MICHELE NORRIS, host:
Pollution from the area around Rocky Mountain National Park in Colorado is so bad that park managers say it's changing the ecosystem. Nitrogen is a particular worry. The nutrient is building up in waterways and soils and nitrogen levels are now twice what's referred to as the "critical load." That's the level where changes in the ecosystem begin to occur, changes that put plants and animals at risk.
From Denver, NPR's Jeff Brady reports.
JEFF BRADY reporting:
For the last couple of decades, researchers have been measuring the amount of nitrogen in the air, soil and the water at Rocky Mountain National Park. Every Tuesday, a technician walks through a grassy prairie to collect samples from a monitoring station.
Mr. CARL CORTOVUS(ph) (Park Biologist, Rocky Mountain National Park): I think we've only missed three or four Tuesdays in the whole 23-year history, including the wintertime.
BRADY: Park biologist Carl Cortovus says nitrogen levels today are up to 20 times what they were 100 years ago.
Mr. CORTOVUS: The nitrogen levels began to increase as industrialization began to occur in the western United States.
BRADY: Cortovus says the extra nitrogen is upsetting the ecosystem. But to see the evidence, you need a microscope.
(Soundbite of water running)
BRADY: Algae in this creek have changed significantly. Cortovus says algae that thrive on nitrogen now dominate.
Mr. CORTOVUS: A hundred years ago, you could look in and you might see eight different species all in equal number. Today you would see three species in greater abundance and the other species would be somewhat undernourished or out-competed.
BRADY: Cortovus says that's because nitrogen levels are well above the critical load number set by the Park Service. Eventually, he says, the damage will work its way up the food chain from algae to the prized trout in the park's streams. Within just a few decades, the park service estimates that fish could start dying off in large numbers.
This is the first time a national park has set a critical load. Managers hope it'll encourage nearby communities and industries to change their polluting ways voluntarily, since the agency can't force change. They're talking with industry groups and state regulators, such as Mike Silverstein with the Colorado Air Pollution Control Division.
Mr. MIKE SILVERSTEIN (Colorado Air Pollution Control Division): There's a number of sources that omit nitrogen. Primarily two categories, the burning of fuels - coal, natural gas, gasoline. The other half of the coin is ammonia emissions. And that primary source of ammonia emissions are from agriculture sources.
BRADY: Silverstein says there's a lot of progress in reducing nitrogen pollution from fossil fuels. Engines burn a lot cleaner these days. Agriculture, though, hasn't received as much attention. Farmers are understandably worried about the focus on their industry. No decisions have been made yet, but some of the suggestions being discussed will cost money to implement.
For example, one idea is to have farmers fertilize their fields several times a year instead of just once. That way less nitrogen would escape into the air before plants can use it. Troy Bredenkamp with the Colorado Farm Bureau is skeptical the increased cost would be worthwhile.
Mr. TROY BREDENKAMP (Colorado Farm Bureau): Most ag producers really need to see the proof before, you know - they're not opposed to doing the right things as long as it makes sense and from a scientific perspective, it can be proven that it's going to make a difference.
BRADY: Already there's a sizeable body of peer reviewed research about the problems in Rocky Mountain National Park and more studies are being conducted. But the Park Service says nitrogen levels need to be reduced soon before more damage is done. This prompted some urgency in the negotiations underway. And there's the federal Environmental Protection Agency, which could step in at any time and force farmers in nearby communities to reduce their pollution.
Jeff Brady, NPR News, Denver. Transcript provided by NPR, Copyright NPR.
