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The combined effects of water diversion and climate change are a major conservation challenge for freshwater ecosystems. In the Lemhi Basin, Idaho (U.S.A.), water diversion causes changes in streamflow, and climate change will further affect streamflow and temperature. Shifts in streamflow and temperature regimes can affect juvenile salmon growth, movement, and survival. We examined the potential effects of water diversion and climate change on juvenile Chinook salmon (Oncorhynchus tshawytscha), a species listed as threatened under the U.S. Endangered Species Act (ESA). To examine the effects for juvenile survival, we created a model relating 19 years of juvenile survival data to streamflow and temperature and found spring streamflow and summer temperature were good predictors of juvenile survival. We used these models to project juvenile survival for 15 diversion and climate-change scenarios. Projected survival was 42-58% lower when streamflows were diverted than when streamflows were undiverted. For diverted streamflows, 2040 climate-change scenarios (ECHO-G and CGCM3.1 T47) resulted in an additional 11-39% decrease in survival. We also created models relating habitat carrying capacity to streamflow and made projections for diversion and climate-change scenarios. Habitat carrying capacity estimated for diverted streamflows was 17-58% lower than for undiverted streamflows. Climate-change scenarios resulted in additional decreases in carrying capacity for the dry (ECHO-G) climate model. Our results indicate climate change will likely pose an additional stressor that should be considered when evaluating the effects of anthropogenic actions on salmon population status. Thus, this type of analysis will be especially important for evaluating effects of specific actions on a particular species. Efectos Interactivos de la Desviación del Agua y el Cambio Climático en Individuos Juveniles de Salmón Chinook en la Cuenca del Río Lemhi (E.U.A.) [ABSTRACT FROM AUTHOR]

As the 30th birthday of the Endangered Species Act (ESA) passes and the act moves toward middle age, it is possible to discern a new generation of ESA-related issues. One of these is the management of the small number of species that have recovered or will recover to the point where they can be delisted. The delisting of some species raises two important questions that are the focus of this article. First, how will the delisting of species affect the relationship between state governments and the federal government? Second, how will state efforts to manage delisted species seek a balance between utilitarian and ecological values? This article examines the planned delisting of the gray wolf in the northern Rocky Mountains and three state management plans (Idaho, Montana, and Wyoming). It argues that the compromises entailed in these management plans suggest a sense of the future direction of the politics of species conservation. [ABSTRACT FROM AUTHOR]