can elevate turbidity to levels well above
400 NTU. Specific conductance, a measurement of the water’s salt content, is
303 uS/cm, a;rming that this area of the
river is primarily fresh water. If significant amounts of seawater reached this
point, conductivity would be greater than
10,000 uS/cm. And at 7. 7, the pH level is
just slightly alkaline and certainly considered safe for fish and other aquatic life.
It’s a new view of the river. And in spelling out these unseen variables so intrinsic
to the character of the river, it o=ers a different category of essential information.
While making sense of the data can require
some e=ort from casual pedestrians, the
real message is that ecological conditions
of the river are always changing. Track-
ing such transitions is important for any
number of reasons. Not the least of these,
explains Stuart Findlay, an aquatic ecolo-
gist at the Cary Institute, is that climate
change will a=ect the river in two major
ways—through water-level rise and the
movement of salt farther upstream.
Walking across a bridge is an exer-
cise that invariably appeals to the human
imagination. And if facts are what feed the
imagination, surely this small cabinet of
ever-changing measurements can lead to
a deeper appreciation of what happens be-
neath the water’s surface.
A break in the clouds allows a moment
of sunlight to play on the scalloped face of
the river below while the display glitters
above like some kind of digital corollary.
If the walkway itself o=ers a broad view of
one of this country’s grandest rivers, this
steady stream of light-emitting diodes offers us the more elusive details. Call it the
marriage of nature and technology. More
and more, I am certain that as we move
forward, river stewardship is likely to depend on both. A
Akiko Busch is the author of The Incidental
Steward: Reflections on Citizen Science,
and lives in the Hudson Valley.
there Is no collective noun for potatoes, but there should be. A nub of potatoes? An ordinariness of potatoes? A prose
of potatoes? A pod, perhaps. In a Potsdam
park, I stumbled on a pod of potatoes scattered over a stone slab, and I fell straight
into the past. It was the humblest of gravestones, with just three words carved into
it: Friedrich der Grosse. Frederick the Great
asked to be buried without pomp, in the
place where eleven of his beloved greyhounds lay: his grave is as blunt as a spud.
In Potsdam, Germany, and nearby Berlin, you tumble through the present to the
past in an instant. I’ve never known a place
so riddled by, haunted by, touched by, delighted by, and devastated by the past. In
to several Superfund sites, artist and farmer Nolan Calisch salvaged seven tires from the water. A local mechanic helped him deter-investigating the psychology of waste and land use in our culture. Photographs by Nolan Calisch and Nina Montenegro