Technical Report

Rio Grande Silvery Minnow Rescue and Salvage

URL: https://webapps.usgs.gov/mrgescp/documents/SmithandMunoz_2002_RGSMRescueandSalvage.pdf

Date: 2002/01/01

Author(s): Smith J.R., Munoz A.

Publication: Prepared by U.S. Fish and Wildlife Service, 16 p.

Abstract:

This project relates to Reasonable and Prudent Measure (RPM) one of the “Programmatic Biological Opinion on the Effects of Actions Associated with the U.S. Bureau of Reclamation’s, U.S. Army Corps of Engineers’, and Non-Federal Entities’ Discretionary Actions Related to Water Management on the Middle Rio Grande, New Mexico” (Opinion). The U.S. Fish and Wildlife Service (Service) determined that this reasonable and prudent measure was necessary and appropriate to minimize impacts of incidental take of the silvery minnow. Minnow salvage will be necessary regardless of the requirements outlined in the Opinion and will likely be a key element in any future Biological Opinions issued by the Service. Over the last 2 years the Service has salvaged silvery minnows from isolated pools during river intermittency and translocated these fish to areas with permanent flowing water. The efficiency of these translocation efforts has improved over the last two years. The 2002 water year was one of the worst on record and has been deemed the worst in 100 years. The Service has conducted approximately 34 individual silvery minnow salvages resulting in over 3400 silvery minnows being collected and moved upstream. Approximately 44 river miles were salvaged with some sections salvaged several times due to rewetting caused by rainstorm events (“acts of nature”). The largest number of silvery minnows collected were usually during the first drying event in each section. The number of silvery minnows collected during drying events declined after July of 2002. The most recent data indicate that approximately 98 percent of the silvery minnows collected were adults and 2 percent young-of-year (YOY). The Service recorded the number of dead silvery minnows found during drying events. To date 248 silvery minnows have been documented that counted against the incidental take statement(ITS) in the Opinion. Less than 100 dead silvery minnows were found that did not count against the ITS, and were attributed to “acts of nature.” These fish were found dead in a reach of river that had already dried previously and subsequently rewetted from rainstorm events. These fish were not consider under the ITS because the rewetting and subsequent drying were not caused by the action agencies’ management.

Related Information
  • Species: Rio Grande Silvery Minnow
  • Organization: U.S. Fish and Wildlife Service
  • Reach: Isleta , San Acacia
  • Keywords: Management
  • Tags: