Presentation to: Water Ecology and Climate Change Workshop Susan Herrod Julius

1. 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 June 15, 2001

2. 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

3. 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

4. Approach: Baseline Water and Air Temps • Identified a sample of 996 sites • Developed relationship between air temperature and water temperature

5. 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

6. 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

7. 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

8. 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

9. 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% Results • 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

10. 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 Results • More tolerant species lose less habitat EPA Global Change Research Program

11. 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

12. Economic Assessment:Key Assumptions and Parameters Assumptions 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 ?

13. 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

14. Primary Specification (Damages) or Benefits in Millions of 1993 Dollars per Year High tolerance Low climate sensitiv. Low value; no ww increase (SA&GC) Low value Primary value; no ww increase (SA&GC) Low tolerance Low value; no sub Wide screen High value; 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

15. Conclusions • 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