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NCEA. National Center for Environmental Assessment. What are the potential impacts of climate change on fresh water recreational fishing opportunities in the U.S.? . Presentation to: Water Ecology and Climate Change Workshop Susan Herrod Julius Global Change Research Program

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National Center for Environmental Assessment

What are the potential impacts of climate change on fresh water recreational fishing opportunities in the U.S.?

Presentation to:

Water Ecology and Climate Change Workshop

Susan Herrod Julius

Global Change Research Program

June 15, 2001

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Background: Recreational Fishing

in the Great Lakes

Source: American Sportfishing Association Fishing Statistics – 1996 Sport Fishing Participation and Economic Impact

EPA Global Change Research Program

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Background: Purpose and Scope

  • Purpose: explore magnitude of potential societal impacts

  • Scope:

    • Limited factors of analysis for tractability

      • Recreational fishing

      • Temperature effects

      • Rivers and streams

    • Estimated effects of climate change on ranges of fish species across US

    • Used effects on fish ranges as inputs to an economic model

    • Conducted sensitivity analyses to examine robustness of results and insights

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Approach: Baseline Water and Air Temps

  • Identified a sample of 996 sites

  • Developed relationship between air temperature and water temperature

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Approach: Thermal Tolerance

  • Used data on weekly maximum temperature tolerance reported by Eaton and Scheller

    • Fish and Temperature Database Matching System (FTDMS) provides tolerance based on 95th percentile weekly average water temperature for most species

    • For species whose ranges extend south of US-Mexico border, tolerance based on Upper Zero Net Growth (UZNG) temperature

  • Evaluated ranges of 31 species

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Cold Water Upper Thermal

Species Tolerance (oC)

Chum salmon 19.8

Pink salmon 21.0

Brook trout 22.4

Mountain whitefish 23.1

Cutthroat trout 23.3

Coho salmon 23.4

Chinook salmon 24.0

Rainbow trout 24.0

Brown trout 24.1

Upper Thermal

Other Species Tolerance (oC)

Northern pike 28.0

Walleye 29.0

Pumpkinseed 29.1

Yellow perch 29.1

Smallmouth bass 29.5

Black crappie 30.5

Flathead Catfish 34.0

Channel Catfish 35.0

Largemouth bass 35.5

Bluegill 36.0

Approach: Thermal Tolerance

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Number of Species Present: Baseline

Number of species <9 9-11 12-15 16-19 20-23 24-27

Approach: Fish Presence

  • Identified baseline ranges of fish, by state

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Approach: Effects of Climate Change onFish Presence

  • Used General Circulation Models (GCMs) projected changes in air temperature

  • Juxtaposed projected increments to air temperatures with locations of sample stations

  • Based on air temperature/water temperature relationship, predicted future water temperatures

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Loss of Habitability for Cold Water Species

Brook Trout Brown Trout Rainbow Trout

Chinook Salmon Chum Salmon Coho Salmon

Percent of available habitat lost

Not present in baseline 0% 1-49% 50-99% 100%


  • Many states lose significant proportions of existing cold water habitat

  • Across guilds, 21 of the 48 states lose 1 or more of the 31 species

EPA Global Change Research Program

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Loss of Habitability for Selected Species

Largemouth Bass Northern Pike

White Crappie Channel Catfish

Percent of available habitat lost

Not present 0% 1-49% 50-99% 100%

in baseline


  • More tolerant species lose less habitat

EPA Global Change Research Program

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Economic Assessment:Vaughan and Russell Model

  • Estimate changes in fishing due to changes in water quality

  • Three-stage estimation:

    • probability of general fishing participation

    • conditional probability of participation by fishing category

    • average days per angler devoted to types of fishing

  • Stream reaches are uniquely assigned to fish guild categories based on highest value

  • Changes in participation days are estimated and valued using unit value approach

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Economic Assessment:Key Assumptions and Parameters


Effect of Assumptions

on Economic Impacts

  • Each fishable acre is uniquely assigned to highest valued use allowed by thermal conditions

  • Population, socioeconomic characteristics and participation rates held constant over the modeling horizon for baseline and climate change scenarios

  • Fishing values held constant over the modeling horizon, with and without climate change

  • No distinction is made between net WTP for stream- and for lake-fishing


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Economic Assessment:Results

  • Estimates of economic impacts for recreational fishing range from damages of $320 million per year to benefits of $81 million per year (1993$)

  • Cold water fishing losses range from $1.3-$3 billion per year

  • In 32 of 42 scenarios conducted, damages result from habitat changes

  • Highest sensitivity is to assumption about cold water acreage substitutability:

    • damages increased across all scenarios

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(Damages) or Benefits in Millions of 1993

Dollars per Year

High tolerance

Low climate sensitiv.



no ww increase (SA&GC)

Low value

Primary value;

no ww increase (SA&GC)

Low tolerance

Low value; no sub

Wide screen



no ww increase (SA&GC)

High value

High climate sensitiv.

Primary value;

no sub

High value;

no sub

Economic Assessment:Sensitivity Analyses

Annual Economic Welfare Effects by Sensitivity Run

and General Circulation Model

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  • In a warmer world, fish losses are likely, particularly for cold water species

  • Climate change is not as immediate as some other threats to fisheries, but it is likely to result in additional stresses

  • Socioeconomic impacts could be significant

  • “Fishes are an excellent indicator of the expected changes from Global Warming”

    • Protecting the ecosystem services of the Great Lakes will require all users, commercial and recreational, to work together to understand the effects and identify management solutions