4. Demographic and Spatial Factors in Evaluation of Risk

4.1 Overview Species extinction risk can be evaluated by considering two separate, but related, types of information: (1) information about the dynamics and distribution of the species itself, and (2) information about threats confronting the species, including their intensity, trends and responses of the species to them (Crawford and Rumsey, 2009). This chapter evaluates information associated with the recent condition and distribution of a species itself. An approach that has been applied to listing and recovery of Pacific salmon under the U.S. Endangered Species Act (McElhany et al., 2000) is based on general conservation biology principles and provides a useful framework for considering the extinction risks to the 82 candidate coral species. The approach entails evaluating the following four species parameters at a variety of spatial scales: (1) abundance, (2) productivity, (3) spatial structure, and (4) diversity.