Article © Nathan Lujan, uploaded September 17, 2013.
As a youth, I was transfixed by the legendary accounts of early tropical explorers like Alexander von Humboldt, Alfred Russell Wallace, and Henry Walter Bates. I had the feeling that I had been born 150 years too late — that I had missed the golden age of scientific exploration and that I now lived in a time when sterile laboratories had replaced wild terrains as the principle venues for scientific discovery. Now, having conducted over a dozen scientific expeditions to remote areas of South America and Africa and having discovered novel ecological interactions, ancient biogeographic connections, and dozens of new species, I realize that my regrets were naive. We continue to live in an exciting age of discovery. Indeed, the wildernesses that await our exploration and the discoveries that remain to be made in untrammeled areas of the Earth far exceed the relatively meager resources and personnel available for expeditionary science. Many great ecological mysteries persist even as increasing threats from human population growth and climate change place Earth's ecological integrity in peril.
Having grown up in middle Tennessee — an area celebrated as both a global epicenter of aquatic biodiversity and as home to the booming city of Nashville — I have long been familiar with the fast pace at which wilderness can be converted for human use and the intense challenges faced by wildlife in heavily altered terrains. As a young boy in a recently developed suburb, I explored remnants of wilderness that still held the potential for adventure and the thrill of the unexpected. Especially fascinating for me were the creeks and streams and the often strange yet beautiful life-forms populating them. Lifting a rock from the water might disturb a darter, reveal a crawdad, or startle a snake. Unable to appreciate these creatures from afar, I appropriated colanders, strainers, jars, and other kitchen implements from my mother, collected my ‘specimens’, and leisurely observed their defensive behaviors and specialized morphologies. These were not merely pets to be stroked and played with, they were truly alien organisms that demanded close examination. I was thrilled by their untamed nature and unpredictability, the proclivity of the snakes and crawdads to bite and pinch, and the distinct colors, shapes, and swimming behaviors of the native fishes that persisted so near my house.
My home was near the watershed divide between the Cumberland and Tennessee rivers, and each of the streams tributary to these biodiverse and historically important rivers struck me as a corridor to another world. Cities in the southern United States are famously bereft of pedestrian amenities like sidewalks, and there were no parks or trail systems near my house, so roads and streambeds made for obvious corridors through which I could travel across the landscape. During the hot afternoons of Southern summers, my choice of creeks as the place to play, explore, and venture out beyond the neighborhood was an easy one. Creeks, streams, and rivers continue to hold that almost magical sense of adventure for me, reinforced by the early adventures of Tom Sawyer and Huck Finn and those of the older explorers mentioned above. From a young age, aquatic biology was in my blood and, more often than not, ground into my clothesand under my fingernails. My high-school and college years gave me a greater academic appreciation for the complexity and interconnectedness of aquatic and terrestrial systems, and exposed me to an increasing variety of streams and aquatic biota. First, in an ever-broadening radius around Nashville then in the famous trout and salmon streams of Michigan where I went for college. It wasn't until after returning to Tennessee, when I worked for two years as a field biologist for the Tennessee Valley Authority, that I fully dedicated my life to this lifelong passion. I was embedded with a tight-knit crew of likeminded fish-heads and allowed to travel throughout the seven-state Tennessee River watershed, exploring and documenting the biotic integrity of this region's spectacularly diverse fish and aquatic insect communities.
The almost year-round TVA fieldwork and biological monitoring that I participated in after college continues to this day, requiring a significant commitment on the part of TVA in terms of equipment, vehicles, hotels, and food — not to mention technical personnel. Like any big business, TVA does not make these investments without carefully and pragmatically listing the justifications, which are far from the idealistic aesthetic values that I fostered from childhood. As the largest publicly owned power company in the United States — charged with operating dozens of hydroelectric dams and coal-fired and nuclear power plants — TVA has a tremendous responsibility to both provide power on the one hand, but also protect the health of the environment. The latter often under immediate threat of strict federal law enforcement. It is in this environmental context that TVA sees an indispensable role for stream biological monitoring. In today's world of human dominated landscapes, rain must pass through air affected by the emissions of cars, factories; it must flow across our yards, streets, and buildings; and it must dilute oils, herbicides, pesticides, and industrial residues before percolating into groundwater or flowing directly into neighborhood creeks like the ones I played in as a child. Of course, there are sophisticated laboratories capable of detecting these pollutants but if a sample isn't taken at many places every time it rains, or at precisely the moment when a pollutant is being released, then many of these pollutants would go undetected. Fish and aquatic insects, though, spend their lives in water — the universal solvent — and their physiologies and life cycles are intimately linked to its composition and cleanliness.
Given a sophisticated understanding of the natural ecological interactions between and among fishes and aquatic insects, scientists can detect the impacts of pollution on these organisms years after it has occurred. This was and continues to be the goal of the biologists I worked with at TVA, and this nuanced, intuitively appealing connection between a well-balanced ecosystem and a pragmatic tool for monitoring environmental health continues to be a distant goal of much of my research. The key to our ability to use natural systems to inform us about the health of our environment is first knowing what these systems might be like in a natural, unaltered state. With the ubiquity of human impacts increasing around the globe, this can sometimes be a difficult task. Since leaving TVA and completing a PhD in aquatic ecology at Auburn University, one of my most imediate goals as a scientist has been the documentation of aquatic biodiversity and ecology in areas of the world that remain relatively unimpacted by man. For over a decade my research has focused on the many river systems of South America and it is to here, to the lower portion of the Xingu River — a mighty southern tributary of the lower Amazon River — that I am now headed.
Having spent my youth exploring not only the creeks and streams around Nashville, but also the handful of aquarium stores within easy driving distance, the Xingu River has long held a mythic status in my mind as one of the greatest sources of spectacularly diverse and rare species of cichlids, plecos, and tetras. I still remember the first time I walked into The Aquatic Critter, my favorite fish store in Nashville, and caught site of the remarkably boldly patterned zebra pleco, and its equally astounding price tag of $400. Even with my occasional Aquatic Critter employee discount, this fish and many of the other Xingu beauties were beyond my reach when I was most interested in maintaining aquaria, but now, with a grant from the US National Science Foundation, I will have to opportunity to visit these gems in their home. As a fellow aquarist and “fish-head”, I share with many of the Planet Catfish audience a boundless desire to comprehend every aspect of freshwater fish biology.
In the project before us now, we have laid out an ambitious goal to catalog both the taxonomic diversity and the ecological structure of one of the most biodiverse stretches of river on Earth. Unfortunately, time is running short for this particular ecosystem because construction of the Belo Monte Dam complex has already begun and is scheduled to be complete in as little as 5 years. Our team faces ever-increasing costs due to the inflated economy surrounding Belo Monte’s construction, yet our original grant proposal was based on out-of-date prices and was ultimately only partially funded. We are therefore looking into every opportunity to stretch our resources, and share the cost of our work. I, along with the rest of the Planet Xingu team, hopes that you see the tremendous urgency of this research and the need to collect as much data as possible given the brief window of time available. Please consider the larger altruistic goals of our study, the future generations that will benefit most from a thorough understanding of the Xingu ecosystem as it existed before the dam. Compare a contribution, however modest, with the cost of a new fish caught from the Xingu and shipped thousands of miles to your own neighborhood aquarium store. Every little bit helps, and is greatly appreciated by myself and the rest of the team.
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