On this side of the Atlantic, the news couldn’t get any older in terms of extinct species. I’m referring, of course, to what is usually considered the first vertebrate species in the New World to have verifiably gone extinct. Way back in 1889 or so, the world lost the whiteline topminnow, and the cause was pretty demonstrably human.
Why am I mourning this critter now? Well, being an ecologist, I already have a soft spot for endangered species, but I had not really heard the complete story of the whiteline until recently.
OK, a little background. This area, northern Alabama/southern Tennessee/northwest Georgia, is a massively rich ecosystem known as the Cumberland Plateau. All the hundreds and thousands of tiny little headwater tributaries and springs that feed the burgeoning Tennessee River have been flowing for millions of years, slowly eroding the edges of the plateau, and developing incredibly specialized habitats for a breathtaking range of species.
In fact, the headwaters of the Tennessee comprise the richest freshwater faunal assemblage in North America, and one of the richest in the world. When you combine the Tennessee River watershed and the adjacent Mobile Bay and Ohio River watersheds (covering amost of the waterways of the southeastern US,) you get the richest freshwater fish assemblage of any place on the planet, save the Amazon.
It’s a freaking Lost World, and I mean that in the most dramatic way possible.
A good portion of the reason for all the fish biodiversity is the uniueness of each and every one of these tiny little headwater reaches in the Tennessee, the Tallapoosa, the Coosa, the Cahaba, etc.
See, they’re ancient. Much older than most freshwater habitat enclaves in the world. Thus, they’ve had plenty of time to develop. As a result, lots of them hold totally unique, endemic critters that, each and every one, are treasures in themselves. You get fish that swim upstream into temporary vernal pools to spawn, and their fry have to make it back down into the main stream before the pools dry up. You get fish that live out their entire species’ lives in a stretch of stream no more than a few hundred yards long. Very exotic stuff. Real, honest-to-God Wild Kingdom material, and in our backyard.
Anyway, the poor, bedeviled whiteline topminnow, RIP 1889, was one such creature. And it lived in a spring that had the bad fortune to be plentiful and gorgeous enough to be the major artery that tied a relatively major metropolitan area like Huntsville, Alabama to the Tennessee River. It was used as a way to transport cotton to the river. It was dammed and locked and channelized and dredged and filled with concrete.
And that tiny, insignificant, glorious little creature died. It made its home in the cold, cold spring head and the clean gravel and cobbles of a gorgeous, gushing artesian well. Ferns and rock cress, foamflower and Indian paintbrush, gentian, and who knows what else lined it.
It made its home in that magical spring, and nowhere else on this planet. The spring and the fish developed together. It didn’t move in…it EVOLVED there. It belonged to that place, and only that place, in the most profound way possible. It was tied to that place’s chemistry. Its structure. Its plant and animal life. Its algae content. Its temperature. A million other things that were never replicated anywhere else, that made it and its home utterly unique on this earth.
It now no longer exists, of course, and now Big Spring is a city park. It’s a pretty place. I’ve taken dates there. I watched Casablanca projected onto a building wall there. I used to run there every day. They have a music festival every year.
But I’d give a lot to see elusive, darting shadows at the surface of the water, instead of goldfish.