For Love of Lakes

Limnos III—Lake Mendota, Wisconsin

· · 137 · · Limnos III—Lake Mendota, Wisconsin Whydolakesdiffersowidelyinproductivityorinability tosupportapopulationofplankton? EDWARD A. BIRGE, 1911 Usually by November I have put my canoe away for the season, fearful of cold water that could quickly sap life away in a capsize. Today is an exception . Geri and I find ourselves slowly paddling under bright November skies on a lake famous the world over. Ostensibly, we have come to Madison, Wisconsin, to attend the annual conference of the North American Lake Management Society. The conference may have been merely an excuse to finally set eyes and canoe on Lake Mendota, birthplace of the scientific study of lakes in North America. I swish my hand through water, surprisingly clear for being situated amidst a city the size of Madison. I have never been on this lake before—in body. But in truth it feels like an old friend. We slowly pass a string of elderly houses fronting the lake. How many times in years long gone by, I wonder, did the owners of these grand homes look out on the lake at a man in a boat dragging strange contraptions through the water? The man, with maybe a partner, would have been Edward A. Birge. North American limnology was born here, and Edward Birge, assisted by Chancey Juday, was its father. Birge and Juday. Birge and Juday. As a mindscapes· · 138 · · graduate student at the University of Minnesota it seemed to me these men had written half the scientific papers I read. Incredibly, nearly a hundred years after their pioneering studies, I find nineteen citations of papers authored by these men, jointly or alone, in a leading college limnology text. Much of that research was conducted on this lake. As our canoe works its way west, the buildings of the University of Wisconsin, Birge’s home base, become more distinct on the far shore. • • • After attending Williams College, Birge chose to pursue further studies under the great Louis Agassiz at Harvard. Only months after Birge arrived at the school, Agassiz died suddenly of a stroke. Birge continued at Harvard, where he became charmed, as have so many others, with the tiny inhabitants of a small shallow pond, those master seducers—waterfleas. His PhD thesis on daphnians became the first intensive study of this group. He left Harvard in 1876 for a teaching position at the University of Wisconsin. • • • We paddle past a park and watch geese walk single file between joggers and the shore. Ahead, numerous tall buildings, we assume dormitories or student apartments, rise not far back from the lake. Lake water turns less clear as we approach campus. Small clumps of cyanobacteria now appear. Birge set out to investigate the distribution and behavior of plankton in Lake Mendota, and in 1895 published his findings on their vertical distribution in the lake. Several years later he hired Juday as his assistant. In six years the two men strained over half a million gallons of Lake Mendota’s water to better understand the ecology and behavior of the plankton. Birge’s groundbreaking plankton work raised more questions than it answered. The two men, trained in zoology, soon discovered they could not come to understand lake life by studying lake life alone, and they became drawn into a wider lake world involving chemistry and the physical aspects of lakes. They learned that the amounts of dissolved oxygen in lake water changed with the seasons and varied with depth. They also recorded changes in water temperature from surface to bottom and coined the word · · 139 · · “thermocline” to denote the stratum of lake water where temperature drops sharply from the warmer surface zone to the cold layer of the depths. In their long careers Birge and Juday added immensely to our understanding of lakes. Birge conducted the first studies on the depth of light penetration and its consequences. They discovered that the amount of oxygen present in lake bottoms depended on the amount of dead plant and animal matter available to decompose there. Their full list of research subjects reads like a table of contents of a limnology book: organic content of lake water, heat budgets of lakes, wind’s influence in thermal stratification, electrical conductance of lake water, concentrations of phosphorus and other minerals in lakes, and light absorption by lake water. They discovered that photosynthesis, cellular respiration, and bacterial action worked together to create the distribution patterns of temperature anddissolvedgasesinlakes.Mostimportant,theyrecognizedtheirbiological backgrounds were insufficient to enable them to adequately understand...