DENVER
-- Airborne nitrogen pollution from power plant emissions and other sources is turning algae in the alpine
lakes of Rocky Mountain National Park into junk food for fish, a study
says.
A similar phenomenon is
occurring in Sweden and Norway, according
to the study of about 90 high-elevation lakes set to be published in
the journal Science today.
Arizona State University
professor James Elser, the study`s
lead author, said the effect of airborne nitrogen on once-pristine
lakes is greater than previously believed. The nitrogen`s sources
include vehicle exhaust, fertilizer used on farms and livestock feed
lots and power plant emissions.
More nitrogen can reduce
long-term lake biodiversity because
algae become poor food for other microscopic organisms and, ultimately,
fish. The algae are high in nitrogen, but low in phosphorous and less
nutritious.
Previous studies have
documented rising nitrogen levels in Rocky Mountain National Park, 70
miles northwest of Denver.
Elser likened the algae to junk
food. "It`s like
eating marshmallows all day and expecting to grow. You can't do it," he
said Thursday.
The fish in the park include
the rare greenback cutthroat trout and other trout species.
Greenback
Cutthroat Trout
The next step is to study how
changes in algae populations are affecting the rest of the ecosystem,
Elser said.
"This is filling in some of
what we didn't know before," said
Jill Baron, a scientist with the U.S. Geological Survey and adjunct
professor at the Natural Resource Ecology Laboratory at Colorado State
University in Fort Collins.
Baron has studied air pollution
levels in Rocky Mountain
National Park since 1981. Her research prompted Vaughn Baker, the
park's superintendent, to push for efforts to cut the pollution.
Along with changes to the
algae, park biologists blame
nitrogen for an increase in sedges, compared to other grasses and
flowering plants known as forbs.
"One of the main reasons this
park was established was for the
protection of tundra and alpine areas," park biologist Jim Cheatham
said.
Rocky Mountain National Park
has 60 peaks higher than 12,000
feet. It is home to elk, deer, moose, bighorn sheep, mountain lions,
bears and eagles.
This year, the National Park
Service reported increases in
nitrogen-rich ammonium that could change ecosystems in 16 parks across
the country.
A 2007 plan signed by state and
federal officials and Rocky
Mountain National Park aims to reduce airborne nitrogen levels over 25
years. Researchers said then that nitrogen levels were 20 times more
than normal.
"We're admitting that we could
never reach the natural levels" because of development elsewhere,
Cheatham said.
The plan aims to cut nitrogen
levels in half, said Mike
Silverstein, manager of planning and policy for the Colorado air
pollution control division. The nitrogen comes from nitrogen oxide,
whose sources include vehicle and power plant emissions, and ammonium,
whose sources include livestock feed lots, farms and water treatment
plants.
Studies show the pollution is
coming from the Denver area and
northeast Colorado, one of the country's largest agricultural areas, as
well as other states, Silverstein said.
Officials hope to cut nitrogen
to 1.5 kilograms per hectare, or 2.47 acres. The current average is 3.1
kilograms.
Silverstein said state and
federal efforts have reduced
pollution from power plants and vehicles and plans are in the works to
cut emissions by another 100,000 tons of nitrogen oxide per year in
Colorado over the next 10 to 15 years.
Ammonium isn't regulated,
Silverstein said. But state
officials, Colorado State researchers and the agriculture industry are
exploring ways to change farming practices to cut emissions.
Additional information from the web:
Read more about 'unclean coal'
practices here.
Eli comments: Since the wind blows west (northwest and southwest) towards the east in RMNP for 98% of the year, it is unlikely that auto sources in the Front Range or fertilizer from 500 miles to the northeast are the primary sources of this pollution. This pollution would have to be from sources much further west, which are primarily coal fired power plants in western CO, WY, UT, NV and then eventually the auto pollution of Los Angeles, Sacramento, Seattle, etc. headed this way. Our pollution from the Front Range is mostly headed east towards Kansas, Missouri, and beyond.
