Publication

Development of Perennial Pools for Rio Grande Silvery Minnow in the Middle Rio Grande Using Cottonwood Snags

URL: https://webapps.usgs.gov/mrgescp/documents/Weshe%20et%20al_2004_Development%20of%20Perennial%20Pools%20for%20RGSM%20in%20the%20MRG%20using%20Cottonwood%20Snags.pdf

Date: 2004/11/01

Author(s): Wesche T.A., Wesche, L.B., Cowley D.E., Najmi Y., Grogran S.

Publication: Report prepared for Middle Rio Grande Endangered Species Act Collaborative Program, 27 p.

Abstract:

Three cottonwood snag habitat improvement structures were designed, installed and evaluated in the middle Rio Grande (MRG) below Bridge Boulevard in Albuquerque, NM from September 2003 through August 2004. Primary purpose of the cottonwood snags is to provide needed woody debris to enhance habitat structure, complexity, cover and food for the endangered Rio Grande silvery minnow (Hybognathus amarus). The bank-anchored structures were easily and rapidly installed in June 2003 by MRGCD personnel using heavy equipment. Monitoring data collected 10 weeks after installation indicated 1) the snags had maintained their structural integrity and stability; 2) hydraulic performance thus far is satisfactory but cannot be fully evaluated until substantial high flow events occur; 3) the habitat provided is similar to that known to be used by RGSM; 4) several fish species have been collected at the snag sites, but no silvery minnow yet; 5) colonization by aquatic macroinvertebrates has been encouraging and supports our hypothesis that large wood was once an important ecological feature of the MRG. We recommend monitoring continue for at least one more year, outreach opportunities be pursued, and when feasible, bed-anchored snags be evaluated in MRG reaches prone to drying.