[en] Recent hydropower research within the U.S. Department of Energy (DOE) has focused on the development of new turbine designs that can produce hydroelectricity without such adverse environmental affects as fish entrainment/impingement or degradation of water quality. In partnership with the hydropower industry, DOE's advanced turbine program issued a Request for Proposals for conceptual designs in October 1994. Two contracts were awarded for this initial program phase, work on which will be complete this year. A technical advisory committee with representatives from industry, regulatory agencies, and natural resource agencies was also formed to guide the DOE turbine research. The lack of quantitative biological performance criteria was identified by the committee as a critical knowledge gap. To fill this need, a new literature review was completed on the mechanisms of fish mortality during turbine passage (e.g., scrape/strike, shear, press change, etc.), ways that fish behavior affects their location and orientation in turbines, and how these turbine passage stresses can be measured. Thus year, new Laboratory tests will be conducted on fish response to shear, the least-well understood mechanism of stress. Additional testing of conceptual turbine designs depends on the level of federal funding for this program