Transcript What are the potential impacts of climate change on fresh

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
Background: Recreational Fishing
in the Great Lakes
MN
MI
WI
ILL
IN
OH
Total Angler Exp
$1,875 m
$1,506 m
$1,072 m
$1,568 m
$799 m
$836 m
Total Economic Impact
$3,678 m
$2,854 m
$2,138 m
$3,618 m
$1,677 m
$1,879 m
# Anglers
1,538,180
1,823,534
1,473,561
1,351,047
992,420
1,231,445
# FW Anglers
1,420,525
1,310,695
1,232,103
1,123,401
862,646
907,729
48,274
674,200
180,652
259,642
59,616
425,555
# Great Lakes Anglers
Total Fishing Days
27,002,340 28,708,731 17,130,434 20,459,075 15,810,948 17,848,215
Great Lakes Fishing Days
162,718
6,084,370
850,474
1,542,490
Source: American Sportfishing Association Fishing Statistics – 1996 Sport Fishing Participation and Economic Impact
EPA Global Change Research Program
786,862
3,539,390
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
Species
Upper Thermal
Tolerance (oC)
Chum salmon
Pink salmon
Brook trout
Mountain whitefish
Cutthroat trout
Coho salmon
Chinook salmon
Rainbow trout
Brown trout
EPA Global Change Research Program
19.8
21.0
22.4
23.1
23.3
23.4
24.0
24.0
24.1
Other Species
Northern pike
Walleye
Pumpkinseed
Yellow perch
Smallmouth bass
Black crappie
Flathead Catfish
Channel Catfish
Largemouth bass
Bluegill
Upper Thermal
Tolerance (oC)
28.0
29.0
29.1
29.1
29.5
30.5
34.0
35.0
35.5
36.0
Approach: Fish Presence
•
Identified baseline ranges of fish, by state
Number of Species Present: Baseline
Number of species
<9
EPA Global Change Research Program
9-11
12-15
16-19
20-23
24-27
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
EPA Global Change Research Program
Results
Loss of Habitability for Cold Water Species
•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
Brook Trout
Brown Trout
Chinook Salmon
Chum Salmon
Rainbow Trout
Coho Salmon
Percent of available habitat lost
Not present in baseline
EPA Global Change Research Program
0%
1-49%
50-99%
100%
Results
Loss of Habitability for Selected Species
Largemouth Bass
•
Northern Pike
More tolerant
species lose
less habitat
White Crappie
Channel Catfish
Percent of available habitat lost
Not present
in baseline
EPA Global Change Research Program
0%
1-49%
50-99%
100%
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
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
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
Annual Economic Welfare Effects by Sensitivity Run
and General Circulation Model
1,500
Primary
Specification
1,000
500
(500)
(1,000)
(1,500)
(2,000)
High
value;
no sub
High
High
High
value;
value
climate no ww
sensitiv. increase
Primary
(SA&GC)
value;
no sub
EPA Global Change Research Program
Low
value;
no sub
Low
tolerance Wide
screen
Primary
value;
no ww
increase
(SA&GC)
Low
value;
no ww
increase
(SA&GC)
Low
value
High
Low tolerance
climate
sensitiv.
Maximum
A verage
Minimum
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
EPA Global Change Research Program