Karl Flessa

Dr. Flessa focuses on the delta of the Colorado River. Since about 1935, upstream water diversions have reduced the amount of water that reaches the river's delta in the northern Gulf of California. In most years, the river no longer reaches the sea. He is examining deposits of mollusk shells, bones of marine mammals, and otoliths of fish in order to assess the impact of upstream water diversions on the delta and estuary of the Colorado River. He was chief scientist in a binational program to monitor a Mexican wetland supported by transboundary flow of agricultural wastewater from the U.S.  He currently serves as the chief scientist of a binational, multi-agency, multi-NGO effort to monitor the effects of environmental flows to the delta under Minute 323 of the US-Mexico water treaty.  He is a founding member of the Colorado River Research Group