A chinook salmon, having returned up the Mokelumne River to spawn, leaps against the closed gates of the fish hatchery at East Bay Municipal Utility Districts’s Camanche Dam.“Civilization creates for me a thousand other worlds that have little to do with my senses, a thousand illusions among which to choose. It is one of the functions of much of contemporary education and politics to convince me that my choices are limited to these creations. Were there a television in my home, it would spend twenty-four hours a day convincing me that life is either a series of dangers and disasters or an endless series of shallow and banal encounters with uninteresting people. Magazines and newspapers tell me the same story. Shopping malls connected by broad paved highways are filled with objects presented as the rewards of existence–the flesh of the world converted to doodads. Big Science has had a good deal to do with the creation of this deadly alternative reality, and science has willingly lent its hand to the great effort to to convince me that the evidence of my senses and the intuitions that arise from their use are illusory.
“But there is a scientific practice that precedes Big Science, a devotion to patient and scrupulous observation of the world and its creatures. I have come to love this discipline, now known as natural history, which delves ever more deeply into the physiological and behavioral differences between my species and others. There is an explosion of this kind of knowledge accumulating in our era, driven by an increasing awareness that many species are disappearing and that we know desperately little about them and therefore little about how to save them. …”
Sunday was spent noodling with HTML in the morning, then in the afternoon getting in the Tiny Car (the Chicago-bred Toyota Echo) and driving from Berkeley out to Antioch, up the Sacramento River to the Delta Cross Channel, then east to where our local utility district stores our water as it flows out of the Sierra Nevada. The destination was chosen because the East Bay Municipal Utility District runs a fish hatchery on the Mokelumne River, and I wanted to see that. The route was dictated because the Delta Cross Channel is the route by which much of the water exported from Northern California down to the San Joaquin Valley and Southern California is diverted from the Sacramento. I’ve driven past and ridden my bike by the Cross Channel gates dozens of times, but, not knowing what the heck they were, I never took note of them. Anyway, the drive was part of a long-term project I think of as filling in my map–touring what is largely terra incognita and figuring out how the pieces relate to each other.
It was a beautiful day, anyway, even with no end in mind. I saw water. I saw levees. I met a lonely bridgetender and photographed him and his antique bridge. I encountered a dead skunk and a curious ostrich. And then when I got out to the hatchery, I was hours too late — it had closed at 3 p.m.
In case you need a break from worrying abut what Al Qaida is going to do you or the horrors you’ll suffer at the hands of Obama-care,or the devastation in store if the Tea Party takes over, here’s another terror to contemplate: the New Zealand mudsnail. Somehow, this critter has not been on my radar. But my ignorance was altered yesterday during a visit to a fish hatchery on the Mokelumne River (that’s pronounced mo-KULL-uh-me, if you’re wondering). It was a short visit as I arrived a good two and a half hours after the place was closed for the day. But this sign was on one of the gates.
The numbers are eye-catching: the snail could occur in densities of 1 million per square yard (that’s 110,000 per square foot), and the snail propagates so rapidly that a single snail could give rise to 40 million within a year. The damage it does: It can outcompete native species and rip apart the food web that even large fish species depend on. In fact, the Mokelumne below this point is a place that has been invaded and studied as part of conferences on the mudsnail. And in recent mudsnail news, the city of Boulder, Colorado, recently closed a park because of the discovery of New Zealand mudsnails in a local creek. A short history from the state of Colorado says that the snail first invaded streams in the northern Rockies and that Yellowstone was one of the first places infested. And here’s everything else you need to know about the critter, thanks to the U.S. Department of Agriculture: New Zealand mud snail (Potamopyrgus antipodarum).
