Professor Emeritus, Environment and Sustainability, U-M (2018 – present)
Professor of Environment and Sustainability, U-M (2004-2017)
Faculty Associate, UM Program in the Environment, U-M (2004-2017)
Faculty Affiliate, UM Erb Institute for Global Sustainable Enterprise, U-M (2004-2017)
Graham Family Professor of Sustainability, U-M (2009-2016)
Professor of Civil and Environmental Engineering, U-M (2009-2016)
Director, Graham Sustainability Institute, U-M (2009-2016)
Special Counsel to the U-M President for Sustainability (2009-2016)
Director,  Michigan Sea Grant Program (2004-2009)
Director, Coop Inst for Limnology and Ecosystems Res. (2004-2007)
Research Associate Dean,  Environment and Sustainability, U-M (2004-2006)

Chief Scientist, National Ocean Service, NOAA (2002 – 2003)
Director, National Centers for Coastal Ocean Science, NOAA (1998-2002)
Director, NOAA’s Coastal Ocean Program Office (1990 – 1998)
Research Scientist, NOAA Great Lakes Research Lab (1975 – 1990)
Adjunct Professor, Biological Sciences, University of Michigan (1980-1990)
Visiting Scientist, National Sea Grant College Program (1987 – 1988)
Visiting Scientist, NOAA Office of the Chief Scientist (1988 – 1990)
Assistant Research Scientist, Rensselaer Polytechnic Institute (1974 – 1975)