Lethal Ranges
Ficke et al. 2007
Effects on Individual Habitat
C = (Mr+Ma+SDA) + (F+U) + (Gs+Gr)
Equation derived in 1977 by Kitchell et al.
C= Energy Consumption
M terms = metabolic rates and increases due to activity
F+U = Waste
G= Growth of Reproductive or Somatic Cells
Yellow Perch Energy Budget
From Ficke et al 2007.
Effects on Individual Habitat
Dissovled Oxygen
-At 0°C dissolved oxygen content is
14.6mg/L whereas at 25°C, only
8.3mg/L
Altered Hydrologic Flows
Increased Pollutant Toxicity
Thermal Habitat: A Case Study
Largemouth Bass
Rainbow Trout
Channel Catfish
Focus on Largemouth Bass
Thermal Habitat: A Case Study
Natural processes are unsystematic
Attempt to encompasses a realistic
fluctuation of temperatures

Fish exposed to a 32 day period of cycling
temperatures
Thermal Habitat: A Case Study
Temperature cycled consistently from
20-30°C
Rate of change: 0.3±0.01°C/min
Maximum temperature occurring at
midnight
Minimum temperature occurring at
midday
Thermal Habitat: A Case Study
Results


Trails were stopped when the fish
experienced a loss of equilibrium
Temperature range for largemouth bass
 Mean maximum 35.6-37.3°C
 Mean minimum 5.9-7.7°C
Case Study: Yellow Perch
(Perca flavescens)
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Photo courtesy of US Fish and Wildlife Service
About Perca flavescens
Size: Up to 18 inches
Yellow/Green color with 6-8 dark
vertical bands
Compressed, elongate body
Adults eat small fish, crustaceans,
insects
Fry eat copepods and cladocerans
Habitat Considerations
Prefer lake shallows
Ideal Summer Temp: 69-77˚F
Adult Temperature SI
Juvenile Temperature SI
Predictions
Juveniles will be most sensitive to
temperature increases, and changes in
prey populations
Decreased vegetatation
Increased turbidity
Ideal pH= 6.5-8.5
Could Climate Change be a good
thing for Yellow Perch?
More successful year-classes due to:


Higher water levels (MO River)
Increased water temperature during
hatching
Communities
Communities
The fish we enjoy are products of their
communities
Have been (relatively) stable
Climate Change could upset the balance
Range Shifts
Climate change ->
increased water
temperatures
Redistribution of
thermal habitat
throughout the lake
Not the same for
each fish
New Communities
Water temps increase-> individual
species shift range-> new communities!
Uncertainty
Diseases? Parasites? Competitors?
Similar fish, similar shifts?
New communities-> new ecosystems
services, products
Food Webs
Another driver of
community structure
-> food!
Competition,
predation
Food Webs
Very interconnected
Kim and LaBar 1996

Trout, salmon and walleye
 Rainbow smelt
Similar to range shifts
Food supply moves, follow it

What if you can’t?
Ecotourism
Ecotourism and Climate
Change
One of the most important and rapidly
growing service industries
Closely tied with environmental quality
Climate dependent
Mixed reactions
Ecotourism and Climate
Change
Fixed waterfront facilities vulnerable to
flux in water levels
Lowered lake levels will cause
conversion to dry land, eventually
Lack of water results in less habitat


Decreases in spawning
Further loss of tourists
Ecotourism and Climate
Change
In Wall’s 1998 paper, he noted that
“…declines in the striped bass sport fishery
associated with reduced freshwater inflows
into the San Francisco bay and delta have
been estimated to have cost the state of
California $28 million since 1970.”
What does this mean for Lake Champlain?
Ecotourism and Lake
Champlain
Several salmonoid species are at the
southern limits of their range in New
England

Projected to be partially or completely
displaced
Will have to travel to other regions
where these species are still available
Loss of income to support conservation
projects
Management
Vermont Fish and Wildlife
Dept.
2009 budget= $17million
Stock: landlocked Atlantic Salmon,
steelhead, brook, lake, brown and
rainbow trout. Also salmon fry and
walleye fingerlings.
Almost 600,000 fish between Lake and
inland waters
Stocking
Loss of genetic variation

Due to bottleneck
Harder to adapt
Wild hybrids?
Already artificial populations

Need as much help as we can give
Fishing
Number of Fishing Tournaments
# Permitted Tournaments
Most of the demand
comes from
tournaments
Increasing, leveling
off, decline
Costs, rules
200
167
137
150
105
176
152
156
131
113
113
100
60
50
0
Year 1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
Problems
Vermont Angler Survey 2000
Residents' Opinions of Tournaments
8% 3%
No Problem
16%
Minor Problem
Moderate Problem
Serious Problem
73%
Boat Traffic
Fish Handling
Conclusions
We Conclude…
Species-dependent range shifts will
break up communities

Magnitude and direction of all shifts is still
uncertain
New communities will form

New food webs, competition, predation
-> stress
We Recommend…
May be too late to prevent range shifts
Adaptive management


Intensive monitoring in years to come
Evaluation of success and methods
We Conclude…
Vermonters pay a bundle for VFWD

$17 million!
Already very carefully managed
Some loss of genetic variation
We Recommend…
No need for complete overhaul of
VFWD practices or procedures

Focus should be on clean disease free
rearing facilities and maintaining genetic
variation
Other Thoughts
# tournament permits has declined
recently


VFWD recently raised the price of permits
Lower price to encourage participation
Better co-ordination by tournament
organizers


Minimize boat traffic
Encourage good fish handling procedures
Questions?