Independent Scientific Advisory Board for the Northwest Power and Conservation Council, Columbia River Basin Indian Tribes, and NOAA Fisheries 851 SW 6 th Avenue, Suite 1100 Portland, Oregon 97204 ISAB@nwcouncil.org Viability of ESUs Containing Multiple Types of Populations Robert E. Bilby Peter A. Bisson Charles C. Coutant Daniel Goodman Susan Hanna Nancy Huntly Eric J. Loudenslager Lyman McDonald David P. Philipp Brian Riddell Ad Hoc Members Jeffrey Olsen Richard Williams April 8, 2005 ISAB 2005-2