Author: Tracey Regan

Publisher:

Published: 2009

Total Pages: 166

ISBN-13:

"The criteria under which species qualify for listing under the ESA have not been clearly defined and, consequently, the levels of threat facing the species which have be en listed have been inconsistent and listing decision have been cumbersome. Here we develop and test the structure for a system to list species under the Endangered Species Act (ESA) using quantitative listing criteria. A flow diagram of the process of developing quantitative criteria (Figure 1) is provided at the end of the Executive Summary. The effort to develop quantitative listing criteria was based on a set of Guiding Principles (Appendix 1) developed by the Steering Committee. The Steering Committee is largely composed of high-level managers from the two agencies responsible for ESA implementation (NOAA Fisheries and Fish and Wildlife Service). Agency scientists (called the Quantitative Working Group (QWG)) were charged with developing quantitative criteria (DeMaster et al. 2004). They proposed the following process for developing this system: (1) overarching definitions (OADs) for both endangered and threatened should be adopted, (2) values of any policy parameters associated with the overarching definitions (e.g., the level of extinction risk corresponding to 'endangered') should be specified, (3) decision metrics that can be used as proxies for (1) and (2) in data-poor cases should be developed for an appropriate range of taxonomic groups or life history types, and (4) all of the above should be done in the context of performance testing (use of simulations to evaluate how well an alternative performs relative to the objective). The Performance Testing Working Group (PTWG) was formed as the successor to the QWG with a large overlap of the scientists involved. The current Report presents 3 years of work done by the PTWG as part of this process. It covers the performance testing of OADs that could be used to accomplish points 1 and 2 above, which could then facilitate the development of point 3. The work was presented to the Steering Committee and an OAD was chosen together with candidate policy parameters. This report summarizes the rationale of the PTWG in developing the structure, results of the performance testing, and rationale of the Steering Committee in choosing an OAD. Technical details are given in appendices"--Executive summary.