[en] This report is one report of four that the Pacific Northwest National Laboratory (PNNL) staff used to address Measure 7.1A in the Northwest Power Planning Council's (Council) fish and Wildlife Program (Program) dated December 1994 (NPPC 1994). Measure 7.1A calls for the Bonneville Power Administration (BPA) to fund an evaluation of salmon survival, ecology, carrying capacity, and limiting factors in freshwater, estuarine, and marine habitats. Additionally, the Measure asks for the development of a study plan based on the critical uncertainties and research needs identified during the evaluation. In the evaluation of carrying capacity the authors concluded that defining capacity and listing the determinants of capacity is not a simple exercise. Capacity is a complex variable among the attributes that all together define salmon performance. To pursue the capacity parameter, that is, a single number or set of numbers that quantify how many salmon the basin or any part of the basin can support, will not lead to the development of a useful study plan. To increase understanding of ecology, carrying capacity, and limiting factors, it is necessary to deal with the complexity of the sustained performance of salmon in the Columbia River Basin. This report describes the elements of a study plan that could be used to increase the understanding of ecology, carrying capacity, and limiting factors that influence salmon survival under current conditions