Climate Change, Recreational Demand and the Future of Lake Champlain Game Fisheries

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Climate Change, Recreational Demand and the
Future of Lake Champlain Game Fisheries

• Chris Childers, Cara Schacher, Jeffrey Passman,
  Lauren Schmitt, Cody Warren

2
Game Fisheries

• The fish people fish for
• In Lake Champlain, thats
• Trout
• Bass
• Perch
• Salmon

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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?

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Why is it important?

• People like fishing
• Economic draw to the region
• The fish were here first

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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 VTs fish and wildlife service,
  providing an economic draw to the region through
  management of the fisheries

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Climate Change
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Climate Modeling

• Start with SRES
• -IPCCs Special Report on Emission Scenarios
• A1F1 1000 ppm CO2
• B2 500 ppm CO2
• (Nakicenovic, N., et al. 2000.)

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Climate Modeling

• AOGCM
• - Atmospheric Ocean General Circulation Model
• Inputs SRES and Physical Processes of Cell
• Outputs Temp. Precip. Humidity

Hayhoe et al., 2007.
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Climate Models

• Heat Waves
• Precipitation
• Extreme Events
• Soil Moisture
• Drought
• Stream Flow
• Winter Storms
• Timing of Seasons
• Sea Level Rise

NECIA, 2006
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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
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Climate Models

• Heat Index and Migrating States

NECIA, 2006
Mary Watzin Presentation
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Effects on Individual Habitat

• Cold Blooded Temperature Controls Metabolism
• Optimal Ranges and Lethal Ranges

Ficke et al. 2007
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Effects on Individual Habitat

• C (MrMaSDA) (FU) (GsGr)
• Equation derived in 1977 by Kitchell et al.
• C Energy Consumption
• M terms metabolic rates and increases due to
  activity
• FU Waste
• G Growth of Reproductive or Somatic Cells
• Yellow Perch Energy Budget

From Ficke et al 2007.
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Effects on Individual Habitat

• Dissovled Oxygen
• -At 0C dissolved oxygen content is 14.6mg/L
  whereas at 25C, only 8.3mg/L
• Altered Hydrologic Flows
• Increased Pollutant Toxicity

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Thermal Habitat A Case Study

• Largemouth Bass
• Rainbow Trout
• Channel Catfish

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Focus on Largemouth Bass
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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

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Thermal Habitat A Case Study

• Temperature cycled consistently from 20-30C
• Rate of change 0.30.01C/min
• Maximum temperature occurring at midnight
• Minimum temperature occurring at midday

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Thermal Habitat A Case Study

• Results
• Trails were stopped when the fish experienced a
  loss of equilibrium
• Temperature range for largemouth bass
• Mean maximum 35.6-37.3C
• Mean minimum 5.9-7.7C

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Case Study Yellow Perch(Perca flavescens)
Photo courtesy of US Fish and Wildlife Service
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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

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Habitat Considerations

• Prefer lake shallows
• Ideal Summer Temp 69-77F

Adult Temperature SI
Juvenile Temperature SI
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Predictions

• Juveniles will be most sensitive to temperature
  increases, and changes in prey populations
• Decreased vegetatation
• Increased turbidity
• Ideal pH 6.5-8.5

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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

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Communities
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Communities

• The fish we enjoy are products of their
  communities
• Have been (relatively) stable
• Climate Change could upset the balance

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Range Shifts

• Climate change -gt increased water temperatures
• Redistribution of thermal habitat throughout the
  lake
• Not the same for each fish

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New Communities

• Water temps increase-gt individual species shift
  range-gt new communities!
• Uncertainty
• Diseases? Parasites? Competitors?
• Similar fish, similar shifts?
• New communities-gt new ecosystems services,
  products

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Food Webs

• Another driver of community structure -gt food!
• Competition, predation

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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 cant?

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Ecotourism
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Ecotourism and Climate Change

• One of the most important and rapidly growing
  service industries
• Closely tied with environmental quality
• Climate dependent
• Mixed reactions

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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

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Ecotourism and Climate Change

• In Walls 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?

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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

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Management
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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

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Stocking

• Loss of genetic variation
• Due to bottleneck
• Harder to adapt
• Wild hybrids?
• Already artificial populations
• Need as much help as we can give

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Fishing

• Most of the demand comes from tournaments
• Increasing, leveling off, decline
• Costs, rules

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Problems

• Boat Traffic
• Fish Handling

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Conclusions
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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-gt stress

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We Recommend

• May be too late to prevent range shifts
• Adaptive management
• Intensive monitoring in years to come
• Evaluation of success and methods

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We Conclude

• Vermonters pay a bundle for VFWD
• 17 million!
• Already very carefully managed
• Some loss of genetic variation

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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

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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

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Questions?