Trout & Salmon Streams Face
Sharp Declines Due to Hotter Temperatures
New Study Predicts Sportfish Species
Will Disappear from Many Waterways;
Global Warming Means Fewer Fish
on Anglers’ Hooks
05/22/2002
FOR IMMEDIATE RELEASE Contact:
Jon Coifman at NRDC, 202/289-2404, or Brad DeVries at
Defenders, 202-772-0237
Complete Report Available online
at: http://www.defenders.org/publications/fishreport.pdf
WASHINGTON
(May 19, 2002) - Trout and salmon could
disappear from many U.S.
waterways due to rising temperatures caused by global
warming. Habitats for some species could shrink as much
as 17 percent by 2030, 34
percent by 2060, and 42 percent by 2090 if emissions
of heat-trapping pollution such as carbon dioxide are not reduced,
according to a study
released today by Defenders of Wildlife and NRDC
(the Natural Resources Defense Council).
The sweeping new analysis covers four
species of trout - brook,
cutthroat, rainbow and brown - and four species
of salmon- pink, coho,
chinook and chum. Researchers looked at air and
water temperature data
from more than 2,000 sites across the U.S. Using
three internationally
recognized climate models, they estimated changes
in stream temperature
under a variety of pollution scenarios.
"Rising temperatures
are increasingly going to curtail the range of
trout and salmon in the U.S. That means more and more of our favorite fishing holes will come up empty," said
Dr. Daniel Lashof, science
director of the NRDC
Climate Center.
"The reason is pollution from cars
and power plants. Fortunately, there are measures
we can take now to start solving the problem."
Trout & Salmon in Hot Water
Salmon and trout are coldwater species,
acutely sensitive to stream
temperature. In many areas the fish are already
living at the margin of
their tolerance, meaning even modest warming
can render a stream uninhabitable. Projected increases in water
temperature vary by
location, but average 0.7 - 1.4° F by 2030, 1.3
-3.2°F by 2060, and 2.2 -4.9°F by 2090, depending
on future emissions of heat-trapping gases and
which climate model is used. Besides temperatures,
timing of summertime highs also changes in some cases, sometimes
by as much as four weeks.
The report predicts
widespread habitat losses that vary by region. For
trout, the most severe losses appear in the South,
Southwest and Northeast.
For salmon, significant losses are seen throughout their current range, with the biggest impact likely
in California.
The extent of predicted
habitat loss also varies somewhat by species.
For example, if emissions continue to increase
at current rates, rainbow
trout habitat would shrink by 8 to 11 percent
by 2030, 14 to 24 percent by 2060, and 24 to 38 percent by 2090. For coho
salmon, by comparison, 6
to 14 percent of habitat could be lost by 2030,
16 to 30 percent by 2060, and 23 to 41 percent by 2090.
For many of the fish
species, the effects of global warming come atop a
battery of existing problems. Cutthroat trout,
native to the Western U.S.,
have been reduced to less than five percent of their
original range and several subspecies are listed as threatened.
Wild pacific salmon
have disappeared from nearly 40 percent of their historic
range in the Northwest, and populations are down more
than 90 percent in the
Columbia River system.
Chinook salmon have been listed under the Endangered Species Act, and several populations
of coho are officially
threatened.
"Wild trout and
salmon populations are already stressed by factors such
as loss of habitat to development, competition
with hatchery fish,
invasive exotic species, and more. Now we must
add climate change to the
list of challenges they face," said Mark
Shaffer, Senior Vice President
for Programs at Defenders of Wildlife. "If
we don't address the cumulative impact of all these factors, we will
see more of these populations
switching from a recreational resource to being listed
as threatened or endangered."
A High Stakes Problem
An estimated nine million U.S.
recreational anglers spend nearly 100
million days fishing each year creating an economic
ripple worth billions of dollars. Many of the species covered
by the study are regional
icons with cultural significance rivaling their recreational and economic value.
"This report warns us not only
of losses to natural resources and
family traditions, but also that the future of
jobs that depend on
healthy recreation are at risk," said Steve
Moyer, Vice President for
Conservation for the group Trout Unlimited. "Our
grandchildren and their
families may not have the pleasure of fishing
for these magnificent creatures in many areas that we know and love
today. Billions of dollars
per year spent on recreational fishing equipment,
guides and resorts may be hit too."
The study covers direct thermal effects
on the stream habitats only, and
does not examine indirect impacts of global warming
such as changes in precipitation or evaporation. It does not include
Alaska
or Hawaii.
Nor does it look
at global warming on ocean environments where salmon
and some trout
species spend much of their lives.
"For many of us, coldwater fisheries
are one of the things that make
life worth living. This data-rich report asks
some sobering questions
about yet another area of our lives that may
be significantly impacted
by global warming," said Paul Hansen, executive
director of the Izaak
Walton League of America. "Many of the early
actions needed to address
this problem are very cost-effective, even before
we consider the impact on trout and salmon, and can be taken immediately."
Global Warming: What We Know
Global warming is a source of growing
concern. Average temperatures have
increased by 1.1°F in the past century - faster
than anything seen in at least a thousand years. 2001 was the second
hottest year on record, just
behind 1998. Since 1990 we have seen nine of
the 10 hottest years in history. Although natural causes may be playing
a role, most experts
believe heat-trapping pollution from cars, power
plants and other sources is the main culprit. These emissions
collect in the atmosphere,
preventing excess heat from escaping, and increasing
temperatures here on the ground.
The Intergovernmental Panel on Climate
Change - a 2,500-member body
representing international scientific consensus
on the subject - concluded in 1995 and again in 2001 that man-made
pollution from fossil
fuel combustion and deforestation is driving
temperature increases. Asked by President Bush to review the scientific
findings, the National
Academy of Sciences reconfirmed in June 2001
that heat-trapping pollution is causing both surface and ocean
temperatures to rise. The
IPCC estimates temperatures will rise 5 - 10°F
over the next 100 years.
In the new report, researchers estimate
the average air temperatures at
sample locations will increase 1.6 to 2.7 °F
by 2030, 2.6 - 6.7 °F by
2060 and 4.5 - 11 °F by 2090. These numbers are
slightly higher than
global average estimates, and consistent with
the expectation that
increases will be greater over land and at higher
latitudes.
Solving the problem means cleaning
up the pollution that causes it -
mainly carbon dioxide emissions. Answers include
cleaner, more advanced technologies in our vehicles and power plants.
Congress is considering
legislation called the Clean Power Act that would
require power companies to reduce carbon dioxide pollution,
along with several other
pollutants that are harming fish stocks.
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The Natural Resources Defense Council
is a national, non-profit
organization of scientists, lawyers and environmental
specialists dedicated
to protecting public health and the environment. Founded
in 1970, NRDC
has more than 500,000 members nationwide, served from
offices in New
York, Washington, Los Angeles and San Francisco. More
information is
available through NRDC’s Web site at www.nrdc.org.
