From the Chickens to the Crabs - The Ripple Effect: The Fate of Freshwater in the Twenty-First Century - page 69

mans manufacture another 190 million tons a year and also convert nitrogen gas into
ammonia, which is turned into fertilizer.
Humans have been applying nitrogen-based fertilizers to cropland since the 1950s,
and the effect has been dramatic. They have provided remarkable crop yields that have
helped to fuel the Green Revolution and stave off mass famine in places such as India
and Mexico. But too much nitrogen can “burn” crops, kill off beneficial microorgan-
isms, and deplete minerals in the soil; and it can lead to cyanosis, the “blue baby” syn-
drome. Farmers commonly overapply nitrogen fertilizer as a precaution against poor
yields and to give their crops an added growth boost.
Carole Morison admits that she and her husband spread so much chicken manure on
their fields that the land became oversaturated. When they had soil samples tested for
nitrogen and phosphorus, they were told their levels were so high that they didn't need
to fertilize again for another fifteen years. “I bet most of the land on the Delmarva Pen-
insula is in the same condition,” Morison said. “If we were still raising chickens, what
would we do with the extra manure? There's nowhere to put it.”
THE MYSTERY OF THE SHENANDOAH
A river is the report card for its watershed.
—Alan Levere
Muddy Creek spills into the South Fork of the Shenandoah River, which is where Bob
Hirsch and I floated downstream in 2008 as part of a flotilla of dark green canoes filled
with scientists. The Shenandoah is a midsize, fairly shallow, and ledgy river, with wa-
ter colored a light brown, like weak tea. It flows north for 150 miles, from Virginia into
West Virginia, and then into the Potomac River at Harpers Ferry.
I canoed with Jeff Kelble, the Shenandoah Riverkeeper, and right away we saw telltale
signs of pollution: bright green algae streaming beneath us, clumps of foam on the
river's surface, cows grazing along the water's edge, a small lumber operation, piles of
garbage spilling down eroded banks. “ Every spring since 2004 we've seen a jump in the
number of dead fish, or fish with sores on their skin,” said Kelble. By 2008, the spring
fish kills had eliminated an estimated 80 percent of adult smallmouth bass and a num-
ber of other species from the river. A task force has found few concrete answers to ex-
plain why the Shenandoah, in particular, has been hit so hard, and why the fish kills
have targeted just the adults from a few species.