Wednesday, May 28, 2008 - 1:45 PM
454

Evaluating the status of a threatened snail in the Snake River Basin, Idaho: A case study

Tristan Arrington, Cole Young, and David Richards. EcoAnalysts Inc., Center for Aquatic Studies, 11 E Main St., Suite M, Bozeman, MT 59715

The greatest diversity of freshwater mollusks occurs in North America, primarily in the southeast, USA. Freshwater mollusk diversity in the western USA is depauperate with the exception of a unique “hotspot,” the Snake River basin, Idaho. Several federally listed threatened and endangered taxa only occur in this area. Scientifically and quantitatively evaluating the status of these species is often complex. Estimating a threatened species abundance is one small part of evaluating its status.

Many other quantitative factors must also be integrated into the evaluation including: population dynamics, biology, life history, ecology, changes in habitat, threats, population viability analysis and risk assessments. Status evaluation is an evolving process and constantly requires incorporation of the latest scientific methods regarding these factors.

We will present and discuss an overview and flow chart of some of the factors and methods needed for an evaluation of the status of a threatened species. This overview is based on a decade of involvement and on-going research and assessment of the threatened Bliss Rapids snail, Taylorconcha serpenticola, in the Snake River basin, Idaho.



Web Page: viability analysis, risk assessment, threatened