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 National Center for Environmental Assessment

Source: American Sportfishing Association Fishing Statistics – 1996 Sport Fishing Participation and Economic Impact Background: Recreational Fishing in the Great Lakes EPA Global Change Research Program

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

EPA Global Change Research Program Approach: Baseline Water and Air Temps Identified a sample of 996 sites Developed relationship between air temperature and water temperature

EPA Global Change Research Program 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

EPA Global Change Research Program Approach: Thermal Tolerance Cold Water Upper Thermal Species Tolerance ( o C) Chum salmon19.8 Pink salmon21.0 Brook trout22.4 Mountain whitefish23.1 Cutthroat trout23.3 Coho salmon23.4 Chinook salmon24.0 Rainbow trout24.0 Brown trout24.1 Upper Thermal Other Species Tolerance ( o C) 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

EPA Global Change Research Program Approach: Fish Presence Identified baseline ranges of fish, by state Number of species < Number of Species Present: Baseline

EPA Global Change Research Program Approach: Effects of Climate Change on Fish 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

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 Loss of Habitability for Cold Water Species Brook Trout Brown Trout Rainbow Trout Chinook Salmon Chum Salmon Coho Salmon Not present in baseline 0% 1-49% 50-99% 100% Percent of available habitat lost

Results More tolerant species lose less habitat EPA Global Change Research Program Largemouth Bass Northern Pike White Crappie Channel Catfish Not present 0% 1-49% 50-99% 100% in baseline Percent of available habitat lost Loss of Habitability for Selected Species

EPA Global Change Research Program 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

EPA Global Change Research Program Economic Assessment: Key Assumptions and Parameters –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 Effect of Assumptions on Economic Impacts ? Assumptions

EPA Global Change Research Program 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

EPA Global Change Research Program Economic Assessment: Sensitivity Analyses (Damages) or Benefits in Millions of 1993 Dollars per Year Primary Specification High value; no sub Primary value; no sub High climate sensitiv. High value; no ww increase (SA&GC) High value Low value; no sub Low tolerance Wide screen Primary value; no ww increase (SA&GC) Low value; no ww increase (SA&GC) Low value Low climate sensitiv. High tolerance Annual Economic Welfare Effects by Sensitivity Run and General Circulation Model

EPA Global Change Research Program 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