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Karl Flessa ’68, professor of geosciences at the University of Arizona, will present “Putting the Dead to Work: Conservation Paleobiology of the Colorado River Delta” noon-1 p.m. Friday, Nov. 10 in Van Wickle Hall room 108.
The lecture is free for students, faculty, and staff.
Flessa and his research team have been studying the Colorado River Delta since 1992, specifically dead clams. When Flessa first began studying the Colorado, he noticed that the dead clams were of one species while the living clams belonged to several other species. By gathering data on the numbers and distribution of dead clams, Flessa believes he can piece together what it was like before humans started affecting the environment.
Of the clams he has studied, almost all date between A.D. 950 and 1950. Flessa notes this corresponds with the completion of the Hoover Dam in the 1930s, which was the first water-diversion project on that scale along the Colorado. The ecosystem continued to decline after the Hoover Dam was built. Almost no freshwater has reached the river’s delta since the completion of the Glen Canyon Dam in the 1960s. Flessa’s team found that clam shells create a record of declining freshwater flows.
A contributor to several books and the author of numerous journal articles, Flessa has shared his work at conferences throughout the United States and in the United Kingdom, Canada, Mexico, Brazil, and Germany. He has been associate editor of the journal Palaios since 2002 and is on the editorial board of Paläontologische Zeitschrift.
He has received grants from the National Science Foundation, Alfred P. Sloan Foundation, Environmental Defense, Udall Center for Studies in Public Policy and Institute for Study of the Planet Earth, Alexander von Humboldt Foundation, Center for Biological Diversity and Defenders of Wildlife, Eppley Foundation for Research, Southwest Center for Biological Diversity, and U.S. Geological Survey. He is currently serving a Mary K. Upson Visiting Professorship at Cornell University.
Flessa’s research interests include the environmental history and conservation biology of the Colorado River Delta, taphonomy and paleoecology of Recent and Pleistocene invertebrates in the Gulf of California, quality of the fossil record, and biogeography of Recent bivalve mollusks.
The geology graduate earned his Ph.D. in geological sciences in 1973 from Brown University.