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Blog Archive Environment Blog

No More Migration?

Some bird species once commonly found in Kentucky and surrounding states are moving farther north each year, according to the Audubon Society. Take the Red-breasted Merganser, for example. This fish-eating duck, the society says, has moved its range northward over the past 40 years more than 300 miles. They’re apparently more abundant in Minnesota now than they once were here. The reason? Climate change.

Even more striking is the news from the U.S. Geological Survey that a large percentage of a sea bird population that once wintered in Mexico is now staying put in Alaska, where, apparently, it’s warm enough to stick around.  From the USGS release:

“The winter distribution of Pacific brant, a small, dark sea goose, has shifted northward from low-temperate areas such as Mexico to sub-Arctic areas as Alaska’s climate has warmed over the last four decades, according to a just-released article in Arctic.

“Until recently, nearly the entire (90 percent) population of Pacific brant wintered in Mexico, but now as many as to 30 percent are opting to spend their winters in Alaska instead, according to the U.S. Geological Survey-led study. Although records are sparse, fewer than 3,000 brant were detected wintering in Alaska before 1977, a number that has jumped to as many as 40,000 birds now. “

Who knows what kind of wider implications these shifts in range – and changes in migration patterns – could have, not only on local ecosystems, but the ecosystems in which birds play a role while on winter vacation?

Citizen scientists can help track data like this, such as the first sighting of a particular bird in your area. See my story on phenology to learn about local efforts to track species’ appearances.

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Environment In-Depth News

Cave Ecosystems Improve; Groundwater Still Vulnerable


Tour guide Nancy Toney leads a group down into Horse Cave in the south-central town of Horse Cave, Kentucky. She points over a railing at one of the two rivers tumbling below.

“And this is the river that the sewage treatment plant was dumping the sewage into, through that sinkhole. So the water you see would have been black, those rocks would have been black, you would have been able to see clusters of blood worms hanging to all of the rocks,” Toney says.
Inside Horse Cave
Today the rivers run clear and clean. And the eyeless white crayfish that disappeared when pollution was killing the cave have made their way back. But it’s been a long haul.

Humans have been leaving their mark on caves for thousands of years. We’ve sheltered in them, told our stories on their walls. In the prohibition-era 1920s, locals even created an entire subterranean nightclub in one of Hidden Cave’s deep-set caverns—complete with orchestra and dance floor. But it wasn’t until recently that people understood that what goes into a cave can come out the other end—with consequences.

“They’re not just simply holes in the ground…”

This is David Foster. He’s head of the American cave conservation association, which is headquartered right above Hidden Cave.

“They’re holes that evolved because rain water was moving through sinkholes and dissolving them and widening them and opening them. And that rain water has to go somewhere. It doesn’t just seep into the ground and continue to the center of the earth. It comes back out in the form of springs.”

Foster says that if you contaminate a cave system, you contaminate the springs that emerge from the cave. And because those springs feed our rivers and streams, you’re ultimately contaminating the water we depend on for drinking. Beneath about 40% of Kentucky’s lands is a geological formation called karst. It’s basically limestone that water can easily dissolve—splitting open cracks, forming sinkholes, and eventually caves. Karst doesn’t remove impurities from the water. It lets it pass right through. So Foster says that when he arrived in Horse Cave 20 years ago, run off from homes and industry had taken their toll on the cave.

Walkway inside Horse Cave“What we had was an open sewer, right in the middle of town,” Foster says.

And the pollution was edging its way into the nearby and better known Mammoth Cave system. But money from the Environmental Protection Agency and the National Park Service helped build a regional sewer treatment system that went online in 1989. The cave got cleaner. But other groundwater contaminants were still causing problems.

“Whenever it would rain, we would smell a gasoline odor. And then we went through a period where the EPA had a program where they were removing all the underground storage tanks that had been leaking. And after that got done, we almost never had that problem,” said Foster.

After years of environmental clean up, the cave’s ecosystem has come back. But it will always be a delicate balance. With few species depending on each other in this rare, sun-less environment, it’s easy to tip the scales. Rick Toomey heads Mammoth Cave’s science and learning center. He says that for example aquatic cave animals rely on the organic material in water that backs up from the Green River or from groundwater that seeps into the cave.

“The cave fish, the cave shrimp, the cave crayfish, these organisms eat the organic material itself, or the organic material gets in the cave and grows bacterial slime. We’re very much dependent on that,” Toomey says.

But they’re also vulnerable for that same reason, because in with that organic material could also come toxins, poisons, pollution.

“Household run off is still potentially an issue. It’s still an agricultural area. We have to make sure we work with people on best management practices, trying to reduce the amount of chemical usage,” said Toomey.

Scientists at both Mammoth Cave and Horse cave monitor groundwater constantly. But caves without national protection or vigilant conservation—caves all over Kentucky—are often still neglected.

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Local News

New Study Finds Eastern U.S. Pollution Worse

Scientists have found that air pollution from coal-fired power plants and vehicle emissions has harmed ecosystems in the eastern United States more than previously thought.  That includes pollution from the Ohio River Valley region, which generally travels West to East.  Researchers from The Nature Conservancy and the Cary Institute for Ecosystem studies found that many previous studies examined the effects of a single pollutant on a certain aspect of an ecosystem. But lead author Gary Lovett says they don’t show the big picture.

“What we found was that all of those ecosystem types are affected by at least one of the pollutants and most of them are affected by more than one.  So when you look at it in a broad scale like that, you see the pervasiveness of the effect, and it strikes you as being a widespread and serious effect, more serious than the impression you get by looking at an individual pollutant,” says Lovett.

Lovett also says that current air pollution regulations focus on human health and what we breathe in.  But ecosystems are more affected by pollutants that settle out of the air and onto the ground.  There, they can acidify rivers and streams, as well as acidify soil, making it more difficult for plants and animals to thrive.

On the Web: Read The Nature Conservancy and the Cary Institute for Ecosystem Studies report here (.pdf file).