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 forIn 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 fishingEconomic draw to the regionThe 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 ScenariosA1F1 – 1000 ppm CO2B2 – 500 ppm CO2

(Nakićenović, N., et al. 2000.)

Climate ModelingAOGCM

- Atmospheric Ocean General Circulation ModelInputs – SRES and Physical Processes of CellOutputs – 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 tempsTwo lines reflect seasonal heating and cooling ‘hysteresis’

Mohseni et al. 2003

Climate ModelsHeat Index and Migrating States

Mary Watzin PresentationNECIA, 2006

Effects on Individual Habitat

Cold Blooded – Temperature Controls MetabolismOptimal Ranges and Lethal Ranges

Ficke et al. 2007

Effects on Individual HabitatC = (Mr+Ma+SDA) + (F+U) + (Gs+Gr)Equation derived in 1977 by Kitchell et al. C= Energy ConsumptionM terms = metabolic rates and increases due to activityF+U = WasteG= Growth of Reproductive or Somatic CellsYellow 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/LAltered Hydrologic FlowsIncreased Pollutant Toxicity

Thermal Habitat: A Case Study

Largemouth BassRainbow TroutChannel Catfish

Focus on Largemouth Bass

Thermal Habitat: A Case Study

Natural processes are unsystematicAttempt 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/minMaximum temperature occurring at midnightMinimum 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 aTIFF (Uncompressed) decompressor

are needed to see this picture.

Photo courtesy of US Fish and Wildlife Service

About Perca flavescens

Size: Up to 18 inchesYellow/Green color with 6-8 dark vertical bandsCompressed, elongate bodyAdults eat small fish, crustaceans, insectsFry eat copepods and cladocerans

Habitat Considerations

Prefer lake shallowsIdeal Summer Temp: 69-77˚F

Adult Temperature SI Juvenile Temperature SI

Predictions

Juveniles will be most sensitive to temperature increases, and changes in prey populationsDecreased vegetatation Increased turbidityIdeal 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 communitiesHave been (relatively) stableClimate Change could upset the balance

Range Shifts

Climate change -> increased water temperaturesRedistribution of thermal habitat throughout the lakeNot the same for each fish

New Communities

Water temps increase-> individual species shift range-> new communities!UncertaintyDiseases? 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 interconnectedKim and LaBar 1996 Trout, salmon and walleye

Rainbow smelt

Similar to range shiftsFood supply moves, follow it What if you can’t?

Ecotourism

Ecotourism and Climate Change

One of the most important and rapidly growing service industriesClosely tied with environmental qualityClimate dependentMixed reactions

Ecotourism and Climate Change

Fixed waterfront facilities vulnerable to flux in water levelsLowered lake levels will cause conversion to dry land, eventuallyLack 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 availableLoss of income to support conservation projects

Management

Vermont Fish and Wildlife Dept.

2009 budget= $17millionStock: 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 adaptWild hybrids?Already artificial populations Need as much help as we can give

Fishing

Most of the demand comes from tournamentsIncreasing, leveling off, declineCosts, rules

Number of Fishing Tournaments

60

105 113137 131

167152 156

176

113

0

50

100

150

200

Year 1996 1997 1998 1999 2000 2001 2002 2003 2004

Year

# Pe

rmitt

ed T

ourn

amen

ts

Problems

Boat TrafficFish Handling

Vermont Angler Survey 2000 Residents' Opinions of Tournaments

73%

16%

8% 3%

No Problem

Minor Problem

Moderate Problem

Serious Problem

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 shiftsAdaptive 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 managedSome 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?