Wednesday, September 29, 2010

Mussel Shoals

This trip divides itself into distinct stages. Navigating the quirky locks of the Trent-Severn Waterway. Admiring the granite-fringed majesty of Georgian Bay. Dodging giant barges on the Illinois and Mississippi Rivers.  This week we started a new phase of our trip. We dodged one last barge--on the narrow and winding Cumberland River--locked through one last, massive lock, navigated one short canal, and entered . . .  what looks like a vast lake.

Dozens of small towns were flooded and thousands of families relocated
to create Kentucky Lake. The shores are dotted with reminders.
Kentucky Lake is actually part of the Tennessee River. This segment became a lake with the construction of the massive Kentucky Dam (built between 1938 and 1944).  

Our government had been considering how to improve navigation and shipping on the Tennessee River as early as Civil War days.  Muscle Shoals, a stretch of particularly treacherous rapids in northern Alabama, prevented boats from navigating all the way up the Tennessee to Knoxville.

The Kentucky Dam was the last in a whole chain of projects, begun in the late 1930s under President Roosevelt’s “New Deal” initiatives, that finally allowed the big tows--with their cargos of grain, coal, petroleum, and iron ore--to reach towns an a region that was, previously, one of the most economically depressed in the country.

When Kentucky Lake was created, a limestone quarry in Pisgah Bay was flooded.  These days it's
"traditional" to paint grafitti here . . .  and to jump off the cliffs on hot summer days.
You likely remember from your high school history class that the Kentucky Dam and other flood control dams in this region are collectively under the control of something called the Tennessee Valley Authority, or TVA.  The Tennessee Valley Authority Act was part of the flurry of legislation accomplished in Roosevelt’s first 100 days in office—one of the most ambitious "New Deal" projects, and one of the most controversial.
A view of Kentucky Dam
Besides providing flood control, and aiding navigation, Kentucky Dam also generates electricity.  "Affordable electricity for rural farms" was part of the pitch when the TVA was created. These days, Kentucky Dam alone generates about 1.3 billion kilowatt hours of electrical power.

Check out that bow wave!  These days, the same
enormous barges that navigate from Chicago to New
Orleans can make the run up the Tennessee Valley
 The TVA was one of America’s largest hydropower projects, with sixteen major dams constructed between 1933 and 1944.  The TVA added coal-burning power plants to its stable in the 1950s and nuclear plants in the 1960s. Today the TVA is still  America’s largest public power company.  

The view from our deck this morning
All this power-related activity--coal barges coming and going, dams raising and lower the water level--is certainly food for thought as we cruise the pretty coves of this vast, forest-fringed lake in our solar-powered boat, passing massive, modern resorts and getting waked by fast-moving daycruisers.

Yesterday, after we anchored in a quiet cove, we dinghied to shore to stretch our legs.  Right now the water is low, and the shore is fringed with a flat shelf of gravel, perfect for exploring. 

We saw a herd of deer mincing through the reeds to drink at the shore, and a family of raccoons scrambled up the bank at our approach. The mud held the tracks of coyotes, and the sycamore-leaf-sized prints of great blue herons--plus a train of narrow grooves where a deer had slipped and skidded on the greasy clay.

When you walk the shore, you might think for a moment you’re at the ocean, there’s such a profusion of shells mixed with the gravel.  Tiny clam shells, the narrow spirals of freshwater snails, and--most impressive--the dark flat shells of freshwater mussels, many of them bigger than a man's hand.

Among the benefits that the TVA dams have brought to the region (and the organization, despite the controversies, CAN reasonably claim that it has done good for the human population), freshwater mussels are one quiet casualty.  It’s hard to be precise about the extent of the problem because, being not-very-charismatic organisms—they’re wet, they're slimy, as juveniles they're parasites on fish, they live in mud—mussels don’t get a lot of press.  But when the dams went in, a profusion of mussel species adapted to living in free-flowing waters were wiped out.

By taming Muscle Shoals, the government made the Tennessee River navigable—but also destroyed some of the world’s best habitat for freshwater mussels, which can’t handle the silt that settles out, and the cold water released by dams.  The river was surveyed for mussels before the dams went in . . . and afterward.  Out of 100 mussel species  initially present, 56 were gone by 1969.

Why should anyone care?  Ah, that’s the key question.  Conservationists sometimes appeal to aesthetics or emotion—individual species are beautiful, they’re awe-inspiring, they remind us of the majesty of God and nature. On many ears, these appeals have fallen flat. 

For a while, the notion of potential “keystone species” was popular, the idea that species which may SEEM insignificant might, if wiped out, bring a whole ecosystem tumbling down.  So, it's worth protecting all species, just in case.  A reasonable argument that didn't sway many non-ecologists.

In the booming 1990s, scientists got savvier and attached dollar signs to their arguments. They noted intact ecosystems provide humans with “essential services,” such as drinkable water and breathable air (everyone likes to breathe, yes?). Then they ran the numbers on the value of those services and what you'd have to pay if nature didn't do the work for free.  

A corollary economic argument is that certain species and ecosystems have maximum  value when you keep them alive, by attracting ecotourism. There's a disincentive to kill gorillas, or elephants, or rhinos, if rich people will pay to see them.

I don’t have the magic answer myself as to "why the world needs a profusion of freshwater mussels" . . . although I am inclined to say, I wish more small children had a chance to wander, quietly and slowly, along a muddy shore, poking among the gravel  to see what they can see.  

And I do think it doesn't have to be a shell game, to be an "either . . . or" choice.   I think of my brother's work, which involves demonstrating to chemical companies that they can pollute less AND save money.   I think the same principal applies to the generation of electrical power, that humans are endlessly clever, that solutions are within our brainpower. 

As I say, we’re anchored in a lovely, quiet cove, enjoying the manufactured scenery . . . and chewing on a lot of food for thought.

1 comment:

  1. This particular blog will help me at our meeting next week of the Energy Commission. Thanks