Full Posts

Bloglines Subscribe in Bloglines
Newsgator Subscribe in NewsGator Online
Google Add to Google
netvibes Add to Netvibes


ESAblawg is an educational effort by Keith W. Rizzardi. Correspondence with this site does not create a lawyer-client relationship. Photos or links may be copyrighted (but used with permission, or as fair use). ESA blawg is published with a Creative Commons License.

Creative Commons License

florida gators... never threatened!

If you ain't a Gator, you should be! Alligators (and endangered crocs) are important indicator species atop their food chains, with sensitivity to pollution and pesticides akin to humans. See ESA blawg. Gator blood could be our pharmaceutical future, too. See ESA musing.


Follow the truth.

"This institution will be based on the illimitable freedom of the human mind. For here we are not afraid to follow truth wherever it may lead, nor to tolerate any error so long as reason is left free to combat it." -- Thomas Jefferson to William Roscoe, December 27, 1820.


Thanks, Kevin.

KEVIN S. PETTITT helped found this blawg. A D.C.-based IT consultant specializing in Lotus Notes & Domino, he also maintains Lotus Guru blog.

« FWS designates critical habitat for Berberis nevinii | Main| Border security vs. wildlife? »

FWS revises critical habitat for Peirson’s milk vetch

Bookmark :  Technorati  Digg This  Add To Furl  Add To YahooMyWeb  Add To Reddit  Add To NewsVine 

73 Fed. Reg. 8748-8785 (FWS revises critical habitat for Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for Astragalus magdalenae var. peirsonii (Peirson’s Milk-Vetch); Final Rule)

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are designating final revised critical habitat for Astragalus magdalenae var. peirsonii (Peirson's milk-vetch) under the Endangered Species Act of 1973, as amended (Act). In total, approximately 12,105 acres (ac) (4,899 hectares (ha)) fall within the boundaries of the revised critical habitat designation for A. m. var. peirsonii. The revised critical habitat is located in Imperial County, California. We are excluding Unit 2 from this revised designation based on the disproportionate economic and social impacts associated with the designation of this unit relative to the other units designated as critical habitat. This final revised designation constitutes a reduction of 9,758 ac (3,949 ha) from our 21,863 ac (8,848 ha) previous final designation of critical habitat for A. m. var. peirsonii published in 2004.  This rule becomes effective on March 17, 2008.  Click below for more on the economic analysis and decision to exclude portions of the habitat from the critical habitat designation.

Photo from Bureau of Land Management

  • This final rule is available on the Internet at
  • FWS economic analysis re: impacts of critical habitat designation for Peirson’s milk-vetch
  • Center for Biological Diversity information page

NOTEABLE ANALYSIS:  In the lengthy Federal Register analysis, FWS thoroughly explained that a portion of the Peirson's milk vetch habitat served as economically important recreational lands for off road vehicles (ORVs), and accordingly, FWS excluded a portion of the plant's habitat from the crticial habitat designation based on the significant potential economic impacts.

   "The Secretary may exclude an area from critical habitat if he determines that the benefits of such exclusion outweigh the benefits of specifying such area as part of the critical habitat, unless he determines, based on the best scientific data available, that the failure to designate such area as critical habitat will result in the extinction of the species. In making that determination, the legislative history is clear that the Secretary has broad discretion regarding which factor(s) to use and how much weight to give to any factor...  

   "Based on public comments received and new information, we developed a final economic analysis of the potential incremental economic effects of the revised designation. The total potential post-designation efficiency impacts for the timeframe 2008-2027 range from a lower bound of zero to an upper bound range of $116-$127 million in undiscounted dollars ($5.80 million to $6.33 million annualized). Discounted future costs are estimated to be $85.8 million to $93.3 million ($5.77 million to $6.27 million annualized) at a 3 percent discount rate, or $60.6 million to $65.7 million ($5.72 million to $6.20 million annualized) at a 7 percent discount rate. Most of the impact results from the potential closure of designated critical habitat areas from recreational OHV use. The critical habitat unit with the greatest potential impacts is Unit 2; impacts in this unit constitute about 93 percent of potential efficiency effects. These costs are attributable to loss of revenue generated by businesses supporting the OHV community as a direct result of the designation of critical habitat...  

   "The primary benefits of including Unit 2 are related to the likely greater level of conservation management of Astragalus magdalenae var. peirsonii in the unit due to the regulatory implications of critical habitat, and the contribution of that management towards species recovery. Although A. m. var. peirsonii would not receive the full conservation benefit that could be achieved by the inclusion of Unit 2 in the critical habitat designation, we still expect this area to contribute to the genetic diversity, gene flow between adjacent units to the northwest and southeast, and the overall conservation of the species. In contrast, the inclusion of Unit 2 in the critical habitat designation would likely result in disproportionately high economic and significant social impacts in this area relative to the impacts of the overall critical habitat designation. Unit 2 contains approximately 8.5 percent of the total observed occurrences of A. m. var. peirsonii within the proposed revised critical habitat, while over 90 percent of the potential incremental economic costs associated with the proposed revised critical habitat designation, and the majority of the unquantifiable impacts associated with the proposal, are attributed to Unit 2.

   "Therefore, based on the above discussions, we have determined that the benefits of excluding Unit 2 (Subunits 2A and 2B) from this critical habitat designation outweigh the benefits of including the unit."