Evaluating Best Practices for Reintroductions: Case Studies in the Columbia Basin

Many conservation and recovery efforts are contemplating the reintroduction of anadromous salmonids to areas from which they have been extirpated.  Given the wide range of settings under which these reintroductions might take place, and the variety of goals for these efforts, appropriate approaches for reintroductions are likely to vary.  We reviewed scientific considerations for reintroduction efforts, and identified conditions particularly conducive to successful reintroductions.  Areas considered include the effect of the reintroduction on overall population and ESU viability, past and current limiting factors, condition of the habitat in the area to be open, the presence of native and introduce species, contingency planning, alternative approaches to recolonization, source stocks, and passage issues.  We also treated emerging issues such as evolutionary responses to habitat blockage and opening, and considerations for reintroductions in a changing climate.  Finally, we applied the principles we developed to several currently extirpated areas in the Columbia River basin to exemplify the process for evaluating the biological utility of reintroductions.